Significant patch series in this pull request:

- The 2 patch series "squashfs: Remove page->mapping references" from
   Matthew Wilcox gets us closer to being able to remove page->mapping.
 
 - The 5 patch series "relayfs: misc changes" from Jason Xing does some
   maintenance and minor feature addition work in relayfs.
 
 - The 5 patch series "kdump: crashkernel reservation from CMA" from Jiri
   Bohac switches us from static preallocation of the kdump crashkernel's
   working memory over to dynamic allocation.  So the difficulty of
   a-priori estimation of the second kernel's needs is removed and the
   first kernel obtains extra memory.
 
 - The 5 patch series "generalize panic_print's dump function to be used
   by other kernel parts" from Feng Tang implements some consolidation and
   rationalizatio of the various ways in which a faiing kernel splats
   information at the operator.
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 jj4JAP9xb+w9DrBY6sa+7KTPIb+aTqQ7Zw3o9O2m+riKQJv6jAEA6aEwRnDA0451
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Merge tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:
 "Significant patch series in this pull request:

   - "squashfs: Remove page->mapping references" (Matthew Wilcox) gets
     us closer to being able to remove page->mapping

   - "relayfs: misc changes" (Jason Xing) does some maintenance and
     minor feature addition work in relayfs

   - "kdump: crashkernel reservation from CMA" (Jiri Bohac) switches
     us from static preallocation of the kdump crashkernel's working
     memory over to dynamic allocation. So the difficulty of a-priori
     estimation of the second kernel's needs is removed and the first
     kernel obtains extra memory

   - "generalize panic_print's dump function to be used by other
     kernel parts" (Feng Tang) implements some consolidation and
     rationalization of the various ways in which a failing kernel
     splats information at the operator

* tag 'mm-nonmm-stable-2025-08-03-12-47' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (80 commits)
  tools/getdelays: add backward compatibility for taskstats version
  kho: add test for kexec handover
  delaytop: enhance error logging and add PSI feature description
  samples: Kconfig: fix spelling mistake "instancess" -> "instances"
  fat: fix too many log in fat_chain_add()
  scripts/spelling.txt: add notifer||notifier to spelling.txt
  xen/xenbus: fix typo "notifer"
  net: mvneta: fix typo "notifer"
  drm/xe: fix typo "notifer"
  cxl: mce: fix typo "notifer"
  KVM: x86: fix typo "notifer"
  MAINTAINERS: add maintainers for delaytop
  ucount: use atomic_long_try_cmpxchg() in atomic_long_inc_below()
  ucount: fix atomic_long_inc_below() argument type
  kexec: enable CMA based contiguous allocation
  stackdepot: make max number of pools boot-time configurable
  lib/xxhash: remove unused functions
  init/Kconfig: restore CONFIG_BROKEN help text
  lib/raid6: update recov_rvv.c zero page usage
  docs: update docs after introducing delaytop
  ...

.mailmap

@@ -673,6 +673,7 @@ Muchun Song <muchun.song@linux.dev> <smuchun@gmail.com>
 Ross Zwisler <zwisler@kernel.org> <ross.zwisler@linux.intel.com>
 Rudolf Marek <R.Marek@sh.cvut.cz>
 Rui Saraiva <rmps@joel.ist.utl.pt>
+Sachin Mokashi <sachin.mokashi@intel.com> <sachinx.mokashi@intel.com>
 Sachin P Sant <ssant@in.ibm.com>
 Sai Prakash Ranjan <quic_saipraka@quicinc.com> <saiprakash.ranjan@codeaurora.org>
 Sakari Ailus <sakari.ailus@linux.intel.com> <sakari.ailus@iki.fi>

Documentation/accounting/delay-accounting.rst

@@ -131,3 +131,59 @@ Get IO accounting for pid 1, it works only with -p::
 	linuxrc: read=65536, write=0, cancelled_write=0
 
 The above command can be used with -v to get more debug information.
+
+After the system starts, use `delaytop` to get the system-wide delay information,
+which includes system-wide PSI information and Top-N high-latency tasks.
+
+`delaytop` supports sorting by CPU latency in descending order by default,
+displays the top 20 high-latency tasks by default, and refreshes the latency
+data every 2 seconds by default.
+
+Get PSI information and Top-N tasks delay, since system boot::
+
+	bash# ./delaytop
+	System Pressure Information: (avg10/avg60/avg300/total)
+	CPU some:       0.0%/   0.0%/   0.0%/     345(ms)
+	CPU full:       0.0%/   0.0%/   0.0%/       0(ms)
+	Memory full:    0.0%/   0.0%/   0.0%/       0(ms)
+	Memory some:    0.0%/   0.0%/   0.0%/       0(ms)
+	IO full:        0.0%/   0.0%/   0.0%/      65(ms)
+	IO some:        0.0%/   0.0%/   0.0%/      79(ms)
+	IRQ full:       0.0%/   0.0%/   0.0%/       0(ms)
+	Top 20 processes (sorted by CPU delay):
+	  PID   TGID  COMMAND          CPU(ms)  IO(ms) SWAP(ms) RCL(ms) THR(ms) CMP(ms)  WP(ms) IRQ(ms)
+	----------------------------------------------------------------------------------------------
+	  161    161  zombie_memcg_re   1.40    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	  130    130  blkcg_punt_bio    1.37    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	  444    444  scsi_tmf_0        0.73    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	 1280   1280  rsyslogd          0.53    0.04    0.00    0.00    0.00    0.00    0.00    0.00
+	   12     12  ksoftirqd/0       0.47    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	 1277   1277  nbd-server        0.44    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	  308    308  kworker/2:2-sys   0.41    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	   55     55  netns             0.36    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	 1187   1187  acpid             0.31    0.03    0.00    0.00    0.00    0.00    0.00    0.00
+	 6184   6184  kworker/1:2-sys   0.24    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	  186    186  kaluad            0.24    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	   18     18  ksoftirqd/1       0.24    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	  185    185  kmpath_rdacd      0.23    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	  190    190  kstrp             0.23    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	 2759   2759  agetty            0.20    0.03    0.00    0.00    0.00    0.00    0.00    0.00
+	 1190   1190  kworker/0:3-sys   0.19    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	 1272   1272  sshd              0.15    0.04    0.00    0.00    0.00    0.00    0.00    0.00
+	 1156   1156  license           0.15    0.11    0.00    0.00    0.00    0.00    0.00    0.00
+	  134    134  md                0.13    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+	 6142   6142  kworker/3:2-xfs   0.13    0.00    0.00    0.00    0.00    0.00    0.00    0.00
+
+Dynamic interactive interface of delaytop::
+
+	# ./delaytop -p pid
+	Print delayacct stats
+
+	# ./delaytop -P num
+	Display the top N tasks
+
+	# ./delaytop -n num
+	Set delaytop refresh frequency (num times)
+
+	# ./delaytop -d secs
+	Specify refresh interval as secs

Documentation/admin-guide/kdump/kdump.rst

@@ -311,6 +311,27 @@ crashkernel syntax
 
             crashkernel=0,low
 
+4) crashkernel=size,cma
+
+	Reserve additional crash kernel memory from CMA. This reservation is
+	usable by the first system's userspace memory and kernel movable
+	allocations (memory balloon, zswap). Pages allocated from this memory
+	range will not be included in the vmcore so this should not be used if
+	dumping of userspace memory is intended and it has to be expected that
+	some movable kernel pages may be missing from the dump.
+
+	A standard crashkernel reservation, as described above, is still needed
+	to hold the crash kernel and initrd.
+
+	This option increases the risk of a kdump failure: DMA transfers
+	configured by the first kernel may end up corrupting the second
+	kernel's memory.
+
+	This reservation method is intended for systems that can't afford to
+	sacrifice enough memory for standard crashkernel reservation and where
+	less reliable and possibly incomplete kdump is preferable to no kdump at
+	all.
+
 Boot into System Kernel
 -----------------------
 1) Update the boot loader (such as grub, yaboot, or lilo) configuration

Documentation/admin-guide/kernel-parameters.txt

@@ -994,6 +994,28 @@
 			0: to disable low allocation.
 			It will be ignored when crashkernel=X,high is not used
 			or memory reserved is below 4G.
+	crashkernel=size[KMG],cma
+			[KNL, X86] Reserve additional crash kernel memory from
+			CMA. This reservation is usable by the first system's
+			userspace memory and kernel movable allocations (memory
+			balloon, zswap). Pages allocated from this memory range
+			will not be included in the vmcore so this should not
+			be used if dumping of userspace memory is intended and
+			it has to be expected that some movable kernel pages
+			may be missing from the dump.
+
+			A standard crashkernel reservation, as described above,
+			is still needed to hold the crash kernel and initrd.
+
+			This option increases the risk of a kdump failure: DMA
+			transfers configured by the first kernel may end up
+			corrupting the second kernel's memory.
+
+			This reservation method is intended for systems that
+			can't afford to sacrifice enough memory for standard
+			crashkernel reservation and where less reliable and
+			possibly incomplete kdump is preferable to no kdump at
+			all.
 
 	cryptomgr.notests
 			[KNL] Disable crypto self-tests
@@ -4557,7 +4579,7 @@
 			bit 2: print timer info
 			bit 3: print locks info if CONFIG_LOCKDEP is on
 			bit 4: print ftrace buffer
-			bit 5: print all printk messages in buffer
+			bit 5: replay all messages on consoles at the end of panic
 			bit 6: print all CPUs backtrace (if available in the arch)
 			bit 7: print only tasks in uninterruptible (blocked) state
 			*Be aware* that this option may print a _lot_ of lines,
@@ -4565,6 +4587,25 @@
 			Use this option carefully, maybe worth to setup a
 			bigger log buffer with "log_buf_len" along with this.
 
+	panic_sys_info= A comma separated list of extra information to be dumped
+                        on panic.
+                        Format: val[,val...]
+                        Where @val can be any of the following:
+
+                        tasks:          print all tasks info
+                        mem:            print system memory info
+			timers:         print timers info
+                        locks:          print locks info if CONFIG_LOCKDEP is on
+                        ftrace:         print ftrace buffer
+                        all_bt:         print all CPUs backtrace (if available in the arch)
+                        blocked_tasks:  print only tasks in uninterruptible (blocked) state
+
+                        This is a human readable alternative to the 'panic_print' option.
+
+	panic_console_replay
+			When panic happens, replay all kernel messages on
+			consoles at the end of panic.
+
 	parkbd.port=	[HW] Parallel port number the keyboard adapter is
 			connected to, default is 0.
 			Format: <parport#>
@@ -7032,6 +7073,11 @@
 			consumed by the stack hash table. By default this is set
 			to false.
 
+	stack_depot_max_pools= [KNL,EARLY]
+			Specify the maximum number of pools to use for storing
+			stack traces. Pools are allocated on-demand up to this
+			limit. Default value is 8191 pools.
+
 	stacktrace	[FTRACE]
 			Enabled the stack tracer on boot up.
 

Documentation/admin-guide/sysctl/kernel.rst

@@ -890,7 +890,7 @@ bit 1  print system memory info
 bit 2  print timer info
 bit 3  print locks info if ``CONFIG_LOCKDEP`` is on
 bit 4  print ftrace buffer
-bit 5  print all printk messages in buffer
+bit 5  replay all messages on consoles at the end of panic
 bit 6  print all CPUs backtrace (if available in the arch)
 bit 7  print only tasks in uninterruptible (blocked) state
 =====  ============================================
@@ -900,6 +900,24 @@ So for example to print tasks and memory info on panic, user can::
   echo 3 > /proc/sys/kernel/panic_print
 
 
+panic_sys_info
+==============
+
+A comma separated list of extra information to be dumped on panic,
+for example, "tasks,mem,timers,...".  It is a human readable alternative
+to 'panic_print'. Possible values are:
+
+=============   ===================================================
+tasks           print all tasks info
+mem             print system memory info
+timer           print timers info
+lock            print locks info if CONFIG_LOCKDEP is on
+ftrace          print ftrace buffer
+all_bt          print all CPUs backtrace (if available in the arch)
+blocked_tasks   print only tasks in uninterruptible (blocked) state
+=============   ===================================================
+
+
 panic_on_rcu_stall
 ==================
 

MAINTAINERS

@@ -13544,6 +13544,7 @@ F:	Documentation/admin-guide/mm/kho.rst
 F:	Documentation/core-api/kho/*
 F:	include/linux/kexec_handover.h
 F:	kernel/kexec_handover.c
+F:	tools/testing/selftests/kho/
 
 KEYS-ENCRYPTED
 M:	Mimi Zohar <zohar@linux.ibm.com>
@@ -19741,6 +19742,16 @@ S:	Maintained
 F:	include/linux/delayacct.h
 F:	kernel/delayacct.c
 
+TASK DELAY MONITORING TOOLS
+M:	Andrew Morton <akpm@linux-foundation.org>
+M:	Wang Yaxin <wang.yaxin@zte.com.cn>
+M:	Fan Yu <fan.yu9@zte.com.cn>
+L:	linux-kernel@vger.kernel.org
+S:	Maintained
+F:	Documentation/accounting/delay-accounting.rst
+F:	tools/accounting/delaytop.c
+F:	tools/accounting/getdelays.c
+
 PERFORMANCE EVENTS SUBSYSTEM
 M:	Peter Zijlstra <peterz@infradead.org>
 M:	Ingo Molnar <mingo@redhat.com>
@@ -23382,6 +23393,7 @@ F:	drivers/md/md*
 F:	drivers/md/raid*
 F:	include/linux/raid/
 F:	include/uapi/linux/raid/
+F:	lib/raid6/
 
 SOLIDRUN CLEARFOG SUPPORT
 M:	Russell King <linux@armlinux.org.uk>

arch/alpha/kernel/core_marvel.c

@@ -17,6 +17,7 @@
 #include <linux/vmalloc.h>
 #include <linux/mc146818rtc.h>
 #include <linux/rtc.h>
+#include <linux/string.h>
 #include <linux/module.h>
 #include <linux/memblock.h>
 
@@ -79,10 +80,12 @@ mk_resource_name(int pe, int port, char *str)
 {
 	char tmp[80];
 	char *name;
-	
+	size_t sz;
-	sprintf(tmp, "PCI %s PE %d PORT %d", str, pe, port);
+
-	name = memblock_alloc_or_panic(strlen(tmp) + 1, SMP_CACHE_BYTES);
+	sz = scnprintf(tmp, sizeof(tmp), "PCI %s PE %d PORT %d", str, pe, port);
-	strcpy(name, tmp);
+	sz += 1; /* NUL terminator */
+	name = memblock_alloc_or_panic(sz, SMP_CACHE_BYTES);
+	strscpy(name, tmp, sz);
 
 	return name;
 }

arch/arm/kernel/setup.c

@@ -1004,7 +1004,7 @@ static void __init reserve_crashkernel(void)
 	total_mem = get_total_mem();
 	ret = parse_crashkernel(boot_command_line, total_mem,
 				&crash_size, &crash_base,
-				NULL, NULL);
+				NULL, NULL, NULL);
 	/* invalid value specified or crashkernel=0 */
 	if (ret || !crash_size)
 		return;

arch/arm64/mm/init.c

@@ -106,7 +106,7 @@ static void __init arch_reserve_crashkernel(void)
 
 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 				&crash_size, &crash_base,
-				&low_size, &high);
+				&low_size, NULL, &high);
 	if (ret)
 		return;
 

arch/loongarch/kernel/setup.c

@@ -265,7 +265,7 @@ static void __init arch_reserve_crashkernel(void)
 		return;
 
 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
-				&crash_size, &crash_base, &low_size, &high);
+				&crash_size, &crash_base, &low_size, NULL, &high);
 	if (ret)
 		return;
 

arch/mips/kernel/setup.c

@@ -458,7 +458,7 @@ static void __init mips_parse_crashkernel(void)
 	total_mem = memblock_phys_mem_size();
 	ret = parse_crashkernel(boot_command_line, total_mem,
 				&crash_size, &crash_base,
-				NULL, NULL);
+				NULL, NULL, NULL);
 	if (ret != 0 || crash_size <= 0)
 		return;
 

arch/powerpc/kernel/fadump.c

@@ -333,7 +333,7 @@ static __init u64 fadump_calculate_reserve_size(void)
 	 * memory at a predefined offset.
 	 */
 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
-				&size, &base, NULL, NULL);
+				&size, &base, NULL, NULL, NULL);
 	if (ret == 0 && size > 0) {
 		unsigned long max_size;
 

arch/powerpc/kexec/core.c

@@ -110,7 +110,7 @@ void __init arch_reserve_crashkernel(void)
 
 	/* use common parsing */
 	ret = parse_crashkernel(boot_command_line, total_mem_sz, &crash_size,
-				&crash_base, NULL, NULL);
+				&crash_base, NULL, NULL, NULL);
 
 	if (ret)
 		return;

arch/powerpc/mm/nohash/kaslr_booke.c

@@ -178,7 +178,7 @@ static void __init get_crash_kernel(void *fdt, unsigned long size)
 	int ret;
 
 	ret = parse_crashkernel(boot_command_line, size, &crash_size,
-				&crash_base, NULL, NULL);
+				&crash_base, NULL, NULL, NULL);
 	if (ret != 0 || crash_size == 0)
 		return;
 	if (crash_base == 0)

arch/riscv/Kconfig

@@ -93,6 +93,7 @@ config RISCV
 	select CLINT_TIMER if RISCV_M_MODE
 	select CLONE_BACKWARDS
 	select COMMON_CLK
+	select CPU_NO_EFFICIENT_FFS if !RISCV_ISA_ZBB
 	select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND
 	select DYNAMIC_FTRACE if FUNCTION_TRACER
 	select EDAC_SUPPORT

arch/riscv/kernel/kexec_elf.c

@@ -95,6 +95,7 @@ static int elf_find_pbase(struct kimage *image, unsigned long kernel_len,
 	kbuf.buf_align = PMD_SIZE;
 	kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
 	kbuf.memsz = ALIGN(kernel_len, PAGE_SIZE);
+	kbuf.cma = NULL;
 	kbuf.top_down = false;
 	ret = arch_kexec_locate_mem_hole(&kbuf);
 	if (!ret) {

arch/riscv/kernel/setup.c

@@ -21,6 +21,8 @@
 #include <linux/efi.h>
 #include <linux/crash_dump.h>
 #include <linux/panic_notifier.h>
+#include <linux/jump_label.h>
+#include <linux/gcd.h>
 
 #include <asm/acpi.h>
 #include <asm/alternative.h>
@@ -362,6 +364,9 @@ void __init setup_arch(char **cmdline_p)
 
 	riscv_user_isa_enable();
 	riscv_spinlock_init();
+
+	if (!IS_ENABLED(CONFIG_RISCV_ISA_ZBB) || !riscv_isa_extension_available(NULL, ZBB))
+		static_branch_disable(&efficient_ffs_key);
 }
 
 bool arch_cpu_is_hotpluggable(int cpu)

arch/riscv/mm/init.c

@@ -1408,7 +1408,7 @@ static void __init arch_reserve_crashkernel(void)
 
 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 				&crash_size, &crash_base,
-				&low_size, &high);
+				&low_size, NULL, &high);
 	if (ret)
 		return;
 

arch/s390/kernel/setup.c

@@ -605,7 +605,7 @@ static void __init reserve_crashkernel(void)
 	int rc;
 
 	rc = parse_crashkernel(boot_command_line, ident_map_size,
-			       &crash_size, &crash_base, NULL, NULL);
+			       &crash_size, &crash_base, NULL, NULL, NULL);
 
 	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
 	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);

arch/sh/kernel/machine_kexec.c

@@ -146,7 +146,7 @@ void __init reserve_crashkernel(void)
 		return;
 
 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
-			&crash_size, &crash_base, NULL, NULL);
+			&crash_size, &crash_base, NULL, NULL, NULL);
 	if (ret == 0 && crash_size > 0) {
 		crashk_res.start = crash_base;
 		crashk_res.end = crash_base + crash_size - 1;

arch/x86/kernel/crash.c

@@ -163,10 +163,10 @@ static struct crash_mem *fill_up_crash_elf_data(void)
 		return NULL;
 
 	/*
-	 * Exclusion of crash region and/or crashk_low_res may cause
+	 * Exclusion of crash region, crashk_low_res and/or crashk_cma_ranges
-	 * another range split. So add extra two slots here.
+	 * may cause range splits. So add extra slots here.
 	 */
-	nr_ranges += 2;
+	nr_ranges += 2 + crashk_cma_cnt;
 	cmem = vzalloc(struct_size(cmem, ranges, nr_ranges));
 	if (!cmem)
 		return NULL;
@@ -184,6 +184,7 @@ static struct crash_mem *fill_up_crash_elf_data(void)
 static int elf_header_exclude_ranges(struct crash_mem *cmem)
 {
 	int ret = 0;
+	int i;
 
 	/* Exclude the low 1M because it is always reserved */
 	ret = crash_exclude_mem_range(cmem, 0, SZ_1M - 1);
@@ -198,8 +199,17 @@ static int elf_header_exclude_ranges(struct crash_mem *cmem)
 	if (crashk_low_res.end)
 		ret = crash_exclude_mem_range(cmem, crashk_low_res.start,
 					      crashk_low_res.end);
+	if (ret)
+		return ret;
 
-	return ret;
+	for (i = 0; i < crashk_cma_cnt; ++i) {
+		ret = crash_exclude_mem_range(cmem, crashk_cma_ranges[i].start,
+					      crashk_cma_ranges[i].end);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
 }
 
 static int prepare_elf64_ram_headers_callback(struct resource *res, void *arg)
@@ -374,6 +384,14 @@ int crash_setup_memmap_entries(struct kimage *image, struct boot_params *params)
 		add_e820_entry(params, &ei);
 	}
 
+	for (i = 0; i < crashk_cma_cnt; ++i) {
+		ei.addr = crashk_cma_ranges[i].start;
+		ei.size = crashk_cma_ranges[i].end -
+			  crashk_cma_ranges[i].start + 1;
+		ei.type = E820_TYPE_RAM;
+		add_e820_entry(params, &ei);
+	}
+
 out:
 	vfree(cmem);
 	return ret;

arch/x86/kernel/setup.c

@@ -603,7 +603,7 @@ static void __init memblock_x86_reserve_range_setup_data(void)
 
 static void __init arch_reserve_crashkernel(void)
 {
-	unsigned long long crash_base, crash_size, low_size = 0;
+	unsigned long long crash_base, crash_size, low_size = 0, cma_size = 0;
 	bool high = false;
 	int ret;
 
@@ -612,7 +612,7 @@ static void __init arch_reserve_crashkernel(void)
 
 	ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
 				&crash_size, &crash_base,
-				&low_size, &high);
+				&low_size, &cma_size, &high);
 	if (ret)
 		return;
 
@@ -622,6 +622,7 @@ static void __init arch_reserve_crashkernel(void)
 	}
 
 	reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
+	reserve_crashkernel_cma(cma_size);
 }
 
 static struct resource standard_io_resources[] = {

arch/x86/kvm/i8254.c

@@ -641,7 +641,7 @@ static void kvm_pit_reset(struct kvm_pit *pit)
 	kvm_pit_reset_reinject(pit);
 }
 
-static void pit_mask_notifer(struct kvm_irq_mask_notifier *kimn, bool mask)
+static void pit_mask_notifier(struct kvm_irq_mask_notifier *kimn, bool mask)
 {
 	struct kvm_pit *pit = container_of(kimn, struct kvm_pit, mask_notifier);
 
@@ -763,7 +763,7 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm, u32 flags)
 
 	pit_state->irq_ack_notifier.gsi = 0;
 	pit_state->irq_ack_notifier.irq_acked = kvm_pit_ack_irq;
-	pit->mask_notifier.func = pit_mask_notifer;
+	pit->mask_notifier.func = pit_mask_notifier;
 
 	kvm_pit_reset(pit);
 

crypto/async_tx/async_pq.c

@@ -119,7 +119,7 @@ do_sync_gen_syndrome(struct page **blocks, unsigned int *offsets, int disks,
 	for (i = 0; i < disks; i++) {
 		if (blocks[i] == NULL) {
 			BUG_ON(i > disks - 3); /* P or Q can't be zero */
-			srcs[i] = (void*)raid6_empty_zero_page;
+			srcs[i] = raid6_get_zero_page();
 		} else {
 			srcs[i] = page_address(blocks[i]) + offsets[i];
 

crypto/async_tx/async_raid6_recov.c

@@ -414,7 +414,7 @@ async_raid6_2data_recov(int disks, size_t bytes, int faila, int failb,
 		async_tx_quiesce(&submit->depend_tx);
 		for (i = 0; i < disks; i++)
 			if (blocks[i] == NULL)
-				ptrs[i] = (void *) raid6_empty_zero_page;
+				ptrs[i] = raid6_get_zero_page();
 			else
 				ptrs[i] = page_address(blocks[i]) + offs[i];
 
@@ -497,7 +497,7 @@ async_raid6_datap_recov(int disks, size_t bytes, int faila,
 		async_tx_quiesce(&submit->depend_tx);
 		for (i = 0; i < disks; i++)
 			if (blocks[i] == NULL)
-				ptrs[i] = (void*)raid6_empty_zero_page;
+				ptrs[i] = raid6_get_zero_page();
 			else
 				ptrs[i] = page_address(blocks[i]) + offs[i];
 

drivers/cxl/core/mce.h

@@ -7,7 +7,7 @@
 
 #ifdef CONFIG_CXL_MCE
 int devm_cxl_register_mce_notifier(struct device *dev,
-				   struct notifier_block *mce_notifer);
+				   struct notifier_block *mce_notifier);
 #else
 static inline int
 devm_cxl_register_mce_notifier(struct device *dev,

drivers/gpu/drm/i915/gt/uc/intel_guc_log.c

@@ -220,8 +220,7 @@ static int guc_action_control_log(struct intel_guc *guc, bool enable,
  */
 static int subbuf_start_callback(struct rchan_buf *buf,
 				 void *subbuf,
-				 void *prev_subbuf,
+				 void *prev_subbuf)
-				 size_t prev_padding)
 {
 	/*
 	 * Use no-overwrite mode by default, where relay will stop accepting

drivers/gpu/drm/xe/xe_vm_types.h

@@ -266,7 +266,7 @@ struct xe_vm {
 		 * up for revalidation. Protected from access with the
 		 * @invalidated_lock. Removing items from the list
 		 * additionally requires @lock in write mode, and adding
-		 * items to the list requires either the @userptr.notifer_lock in
+		 * items to the list requires either the @userptr.notifier_lock in
 		 * write mode, OR @lock in write mode.
 		 */
 		struct list_head invalidated;

drivers/net/ethernet/marvell/mvneta.c

@@ -4610,7 +4610,7 @@ static int mvneta_stop(struct net_device *dev)
 		/* Inform that we are stopping so we don't want to setup the
 		 * driver for new CPUs in the notifiers. The code of the
 		 * notifier for CPU online is protected by the same spinlock,
-		 * so when we get the lock, the notifer work is done.
+		 * so when we get the lock, the notifier work is done.
 		 */
 		spin_lock(&pp->lock);
 		pp->is_stopped = true;

drivers/net/wwan/iosm/iosm_ipc_trace.c

@@ -51,8 +51,7 @@ static int ipc_trace_remove_buf_file_handler(struct dentry *dentry)
 }
 
 static int ipc_trace_subbuf_start_handler(struct rchan_buf *buf, void *subbuf,
-					  void *prev_subbuf,
+					  void *prev_subbuf)
-					  size_t prev_padding)
 {
 	if (relay_buf_full(buf)) {
 		pr_err_ratelimited("Relay_buf full dropping traces");

drivers/net/wwan/t7xx/t7xx_port_trace.c

@@ -33,7 +33,7 @@ static int t7xx_trace_remove_buf_file_handler(struct dentry *dentry)
 }
 
 static int t7xx_trace_subbuf_start_handler(struct rchan_buf *buf, void *subbuf,
-					   void *prev_subbuf, size_t prev_padding)
+					   void *prev_subbuf)
 {
 	if (relay_buf_full(buf)) {
 		pr_err_ratelimited("Relay_buf full dropping traces");

fs/fat/fatent.c

@@ -356,7 +356,7 @@ int fat_ent_read(struct inode *inode, struct fat_entry *fatent, int entry)
 
 	if (!fat_valid_entry(sbi, entry)) {
 		fatent_brelse(fatent);
-		fat_fs_error(sb, "invalid access to FAT (entry 0x%08x)", entry);
+		fat_fs_error_ratelimit(sb, "invalid access to FAT (entry 0x%08x)", entry);
 		return -EIO;
 	}
 

fs/fat/misc.c

@@ -158,9 +158,9 @@ int fat_chain_add(struct inode *inode, int new_dclus, int nr_cluster)
 			mark_inode_dirty(inode);
 	}
 	if (new_fclus != (inode->i_blocks >> (sbi->cluster_bits - 9))) {
-		fat_fs_error(sb, "clusters badly computed (%d != %llu)",
+		fat_fs_error_ratelimit(
-			     new_fclus,
+			sb, "clusters badly computed (%d != %llu)", new_fclus,
-			     (llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
+			(llu)(inode->i_blocks >> (sbi->cluster_bits - 9)));
 		fat_cache_inval_inode(inode);
 	}
 	inode->i_blocks += nr_cluster << (sbi->cluster_bits - 9);

fs/ocfs2/aops.c

@@ -1071,6 +1071,7 @@ static int ocfs2_grab_folios_for_write(struct address_space *mapping,
 			if (IS_ERR(wc->w_folios[i])) {
 				ret = PTR_ERR(wc->w_folios[i]);
 				mlog_errno(ret);
+				wc->w_folios[i] = NULL;
 				goto out;
 			}
 		}

fs/ocfs2/dir.c

@@ -798,6 +798,14 @@ static int ocfs2_dx_dir_lookup_rec(struct inode *inode,
 		}
 	}
 
+	if (le16_to_cpu(el->l_next_free_rec) == 0) {
+		ret = ocfs2_error(inode->i_sb,
+				  "Inode %lu has empty extent list at depth %u\n",
+				  inode->i_ino,
+				  le16_to_cpu(el->l_tree_depth));
+		goto out;
+	}
+
 	found = 0;
 	for (i = le16_to_cpu(el->l_next_free_rec) - 1; i >= 0; i--) {
 		rec = &el->l_recs[i];

fs/ocfs2/dlm/dlmrecovery.c

@@ -2632,7 +2632,7 @@ again:
 					 dlm_reco_master_ready(dlm),
 					 msecs_to_jiffies(1000));
 		if (!dlm_reco_master_ready(dlm)) {
-			mlog(0, "%s: reco master taking awhile\n",
+			mlog(0, "%s: reco master taking a while\n",
 			     dlm->name);
 			goto again;
 		}

fs/ocfs2/inode.c

@@ -50,8 +50,6 @@ struct ocfs2_find_inode_args
 	unsigned int	fi_sysfile_type;
 };
 
-static struct lock_class_key ocfs2_sysfile_lock_key[NUM_SYSTEM_INODES];
-
 static int ocfs2_read_locked_inode(struct inode *inode,
 				   struct ocfs2_find_inode_args *args);
 static int ocfs2_init_locked_inode(struct inode *inode, void *opaque);
@@ -250,14 +248,77 @@ bail:
 static int ocfs2_init_locked_inode(struct inode *inode, void *opaque)
 {
 	struct ocfs2_find_inode_args *args = opaque;
+#ifdef CONFIG_LOCKDEP
+	static struct lock_class_key ocfs2_sysfile_lock_key[NUM_SYSTEM_INODES];
 	static struct lock_class_key ocfs2_quota_ip_alloc_sem_key,
 				     ocfs2_file_ip_alloc_sem_key;
+#endif
 
 	inode->i_ino = args->fi_ino;
 	OCFS2_I(inode)->ip_blkno = args->fi_blkno;
-	if (args->fi_sysfile_type != 0)
+#ifdef CONFIG_LOCKDEP
+	switch (args->fi_sysfile_type) {
+	case BAD_BLOCK_SYSTEM_INODE:
+		break;
+	case GLOBAL_INODE_ALLOC_SYSTEM_INODE:
 		lockdep_set_class(&inode->i_rwsem,
-			&ocfs2_sysfile_lock_key[args->fi_sysfile_type]);
+				  &ocfs2_sysfile_lock_key[GLOBAL_INODE_ALLOC_SYSTEM_INODE]);
+		break;
+	case SLOT_MAP_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[SLOT_MAP_SYSTEM_INODE]);
+		break;
+	case HEARTBEAT_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[HEARTBEAT_SYSTEM_INODE]);
+		break;
+	case GLOBAL_BITMAP_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[GLOBAL_BITMAP_SYSTEM_INODE]);
+		break;
+	case USER_QUOTA_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[USER_QUOTA_SYSTEM_INODE]);
+		break;
+	case GROUP_QUOTA_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[GROUP_QUOTA_SYSTEM_INODE]);
+		break;
+	case ORPHAN_DIR_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE]);
+		break;
+	case EXTENT_ALLOC_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[EXTENT_ALLOC_SYSTEM_INODE]);
+		break;
+	case INODE_ALLOC_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[INODE_ALLOC_SYSTEM_INODE]);
+		break;
+	case JOURNAL_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[JOURNAL_SYSTEM_INODE]);
+		break;
+	case LOCAL_ALLOC_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[LOCAL_ALLOC_SYSTEM_INODE]);
+		break;
+	case TRUNCATE_LOG_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[TRUNCATE_LOG_SYSTEM_INODE]);
+		break;
+	case LOCAL_USER_QUOTA_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[LOCAL_USER_QUOTA_SYSTEM_INODE]);
+		break;
+	case LOCAL_GROUP_QUOTA_SYSTEM_INODE:
+		lockdep_set_class(&inode->i_rwsem,
+				  &ocfs2_sysfile_lock_key[LOCAL_GROUP_QUOTA_SYSTEM_INODE]);
+		break;
+	default:
+		WARN_ONCE(1, "Unknown sysfile type %d\n", args->fi_sysfile_type);
+	}
 	if (args->fi_sysfile_type == USER_QUOTA_SYSTEM_INODE ||
 	    args->fi_sysfile_type == GROUP_QUOTA_SYSTEM_INODE ||
 	    args->fi_sysfile_type == LOCAL_USER_QUOTA_SYSTEM_INODE ||
@@ -267,6 +328,7 @@ static int ocfs2_init_locked_inode(struct inode *inode, void *opaque)
 	else
 		lockdep_set_class(&OCFS2_I(inode)->ip_alloc_sem,
 				  &ocfs2_file_ip_alloc_sem_key);
+#endif
 
 	return 0;
 }

fs/ocfs2/move_extents.c

@@ -617,6 +617,8 @@ static int ocfs2_move_extent(struct ocfs2_move_extents_context *context,
 	 */
 	credits += OCFS2_INODE_UPDATE_CREDITS + 1;
 
+	inode_lock(tl_inode);
+
 	/*
 	 * ocfs2_move_extent() didn't reserve any clusters in lock_allocators()
 	 * logic, while we still need to lock the global_bitmap.
@@ -626,7 +628,7 @@ static int ocfs2_move_extent(struct ocfs2_move_extents_context *context,
 	if (!gb_inode) {
 		mlog(ML_ERROR, "unable to get global_bitmap inode\n");
 		ret = -EIO;
-		goto out;
+		goto out_unlock_tl_inode;
 	}
 
 	inode_lock(gb_inode);
@@ -634,16 +636,14 @@ static int ocfs2_move_extent(struct ocfs2_move_extents_context *context,
 	ret = ocfs2_inode_lock(gb_inode, &gb_bh, 1);
 	if (ret) {
 		mlog_errno(ret);
-		goto out_unlock_gb_mutex;
+		goto out_unlock_gb_inode;
 	}
 
-	inode_lock(tl_inode);
-
 	handle = ocfs2_start_trans(osb, credits);
 	if (IS_ERR(handle)) {
 		ret = PTR_ERR(handle);
 		mlog_errno(ret);
-		goto out_unlock_tl_inode;
+		goto out_unlock;
 	}
 
 	new_phys_blkno = ocfs2_clusters_to_blocks(inode->i_sb, *new_phys_cpos);
@@ -703,15 +703,14 @@ static int ocfs2_move_extent(struct ocfs2_move_extents_context *context,
 out_commit:
 	ocfs2_commit_trans(osb, handle);
 	brelse(gd_bh);
-
+out_unlock:
-out_unlock_tl_inode:
-	inode_unlock(tl_inode);
-
 	ocfs2_inode_unlock(gb_inode, 1);
-out_unlock_gb_mutex:
+out_unlock_gb_inode:
 	inode_unlock(gb_inode);
 	brelse(gb_bh);
 	iput(gb_inode);
+out_unlock_tl_inode:
+	inode_unlock(tl_inode);
 
 out:
 	if (context->meta_ac) {

fs/ocfs2/namei.c

@@ -142,6 +142,8 @@ static struct dentry *ocfs2_lookup(struct inode *dir, struct dentry *dentry,
 
 bail_add:
 	ret = d_splice_alias(inode, dentry);
+	if (IS_ERR(ret))
+		goto bail_unlock;
 
 	if (inode) {
 		/*
@@ -154,15 +156,16 @@ bail_add:
 		 * NOTE: This dentry already has ->d_op set from
 		 * ocfs2_get_parent() and ocfs2_get_dentry()
 		 */
-		if (!IS_ERR_OR_NULL(ret))
+		if (ret)
 			dentry = ret;
 
 		status = ocfs2_dentry_attach_lock(dentry, inode,
 						  OCFS2_I(dir)->ip_blkno);
 		if (status) {
 			mlog_errno(status);
+			if (ret)
+				dput(ret);
 			ret = ERR_PTR(status);
-			goto bail_unlock;
 		}
 	} else
 		ocfs2_dentry_attach_gen(dentry);
@@ -1452,8 +1455,8 @@ static int ocfs2_rename(struct mnt_idmap *idmap,
 		newfe = (struct ocfs2_dinode *) newfe_bh->b_data;
 
 		trace_ocfs2_rename_over_existing(
-		     (unsigned long long)newfe_blkno, newfe_bh, newfe_bh ?
+		     (unsigned long long)newfe_blkno, newfe_bh,
-		     (unsigned long long)newfe_bh->b_blocknr : 0ULL);
+		     (unsigned long long)newfe_bh->b_blocknr);
 
 		if (S_ISDIR(new_inode->i_mode) || (new_inode->i_nlink == 1)) {
 			status = ocfs2_prepare_orphan_dir(osb, &orphan_dir,

fs/ocfs2/stack_user.c

@@ -360,7 +360,6 @@ static int ocfs2_control_do_setnode_msg(struct file *file,
 					struct ocfs2_control_message_setn *msg)
 {
 	long nodenum;
-	char *ptr = NULL;
 	struct ocfs2_control_private *p = file->private_data;
 
 	if (ocfs2_control_get_handshake_state(file) !=
@@ -375,8 +374,7 @@ static int ocfs2_control_do_setnode_msg(struct file *file,
 		return -EINVAL;
 	msg->space = msg->newline = '\0';
 
-	nodenum = simple_strtol(msg->nodestr, &ptr, 16);
+	if (kstrtol(msg->nodestr, 16, &nodenum))
-	if (!ptr || *ptr)
 		return -EINVAL;
 
 	if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) ||
@@ -391,7 +389,6 @@ static int ocfs2_control_do_setversion_msg(struct file *file,
 					   struct ocfs2_control_message_setv *msg)
 {
 	long major, minor;
-	char *ptr = NULL;
 	struct ocfs2_control_private *p = file->private_data;
 	struct ocfs2_protocol_version *max =
 		&ocfs2_user_plugin.sp_max_proto;
@@ -409,11 +406,9 @@ static int ocfs2_control_do_setversion_msg(struct file *file,
 		return -EINVAL;
 	msg->space1 = msg->space2 = msg->newline = '\0';
 
-	major = simple_strtol(msg->major, &ptr, 16);
+	if (kstrtol(msg->major, 16, &major))
-	if (!ptr || *ptr)
 		return -EINVAL;
-	minor = simple_strtol(msg->minor, &ptr, 16);
+	if (kstrtol(msg->minor, 16, &minor))
-	if (!ptr || *ptr)
 		return -EINVAL;
 
 	/*
@@ -441,7 +436,6 @@ static int ocfs2_control_do_down_msg(struct file *file,
 				     struct ocfs2_control_message_down *msg)
 {
 	long nodenum;
-	char *p = NULL;
 
 	if (ocfs2_control_get_handshake_state(file) !=
 	    OCFS2_CONTROL_HANDSHAKE_VALID)
@@ -456,8 +450,7 @@ static int ocfs2_control_do_down_msg(struct file *file,
 		return -EINVAL;
 	msg->space1 = msg->space2 = msg->newline = '\0';
 
-	nodenum = simple_strtol(msg->nodestr, &p, 16);
+	if (kstrtol(msg->nodestr, 16, &nodenum))
-	if (!p || *p)
 		return -EINVAL;
 
 	if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) ||

fs/proc/vmcore.c

@@ -1490,10 +1490,8 @@ int vmcore_add_device_dump(struct vmcoredd_data *data)
 		return -EINVAL;
 
 	dump = vzalloc(sizeof(*dump));
-	if (!dump) {
+	if (!dump)
-		ret = -ENOMEM;
+		return -ENOMEM;
-		goto out_err;
-	}
 
 	/* Keep size of the buffer page aligned so that it can be mmaped */
 	data_size = roundup(sizeof(struct vmcoredd_header) + data->size,
@@ -1519,22 +1517,19 @@ int vmcore_add_device_dump(struct vmcoredd_data *data)
 	dump->size = data_size;
 
 	/* Add the dump to driver sysfs list and update the elfcore hdr */
-	mutex_lock(&vmcore_mutex);
+	scoped_guard(mutex, &vmcore_mutex) {
-	if (vmcore_opened)
+		if (vmcore_opened)
-		pr_warn_once("Unexpected adding of device dump\n");
+			pr_warn_once("Unexpected adding of device dump\n");
-	if (vmcore_open) {
+		if (vmcore_open) {
-		ret = -EBUSY;
+			ret = -EBUSY;
-		goto unlock;
+			goto out_err;
+		}
+
+		list_add_tail(&dump->list, &vmcoredd_list);
+		vmcoredd_update_size(data_size);
 	}
-
-	list_add_tail(&dump->list, &vmcoredd_list);
-	vmcoredd_update_size(data_size);
-	mutex_unlock(&vmcore_mutex);
 	return 0;
 
-unlock:
-	mutex_unlock(&vmcore_mutex);
-
 out_err:
 	vfree(buf);
 	vfree(dump);

fs/squashfs/block.c

@@ -80,23 +80,22 @@ static int squashfs_bio_read_cached(struct bio *fullbio,
 		struct address_space *cache_mapping, u64 index, int length,
 		u64 read_start, u64 read_end, int page_count)
 {
-	struct page *head_to_cache = NULL, *tail_to_cache = NULL;
+	struct folio *head_to_cache = NULL, *tail_to_cache = NULL;
 	struct block_device *bdev = fullbio->bi_bdev;
 	int start_idx = 0, end_idx = 0;
-	struct bvec_iter_all iter_all;
+	struct folio_iter fi;
 	struct bio *bio = NULL;
-	struct bio_vec *bv;
 	int idx = 0;
 	int err = 0;
 #ifdef CONFIG_SQUASHFS_COMP_CACHE_FULL
-	struct page **cache_pages = kmalloc_array(page_count,
+	struct folio **cache_folios = kmalloc_array(page_count,
-			sizeof(void *), GFP_KERNEL | __GFP_ZERO);
+			sizeof(*cache_folios), GFP_KERNEL | __GFP_ZERO);
 #endif
 
-	bio_for_each_segment_all(bv, fullbio, iter_all) {
+	bio_for_each_folio_all(fi, fullbio) {
-		struct page *page = bv->bv_page;
+		struct folio *folio = fi.folio;
 
-		if (page->mapping == cache_mapping) {
+		if (folio->mapping == cache_mapping) {
 			idx++;
 			continue;
 		}
@@ -111,13 +110,13 @@ static int squashfs_bio_read_cached(struct bio *fullbio,
 		 * adjacent blocks.
 		 */
 		if (idx == 0 && index != read_start)
-			head_to_cache = page;
+			head_to_cache = folio;
 		else if (idx == page_count - 1 && index + length != read_end)
-			tail_to_cache = page;
+			tail_to_cache = folio;
 #ifdef CONFIG_SQUASHFS_COMP_CACHE_FULL
 		/* Cache all pages in the BIO for repeated reads */
-		else if (cache_pages)
+		else if (cache_folios)
-			cache_pages[idx] = page;
+			cache_folios[idx] = folio;
 #endif
 
 		if (!bio || idx != end_idx) {
@@ -150,45 +149,45 @@ static int squashfs_bio_read_cached(struct bio *fullbio,
 		return err;
 
 	if (head_to_cache) {
-		int ret = add_to_page_cache_lru(head_to_cache, cache_mapping,
+		int ret = filemap_add_folio(cache_mapping, head_to_cache,
 						read_start >> PAGE_SHIFT,
 						GFP_NOIO);
 
 		if (!ret) {
-			SetPageUptodate(head_to_cache);
+			folio_mark_uptodate(head_to_cache);
-			unlock_page(head_to_cache);
+			folio_unlock(head_to_cache);
 		}
 
 	}
 
 	if (tail_to_cache) {
-		int ret = add_to_page_cache_lru(tail_to_cache, cache_mapping,
+		int ret = filemap_add_folio(cache_mapping, tail_to_cache,
 						(read_end >> PAGE_SHIFT) - 1,
 						GFP_NOIO);
 
 		if (!ret) {
-			SetPageUptodate(tail_to_cache);
+			folio_mark_uptodate(tail_to_cache);
-			unlock_page(tail_to_cache);
+			folio_unlock(tail_to_cache);
 		}
 	}
 
 #ifdef CONFIG_SQUASHFS_COMP_CACHE_FULL
-	if (!cache_pages)
+	if (!cache_folios)
 		goto out;
 
 	for (idx = 0; idx < page_count; idx++) {
-		if (!cache_pages[idx])
+		if (!cache_folios[idx])
 			continue;
-		int ret = add_to_page_cache_lru(cache_pages[idx], cache_mapping,
+		int ret = filemap_add_folio(cache_mapping, cache_folios[idx],
 						(read_start >> PAGE_SHIFT) + idx,
 						GFP_NOIO);
 
 		if (!ret) {
-			SetPageUptodate(cache_pages[idx]);
+			folio_mark_uptodate(cache_folios[idx]);
-			unlock_page(cache_pages[idx]);
+			folio_unlock(cache_folios[idx]);
 		}
 	}
-	kfree(cache_pages);
+	kfree(cache_folios);
 out:
 #endif
 	return 0;

fs/squashfs/file.c

@@ -493,10 +493,9 @@ out:
 	return res;
 }
 
-static int squashfs_readahead_fragment(struct page **page,
+static int squashfs_readahead_fragment(struct inode *inode, struct page **page,
 	unsigned int pages, unsigned int expected, loff_t start)
 {
-	struct inode *inode = page[0]->mapping->host;
 	struct squashfs_cache_entry *buffer = squashfs_get_fragment(inode->i_sb,
 		squashfs_i(inode)->fragment_block,
 		squashfs_i(inode)->fragment_size);
@@ -605,8 +604,8 @@ static void squashfs_readahead(struct readahead_control *ractl)
 
 		if (start >> msblk->block_log == file_end &&
 				squashfs_i(inode)->fragment_block != SQUASHFS_INVALID_BLK) {
-			res = squashfs_readahead_fragment(pages, nr_pages,
+			res = squashfs_readahead_fragment(inode, pages,
-							  expected, start);
+					nr_pages, expected, start);
 			if (res)
 				goto skip_pages;
 			continue;

include/linux/crash_reserve.h

@@ -13,10 +13,23 @@
  */
 extern struct resource crashk_res;
 extern struct resource crashk_low_res;
+extern struct range crashk_cma_ranges[];
+#if defined(CONFIG_CMA) && defined(CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION)
+#define CRASHKERNEL_CMA
+#define CRASHKERNEL_CMA_RANGES_MAX 4
+extern int crashk_cma_cnt;
+#else
+#define crashk_cma_cnt 0
+#define CRASHKERNEL_CMA_RANGES_MAX 0
+#endif
+
 
 int __init parse_crashkernel(char *cmdline, unsigned long long system_ram,
 		unsigned long long *crash_size, unsigned long long *crash_base,
-		unsigned long long *low_size, bool *high);
+		unsigned long long *low_size, unsigned long long *cma_size,
+		bool *high);
+
+void __init reserve_crashkernel_cma(unsigned long long cma_size);
 
 #ifdef CONFIG_ARCH_HAS_GENERIC_CRASHKERNEL_RESERVATION
 #ifndef DEFAULT_CRASH_KERNEL_LOW_SIZE

include/linux/gcd.h

@@ -3,6 +3,9 @@
 #define _GCD_H
 
 #include <linux/compiler.h>
+#include <linux/jump_label.h>
+
+DECLARE_STATIC_KEY_TRUE(efficient_ffs_key);
 
 unsigned long gcd(unsigned long a, unsigned long b) __attribute_const__;
 

include/linux/hung_task.h

@@ -21,17 +21,17 @@
  * type.
  *
  * Type encoding:
- * 00 - Blocked on mutex        (BLOCKER_TYPE_MUTEX)
+ * 00 - Blocked on mutex			(BLOCKER_TYPE_MUTEX)
- * 01 - Blocked on semaphore    (BLOCKER_TYPE_SEM)
+ * 01 - Blocked on semaphore			(BLOCKER_TYPE_SEM)
- * 10 - Blocked on rt-mutex     (BLOCKER_TYPE_RTMUTEX)
+ * 10 - Blocked on rw-semaphore as READER	(BLOCKER_TYPE_RWSEM_READER)
- * 11 - Blocked on rw-semaphore (BLOCKER_TYPE_RWSEM)
+ * 11 - Blocked on rw-semaphore as WRITER	(BLOCKER_TYPE_RWSEM_WRITER)
  */
-#define BLOCKER_TYPE_MUTEX      0x00UL
+#define BLOCKER_TYPE_MUTEX		0x00UL
-#define BLOCKER_TYPE_SEM        0x01UL
+#define BLOCKER_TYPE_SEM		0x01UL
-#define BLOCKER_TYPE_RTMUTEX    0x02UL
+#define BLOCKER_TYPE_RWSEM_READER	0x02UL
-#define BLOCKER_TYPE_RWSEM      0x03UL
+#define BLOCKER_TYPE_RWSEM_WRITER	0x03UL
 
-#define BLOCKER_TYPE_MASK       0x03UL
+#define BLOCKER_TYPE_MASK		0x03UL
 
 #ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER
 static inline void hung_task_set_blocker(void *lock, unsigned long type)

include/linux/jhash.h

@@ -24,7 +24,7 @@
  * Jozsef
  */
 #include <linux/bitops.h>
-#include <linux/unaligned/packed_struct.h>
+#include <linux/unaligned.h>
 
 /* Best hash sizes are of power of two */
 #define jhash_size(n)   ((u32)1<<(n))
@@ -77,9 +77,9 @@ static inline u32 jhash(const void *key, u32 length, u32 initval)
 
 	/* All but the last block: affect some 32 bits of (a,b,c) */
 	while (length > 12) {
-		a += __get_unaligned_cpu32(k);
+		a += get_unaligned((u32 *)k);
-		b += __get_unaligned_cpu32(k + 4);
+		b += get_unaligned((u32 *)(k + 4));
-		c += __get_unaligned_cpu32(k + 8);
+		c += get_unaligned((u32 *)(k + 8));
 		__jhash_mix(a, b, c);
 		length -= 12;
 		k += 12;

include/linux/kexec.h

@@ -79,6 +79,12 @@ extern note_buf_t __percpu *crash_notes;
 
 typedef unsigned long kimage_entry_t;
 
+/*
+ * This is a copy of the UAPI struct kexec_segment and must be identical
+ * to it because it gets copied straight from user space into kernel
+ * memory. Do not modify this structure unless you change the way segments
+ * get ingested from user space.
+ */
 struct kexec_segment {
 	/*
 	 * This pointer can point to user memory if kexec_load() system
@@ -172,6 +178,7 @@ int kexec_image_post_load_cleanup_default(struct kimage *image);
  * @buf_align:	Minimum alignment needed.
  * @buf_min:	The buffer can't be placed below this address.
  * @buf_max:	The buffer can't be placed above this address.
+ * @cma:	CMA page if the buffer is backed by CMA.
  * @top_down:	Allocate from top of memory.
  * @random:	Place the buffer at a random position.
  */
@@ -184,6 +191,7 @@ struct kexec_buf {
 	unsigned long buf_align;
 	unsigned long buf_min;
 	unsigned long buf_max;
+	struct page *cma;
 	bool top_down;
 #ifdef CONFIG_CRASH_DUMP
 	bool random;
@@ -340,6 +348,7 @@ struct kimage {
 
 	unsigned long nr_segments;
 	struct kexec_segment segment[KEXEC_SEGMENT_MAX];
+	struct page *segment_cma[KEXEC_SEGMENT_MAX];
 
 	struct list_head control_pages;
 	struct list_head dest_pages;
@@ -361,6 +370,7 @@ struct kimage {
 	 */
 	unsigned int hotplug_support:1;
 #endif
+	unsigned int no_cma:1;
 
 #ifdef ARCH_HAS_KIMAGE_ARCH
 	struct kimage_arch arch;

include/linux/raid/pq.h

@@ -11,8 +11,13 @@
 #ifdef __KERNEL__
 
 #include <linux/blkdev.h>
+#include <linux/mm.h>
 
-extern const char raid6_empty_zero_page[PAGE_SIZE];
+/* This should be const but the raid6 code is too convoluted for that. */
+static inline void *raid6_get_zero_page(void)
+{
+	return page_address(ZERO_PAGE(0));
+}
 
 #else /* ! __KERNEL__ */
 /* Used for testing in user space */
@@ -191,6 +196,11 @@ static inline uint32_t raid6_jiffies(void)
 	return tv.tv_sec*1000 + tv.tv_usec/1000;
 }
 
+static inline void *raid6_get_zero_page(void)
+{
+	return raid6_empty_zero_page;
+}
+
 #endif /* ! __KERNEL__ */
 
 #endif /* LINUX_RAID_RAID6_H */

include/linux/relay.h

@@ -28,6 +28,22 @@
  */
 #define RELAYFS_CHANNEL_VERSION		7
 
+/*
+ * Relay buffer statistics
+ */
+enum {
+	RELAY_STATS_BUF_FULL = (1 << 0),
+	RELAY_STATS_WRT_BIG = (1 << 1),
+
+	RELAY_STATS_LAST = RELAY_STATS_WRT_BIG,
+};
+
+struct rchan_buf_stats
+{
+	unsigned int full_count;	/* counter for buffer full */
+	unsigned int big_count;		/* counter for too big to write */
+};
+
 /*
  * Per-cpu relay channel buffer
  */
@@ -43,11 +59,11 @@ struct rchan_buf
 	struct irq_work wakeup_work;	/* reader wakeup */
 	struct dentry *dentry;		/* channel file dentry */
 	struct kref kref;		/* channel buffer refcount */
+	struct rchan_buf_stats stats;	/* buffer stats */
 	struct page **page_array;	/* array of current buffer pages */
 	unsigned int page_count;	/* number of current buffer pages */
 	unsigned int finalized;		/* buffer has been finalized */
 	size_t *padding;		/* padding counts per sub-buffer */
-	size_t prev_padding;		/* temporary variable */
 	size_t bytes_consumed;		/* bytes consumed in cur read subbuf */
 	size_t early_bytes;		/* bytes consumed before VFS inited */
 	unsigned int cpu;		/* this buf's cpu */
@@ -65,7 +81,6 @@ struct rchan
 	const struct rchan_callbacks *cb; /* client callbacks */
 	struct kref kref;		/* channel refcount */
 	void *private_data;		/* for user-defined data */
-	size_t last_toobig;		/* tried to log event > subbuf size */
 	struct rchan_buf * __percpu *buf; /* per-cpu channel buffers */
 	int is_global;			/* One global buffer ? */
 	struct list_head list;		/* for channel list */
@@ -84,7 +99,6 @@ struct rchan_callbacks
 	 * @buf: the channel buffer containing the new sub-buffer
 	 * @subbuf: the start of the new sub-buffer
 	 * @prev_subbuf: the start of the previous sub-buffer
-	 * @prev_padding: unused space at the end of previous sub-buffer
 	 *
 	 * The client should return 1 to continue logging, 0 to stop
 	 * logging.
@@ -100,8 +114,7 @@ struct rchan_callbacks
 	 */
 	int (*subbuf_start) (struct rchan_buf *buf,
 			     void *subbuf,
-			     void *prev_subbuf,
+			     void *prev_subbuf);
-			     size_t prev_padding);
 
 	/*
 	 * create_buf_file - create file to represent a relay channel buffer
@@ -161,6 +174,7 @@ struct rchan *relay_open(const char *base_filename,
 			 void *private_data);
 extern void relay_close(struct rchan *chan);
 extern void relay_flush(struct rchan *chan);
+size_t relay_stats(struct rchan *chan, int flags);
 extern void relay_subbufs_consumed(struct rchan *chan,
 				   unsigned int cpu,
 				   size_t consumed);

include/linux/rwsem.h

@@ -132,6 +132,18 @@ static inline int rwsem_is_contended(struct rw_semaphore *sem)
 	return !list_empty(&sem->wait_list);
 }
 
+#if defined(CONFIG_DEBUG_RWSEMS) || defined(CONFIG_DETECT_HUNG_TASK_BLOCKER)
+/*
+ * Return just the real task structure pointer of the owner
+ */
+extern struct task_struct *rwsem_owner(struct rw_semaphore *sem);
+
+/*
+ * Return true if the rwsem is owned by a reader.
+ */
+extern bool is_rwsem_reader_owned(struct rw_semaphore *sem);
+#endif
+
 #else /* !CONFIG_PREEMPT_RT */
 
 #include <linux/rwbase_rt.h>

include/linux/sys_info.h

@@ -0,0 +1,28 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_SYS_INFO_H
+#define _LINUX_SYS_INFO_H
+
+#include <linux/sysctl.h>
+
+/*
+ * SYS_INFO_PANIC_CONSOLE_REPLAY is for panic case only, as it needs special
+ * handling which only fits panic case.
+ */
+#define SYS_INFO_TASKS			0x00000001
+#define SYS_INFO_MEM			0x00000002
+#define SYS_INFO_TIMERS			0x00000004
+#define SYS_INFO_LOCKS			0x00000008
+#define SYS_INFO_FTRACE			0x00000010
+#define SYS_INFO_PANIC_CONSOLE_REPLAY	0x00000020
+#define SYS_INFO_ALL_CPU_BT		0x00000040
+#define SYS_INFO_BLOCKED_TASKS		0x00000080
+
+void sys_info(unsigned long si_mask);
+unsigned long sys_info_parse_param(char *str);
+
+#ifdef CONFIG_SYSCTL
+int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write,
+					  void *buffer, size_t *lenp,
+					  loff_t *ppos);
+#endif
+#endif	/* _LINUX_SYS_INFO_H */

include/linux/xxhash.h

@@ -177,32 +177,6 @@ struct xxh64_state {
  */
 void xxh32_reset(struct xxh32_state *state, uint32_t seed);
 
-/**
- * xxh32_update() - hash the data given and update the xxh32 state
- *
- * @state:  The xxh32 state to update.
- * @input:  The data to hash.
- * @length: The length of the data to hash.
- *
- * After calling xxh32_reset() call xxh32_update() as many times as necessary.
- *
- * Return:  Zero on success, otherwise an error code.
- */
-int xxh32_update(struct xxh32_state *state, const void *input, size_t length);
-
-/**
- * xxh32_digest() - produce the current xxh32 hash
- *
- * @state: Produce the current xxh32 hash of this state.
- *
- * A hash value can be produced at any time. It is still possible to continue
- * inserting input into the hash state after a call to xxh32_digest(), and
- * generate new hashes later on, by calling xxh32_digest() again.
- *
- * Return: The xxh32 hash stored in the state.
- */
-uint32_t xxh32_digest(const struct xxh32_state *state);
-
 /**
  * xxh64_reset() - reset the xxh64 state to start a new hashing operation
  *

include/uapi/linux/kexec.h

@@ -27,6 +27,7 @@
 #define KEXEC_FILE_ON_CRASH	0x00000002
 #define KEXEC_FILE_NO_INITRAMFS	0x00000004
 #define KEXEC_FILE_DEBUG	0x00000008
+#define KEXEC_FILE_NO_CMA	0x00000010
 
 /* These values match the ELF architecture values.
  * Unless there is a good reason that should continue to be the case.

include/xen/xenbus.h

@@ -178,7 +178,7 @@ int xenbus_printf(struct xenbus_transaction t,
  * sprintf-style type string, and pointer. Returns 0 or errno.*/
 int xenbus_gather(struct xenbus_transaction t, const char *dir, ...);
 
-/* notifer routines for when the xenstore comes up */
+/* notifier routines for when the xenstore comes up */
 extern int xenstored_ready;
 int register_xenstore_notifier(struct notifier_block *nb);
 void unregister_xenstore_notifier(struct notifier_block *nb);

init/Kconfig

@@ -172,6 +172,10 @@ menu "General setup"
 
 config BROKEN
 	bool
+	help
+	  This option allows you to choose whether you want to try to
+	  compile (and fix) old drivers that haven't been updated to
+	  new infrastructure.
 
 config BROKEN_ON_SMP
 	bool

init/main.c

@@ -1587,7 +1587,11 @@ static noinline void __init kernel_init_freeable(void)
 	 * check if there is an early userspace init.  If yes, let it do all
 	 * the work
 	 */
-	if (init_eaccess(ramdisk_execute_command) != 0) {
+	int ramdisk_command_access;
+	ramdisk_command_access = init_eaccess(ramdisk_execute_command);
+	if (ramdisk_command_access != 0) {
+		pr_warn("check access for rdinit=%s failed: %i, ignoring\n",
+			ramdisk_execute_command, ramdisk_command_access);
 		ramdisk_execute_command = NULL;
 		prepare_namespace();
 	}

kernel/crash_core.c

@@ -21,6 +21,7 @@
 #include <linux/reboot.h>
 #include <linux/btf.h>
 #include <linux/objtool.h>
+#include <linux/delay.h>
 
 #include <asm/page.h>
 #include <asm/sections.h>
@@ -33,6 +34,11 @@
 /* Per cpu memory for storing cpu states in case of system crash. */
 note_buf_t __percpu *crash_notes;
 
+/* time to wait for possible DMA to finish before starting the kdump kernel
+ * when a CMA reservation is used
+ */
+#define CMA_DMA_TIMEOUT_SEC 10
+
 #ifdef CONFIG_CRASH_DUMP
 
 int kimage_crash_copy_vmcoreinfo(struct kimage *image)
@@ -97,6 +103,14 @@ int kexec_crash_loaded(void)
 }
 EXPORT_SYMBOL_GPL(kexec_crash_loaded);
 
+static void crash_cma_clear_pending_dma(void)
+{
+	if (!crashk_cma_cnt)
+		return;
+
+	mdelay(CMA_DMA_TIMEOUT_SEC * 1000);
+}
+
 /*
  * No panic_cpu check version of crash_kexec().  This function is called
  * only when panic_cpu holds the current CPU number; this is the only CPU
@@ -119,6 +133,7 @@ void __noclone __crash_kexec(struct pt_regs *regs)
 			crash_setup_regs(&fixed_regs, regs);
 			crash_save_vmcoreinfo();
 			machine_crash_shutdown(&fixed_regs);
+			crash_cma_clear_pending_dma();
 			machine_kexec(kexec_crash_image);
 		}
 		kexec_unlock();

kernel/crash_reserve.c

@@ -14,6 +14,8 @@
 #include <linux/cpuhotplug.h>
 #include <linux/memblock.h>
 #include <linux/kmemleak.h>
+#include <linux/cma.h>
+#include <linux/crash_reserve.h>
 
 #include <asm/page.h>
 #include <asm/sections.h>
@@ -172,17 +174,19 @@ static int __init parse_crashkernel_simple(char *cmdline,
 
 #define SUFFIX_HIGH 0
 #define SUFFIX_LOW  1
-#define SUFFIX_NULL 2
+#define SUFFIX_CMA  2
+#define SUFFIX_NULL 3
 static __initdata char *suffix_tbl[] = {
 	[SUFFIX_HIGH] = ",high",
 	[SUFFIX_LOW]  = ",low",
+	[SUFFIX_CMA]  = ",cma",
 	[SUFFIX_NULL] = NULL,
 };
 
 /*
  * That function parses "suffix"  crashkernel command lines like
  *
- *	crashkernel=size,[high|low]
+ *	crashkernel=size,[high|low|cma]
  *
  * It returns 0 on success and -EINVAL on failure.
  */
@@ -298,9 +302,11 @@ int __init parse_crashkernel(char *cmdline,
 			     unsigned long long *crash_size,
 			     unsigned long long *crash_base,
 			     unsigned long long *low_size,
+			     unsigned long long *cma_size,
 			     bool *high)
 {
 	int ret;
+	unsigned long long __always_unused cma_base;
 
 	/* crashkernel=X[@offset] */
 	ret = __parse_crashkernel(cmdline, system_ram, crash_size,
@@ -331,6 +337,14 @@ int __init parse_crashkernel(char *cmdline,
 
 		*high = true;
 	}
+
+	/*
+	 * optional CMA reservation
+	 * cma_base is ignored
+	 */
+	if (cma_size)
+		__parse_crashkernel(cmdline, 0, cma_size,
+			&cma_base, suffix_tbl[SUFFIX_CMA]);
 #endif
 	if (!*crash_size)
 		ret = -EINVAL;
@@ -457,6 +471,56 @@ retry:
 #endif
 }
 
+struct range crashk_cma_ranges[CRASHKERNEL_CMA_RANGES_MAX];
+#ifdef CRASHKERNEL_CMA
+int crashk_cma_cnt;
+void __init reserve_crashkernel_cma(unsigned long long cma_size)
+{
+	unsigned long long request_size = roundup(cma_size, PAGE_SIZE);
+	unsigned long long reserved_size = 0;
+
+	if (!cma_size)
+		return;
+
+	while (cma_size > reserved_size &&
+	       crashk_cma_cnt < CRASHKERNEL_CMA_RANGES_MAX) {
+
+		struct cma *res;
+
+		if (cma_declare_contiguous(0, request_size, 0, 0, 0, false,
+				       "crashkernel", &res)) {
+			/* reservation failed, try half-sized blocks */
+			if (request_size <= PAGE_SIZE)
+				break;
+
+			request_size = roundup(request_size / 2, PAGE_SIZE);
+			continue;
+		}
+
+		crashk_cma_ranges[crashk_cma_cnt].start = cma_get_base(res);
+		crashk_cma_ranges[crashk_cma_cnt].end =
+			crashk_cma_ranges[crashk_cma_cnt].start +
+			cma_get_size(res) - 1;
+		++crashk_cma_cnt;
+		reserved_size += request_size;
+	}
+
+	if (cma_size > reserved_size)
+		pr_warn("crashkernel CMA reservation failed: %lld MB requested, %lld MB reserved in %d ranges\n",
+			cma_size >> 20, reserved_size >> 20, crashk_cma_cnt);
+	else
+		pr_info("crashkernel CMA reserved: %lld MB in %d ranges\n",
+			reserved_size >> 20, crashk_cma_cnt);
+}
+
+#else /* CRASHKERNEL_CMA */
+void __init reserve_crashkernel_cma(unsigned long long cma_size)
+{
+	if (cma_size)
+		pr_warn("crashkernel CMA reservation not supported\n");
+}
+#endif
+
 #ifndef HAVE_ARCH_ADD_CRASH_RES_TO_IOMEM_EARLY
 static __init int insert_crashkernel_resources(void)
 {

kernel/events/uprobes.c

@@ -580,8 +580,8 @@ retry:
 
 out:
 	/* Revert back reference counter if instruction update failed. */
-	if (ret < 0 && is_register && ref_ctr_updated)
+	if (ret < 0 && ref_ctr_updated)
-		update_ref_ctr(uprobe, mm, -1);
+		update_ref_ctr(uprobe, mm, is_register ? -1 : 1);
 
 	/* try collapse pmd for compound page */
 	if (ret > 0)

kernel/exit.c

@@ -693,12 +693,7 @@ static void reparent_leader(struct task_struct *father, struct task_struct *p,
 }
 
 /*
- * This does two things:
+ * Make init inherit all the child processes
- *
- * A.  Make init inherit all the child processes
- * B.  Check to see if any process groups have become orphaned
- *	as a result of our exiting, and if they have any stopped
- *	jobs, send them a SIGHUP and then a SIGCONT.  (POSIX 3.2.2.2)
  */
 static void forget_original_parent(struct task_struct *father,
 					struct list_head *dead)

kernel/fork.c

@@ -189,33 +189,33 @@ static inline void free_task_struct(struct task_struct *tsk)
 	kmem_cache_free(task_struct_cachep, tsk);
 }
 
-/*
+#ifdef CONFIG_VMAP_STACK
- * Allocate pages if THREAD_SIZE is >= PAGE_SIZE, otherwise use a
- * kmemcache based allocator.
- */
-# if THREAD_SIZE >= PAGE_SIZE || defined(CONFIG_VMAP_STACK)
-
-#  ifdef CONFIG_VMAP_STACK
 /*
  * vmalloc() is a bit slow, and calling vfree() enough times will force a TLB
  * flush.  Try to minimize the number of calls by caching stacks.
  */
 #define NR_CACHED_STACKS 2
 static DEFINE_PER_CPU(struct vm_struct *, cached_stacks[NR_CACHED_STACKS]);
+/*
+ * Allocated stacks are cached and later reused by new threads, so memcg
+ * accounting is performed by the code assigning/releasing stacks to tasks.
+ * We need a zeroed memory without __GFP_ACCOUNT.
+ */
+#define GFP_VMAP_STACK (GFP_KERNEL | __GFP_ZERO)
 
 struct vm_stack {
 	struct rcu_head rcu;
 	struct vm_struct *stack_vm_area;
 };
 
-static bool try_release_thread_stack_to_cache(struct vm_struct *vm)
+static bool try_release_thread_stack_to_cache(struct vm_struct *vm_area)
 {
 	unsigned int i;
 
 	for (i = 0; i < NR_CACHED_STACKS; i++) {
 		struct vm_struct *tmp = NULL;
 
-		if (this_cpu_try_cmpxchg(cached_stacks[i], &tmp, vm))
+		if (this_cpu_try_cmpxchg(cached_stacks[i], &tmp, vm_area))
 			return true;
 	}
 	return false;
@@ -224,11 +224,12 @@ static bool try_release_thread_stack_to_cache(struct vm_struct *vm)
 static void thread_stack_free_rcu(struct rcu_head *rh)
 {
 	struct vm_stack *vm_stack = container_of(rh, struct vm_stack, rcu);
+	struct vm_struct *vm_area = vm_stack->stack_vm_area;
 
 	if (try_release_thread_stack_to_cache(vm_stack->stack_vm_area))
 		return;
 
-	vfree(vm_stack);
+	vfree(vm_area->addr);
 }
 
 static void thread_stack_delayed_free(struct task_struct *tsk)
@@ -241,32 +242,32 @@ static void thread_stack_delayed_free(struct task_struct *tsk)
 
 static int free_vm_stack_cache(unsigned int cpu)
 {
-	struct vm_struct **cached_vm_stacks = per_cpu_ptr(cached_stacks, cpu);
+	struct vm_struct **cached_vm_stack_areas = per_cpu_ptr(cached_stacks, cpu);
 	int i;
 
 	for (i = 0; i < NR_CACHED_STACKS; i++) {
-		struct vm_struct *vm_stack = cached_vm_stacks[i];
+		struct vm_struct *vm_area = cached_vm_stack_areas[i];
 
-		if (!vm_stack)
+		if (!vm_area)
 			continue;
 
-		vfree(vm_stack->addr);
+		vfree(vm_area->addr);
-		cached_vm_stacks[i] = NULL;
+		cached_vm_stack_areas[i] = NULL;
 	}
 
 	return 0;
 }
 
-static int memcg_charge_kernel_stack(struct vm_struct *vm)
+static int memcg_charge_kernel_stack(struct vm_struct *vm_area)
 {
 	int i;
 	int ret;
 	int nr_charged = 0;
 
-	BUG_ON(vm->nr_pages != THREAD_SIZE / PAGE_SIZE);
+	BUG_ON(vm_area->nr_pages != THREAD_SIZE / PAGE_SIZE);
 
 	for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++) {
-		ret = memcg_kmem_charge_page(vm->pages[i], GFP_KERNEL, 0);
+		ret = memcg_kmem_charge_page(vm_area->pages[i], GFP_KERNEL, 0);
 		if (ret)
 			goto err;
 		nr_charged++;
@@ -274,55 +275,47 @@ static int memcg_charge_kernel_stack(struct vm_struct *vm)
 	return 0;
 err:
 	for (i = 0; i < nr_charged; i++)
-		memcg_kmem_uncharge_page(vm->pages[i], 0);
+		memcg_kmem_uncharge_page(vm_area->pages[i], 0);
 	return ret;
 }
 
 static int alloc_thread_stack_node(struct task_struct *tsk, int node)
 {
-	struct vm_struct *vm;
+	struct vm_struct *vm_area;
 	void *stack;
 	int i;
 
 	for (i = 0; i < NR_CACHED_STACKS; i++) {
-		struct vm_struct *s;
+		vm_area = this_cpu_xchg(cached_stacks[i], NULL);
-
+		if (!vm_area)
-		s = this_cpu_xchg(cached_stacks[i], NULL);
-
-		if (!s)
 			continue;
 
 		/* Reset stack metadata. */
-		kasan_unpoison_range(s->addr, THREAD_SIZE);
+		kasan_unpoison_range(vm_area->addr, THREAD_SIZE);
 
-		stack = kasan_reset_tag(s->addr);
+		stack = kasan_reset_tag(vm_area->addr);
 
 		/* Clear stale pointers from reused stack. */
 		memset(stack, 0, THREAD_SIZE);
 
-		if (memcg_charge_kernel_stack(s)) {
+		if (memcg_charge_kernel_stack(vm_area)) {
-			vfree(s->addr);
+			vfree(vm_area->addr);
 			return -ENOMEM;
 		}
 
-		tsk->stack_vm_area = s;
+		tsk->stack_vm_area = vm_area;
 		tsk->stack = stack;
 		return 0;
 	}
 
-	/*
-	 * Allocated stacks are cached and later reused by new threads,
-	 * so memcg accounting is performed manually on assigning/releasing
-	 * stacks to tasks. Drop __GFP_ACCOUNT.
-	 */
 	stack = __vmalloc_node(THREAD_SIZE, THREAD_ALIGN,
-				     THREADINFO_GFP & ~__GFP_ACCOUNT,
+				     GFP_VMAP_STACK,
 				     node, __builtin_return_address(0));
 	if (!stack)
 		return -ENOMEM;
 
-	vm = find_vm_area(stack);
+	vm_area = find_vm_area(stack);
-	if (memcg_charge_kernel_stack(vm)) {
+	if (memcg_charge_kernel_stack(vm_area)) {
 		vfree(stack);
 		return -ENOMEM;
 	}
@@ -331,7 +324,7 @@ static int alloc_thread_stack_node(struct task_struct *tsk, int node)
 	 * free_thread_stack() can be called in interrupt context,
 	 * so cache the vm_struct.
 	 */
-	tsk->stack_vm_area = vm;
+	tsk->stack_vm_area = vm_area;
 	stack = kasan_reset_tag(stack);
 	tsk->stack = stack;
 	return 0;
@@ -346,7 +339,13 @@ static void free_thread_stack(struct task_struct *tsk)
 	tsk->stack_vm_area = NULL;
 }
 
-#  else /* !CONFIG_VMAP_STACK */
+#else /* !CONFIG_VMAP_STACK */
+
+/*
+ * Allocate pages if THREAD_SIZE is >= PAGE_SIZE, otherwise use a
+ * kmemcache based allocator.
+ */
+#if THREAD_SIZE >= PAGE_SIZE
 
 static void thread_stack_free_rcu(struct rcu_head *rh)
 {
@@ -378,8 +377,7 @@ static void free_thread_stack(struct task_struct *tsk)
 	tsk->stack = NULL;
 }
 
-#  endif /* CONFIG_VMAP_STACK */
+#else /* !(THREAD_SIZE >= PAGE_SIZE) */
-# else /* !(THREAD_SIZE >= PAGE_SIZE || defined(CONFIG_VMAP_STACK)) */
 
 static struct kmem_cache *thread_stack_cache;
 
@@ -418,7 +416,8 @@ void thread_stack_cache_init(void)
 	BUG_ON(thread_stack_cache == NULL);
 }
 
-# endif /* THREAD_SIZE >= PAGE_SIZE || defined(CONFIG_VMAP_STACK) */
+#endif /* THREAD_SIZE >= PAGE_SIZE */
+#endif /* CONFIG_VMAP_STACK */
 
 /* SLAB cache for signal_struct structures (tsk->signal) */
 static struct kmem_cache *signal_cachep;
@@ -438,11 +437,11 @@ static struct kmem_cache *mm_cachep;
 static void account_kernel_stack(struct task_struct *tsk, int account)
 {
 	if (IS_ENABLED(CONFIG_VMAP_STACK)) {
-		struct vm_struct *vm = task_stack_vm_area(tsk);
+		struct vm_struct *vm_area = task_stack_vm_area(tsk);
 		int i;
 
 		for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++)
-			mod_lruvec_page_state(vm->pages[i], NR_KERNEL_STACK_KB,
+			mod_lruvec_page_state(vm_area->pages[i], NR_KERNEL_STACK_KB,
 					      account * (PAGE_SIZE / 1024));
 	} else {
 		void *stack = task_stack_page(tsk);
@@ -458,12 +457,12 @@ void exit_task_stack_account(struct task_struct *tsk)
 	account_kernel_stack(tsk, -1);
 
 	if (IS_ENABLED(CONFIG_VMAP_STACK)) {
-		struct vm_struct *vm;
+		struct vm_struct *vm_area;
 		int i;
 
-		vm = task_stack_vm_area(tsk);
+		vm_area = task_stack_vm_area(tsk);
 		for (i = 0; i < THREAD_SIZE / PAGE_SIZE; i++)
-			memcg_kmem_uncharge_page(vm->pages[i], 0);
+			memcg_kmem_uncharge_page(vm_area->pages[i], 0);
 	}
 }
 

kernel/hung_task.c

@@ -23,6 +23,7 @@
 #include <linux/sched/debug.h>
 #include <linux/sched/sysctl.h>
 #include <linux/hung_task.h>
+#include <linux/rwsem.h>
 
 #include <trace/events/sched.h>
 
@@ -100,6 +101,7 @@ static void debug_show_blocker(struct task_struct *task)
 {
 	struct task_struct *g, *t;
 	unsigned long owner, blocker, blocker_type;
+	const char *rwsem_blocked_by, *rwsem_blocked_as;
 
 	RCU_LOCKDEP_WARN(!rcu_read_lock_held(), "No rcu lock held");
 
@@ -111,12 +113,20 @@ static void debug_show_blocker(struct task_struct *task)
 
 	switch (blocker_type) {
 	case BLOCKER_TYPE_MUTEX:
-		owner = mutex_get_owner(
+		owner = mutex_get_owner(hung_task_blocker_to_lock(blocker));
-			(struct mutex *)hung_task_blocker_to_lock(blocker));
 		break;
 	case BLOCKER_TYPE_SEM:
-		owner = sem_last_holder(
+		owner = sem_last_holder(hung_task_blocker_to_lock(blocker));
-			(struct semaphore *)hung_task_blocker_to_lock(blocker));
+		break;
+	case BLOCKER_TYPE_RWSEM_READER:
+	case BLOCKER_TYPE_RWSEM_WRITER:
+		owner = (unsigned long)rwsem_owner(
+					hung_task_blocker_to_lock(blocker));
+		rwsem_blocked_as = (blocker_type == BLOCKER_TYPE_RWSEM_READER) ?
+					"reader" : "writer";
+		rwsem_blocked_by = is_rwsem_reader_owned(
+					hung_task_blocker_to_lock(blocker)) ?
+					"reader" : "writer";
 		break;
 	default:
 		WARN_ON_ONCE(1);
@@ -134,6 +144,11 @@ static void debug_show_blocker(struct task_struct *task)
 			pr_err("INFO: task %s:%d is blocked on a semaphore, but the last holder is not found.\n",
 			       task->comm, task->pid);
 			break;
+		case BLOCKER_TYPE_RWSEM_READER:
+		case BLOCKER_TYPE_RWSEM_WRITER:
+			pr_err("INFO: task %s:%d is blocked on an rw-semaphore, but the owner is not found.\n",
+			       task->comm, task->pid);
+			break;
 		}
 		return;
 	}
@@ -152,6 +167,12 @@ static void debug_show_blocker(struct task_struct *task)
 			pr_err("INFO: task %s:%d blocked on a semaphore likely last held by task %s:%d\n",
 			       task->comm, task->pid, t->comm, t->pid);
 			break;
+		case BLOCKER_TYPE_RWSEM_READER:
+		case BLOCKER_TYPE_RWSEM_WRITER:
+			pr_err("INFO: task %s:%d <%s> blocked on an rw-semaphore likely owned by task %s:%d <%s>\n",
+			       task->comm, task->pid, rwsem_blocked_as, t->comm,
+			       t->pid, rwsem_blocked_by);
+			break;
 		}
 		sched_show_task(t);
 		return;

kernel/kcov.c

@@ -552,7 +552,7 @@ static int kcov_get_mode(unsigned long arg)
 
 /*
  * Fault in a lazily-faulted vmalloc area before it can be used by
- * __santizer_cov_trace_pc(), to avoid recursion issues if any code on the
+ * __sanitizer_cov_trace_pc(), to avoid recursion issues if any code on the
  * vmalloc fault handling path is instrumented.
  */
 static void kcov_fault_in_area(struct kcov *kcov)

kernel/kexec.c

@@ -152,7 +152,7 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments,
 		goto out;
 
 	for (i = 0; i < nr_segments; i++) {
-		ret = kimage_load_segment(image, &image->segment[i]);
+		ret = kimage_load_segment(image, i);
 		if (ret)
 			goto out;
 	}

kernel/kexec_core.c

@@ -40,6 +40,7 @@
 #include <linux/hugetlb.h>
 #include <linux/objtool.h>
 #include <linux/kmsg_dump.h>
+#include <linux/dma-map-ops.h>
 
 #include <asm/page.h>
 #include <asm/sections.h>
@@ -553,6 +554,24 @@ static void kimage_free_entry(kimage_entry_t entry)
 	kimage_free_pages(page);
 }
 
+static void kimage_free_cma(struct kimage *image)
+{
+	unsigned long i;
+
+	for (i = 0; i < image->nr_segments; i++) {
+		struct page *cma = image->segment_cma[i];
+		u32 nr_pages = image->segment[i].memsz >> PAGE_SHIFT;
+
+		if (!cma)
+			continue;
+
+		arch_kexec_pre_free_pages(page_address(cma), nr_pages);
+		dma_release_from_contiguous(NULL, cma, nr_pages);
+		image->segment_cma[i] = NULL;
+	}
+
+}
+
 void kimage_free(struct kimage *image)
 {
 	kimage_entry_t *ptr, entry;
@@ -591,6 +610,9 @@ void kimage_free(struct kimage *image)
 	/* Free the kexec control pages... */
 	kimage_free_page_list(&image->control_pages);
 
+	/* Free CMA allocations */
+	kimage_free_cma(image);
+
 	/*
 	 * Free up any temporary buffers allocated. This might hit if
 	 * error occurred much later after buffer allocation.
@@ -716,9 +738,69 @@ static struct page *kimage_alloc_page(struct kimage *image,
 	return page;
 }
 
-static int kimage_load_normal_segment(struct kimage *image,
+static int kimage_load_cma_segment(struct kimage *image, int idx)
-					 struct kexec_segment *segment)
 {
+	struct kexec_segment *segment = &image->segment[idx];
+	struct page *cma = image->segment_cma[idx];
+	char *ptr = page_address(cma);
+	unsigned long maddr;
+	size_t ubytes, mbytes;
+	int result = 0;
+	unsigned char __user *buf = NULL;
+	unsigned char *kbuf = NULL;
+
+	if (image->file_mode)
+		kbuf = segment->kbuf;
+	else
+		buf = segment->buf;
+	ubytes = segment->bufsz;
+	mbytes = segment->memsz;
+	maddr = segment->mem;
+
+	/* Then copy from source buffer to the CMA one */
+	while (mbytes) {
+		size_t uchunk, mchunk;
+
+		ptr += maddr & ~PAGE_MASK;
+		mchunk = min_t(size_t, mbytes,
+				PAGE_SIZE - (maddr & ~PAGE_MASK));
+		uchunk = min(ubytes, mchunk);
+
+		if (uchunk) {
+			/* For file based kexec, source pages are in kernel memory */
+			if (image->file_mode)
+				memcpy(ptr, kbuf, uchunk);
+			else
+				result = copy_from_user(ptr, buf, uchunk);
+			ubytes -= uchunk;
+			if (image->file_mode)
+				kbuf += uchunk;
+			else
+				buf += uchunk;
+		}
+
+		if (result) {
+			result = -EFAULT;
+			goto out;
+		}
+
+		ptr    += mchunk;
+		maddr  += mchunk;
+		mbytes -= mchunk;
+
+		cond_resched();
+	}
+
+	/* Clear any remainder */
+	memset(ptr, 0, mbytes);
+
+out:
+	return result;
+}
+
+static int kimage_load_normal_segment(struct kimage *image, int idx)
+{
+	struct kexec_segment *segment = &image->segment[idx];
 	unsigned long maddr;
 	size_t ubytes, mbytes;
 	int result;
@@ -733,6 +815,9 @@ static int kimage_load_normal_segment(struct kimage *image,
 	mbytes = segment->memsz;
 	maddr = segment->mem;
 
+	if (image->segment_cma[idx])
+		return kimage_load_cma_segment(image, idx);
+
 	result = kimage_set_destination(image, maddr);
 	if (result < 0)
 		goto out;
@@ -787,13 +872,13 @@ out:
 }
 
 #ifdef CONFIG_CRASH_DUMP
-static int kimage_load_crash_segment(struct kimage *image,
+static int kimage_load_crash_segment(struct kimage *image, int idx)
-					struct kexec_segment *segment)
 {
 	/* For crash dumps kernels we simply copy the data from
 	 * user space to it's destination.
 	 * We do things a page at a time for the sake of kmap.
 	 */
+	struct kexec_segment *segment = &image->segment[idx];
 	unsigned long maddr;
 	size_t ubytes, mbytes;
 	int result;
@@ -858,18 +943,17 @@ out:
 }
 #endif
 
-int kimage_load_segment(struct kimage *image,
+int kimage_load_segment(struct kimage *image, int idx)
-				struct kexec_segment *segment)
 {
 	int result = -ENOMEM;
 
 	switch (image->type) {
 	case KEXEC_TYPE_DEFAULT:
-		result = kimage_load_normal_segment(image, segment);
+		result = kimage_load_normal_segment(image, idx);
 		break;
 #ifdef CONFIG_CRASH_DUMP
 	case KEXEC_TYPE_CRASH:
-		result = kimage_load_crash_segment(image, segment);
+		result = kimage_load_crash_segment(image, idx);
 		break;
 #endif
 	}

kernel/kexec_file.c

@@ -26,6 +26,7 @@
 #include <linux/kernel_read_file.h>
 #include <linux/syscalls.h>
 #include <linux/vmalloc.h>
+#include <linux/dma-map-ops.h>
 #include "kexec_internal.h"
 
 #ifdef CONFIG_KEXEC_SIG
@@ -253,6 +254,8 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd,
 		ret = 0;
 	}
 
+	image->no_cma = !!(flags & KEXEC_FILE_NO_CMA);
+
 	if (cmdline_len) {
 		image->cmdline_buf = memdup_user(cmdline_ptr, cmdline_len);
 		if (IS_ERR(image->cmdline_buf)) {
@@ -434,7 +437,7 @@ SYSCALL_DEFINE5(kexec_file_load, int, kernel_fd, int, initrd_fd,
 			      i, ksegment->buf, ksegment->bufsz, ksegment->mem,
 			      ksegment->memsz);
 
-		ret = kimage_load_segment(image, &image->segment[i]);
+		ret = kimage_load_segment(image, i);
 		if (ret)
 			goto out;
 	}
@@ -663,6 +666,43 @@ static int kexec_walk_resources(struct kexec_buf *kbuf,
 		return walk_system_ram_res(0, ULONG_MAX, kbuf, func);
 }
 
+static int kexec_alloc_contig(struct kexec_buf *kbuf)
+{
+	size_t nr_pages = kbuf->memsz >> PAGE_SHIFT;
+	unsigned long mem;
+	struct page *p;
+
+	/* User space disabled CMA allocations, bail out. */
+	if (kbuf->image->no_cma)
+		return -EPERM;
+
+	/* Skip CMA logic for crash kernel */
+	if (kbuf->image->type == KEXEC_TYPE_CRASH)
+		return -EPERM;
+
+	p = dma_alloc_from_contiguous(NULL, nr_pages, get_order(kbuf->buf_align), true);
+	if (!p)
+		return -ENOMEM;
+
+	pr_debug("allocated %zu DMA pages at 0x%lx", nr_pages, page_to_boot_pfn(p));
+
+	mem = page_to_boot_pfn(p) << PAGE_SHIFT;
+
+	if (kimage_is_destination_range(kbuf->image, mem, mem + kbuf->memsz)) {
+		/* Our region is already in use by a statically defined one. Bail out. */
+		pr_debug("CMA overlaps existing mem: 0x%lx+0x%lx\n", mem, kbuf->memsz);
+		dma_release_from_contiguous(NULL, p, nr_pages);
+		return -EBUSY;
+	}
+
+	kbuf->mem = page_to_boot_pfn(p) << PAGE_SHIFT;
+	kbuf->cma = p;
+
+	arch_kexec_post_alloc_pages(page_address(p), (int)nr_pages, 0);
+
+	return 0;
+}
+
 /**
  * kexec_locate_mem_hole - find free memory for the purgatory or the next kernel
  * @kbuf:	Parameters for the memory search.
@@ -687,6 +727,13 @@ int kexec_locate_mem_hole(struct kexec_buf *kbuf)
 	if (ret <= 0)
 		return ret;
 
+	/*
+	 * Try to find a free physically contiguous block of memory first. With that, we
+	 * can avoid any copying at kexec time.
+	 */
+	if (!kexec_alloc_contig(kbuf))
+		return 0;
+
 	if (!IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK))
 		ret = kexec_walk_resources(kbuf, locate_mem_hole_callback);
 	else
@@ -732,6 +779,7 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
 	/* Ensure minimum alignment needed for segments. */
 	kbuf->memsz = ALIGN(kbuf->memsz, PAGE_SIZE);
 	kbuf->buf_align = max(kbuf->buf_align, PAGE_SIZE);
+	kbuf->cma = NULL;
 
 	/* Walk the RAM ranges and allocate a suitable range for the buffer */
 	ret = arch_kexec_locate_mem_hole(kbuf);
@@ -744,6 +792,7 @@ int kexec_add_buffer(struct kexec_buf *kbuf)
 	ksegment->bufsz = kbuf->bufsz;
 	ksegment->mem = kbuf->mem;
 	ksegment->memsz = kbuf->memsz;
+	kbuf->image->segment_cma[kbuf->image->nr_segments] = kbuf->cma;
 	kbuf->image->nr_segments++;
 	return 0;
 }

kernel/kexec_internal.h

@@ -10,7 +10,7 @@ struct kimage *do_kimage_alloc_init(void);
 int sanity_check_segment_list(struct kimage *image);
 void kimage_free_page_list(struct list_head *list);
 void kimage_free(struct kimage *image);
-int kimage_load_segment(struct kimage *image, struct kexec_segment *segment);
+int kimage_load_segment(struct kimage *image, int idx);
 void kimage_terminate(struct kimage *image);
 int kimage_is_destination_range(struct kimage *image,
 				unsigned long start, unsigned long end);

kernel/kthread.c

@@ -88,13 +88,12 @@ static inline struct kthread *to_kthread(struct task_struct *k)
 /*
  * Variant of to_kthread() that doesn't assume @p is a kthread.
  *
- * Per construction; when:
+ * When "(p->flags & PF_KTHREAD)" is set the task is a kthread and will
+ * always remain a kthread.  For kthreads p->worker_private always
+ * points to a struct kthread.  For tasks that are not kthreads
+ * p->worker_private is used to point to other things.
  *
- *   (p->flags & PF_KTHREAD) && p->worker_private
+ * Return NULL for any task that is not a kthread.
- *
- * the task is both a kthread and struct kthread is persistent. However
- * PF_KTHREAD on it's own is not, kernel_thread() can exec() (See umh.c and
- * begin_new_exec()).
  */
 static inline struct kthread *__to_kthread(struct task_struct *p)
 {

kernel/locking/rwsem.c

@@ -27,6 +27,7 @@
 #include <linux/export.h>
 #include <linux/rwsem.h>
 #include <linux/atomic.h>
+#include <linux/hung_task.h>
 #include <trace/events/lock.h>
 
 #ifndef CONFIG_PREEMPT_RT
@@ -181,11 +182,11 @@ static inline void rwsem_set_reader_owned(struct rw_semaphore *sem)
 	__rwsem_set_reader_owned(sem, current);
 }
 
-#ifdef CONFIG_DEBUG_RWSEMS
+#if defined(CONFIG_DEBUG_RWSEMS) || defined(CONFIG_DETECT_HUNG_TASK_BLOCKER)
 /*
  * Return just the real task structure pointer of the owner
  */
-static inline struct task_struct *rwsem_owner(struct rw_semaphore *sem)
+struct task_struct *rwsem_owner(struct rw_semaphore *sem)
 {
 	return (struct task_struct *)
 		(atomic_long_read(&sem->owner) & ~RWSEM_OWNER_FLAGS_MASK);
@@ -194,7 +195,7 @@ static inline struct task_struct *rwsem_owner(struct rw_semaphore *sem)
 /*
  * Return true if the rwsem is owned by a reader.
  */
-static inline bool is_rwsem_reader_owned(struct rw_semaphore *sem)
+bool is_rwsem_reader_owned(struct rw_semaphore *sem)
 {
 	/*
 	 * Check the count to see if it is write-locked.
@@ -207,10 +208,10 @@ static inline bool is_rwsem_reader_owned(struct rw_semaphore *sem)
 }
 
 /*
- * With CONFIG_DEBUG_RWSEMS configured, it will make sure that if there
+ * With CONFIG_DEBUG_RWSEMS or CONFIG_DETECT_HUNG_TASK_BLOCKER configured,
- * is a task pointer in owner of a reader-owned rwsem, it will be the
+ * it will make sure that the owner field of a reader-owned rwsem either
- * real owner or one of the real owners. The only exception is when the
+ * points to a real reader-owner(s) or gets cleared. The only exception is
- * unlock is done by up_read_non_owner().
+ * when the unlock is done by up_read_non_owner().
  */
 static inline void rwsem_clear_reader_owned(struct rw_semaphore *sem)
 {
@@ -1063,10 +1064,13 @@ queue:
 		wake_up_q(&wake_q);
 
 	trace_contention_begin(sem, LCB_F_READ);
+	set_current_state(state);
+
+	if (state == TASK_UNINTERRUPTIBLE)
+		hung_task_set_blocker(sem, BLOCKER_TYPE_RWSEM_READER);
 
 	/* wait to be given the lock */
 	for (;;) {
-		set_current_state(state);
 		if (!smp_load_acquire(&waiter.task)) {
 			/* Matches rwsem_mark_wake()'s smp_store_release(). */
 			break;
@@ -1081,8 +1085,12 @@ queue:
 		}
 		schedule_preempt_disabled();
 		lockevent_inc(rwsem_sleep_reader);
+		set_current_state(state);
 	}
 
+	if (state == TASK_UNINTERRUPTIBLE)
+		hung_task_clear_blocker();
+
 	__set_current_state(TASK_RUNNING);
 	lockevent_inc(rwsem_rlock);
 	trace_contention_end(sem, 0);
@@ -1144,6 +1152,9 @@ rwsem_down_write_slowpath(struct rw_semaphore *sem, int state)
 	set_current_state(state);
 	trace_contention_begin(sem, LCB_F_WRITE);
 
+	if (state == TASK_UNINTERRUPTIBLE)
+		hung_task_set_blocker(sem, BLOCKER_TYPE_RWSEM_WRITER);
+
 	for (;;) {
 		if (rwsem_try_write_lock(sem, &waiter)) {
 			/* rwsem_try_write_lock() implies ACQUIRE on success */
@@ -1177,6 +1188,10 @@ rwsem_down_write_slowpath(struct rw_semaphore *sem, int state)
 trylock_again:
 		raw_spin_lock_irq(&sem->wait_lock);
 	}
+
+	if (state == TASK_UNINTERRUPTIBLE)
+		hung_task_clear_blocker();
+
 	__set_current_state(TASK_RUNNING);
 	raw_spin_unlock_irq(&sem->wait_lock);
 	lockevent_inc(rwsem_wlock);

kernel/panic.c

@@ -36,6 +36,7 @@
 #include <linux/sysfs.h>
 #include <linux/context_tracking.h>
 #include <linux/seq_buf.h>
+#include <linux/sys_info.h>
 #include <trace/events/error_report.h>
 #include <asm/sections.h>
 
@@ -63,20 +64,13 @@ int panic_on_warn __read_mostly;
 unsigned long panic_on_taint;
 bool panic_on_taint_nousertaint = false;
 static unsigned int warn_limit __read_mostly;
+static bool panic_console_replay;
 
 bool panic_triggering_all_cpu_backtrace;
 
 int panic_timeout = CONFIG_PANIC_TIMEOUT;
 EXPORT_SYMBOL_GPL(panic_timeout);
 
-#define PANIC_PRINT_TASK_INFO		0x00000001
-#define PANIC_PRINT_MEM_INFO		0x00000002
-#define PANIC_PRINT_TIMER_INFO		0x00000004
-#define PANIC_PRINT_LOCK_INFO		0x00000008
-#define PANIC_PRINT_FTRACE_INFO		0x00000010
-#define PANIC_PRINT_ALL_PRINTK_MSG	0x00000020
-#define PANIC_PRINT_ALL_CPU_BT		0x00000040
-#define PANIC_PRINT_BLOCKED_TASKS	0x00000080
 unsigned long panic_print;
 
 ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
@@ -128,6 +122,13 @@ static int proc_taint(const struct ctl_table *table, int write,
 	return err;
 }
 
+static int sysctl_panic_print_handler(const struct ctl_table *table, int write,
+			   void *buffer, size_t *lenp, loff_t *ppos)
+{
+	pr_info_once("Kernel: 'panic_print' sysctl interface will be obsoleted by both 'panic_sys_info' and 'panic_console_replay'\n");
+	return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
+}
+
 static const struct ctl_table kern_panic_table[] = {
 #ifdef CONFIG_SMP
 	{
@@ -165,7 +166,7 @@ static const struct ctl_table kern_panic_table[] = {
 		.data		= &panic_print,
 		.maxlen		= sizeof(unsigned long),
 		.mode		= 0644,
-		.proc_handler	= proc_doulongvec_minmax,
+		.proc_handler	= sysctl_panic_print_handler,
 	},
 	{
 		.procname	= "panic_on_warn",
@@ -193,6 +194,13 @@ static const struct ctl_table kern_panic_table[] = {
 		.proc_handler	= proc_dointvec,
 	},
 #endif
+	{
+		.procname	= "panic_sys_info",
+		.data		= &panic_print,
+		.maxlen         = sizeof(panic_print),
+		.mode		= 0644,
+		.proc_handler	= sysctl_sys_info_handler,
+	},
 };
 
 static __init int kernel_panic_sysctls_init(void)
@@ -203,6 +211,15 @@ static __init int kernel_panic_sysctls_init(void)
 late_initcall(kernel_panic_sysctls_init);
 #endif
 
+/* The format is "panic_sys_info=tasks,mem,locks,ftrace,..." */
+static int __init setup_panic_sys_info(char *buf)
+{
+	/* There is no risk of race in kernel boot phase */
+	panic_print = sys_info_parse_param(buf);
+	return 1;
+}
+__setup("panic_sys_info=", setup_panic_sys_info);
+
 static atomic_t warn_count = ATOMIC_INIT(0);
 
 #ifdef CONFIG_SYSFS
@@ -298,33 +315,6 @@ void nmi_panic(struct pt_regs *regs, const char *msg)
 }
 EXPORT_SYMBOL(nmi_panic);
 
-static void panic_print_sys_info(bool console_flush)
-{
-	if (console_flush) {
-		if (panic_print & PANIC_PRINT_ALL_PRINTK_MSG)
-			console_flush_on_panic(CONSOLE_REPLAY_ALL);
-		return;
-	}
-
-	if (panic_print & PANIC_PRINT_TASK_INFO)
-		show_state();
-
-	if (panic_print & PANIC_PRINT_MEM_INFO)
-		show_mem();
-
-	if (panic_print & PANIC_PRINT_TIMER_INFO)
-		sysrq_timer_list_show();
-
-	if (panic_print & PANIC_PRINT_LOCK_INFO)
-		debug_show_all_locks();
-
-	if (panic_print & PANIC_PRINT_FTRACE_INFO)
-		ftrace_dump(DUMP_ALL);
-
-	if (panic_print & PANIC_PRINT_BLOCKED_TASKS)
-		show_state_filter(TASK_UNINTERRUPTIBLE);
-}
-
 void check_panic_on_warn(const char *origin)
 {
 	unsigned int limit;
@@ -345,7 +335,7 @@ void check_panic_on_warn(const char *origin)
  */
 static void panic_other_cpus_shutdown(bool crash_kexec)
 {
-	if (panic_print & PANIC_PRINT_ALL_CPU_BT) {
+	if (panic_print & SYS_INFO_ALL_CPU_BT) {
 		/* Temporary allow non-panic CPUs to write their backtraces. */
 		panic_triggering_all_cpu_backtrace = true;
 		trigger_all_cpu_backtrace();
@@ -468,7 +458,7 @@ void vpanic(const char *fmt, va_list args)
 	 */
 	atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
 
-	panic_print_sys_info(false);
+	sys_info(panic_print);
 
 	kmsg_dump_desc(KMSG_DUMP_PANIC, buf);
 
@@ -497,7 +487,9 @@ void vpanic(const char *fmt, va_list args)
 	debug_locks_off();
 	console_flush_on_panic(CONSOLE_FLUSH_PENDING);
 
-	panic_print_sys_info(true);
+	if ((panic_print & SYS_INFO_PANIC_CONSOLE_REPLAY) ||
+		panic_console_replay)
+		console_flush_on_panic(CONSOLE_REPLAY_ALL);
 
 	if (!panic_blink)
 		panic_blink = no_blink;
@@ -949,6 +941,7 @@ core_param(panic_print, panic_print, ulong, 0644);
 core_param(pause_on_oops, pause_on_oops, int, 0644);
 core_param(panic_on_warn, panic_on_warn, int, 0644);
 core_param(crash_kexec_post_notifiers, crash_kexec_post_notifiers, bool, 0644);
+core_param(panic_console_replay, panic_console_replay, bool, 0644);
 
 static int __init oops_setup(char *s)
 {

kernel/relay.c

@@ -118,7 +118,7 @@ static void *relay_alloc_buf(struct rchan_buf *buf, size_t *size)
 		return NULL;
 
 	for (i = 0; i < n_pages; i++) {
-		buf->page_array[i] = alloc_page(GFP_KERNEL);
+		buf->page_array[i] = alloc_page(GFP_KERNEL | __GFP_ZERO);
 		if (unlikely(!buf->page_array[i]))
 			goto depopulate;
 		set_page_private(buf->page_array[i], (unsigned long)buf);
@@ -127,7 +127,6 @@ static void *relay_alloc_buf(struct rchan_buf *buf, size_t *size)
 	if (!mem)
 		goto depopulate;
 
-	memset(mem, 0, *size);
 	buf->page_count = n_pages;
 	return mem;
 
@@ -250,13 +249,18 @@ EXPORT_SYMBOL_GPL(relay_buf_full);
  */
 
 static int relay_subbuf_start(struct rchan_buf *buf, void *subbuf,
-			      void *prev_subbuf, size_t prev_padding)
+			      void *prev_subbuf)
 {
+	int full = relay_buf_full(buf);
+
+	if (full)
+		buf->stats.full_count++;
+
 	if (!buf->chan->cb->subbuf_start)
-		return !relay_buf_full(buf);
+		return !full;
 
 	return buf->chan->cb->subbuf_start(buf, subbuf,
-					   prev_subbuf, prev_padding);
+					   prev_subbuf);
 }
 
 /**
@@ -298,11 +302,13 @@ static void __relay_reset(struct rchan_buf *buf, unsigned int init)
 	buf->finalized = 0;
 	buf->data = buf->start;
 	buf->offset = 0;
+	buf->stats.full_count = 0;
+	buf->stats.big_count = 0;
 
 	for (i = 0; i < buf->chan->n_subbufs; i++)
 		buf->padding[i] = 0;
 
-	relay_subbuf_start(buf, buf->data, NULL, 0);
+	relay_subbuf_start(buf, buf->data, NULL);
 }
 
 /**
@@ -555,9 +561,11 @@ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length)
 		goto toobig;
 
 	if (buf->offset != buf->chan->subbuf_size + 1) {
-		buf->prev_padding = buf->chan->subbuf_size - buf->offset;
+		size_t prev_padding;
+
+		prev_padding = buf->chan->subbuf_size - buf->offset;
 		old_subbuf = buf->subbufs_produced % buf->chan->n_subbufs;
-		buf->padding[old_subbuf] = buf->prev_padding;
+		buf->padding[old_subbuf] = prev_padding;
 		buf->subbufs_produced++;
 		if (buf->dentry)
 			d_inode(buf->dentry)->i_size +=
@@ -582,7 +590,7 @@ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length)
 	new_subbuf = buf->subbufs_produced % buf->chan->n_subbufs;
 	new = buf->start + new_subbuf * buf->chan->subbuf_size;
 	buf->offset = 0;
-	if (!relay_subbuf_start(buf, new, old, buf->prev_padding)) {
+	if (!relay_subbuf_start(buf, new, old)) {
 		buf->offset = buf->chan->subbuf_size + 1;
 		return 0;
 	}
@@ -595,7 +603,7 @@ size_t relay_switch_subbuf(struct rchan_buf *buf, size_t length)
 	return length;
 
 toobig:
-	buf->chan->last_toobig = length;
+	buf->stats.big_count++;
 	return 0;
 }
 EXPORT_SYMBOL_GPL(relay_switch_subbuf);
@@ -655,11 +663,6 @@ void relay_close(struct rchan *chan)
 			if ((buf = *per_cpu_ptr(chan->buf, i)))
 				relay_close_buf(buf);
 
-	if (chan->last_toobig)
-		printk(KERN_WARNING "relay: one or more items not logged "
-		       "[item size (%zd) > sub-buffer size (%zd)]\n",
-		       chan->last_toobig, chan->subbuf_size);
-
 	list_del(&chan->list);
 	kref_put(&chan->kref, relay_destroy_channel);
 	mutex_unlock(&relay_channels_mutex);
@@ -693,6 +696,42 @@ void relay_flush(struct rchan *chan)
 }
 EXPORT_SYMBOL_GPL(relay_flush);
 
+/**
+ *	relay_stats - get channel buffer statistics
+ *	@chan: the channel
+ *	@flags: select particular information to get
+ *
+ *	Returns the count of certain field that caller specifies.
+ */
+size_t relay_stats(struct rchan *chan, int flags)
+{
+	unsigned int i, count = 0;
+	struct rchan_buf *rbuf;
+
+	if (!chan || flags > RELAY_STATS_LAST)
+		return 0;
+
+	if (chan->is_global) {
+		rbuf = *per_cpu_ptr(chan->buf, 0);
+		if (flags & RELAY_STATS_BUF_FULL)
+			count = rbuf->stats.full_count;
+		else if (flags & RELAY_STATS_WRT_BIG)
+			count = rbuf->stats.big_count;
+	} else {
+		for_each_online_cpu(i) {
+			rbuf = *per_cpu_ptr(chan->buf, i);
+			if (rbuf) {
+				if (flags & RELAY_STATS_BUF_FULL)
+					count += rbuf->stats.full_count;
+				else if (flags & RELAY_STATS_WRT_BIG)
+					count += rbuf->stats.big_count;
+			}
+		}
+	}
+
+	return count;
+}
+
 /**
  *	relay_file_open - open file op for relay files
  *	@inode: the inode

kernel/trace/blktrace.c

@@ -415,9 +415,10 @@ static ssize_t blk_dropped_read(struct file *filp, char __user *buffer,
 				size_t count, loff_t *ppos)
 {
 	struct blk_trace *bt = filp->private_data;
+	size_t dropped = relay_stats(bt->rchan, RELAY_STATS_BUF_FULL);
 	char buf[16];
 
-	snprintf(buf, sizeof(buf), "%u\n", atomic_read(&bt->dropped));
+	snprintf(buf, sizeof(buf), "%zu\n", dropped);
 
 	return simple_read_from_buffer(buffer, count, ppos, buf, strlen(buf));
 }
@@ -456,23 +457,6 @@ static const struct file_operations blk_msg_fops = {
 	.llseek =	noop_llseek,
 };
 
-/*
- * Keep track of how many times we encountered a full subbuffer, to aid
- * the user space app in telling how many lost events there were.
- */
-static int blk_subbuf_start_callback(struct rchan_buf *buf, void *subbuf,
-				     void *prev_subbuf, size_t prev_padding)
-{
-	struct blk_trace *bt;
-
-	if (!relay_buf_full(buf))
-		return 1;
-
-	bt = buf->chan->private_data;
-	atomic_inc(&bt->dropped);
-	return 0;
-}
-
 static int blk_remove_buf_file_callback(struct dentry *dentry)
 {
 	debugfs_remove(dentry);
@@ -491,7 +475,6 @@ static struct dentry *blk_create_buf_file_callback(const char *filename,
 }
 
 static const struct rchan_callbacks blk_relay_callbacks = {
-	.subbuf_start		= blk_subbuf_start_callback,
 	.create_buf_file	= blk_create_buf_file_callback,
 	.remove_buf_file	= blk_remove_buf_file_callback,
 };
@@ -580,7 +563,6 @@ static int do_blk_trace_setup(struct request_queue *q, char *name, dev_t dev,
 	}
 
 	bt->dev = dev;
-	atomic_set(&bt->dropped, 0);
 	INIT_LIST_HEAD(&bt->running_list);
 
 	ret = -EIO;

kernel/ucount.c

@@ -199,18 +199,16 @@ void put_ucounts(struct ucounts *ucounts)
 	}
 }
 
-static inline bool atomic_long_inc_below(atomic_long_t *v, int u)
+static inline bool atomic_long_inc_below(atomic_long_t *v, long u)
 {
-	long c, old;
+	long c = atomic_long_read(v);
-	c = atomic_long_read(v);
+
-	for (;;) {
+	do {
 		if (unlikely(c >= u))
 			return false;
-		old = atomic_long_cmpxchg(v, c, c+1);
+	} while (!atomic_long_try_cmpxchg(v, &c, c+1));
-		if (likely(old == c))
+
-			return true;
+	return true;
-		c = old;
-	}
 }
 
 struct ucounts *inc_ucount(struct user_namespace *ns, kuid_t uid,

lib/Kconfig.debug

@@ -3214,6 +3214,26 @@ config TEST_OBJPOOL
 
 	  If unsure, say N.
 
+config TEST_KEXEC_HANDOVER
+	bool "Test for Kexec HandOver"
+	default n
+	depends on KEXEC_HANDOVER
+	help
+	  This option enables test for Kexec HandOver (KHO).
+	  The test consists of two parts: saving kernel data before kexec and
+	  restoring the data after kexec and verifying that it was properly
+	  handed over. This test module creates and saves data on the boot of
+	  the first kernel and restores and verifies the data on the boot of
+	  kexec'ed kernel.
+
+	  For detailed documentation about KHO, see Documentation/core-api/kho.
+
+	  To run the test run:
+
+	  tools/testing/selftests/kho/vmtest.sh -h
+
+	  If unsure, say N.
+
 config RATELIMIT_KUNIT_TEST
 	tristate "KUnit Test for correctness and stress of ratelimit" if !KUNIT_ALL_TESTS
 	depends on KUNIT

lib/Makefile

@@ -40,7 +40,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \
 	 is_single_threaded.o plist.o decompress.o kobject_uevent.o \
 	 earlycpio.o seq_buf.o siphash.o dec_and_lock.o \
 	 nmi_backtrace.o win_minmax.o memcat_p.o \
-	 buildid.o objpool.o iomem_copy.o
+	 buildid.o objpool.o iomem_copy.o sys_info.o
 
 lib-$(CONFIG_UNION_FIND) += union_find.o
 lib-$(CONFIG_PRINTK) += dump_stack.o
@@ -102,6 +102,7 @@ obj-$(CONFIG_TEST_HMM) += test_hmm.o
 obj-$(CONFIG_TEST_FREE_PAGES) += test_free_pages.o
 obj-$(CONFIG_TEST_REF_TRACKER) += test_ref_tracker.o
 obj-$(CONFIG_TEST_OBJPOOL) += test_objpool.o
+obj-$(CONFIG_TEST_KEXEC_HANDOVER) += test_kho.o
 
 obj-$(CONFIG_TEST_FPU) += test_fpu.o
 test_fpu-y := test_fpu_glue.o test_fpu_impl.o

lib/math/div64.c

@@ -212,12 +212,13 @@ u64 mul_u64_u64_div_u64(u64 a, u64 b, u64 c)
 
 #endif
 
-	/* make sure c is not zero, trigger exception otherwise */
+	/* make sure c is not zero, trigger runtime exception otherwise */
-#pragma GCC diagnostic push
+	if (unlikely(c == 0)) {
-#pragma GCC diagnostic ignored "-Wdiv-by-zero"
+		unsigned long zero = 0;
-	if (unlikely(c == 0))
+
-		return 1/0;
+		OPTIMIZER_HIDE_VAR(zero);
-#pragma GCC diagnostic pop
+		return ~0UL/zero;
+	}
 
 	int shift = __builtin_ctzll(c);
 

lib/math/gcd.c

@@ -11,22 +11,16 @@
  * has decent hardware division.
  */
 
+DEFINE_STATIC_KEY_TRUE(efficient_ffs_key);
+
 #if !defined(CONFIG_CPU_NO_EFFICIENT_FFS)
 
 /* If __ffs is available, the even/odd algorithm benchmarks slower. */
 
-/**
+static unsigned long binary_gcd(unsigned long a, unsigned long b)
- * gcd - calculate and return the greatest common divisor of 2 unsigned longs
- * @a: first value
- * @b: second value
- */
-unsigned long gcd(unsigned long a, unsigned long b)
 {
 	unsigned long r = a | b;
 
-	if (!a || !b)
-		return r;
-
 	b >>= __ffs(b);
 	if (b == 1)
 		return r & -r;
@@ -44,9 +38,15 @@ unsigned long gcd(unsigned long a, unsigned long b)
 	}
 }
 
-#else
+#endif
 
 /* If normalization is done by loops, the even/odd algorithm is a win. */
+
+/**
+ * gcd - calculate and return the greatest common divisor of 2 unsigned longs
+ * @a: first value
+ * @b: second value
+ */
 unsigned long gcd(unsigned long a, unsigned long b)
 {
 	unsigned long r = a | b;
@@ -54,6 +54,11 @@ unsigned long gcd(unsigned long a, unsigned long b)
 	if (!a || !b)
 		return r;
 
+#if !defined(CONFIG_CPU_NO_EFFICIENT_FFS)
+	if (static_branch_likely(&efficient_ffs_key))
+		return binary_gcd(a, b);
+#endif
+
 	/* Isolate lsbit of r */
 	r &= -r;
 
@@ -80,6 +85,4 @@ unsigned long gcd(unsigned long a, unsigned long b)
 	}
 }
 
-#endif
-
 EXPORT_SYMBOL_GPL(gcd);

lib/raid6/algos.c

@@ -18,9 +18,6 @@
 #else
 #include <linux/module.h>
 #include <linux/gfp.h>
-/* In .bss so it's zeroed */
-const char raid6_empty_zero_page[PAGE_SIZE] __attribute__((aligned(256)));
-EXPORT_SYMBOL(raid6_empty_zero_page);
 #endif
 
 struct raid6_calls raid6_call;

lib/raid6/recov.c

@@ -31,10 +31,10 @@ static void raid6_2data_recov_intx1(int disks, size_t bytes, int faila,
 	   Use the dead data pages as temporary storage for
 	   delta p and delta q */
 	dp = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks-2] = dp;
 	dq = (u8 *)ptrs[failb];
-	ptrs[failb] = (void *)raid6_empty_zero_page;
+	ptrs[failb] = raid6_get_zero_page();
 	ptrs[disks-1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);
@@ -72,7 +72,7 @@ static void raid6_datap_recov_intx1(int disks, size_t bytes, int faila,
 	/* Compute syndrome with zero for the missing data page
 	   Use the dead data page as temporary storage for delta q */
 	dq = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks-1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);

lib/raid6/recov_avx2.c

@@ -28,10 +28,10 @@ static void raid6_2data_recov_avx2(int disks, size_t bytes, int faila,
 	   Use the dead data pages as temporary storage for
 	   delta p and delta q */
 	dp = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks-2] = dp;
 	dq = (u8 *)ptrs[failb];
-	ptrs[failb] = (void *)raid6_empty_zero_page;
+	ptrs[failb] = raid6_get_zero_page();
 	ptrs[disks-1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);
@@ -196,7 +196,7 @@ static void raid6_datap_recov_avx2(int disks, size_t bytes, int faila,
 	/* Compute syndrome with zero for the missing data page
 	   Use the dead data page as temporary storage for delta q */
 	dq = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks-1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);

lib/raid6/recov_avx512.c

@@ -37,10 +37,10 @@ static void raid6_2data_recov_avx512(int disks, size_t bytes, int faila,
 	 */
 
 	dp = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks-2] = dp;
 	dq = (u8 *)ptrs[failb];
-	ptrs[failb] = (void *)raid6_empty_zero_page;
+	ptrs[failb] = raid6_get_zero_page();
 	ptrs[disks-1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);
@@ -238,7 +238,7 @@ static void raid6_datap_recov_avx512(int disks, size_t bytes, int faila,
 	 */
 
 	dq = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks-1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);

lib/raid6/recov_loongarch_simd.c

@@ -42,10 +42,10 @@ static void raid6_2data_recov_lsx(int disks, size_t bytes, int faila,
 	 * delta p and delta q
 	 */
 	dp = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks - 2] = dp;
 	dq = (u8 *)ptrs[failb];
-	ptrs[failb] = (void *)raid6_empty_zero_page;
+	ptrs[failb] = raid6_get_zero_page();
 	ptrs[disks - 1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);
@@ -197,7 +197,7 @@ static void raid6_datap_recov_lsx(int disks, size_t bytes, int faila,
 	 * Use the dead data page as temporary storage for delta q
 	 */
 	dq = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks - 1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);
@@ -316,10 +316,10 @@ static void raid6_2data_recov_lasx(int disks, size_t bytes, int faila,
 	 * delta p and delta q
 	 */
 	dp = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks - 2] = dp;
 	dq = (u8 *)ptrs[failb];
-	ptrs[failb] = (void *)raid6_empty_zero_page;
+	ptrs[failb] = raid6_get_zero_page();
 	ptrs[disks - 1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);
@@ -436,7 +436,7 @@ static void raid6_datap_recov_lasx(int disks, size_t bytes, int faila,
 	 * Use the dead data page as temporary storage for delta q
 	 */
 	dq = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks - 1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);

lib/raid6/recov_neon.c

@@ -36,10 +36,10 @@ static void raid6_2data_recov_neon(int disks, size_t bytes, int faila,
 	 * delta p and delta q
 	 */
 	dp = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks - 2] = dp;
 	dq = (u8 *)ptrs[failb];
-	ptrs[failb] = (void *)raid6_empty_zero_page;
+	ptrs[failb] = raid6_get_zero_page();
 	ptrs[disks - 1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);
@@ -74,7 +74,7 @@ static void raid6_datap_recov_neon(int disks, size_t bytes, int faila,
 	 * Use the dead data page as temporary storage for delta q
 	 */
 	dq = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks - 1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);

lib/raid6/recov_rvv.c

@@ -165,10 +165,10 @@ static void raid6_2data_recov_rvv(int disks, size_t bytes, int faila,
 	 * delta p and delta q
 	 */
 	dp = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks - 2] = dp;
 	dq = (u8 *)ptrs[failb];
-	ptrs[failb] = (void *)raid6_empty_zero_page;
+	ptrs[failb] = raid6_get_zero_page();
 	ptrs[disks - 1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);
@@ -203,7 +203,7 @@ static void raid6_datap_recov_rvv(int disks, size_t bytes, int faila,
 	 * Use the dead data page as temporary storage for delta q
 	 */
 	dq = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks - 1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);

lib/raid6/recov_s390xc.c

@@ -34,10 +34,10 @@ static void raid6_2data_recov_s390xc(int disks, size_t bytes, int faila,
 	   Use the dead data pages as temporary storage for
 	   delta p and delta q */
 	dp = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks-2] = dp;
 	dq = (u8 *)ptrs[failb];
-	ptrs[failb] = (void *)raid6_empty_zero_page;
+	ptrs[failb] = raid6_get_zero_page();
 	ptrs[disks-1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);
@@ -81,7 +81,7 @@ static void raid6_datap_recov_s390xc(int disks, size_t bytes, int faila,
 	/* Compute syndrome with zero for the missing data page
 	   Use the dead data page as temporary storage for delta q */
 	dq = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks-1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);

lib/raid6/recov_ssse3.c

@@ -30,10 +30,10 @@ static void raid6_2data_recov_ssse3(int disks, size_t bytes, int faila,
 	   Use the dead data pages as temporary storage for
 	   delta p and delta q */
 	dp = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks-2] = dp;
 	dq = (u8 *)ptrs[failb];
-	ptrs[failb] = (void *)raid6_empty_zero_page;
+	ptrs[failb] = raid6_get_zero_page();
 	ptrs[disks-1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);
@@ -203,7 +203,7 @@ static void raid6_datap_recov_ssse3(int disks, size_t bytes, int faila,
 	/* Compute syndrome with zero for the missing data page
 	   Use the dead data page as temporary storage for delta q */
 	dq = (u8 *)ptrs[faila];
-	ptrs[faila] = (void *)raid6_empty_zero_page;
+	ptrs[faila] = raid6_get_zero_page();
 	ptrs[disks-1] = dq;
 
 	raid6_call.gen_syndrome(disks, bytes, ptrs);

lib/stackdepot.c

@@ -36,11 +36,11 @@
 #include <linux/memblock.h>
 #include <linux/kasan-enabled.h>
 
-#define DEPOT_POOLS_CAP 8192
+/*
-/* The pool_index is offset by 1 so the first record does not have a 0 handle. */
+ * The pool_index is offset by 1 so the first record does not have a 0 handle.
-#define DEPOT_MAX_POOLS \
+ */
-	(((1LL << (DEPOT_POOL_INDEX_BITS)) - 1 < DEPOT_POOLS_CAP) ? \
+static unsigned int stack_max_pools __read_mostly =
-	 (1LL << (DEPOT_POOL_INDEX_BITS)) - 1 : DEPOT_POOLS_CAP)
+	MIN((1LL << DEPOT_POOL_INDEX_BITS) - 1, 8192);
 
 static bool stack_depot_disabled;
 static bool __stack_depot_early_init_requested __initdata = IS_ENABLED(CONFIG_STACKDEPOT_ALWAYS_INIT);
@@ -62,7 +62,7 @@ static unsigned int stack_bucket_number_order;
 static unsigned int stack_hash_mask;
 
 /* Array of memory regions that store stack records. */
-static void *stack_pools[DEPOT_MAX_POOLS];
+static void **stack_pools;
 /* Newly allocated pool that is not yet added to stack_pools. */
 static void *new_pool;
 /* Number of pools in stack_pools. */
@@ -101,6 +101,34 @@ static int __init disable_stack_depot(char *str)
 }
 early_param("stack_depot_disable", disable_stack_depot);
 
+static int __init parse_max_pools(char *str)
+{
+	const long long limit = (1LL << (DEPOT_POOL_INDEX_BITS)) - 1;
+	unsigned int max_pools;
+	int rv;
+
+	rv = kstrtouint(str, 0, &max_pools);
+	if (rv)
+		return rv;
+
+	if (max_pools < 1024) {
+		pr_err("stack_depot_max_pools below 1024, using default of %u\n",
+		       stack_max_pools);
+		goto out;
+	}
+
+	if (max_pools > limit) {
+		pr_err("stack_depot_max_pools exceeds %lld, using default of %u\n",
+		       limit, stack_max_pools);
+		goto out;
+	}
+
+	stack_max_pools = max_pools;
+out:
+	return 0;
+}
+early_param("stack_depot_max_pools", parse_max_pools);
+
 void __init stack_depot_request_early_init(void)
 {
 	/* Too late to request early init now. */
@@ -182,6 +210,17 @@ int __init stack_depot_early_init(void)
 	}
 	init_stack_table(entries);
 
+	pr_info("allocating space for %u stack pools via memblock\n",
+		stack_max_pools);
+	stack_pools =
+		memblock_alloc(stack_max_pools * sizeof(void *), PAGE_SIZE);
+	if (!stack_pools) {
+		pr_err("stack pools allocation failed, disabling\n");
+		memblock_free(stack_table, entries * sizeof(struct list_head));
+		stack_depot_disabled = true;
+		return -ENOMEM;
+	}
+
 	return 0;
 }
 
@@ -231,6 +270,16 @@ int stack_depot_init(void)
 	stack_hash_mask = entries - 1;
 	init_stack_table(entries);
 
+	pr_info("allocating space for %u stack pools via kvcalloc\n",
+		stack_max_pools);
+	stack_pools = kvcalloc(stack_max_pools, sizeof(void *), GFP_KERNEL);
+	if (!stack_pools) {
+		pr_err("stack pools allocation failed, disabling\n");
+		kvfree(stack_table);
+		stack_depot_disabled = true;
+		ret = -ENOMEM;
+	}
+
 out_unlock:
 	mutex_unlock(&stack_depot_init_mutex);
 
@@ -245,9 +294,9 @@ static bool depot_init_pool(void **prealloc)
 {
 	lockdep_assert_held(&pool_lock);
 
-	if (unlikely(pools_num >= DEPOT_MAX_POOLS)) {
+	if (unlikely(pools_num >= stack_max_pools)) {
 		/* Bail out if we reached the pool limit. */
-		WARN_ON_ONCE(pools_num > DEPOT_MAX_POOLS); /* should never happen */
+		WARN_ON_ONCE(pools_num > stack_max_pools); /* should never happen */
 		WARN_ON_ONCE(!new_pool); /* to avoid unnecessary pre-allocation */
 		WARN_ONCE(1, "Stack depot reached limit capacity");
 		return false;
@@ -273,7 +322,7 @@ static bool depot_init_pool(void **prealloc)
 	 * NULL; do not reset to NULL if we have reached the maximum number of
 	 * pools.
 	 */
-	if (pools_num < DEPOT_MAX_POOLS)
+	if (pools_num < stack_max_pools)
 		WRITE_ONCE(new_pool, NULL);
 	else
 		WRITE_ONCE(new_pool, STACK_DEPOT_POISON);

lib/sys_info.c

@@ -0,0 +1,122 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/sched/debug.h>
+#include <linux/console.h>
+#include <linux/kernel.h>
+#include <linux/ftrace.h>
+#include <linux/sysctl.h>
+#include <linux/nmi.h>
+
+#include <linux/sys_info.h>
+
+struct sys_info_name {
+	unsigned long bit;
+	const char *name;
+};
+
+/*
+ * When 'si_names' gets updated,  please make sure the 'sys_info_avail'
+ * below is updated accordingly.
+ */
+static const struct sys_info_name  si_names[] = {
+	{ SYS_INFO_TASKS,		"tasks" },
+	{ SYS_INFO_MEM,			"mem" },
+	{ SYS_INFO_TIMERS,		"timers" },
+	{ SYS_INFO_LOCKS,		"locks" },
+	{ SYS_INFO_FTRACE,		"ftrace" },
+	{ SYS_INFO_ALL_CPU_BT,		"all_bt" },
+	{ SYS_INFO_BLOCKED_TASKS,	"blocked_tasks" },
+};
+
+/* Expecting string like "xxx_sys_info=tasks,mem,timers,locks,ftrace,..." */
+unsigned long sys_info_parse_param(char *str)
+{
+	unsigned long si_bits = 0;
+	char *s, *name;
+	int i;
+
+	s = str;
+	while ((name = strsep(&s, ",")) && *name) {
+		for (i = 0; i < ARRAY_SIZE(si_names); i++) {
+			if (!strcmp(name, si_names[i].name)) {
+				si_bits |= si_names[i].bit;
+				break;
+			}
+		}
+	}
+
+	return si_bits;
+}
+
+#ifdef CONFIG_SYSCTL
+
+static const char sys_info_avail[] __maybe_unused = "tasks,mem,timers,locks,ftrace,all_bt,blocked_tasks";
+
+int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write,
+					  void *buffer, size_t *lenp,
+					  loff_t *ppos)
+{
+	char names[sizeof(sys_info_avail) + 1];
+	struct ctl_table table;
+	unsigned long *si_bits_global;
+
+	si_bits_global = ro_table->data;
+
+	if (write) {
+		unsigned long si_bits;
+		int ret;
+
+		table = *ro_table;
+		table.data = names;
+		table.maxlen = sizeof(names);
+		ret = proc_dostring(&table, write, buffer, lenp, ppos);
+		if (ret)
+			return ret;
+
+		si_bits = sys_info_parse_param(names);
+		/* The access to the global value is not synchronized. */
+		WRITE_ONCE(*si_bits_global, si_bits);
+		return 0;
+	} else {
+		/* for 'read' operation */
+		char *delim = "";
+		int i, len = 0;
+
+		for (i = 0; i < ARRAY_SIZE(si_names); i++) {
+			if (*si_bits_global & si_names[i].bit) {
+				len += scnprintf(names + len, sizeof(names) - len,
+					"%s%s", delim, si_names[i].name);
+				delim = ",";
+			}
+		}
+
+		table = *ro_table;
+		table.data = names;
+		table.maxlen = sizeof(names);
+		return proc_dostring(&table, write, buffer, lenp, ppos);
+	}
+}
+#endif
+
+void sys_info(unsigned long si_mask)
+{
+	if (si_mask & SYS_INFO_TASKS)
+		show_state();
+
+	if (si_mask & SYS_INFO_MEM)
+		show_mem();
+
+	if (si_mask & SYS_INFO_TIMERS)
+		sysrq_timer_list_show();
+
+	if (si_mask & SYS_INFO_LOCKS)
+		debug_show_all_locks();
+
+	if (si_mask & SYS_INFO_FTRACE)
+		ftrace_dump(DUMP_ALL);
+
+	if (si_mask & SYS_INFO_ALL_CPU_BT)
+		trigger_all_cpu_backtrace();
+
+	if (si_mask & SYS_INFO_BLOCKED_TASKS)
+		show_state_filter(TASK_UNINTERRUPTIBLE);
+}

lib/test_kho.c

@@ -0,0 +1,305 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Test module for KHO
+ * Copyright (c) 2025 Microsoft Corporation.
+ *
+ * Authors:
+ *   Saurabh Sengar <ssengar@microsoft.com>
+ *   Mike Rapoport <rppt@kernel.org>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/mm.h>
+#include <linux/gfp.h>
+#include <linux/slab.h>
+#include <linux/kexec.h>
+#include <linux/libfdt.h>
+#include <linux/module.h>
+#include <linux/printk.h>
+#include <linux/vmalloc.h>
+#include <linux/kexec_handover.h>
+
+#include <net/checksum.h>
+
+#define KHO_TEST_MAGIC	0x4b484f21	/* KHO! */
+#define KHO_TEST_FDT	"kho_test"
+#define KHO_TEST_COMPAT "kho-test-v1"
+
+static long max_mem = (PAGE_SIZE << MAX_PAGE_ORDER) * 2;
+module_param(max_mem, long, 0644);
+
+struct kho_test_state {
+	unsigned int nr_folios;
+	struct folio **folios;
+	struct folio *fdt;
+	__wsum csum;
+};
+
+static struct kho_test_state kho_test_state;
+
+static int kho_test_notifier(struct notifier_block *self, unsigned long cmd,
+			     void *v)
+{
+	struct kho_test_state *state = &kho_test_state;
+	struct kho_serialization *ser = v;
+	int err = 0;
+
+	switch (cmd) {
+	case KEXEC_KHO_ABORT:
+		return NOTIFY_DONE;
+	case KEXEC_KHO_FINALIZE:
+		/* Handled below */
+		break;
+	default:
+		return NOTIFY_BAD;
+	}
+
+	err |= kho_preserve_folio(state->fdt);
+	err |= kho_add_subtree(ser, KHO_TEST_FDT, folio_address(state->fdt));
+
+	return err ? NOTIFY_BAD : NOTIFY_DONE;
+}
+
+static struct notifier_block kho_test_nb = {
+	.notifier_call = kho_test_notifier,
+};
+
+static int kho_test_save_data(struct kho_test_state *state, void *fdt)
+{
+	phys_addr_t *folios_info __free(kvfree) = NULL;
+	int err = 0;
+
+	folios_info = kvmalloc_array(state->nr_folios, sizeof(*folios_info),
+				     GFP_KERNEL);
+	if (!folios_info)
+		return -ENOMEM;
+
+	for (int i = 0; i < state->nr_folios; i++) {
+		struct folio *folio = state->folios[i];
+		unsigned int order = folio_order(folio);
+
+		folios_info[i] = virt_to_phys(folio_address(folio)) | order;
+
+		err = kho_preserve_folio(folio);
+		if (err)
+			return err;
+	}
+
+	err |= fdt_begin_node(fdt, "data");
+	err |= fdt_property(fdt, "nr_folios", &state->nr_folios,
+			    sizeof(state->nr_folios));
+	err |= fdt_property(fdt, "folios_info", folios_info,
+			    state->nr_folios * sizeof(*folios_info));
+	err |= fdt_property(fdt, "csum", &state->csum, sizeof(state->csum));
+	err |= fdt_end_node(fdt);
+
+	return err;
+}
+
+static int kho_test_prepare_fdt(struct kho_test_state *state)
+{
+	const char compatible[] = KHO_TEST_COMPAT;
+	unsigned int magic = KHO_TEST_MAGIC;
+	ssize_t fdt_size;
+	int err = 0;
+	void *fdt;
+
+	fdt_size = state->nr_folios * sizeof(phys_addr_t) + PAGE_SIZE;
+	state->fdt = folio_alloc(GFP_KERNEL, get_order(fdt_size));
+	if (!state->fdt)
+		return -ENOMEM;
+
+	fdt = folio_address(state->fdt);
+
+	err |= fdt_create(fdt, fdt_size);
+	err |= fdt_finish_reservemap(fdt);
+
+	err |= fdt_begin_node(fdt, "");
+	err |= fdt_property(fdt, "compatible", compatible, sizeof(compatible));
+	err |= fdt_property(fdt, "magic", &magic, sizeof(magic));
+	err |= kho_test_save_data(state, fdt);
+	err |= fdt_end_node(fdt);
+
+	err |= fdt_finish(fdt);
+
+	if (err)
+		folio_put(state->fdt);
+
+	return err;
+}
+
+static int kho_test_generate_data(struct kho_test_state *state)
+{
+	size_t alloc_size = 0;
+	__wsum csum = 0;
+
+	while (alloc_size < max_mem) {
+		int order = get_random_u32() % NR_PAGE_ORDERS;
+		struct folio *folio;
+		unsigned int size;
+		void *addr;
+
+		/* cap allocation so that we won't exceed max_mem */
+		if (alloc_size + (PAGE_SIZE << order) > max_mem) {
+			order = get_order(max_mem - alloc_size);
+			if (order)
+				order--;
+		}
+		size = PAGE_SIZE << order;
+
+		folio = folio_alloc(GFP_KERNEL | __GFP_NORETRY, order);
+		if (!folio)
+			goto err_free_folios;
+
+		state->folios[state->nr_folios++] = folio;
+		addr = folio_address(folio);
+		get_random_bytes(addr, size);
+		csum = csum_partial(addr, size, csum);
+		alloc_size += size;
+	}
+
+	state->csum = csum;
+	return 0;
+
+err_free_folios:
+	for (int i = 0; i < state->nr_folios; i++)
+		folio_put(state->folios[i]);
+	return -ENOMEM;
+}
+
+static int kho_test_save(void)
+{
+	struct kho_test_state *state = &kho_test_state;
+	struct folio **folios __free(kvfree) = NULL;
+	unsigned long max_nr;
+	int err;
+
+	max_mem = PAGE_ALIGN(max_mem);
+	max_nr = max_mem >> PAGE_SHIFT;
+
+	folios = kvmalloc_array(max_nr, sizeof(*state->folios), GFP_KERNEL);
+	if (!folios)
+		return -ENOMEM;
+	state->folios = folios;
+
+	err = kho_test_generate_data(state);
+	if (err)
+		return err;
+
+	err = kho_test_prepare_fdt(state);
+	if (err)
+		return err;
+
+	return register_kho_notifier(&kho_test_nb);
+}
+
+static int kho_test_restore_data(const void *fdt, int node)
+{
+	const unsigned int *nr_folios;
+	const phys_addr_t *folios_info;
+	const __wsum *old_csum;
+	__wsum csum = 0;
+	int len;
+
+	node = fdt_path_offset(fdt, "/data");
+
+	nr_folios = fdt_getprop(fdt, node, "nr_folios", &len);
+	if (!nr_folios || len != sizeof(*nr_folios))
+		return -EINVAL;
+
+	old_csum = fdt_getprop(fdt, node, "csum", &len);
+	if (!old_csum || len != sizeof(*old_csum))
+		return -EINVAL;
+
+	folios_info = fdt_getprop(fdt, node, "folios_info", &len);
+	if (!folios_info || len != sizeof(*folios_info) * *nr_folios)
+		return -EINVAL;
+
+	for (int i = 0; i < *nr_folios; i++) {
+		unsigned int order = folios_info[i] & ~PAGE_MASK;
+		phys_addr_t phys = folios_info[i] & PAGE_MASK;
+		unsigned int size = PAGE_SIZE << order;
+		struct folio *folio;
+
+		folio = kho_restore_folio(phys);
+		if (!folio)
+			break;
+
+		if (folio_order(folio) != order)
+			break;
+
+		csum = csum_partial(folio_address(folio), size, csum);
+		folio_put(folio);
+	}
+
+	if (csum != *old_csum)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int kho_test_restore(phys_addr_t fdt_phys)
+{
+	void *fdt = phys_to_virt(fdt_phys);
+	const unsigned int *magic;
+	int node, len, err;
+
+	node = fdt_path_offset(fdt, "/");
+	if (node < 0)
+		return -EINVAL;
+
+	if (fdt_node_check_compatible(fdt, node, KHO_TEST_COMPAT))
+		return -EINVAL;
+
+	magic = fdt_getprop(fdt, node, "magic", &len);
+	if (!magic || len != sizeof(*magic))
+		return -EINVAL;
+
+	if (*magic != KHO_TEST_MAGIC)
+		return -EINVAL;
+
+	err = kho_test_restore_data(fdt, node);
+	if (err)
+		return err;
+
+	pr_info("KHO restore succeeded\n");
+	return 0;
+}
+
+static int __init kho_test_init(void)
+{
+	phys_addr_t fdt_phys;
+	int err;
+
+	err = kho_retrieve_subtree(KHO_TEST_FDT, &fdt_phys);
+	if (!err)
+		return kho_test_restore(fdt_phys);
+
+	if (err != -ENOENT) {
+		pr_warn("failed to retrieve %s FDT: %d\n", KHO_TEST_FDT, err);
+		return err;
+	}
+
+	return kho_test_save();
+}
+module_init(kho_test_init);
+
+static void kho_test_cleanup(void)
+{
+	for (int i = 0; i < kho_test_state.nr_folios; i++)
+		folio_put(kho_test_state.folios[i]);
+
+	kvfree(kho_test_state.folios);
+}
+
+static void __exit kho_test_exit(void)
+{
+	unregister_kho_notifier(&kho_test_nb);
+	kho_test_cleanup();
+}
+module_exit(kho_test_exit);
+
+MODULE_AUTHOR("Mike Rapoport <rppt@kernel.org>");
+MODULE_DESCRIPTION("KHO test module");
+MODULE_LICENSE("GPL");

lib/xxhash.c

@@ -267,113 +267,6 @@ void xxh64_reset(struct xxh64_state *statePtr, const uint64_t seed)
 }
 EXPORT_SYMBOL(xxh64_reset);
 
-int xxh32_update(struct xxh32_state *state, const void *input, const size_t len)
-{
-	const uint8_t *p = (const uint8_t *)input;
-	const uint8_t *const b_end = p + len;
-
-	if (input == NULL)
-		return -EINVAL;
-
-	state->total_len_32 += (uint32_t)len;
-	state->large_len |= (len >= 16) | (state->total_len_32 >= 16);
-
-	if (state->memsize + len < 16) { /* fill in tmp buffer */
-		memcpy((uint8_t *)(state->mem32) + state->memsize, input, len);
-		state->memsize += (uint32_t)len;
-		return 0;
-	}
-
-	if (state->memsize) { /* some data left from previous update */
-		const uint32_t *p32 = state->mem32;
-
-		memcpy((uint8_t *)(state->mem32) + state->memsize, input,
-			16 - state->memsize);
-
-		state->v1 = xxh32_round(state->v1, get_unaligned_le32(p32));
-		p32++;
-		state->v2 = xxh32_round(state->v2, get_unaligned_le32(p32));
-		p32++;
-		state->v3 = xxh32_round(state->v3, get_unaligned_le32(p32));
-		p32++;
-		state->v4 = xxh32_round(state->v4, get_unaligned_le32(p32));
-		p32++;
-
-		p += 16-state->memsize;
-		state->memsize = 0;
-	}
-
-	if (p <= b_end - 16) {
-		const uint8_t *const limit = b_end - 16;
-		uint32_t v1 = state->v1;
-		uint32_t v2 = state->v2;
-		uint32_t v3 = state->v3;
-		uint32_t v4 = state->v4;
-
-		do {
-			v1 = xxh32_round(v1, get_unaligned_le32(p));
-			p += 4;
-			v2 = xxh32_round(v2, get_unaligned_le32(p));
-			p += 4;
-			v3 = xxh32_round(v3, get_unaligned_le32(p));
-			p += 4;
-			v4 = xxh32_round(v4, get_unaligned_le32(p));
-			p += 4;
-		} while (p <= limit);
-
-		state->v1 = v1;
-		state->v2 = v2;
-		state->v3 = v3;
-		state->v4 = v4;
-	}
-
-	if (p < b_end) {
-		memcpy(state->mem32, p, (size_t)(b_end-p));
-		state->memsize = (uint32_t)(b_end-p);
-	}
-
-	return 0;
-}
-EXPORT_SYMBOL(xxh32_update);
-
-uint32_t xxh32_digest(const struct xxh32_state *state)
-{
-	const uint8_t *p = (const uint8_t *)state->mem32;
-	const uint8_t *const b_end = (const uint8_t *)(state->mem32) +
-		state->memsize;
-	uint32_t h32;
-
-	if (state->large_len) {
-		h32 = xxh_rotl32(state->v1, 1) + xxh_rotl32(state->v2, 7) +
-			xxh_rotl32(state->v3, 12) + xxh_rotl32(state->v4, 18);
-	} else {
-		h32 = state->v3 /* == seed */ + PRIME32_5;
-	}
-
-	h32 += state->total_len_32;
-
-	while (p + 4 <= b_end) {
-		h32 += get_unaligned_le32(p) * PRIME32_3;
-		h32 = xxh_rotl32(h32, 17) * PRIME32_4;
-		p += 4;
-	}
-
-	while (p < b_end) {
-		h32 += (*p) * PRIME32_5;
-		h32 = xxh_rotl32(h32, 11) * PRIME32_1;
-		p++;
-	}
-
-	h32 ^= h32 >> 15;
-	h32 *= PRIME32_2;
-	h32 ^= h32 >> 13;
-	h32 *= PRIME32_3;
-	h32 ^= h32 >> 16;
-
-	return h32;
-}
-EXPORT_SYMBOL(xxh32_digest);
-
 int xxh64_update(struct xxh64_state *state, const void *input, const size_t len)
 {
 	const uint8_t *p = (const uint8_t *)input;

samples/Kconfig

@@ -54,7 +54,7 @@ config SAMPLE_FTRACE_OPS
 	  measures the time taken to invoke one function a number of times.
 
 config SAMPLE_TRACE_ARRAY
-        tristate "Build sample module for kernel access to Ftrace instancess"
+        tristate "Build sample module for kernel access to Ftrace instances"
 	depends on EVENT_TRACING && m
 	help
 	 This builds a module that demonstrates the use of various APIs to
@@ -316,10 +316,9 @@ config SAMPLE_HUNG_TASK
 	depends on DETECT_HUNG_TASK && DEBUG_FS
 	help
 	  Build a module that provides debugfs files (e.g., mutex, semaphore,
-	  etc.) under <debugfs>/hung_task. If user reads one of these files,
+	  rw_semaphore_read, rw_semaphore_write) under <debugfs>/hung_task.
-	  it will sleep long time (256 seconds) with holding a lock. Thus,
+	  Reading these files with multiple processes triggers hung task
-	  if 2 or more processes read the same file concurrently, it will
+	  detection by holding locks for a long time (256 seconds).
-	  be detected by the hung_task watchdog.
 
 source "samples/rust/Kconfig"
 

samples/hung_task/hung_task_tests.c

@@ -4,11 +4,12 @@
  * semaphore, etc.
  *
  * Usage: Load this module and read `<debugfs>/hung_task/mutex`,
- *        `<debugfs>/hung_task/semaphore`, etc., with 2 or more processes.
+ *        `<debugfs>/hung_task/semaphore`, `<debugfs>/hung_task/rw_semaphore_read`,
+ *        `<debugfs>/hung_task/rw_semaphore_write`, etc., with 2 or more processes.
  *
  * This is for testing kernel hung_task error messages with various locking
- * mechanisms (e.g., mutex, semaphore, etc.). Note that this may freeze
+ * mechanisms (e.g., mutex, semaphore, rw_semaphore_read, rw_semaphore_write, etc.).
- * your system or cause a panic. Use only for testing purposes.
+ * Note that this may freeze your system or cause a panic. Use only for testing purposes.
  */
 
 #include <linux/debugfs.h>
@@ -17,21 +18,29 @@
 #include <linux/module.h>
 #include <linux/mutex.h>
 #include <linux/semaphore.h>
+#include <linux/rwsem.h>
 
-#define HUNG_TASK_DIR		"hung_task"
+#define HUNG_TASK_DIR			"hung_task"
-#define HUNG_TASK_MUTEX_FILE	"mutex"
+#define HUNG_TASK_MUTEX_FILE		"mutex"
-#define HUNG_TASK_SEM_FILE	"semaphore"
+#define HUNG_TASK_SEM_FILE		"semaphore"
-#define SLEEP_SECOND		256
+#define HUNG_TASK_RWSEM_READ_FILE	"rw_semaphore_read"
+#define HUNG_TASK_RWSEM_WRITE_FILE	"rw_semaphore_write"
+#define SLEEP_SECOND			256
 
 static const char dummy_string[] = "This is a dummy string.";
 static DEFINE_MUTEX(dummy_mutex);
 static DEFINE_SEMAPHORE(dummy_sem, 1);
+static DECLARE_RWSEM(dummy_rwsem);
 static struct dentry *hung_task_dir;
 
 /* Mutex-based read function */
 static ssize_t read_dummy_mutex(struct file *file, char __user *user_buf,
 				size_t count, loff_t *ppos)
 {
+	/* Check if data is already read */
+	if (*ppos >= sizeof(dummy_string))
+		return 0;
+
 	/* Second task waits on mutex, entering uninterruptible sleep */
 	guard(mutex)(&dummy_mutex);
 
@@ -46,6 +55,10 @@ static ssize_t read_dummy_mutex(struct file *file, char __user *user_buf,
 static ssize_t read_dummy_semaphore(struct file *file, char __user *user_buf,
 				    size_t count, loff_t *ppos)
 {
+	/* Check if data is already read */
+	if (*ppos >= sizeof(dummy_string))
+		return 0;
+
 	/* Second task waits on semaphore, entering uninterruptible sleep */
 	down(&dummy_sem);
 
@@ -58,6 +71,46 @@ static ssize_t read_dummy_semaphore(struct file *file, char __user *user_buf,
 				       sizeof(dummy_string));
 }
 
+/* Read-write semaphore read function */
+static ssize_t read_dummy_rwsem_read(struct file *file, char __user *user_buf,
+				     size_t count, loff_t *ppos)
+{
+	/* Check if data is already read */
+	if (*ppos >= sizeof(dummy_string))
+		return 0;
+
+	/* Acquires read lock, allowing concurrent readers but blocks if write lock is held */
+	down_read(&dummy_rwsem);
+
+	/* Sleeps here, potentially triggering hung task detection if lock is held too long */
+	msleep_interruptible(SLEEP_SECOND * 1000);
+
+	up_read(&dummy_rwsem);
+
+	return simple_read_from_buffer(user_buf, count, ppos, dummy_string,
+				       sizeof(dummy_string));
+}
+
+/* Read-write semaphore write function */
+static ssize_t read_dummy_rwsem_write(struct file *file, char __user *user_buf,
+				      size_t count, loff_t *ppos)
+{
+	/* Check if data is already read */
+	if (*ppos >= sizeof(dummy_string))
+		return 0;
+
+	/* Acquires exclusive write lock, blocking all other readers and writers */
+	down_write(&dummy_rwsem);
+
+	/* Sleeps here, potentially triggering hung task detection if lock is held too long */
+	msleep_interruptible(SLEEP_SECOND * 1000);
+
+	up_write(&dummy_rwsem);
+
+	return simple_read_from_buffer(user_buf, count, ppos, dummy_string,
+				       sizeof(dummy_string));
+}
+
 /* File operations for mutex */
 static const struct file_operations hung_task_mutex_fops = {
 	.read = read_dummy_mutex,
@@ -68,6 +121,16 @@ static const struct file_operations hung_task_sem_fops = {
 	.read = read_dummy_semaphore,
 };
 
+/* File operations for rw_semaphore read */
+static const struct file_operations hung_task_rwsem_read_fops = {
+	.read = read_dummy_rwsem_read,
+};
+
+/* File operations for rw_semaphore write */
+static const struct file_operations hung_task_rwsem_write_fops = {
+	.read = read_dummy_rwsem_write,
+};
+
 static int __init hung_task_tests_init(void)
 {
 	hung_task_dir = debugfs_create_dir(HUNG_TASK_DIR, NULL);
@@ -79,6 +142,10 @@ static int __init hung_task_tests_init(void)
 			    &hung_task_mutex_fops);
 	debugfs_create_file(HUNG_TASK_SEM_FILE, 0400, hung_task_dir, NULL,
 			    &hung_task_sem_fops);
+	debugfs_create_file(HUNG_TASK_RWSEM_READ_FILE, 0400, hung_task_dir, NULL,
+			    &hung_task_rwsem_read_fops);
+	debugfs_create_file(HUNG_TASK_RWSEM_WRITE_FILE, 0400, hung_task_dir, NULL,
+			    &hung_task_rwsem_write_fops);
 
 	return 0;
 }

scripts/checkpatch.pl

@@ -685,6 +685,9 @@ our $tracing_logging_tags = qr{(?xi:
 	[\.\!:\s]*
 )};
 
+# Device ID types like found in include/linux/mod_devicetable.h.
+our $dev_id_types = qr{\b[a-z]\w*_device_id\b};
+
 sub edit_distance_min {
 	my (@arr) = @_;
 	my $len = scalar @arr;
@@ -3500,9 +3503,10 @@ sub process {
 # Check for various typo / spelling mistakes
 		if (defined($misspellings) &&
 		    ($in_commit_log || $line =~ /^(?:\+|Subject:)/i)) {
-			while ($rawline =~ /(?:^|[^\w\-'`])($misspellings)(?:[^\w\-'`]|$)/gi) {
+			my $rawline_utf8 = decode("utf8", $rawline);
+			while ($rawline_utf8 =~ /(?:^|[^\w\-'`])($misspellings)(?:[^\w\-'`]|$)/gi) {
 				my $typo = $1;
-				my $blank = copy_spacing($rawline);
+				my $blank = copy_spacing($rawline_utf8);
 				my $ptr = substr($blank, 0, $-[1]) . "^" x length($typo);
 				my $hereptr = "$hereline$ptr\n";
 				my $typo_fix = $spelling_fix{lc($typo)};
@@ -7688,6 +7692,31 @@ sub process {
 			WARN("DUPLICATED_SYSCTL_CONST",
 				"duplicated sysctl range checking value '$1', consider using the shared one in include/linux/sysctl.h\n" . $herecurr);
 		}
+
+# Check that *_device_id tables have sentinel entries.
+		if (defined $stat && $line =~ /struct\s+$dev_id_types\s+\w+\s*\[\s*\]\s*=\s*\{/) {
+			my $stripped = $stat;
+
+			# Strip diff line prefixes.
+			$stripped =~ s/(^|\n)./$1/g;
+			# Line continuations.
+			$stripped =~ s/\\\n/\n/g;
+			# Strip whitespace, empty strings, zeroes, and commas.
+			$stripped =~ s/""//g;
+			$stripped =~ s/0x0//g;
+			$stripped =~ s/[\s$;,0]//g;
+			# Strip field assignments.
+			$stripped =~ s/\.$Ident=//g;
+
+			if (!(substr($stripped, -4) eq "{}};" ||
+			      substr($stripped, -6) eq "{{}}};" ||
+			      $stripped =~ /ISAPNP_DEVICE_SINGLE_END}};$/ ||
+			      $stripped =~ /ISAPNP_CARD_END}};$/ ||
+			      $stripped =~ /NULL};$/ ||
+			      $stripped =~ /PCMCIA_DEVICE_NULL};$/)) {
+				ERROR("MISSING_SENTINEL", "missing sentinel in ID array\n" . "$here\n$stat\n");
+			}
+		}
 	}
 
 	# If we have no input at all, then there is nothing to report on

scripts/coccinelle/misc/secs_to_jiffies.cocci

@@ -7,26 +7,65 @@
 // Confidence: High
 // Copyright: (C) 2024 Easwar Hariharan, Microsoft
 // Keywords: secs, seconds, jiffies
-//
+// Options: --include-headers
 
 virtual patch
+virtual report
+virtual context
 
-@depends on patch@ constant C; @@
+@pconst depends on patch@ constant C; @@
 
 - msecs_to_jiffies(C * 1000)
 + secs_to_jiffies(C)
 
-@depends on patch@ constant C; @@
+@pconstms depends on patch@ constant C; @@
 
 - msecs_to_jiffies(C * MSEC_PER_SEC)
 + secs_to_jiffies(C)
 
-@depends on patch@ expression E; @@
+@pexpr depends on patch@ expression E; @@
 
 - msecs_to_jiffies(E * 1000)
 + secs_to_jiffies(E)
 
-@depends on patch@ expression E; @@
+@pexprms depends on patch@ expression E; @@
 
 - msecs_to_jiffies(E * MSEC_PER_SEC)
 + secs_to_jiffies(E)
+
+@r depends on report && !patch@
+constant C;
+expression E;
+position p;
+@@
+
+(
+  msecs_to_jiffies(C@p * 1000)
+|
+  msecs_to_jiffies(C@p * MSEC_PER_SEC)
+|
+  msecs_to_jiffies(E@p * 1000)
+|
+  msecs_to_jiffies(E@p * MSEC_PER_SEC)
+)
+
+@c depends on context && !patch@
+constant C;
+expression E;
+@@
+
+(
+* msecs_to_jiffies(C * 1000)
+|
+* msecs_to_jiffies(C * MSEC_PER_SEC)
+|
+* msecs_to_jiffies(E * 1000)
+|
+* msecs_to_jiffies(E * MSEC_PER_SEC)
+)
+
+@script:python depends on report@
+p << r.p;
+@@
+
+coccilib.report.print_report(p[0], "WARNING opportunity for secs_to_jiffies()")

scripts/gdb/linux/constants.py.in

@@ -74,12 +74,12 @@ if IS_BUILTIN(CONFIG_MODULES):
     LX_GDBPARSED(MOD_RO_AFTER_INIT)
 
 /* linux/mount.h */
-LX_VALUE(MNT_NOSUID)
+LX_GDBPARSED(MNT_NOSUID)
-LX_VALUE(MNT_NODEV)
+LX_GDBPARSED(MNT_NODEV)
-LX_VALUE(MNT_NOEXEC)
+LX_GDBPARSED(MNT_NOEXEC)
-LX_VALUE(MNT_NOATIME)
+LX_GDBPARSED(MNT_NOATIME)
-LX_VALUE(MNT_NODIRATIME)
+LX_GDBPARSED(MNT_NODIRATIME)
-LX_VALUE(MNT_RELATIME)
+LX_GDBPARSED(MNT_RELATIME)
 
 /* linux/threads.h */
 LX_VALUE(NR_CPUS)

scripts/spelling.txt

@@ -1099,6 +1099,7 @@ notication||notification
 notications||notifications
 notifcations||notifications
 notifed||notified
+notifer||notifier
 notity||notify
 notfify||notify
 nubmer||number

tools/accounting/Makefile

@@ -2,7 +2,7 @@
 CC := $(CROSS_COMPILE)gcc
 CFLAGS := -I../../usr/include
 
-PROGS := getdelays procacct
+PROGS := getdelays procacct delaytop
 
 all: $(PROGS)
 

tools/accounting/delaytop.c

@@ -0,0 +1,862 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * delaytop.c - system-wide delay monitoring tool.
+ *
+ * This tool provides real-time monitoring and statistics of
+ * system, container, and task-level delays, including CPU,
+ * memory, IO, and IRQ. It supports both interactive (top-like),
+ * and can output delay information for the whole system, specific
+ * containers (cgroups), or individual tasks (PIDs).
+ *
+ * Key features:
+ *	- Collects per-task delay accounting statistics via taskstats.
+ *	- Collects system-wide PSI information.
+ *	- Supports sorting, filtering.
+ *	- Supports both interactive (screen refresh).
+ *
+ * Copyright (C) Fan Yu, ZTE Corp. 2025
+ * Copyright (C) Wang Yaxin, ZTE Corp. 2025
+ *
+ * Compile with
+ *	gcc -I/usr/src/linux/include delaytop.c -o delaytop
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <getopt.h>
+#include <signal.h>
+#include <time.h>
+#include <dirent.h>
+#include <ctype.h>
+#include <stdbool.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/socket.h>
+#include <sys/select.h>
+#include <termios.h>
+#include <limits.h>
+#include <linux/genetlink.h>
+#include <linux/taskstats.h>
+#include <linux/cgroupstats.h>
+
+#define PSI_CPU_SOME "/proc/pressure/cpu"
+#define PSI_CPU_FULL	"/proc/pressure/cpu"
+#define PSI_MEMORY_SOME "/proc/pressure/memory"
+#define PSI_MEMORY_FULL "/proc/pressure/memory"
+#define PSI_IO_SOME "/proc/pressure/io"
+#define PSI_IO_FULL "/proc/pressure/io"
+#define PSI_IRQ_FULL	"/proc/pressure/irq"
+
+#define NLA_NEXT(na)			((struct nlattr *)((char *)(na) + NLA_ALIGN((na)->nla_len)))
+#define NLA_DATA(na)			((void *)((char *)(na) + NLA_HDRLEN))
+#define NLA_PAYLOAD(len)		(len - NLA_HDRLEN)
+
+#define GENLMSG_DATA(glh)		((void *)(NLMSG_DATA(glh) + GENL_HDRLEN))
+#define GENLMSG_PAYLOAD(glh)	(NLMSG_PAYLOAD(glh, 0) - GENL_HDRLEN)
+
+#define TASK_COMM_LEN	16
+#define MAX_MSG_SIZE	1024
+#define MAX_TASKS		1000
+#define SET_TASK_STAT(task_count, field) tasks[task_count].field = stats.field
+#define BOOL_FPRINT(stream, fmt, ...) \
+({ \
+	int ret = fprintf(stream, fmt, ##__VA_ARGS__); \
+	ret >= 0; \
+})
+#define PSI_LINE_FORMAT "%-12s %6.1f%%/%6.1f%%/%6.1f%%/%8llu(ms)\n"
+
+/* Program settings structure */
+struct config {
+	int delay;				/* Update interval in seconds */
+	int iterations;			/* Number of iterations, 0 == infinite */
+	int max_processes;		/* Maximum number of processes to show */
+	char sort_field;		/* Field to sort by */
+	int output_one_time;	/* Output once and exit */
+	int monitor_pid;		/* Monitor specific PID */
+	char *container_path;	/* Path to container cgroup */
+};
+
+/* PSI statistics structure */
+struct psi_stats {
+	double cpu_some_avg10, cpu_some_avg60, cpu_some_avg300;
+	unsigned long long cpu_some_total;
+	double cpu_full_avg10, cpu_full_avg60, cpu_full_avg300;
+	unsigned long long cpu_full_total;
+	double memory_some_avg10, memory_some_avg60, memory_some_avg300;
+	unsigned long long memory_some_total;
+	double memory_full_avg10, memory_full_avg60, memory_full_avg300;
+	unsigned long long memory_full_total;
+	double io_some_avg10, io_some_avg60, io_some_avg300;
+	unsigned long long io_some_total;
+	double io_full_avg10, io_full_avg60, io_full_avg300;
+	unsigned long long io_full_total;
+	double irq_full_avg10, irq_full_avg60, irq_full_avg300;
+	unsigned long long irq_full_total;
+};
+
+/* Task delay information structure */
+struct task_info {
+	int pid;
+	int tgid;
+	char command[TASK_COMM_LEN];
+	unsigned long long cpu_count;
+	unsigned long long cpu_delay_total;
+	unsigned long long blkio_count;
+	unsigned long long blkio_delay_total;
+	unsigned long long swapin_count;
+	unsigned long long swapin_delay_total;
+	unsigned long long freepages_count;
+	unsigned long long freepages_delay_total;
+	unsigned long long thrashing_count;
+	unsigned long long thrashing_delay_total;
+	unsigned long long compact_count;
+	unsigned long long compact_delay_total;
+	unsigned long long wpcopy_count;
+	unsigned long long wpcopy_delay_total;
+	unsigned long long irq_count;
+	unsigned long long irq_delay_total;
+};
+
+/* Container statistics structure */
+struct container_stats {
+	int nr_sleeping;		/* Number of sleeping processes */
+	int nr_running;			/* Number of running processes */
+	int nr_stopped;			/* Number of stopped processes */
+	int nr_uninterruptible; /* Number of uninterruptible processes */
+	int nr_io_wait;			/* Number of processes in IO wait */
+};
+
+/* Global variables */
+static struct config cfg;
+static struct psi_stats psi;
+static struct task_info tasks[MAX_TASKS];
+static int task_count;
+static int running = 1;
+static struct container_stats container_stats;
+
+/* Netlink socket variables */
+static int nl_sd = -1;
+static int family_id;
+
+/* Set terminal to non-canonical mode for q-to-quit */
+static struct termios orig_termios;
+static void enable_raw_mode(void)
+{
+	struct termios raw;
+
+	tcgetattr(STDIN_FILENO, &orig_termios);
+	raw = orig_termios;
+	raw.c_lflag &= ~(ICANON | ECHO);
+	tcsetattr(STDIN_FILENO, TCSAFLUSH, &raw);
+}
+static void disable_raw_mode(void)
+{
+	tcsetattr(STDIN_FILENO, TCSAFLUSH, &orig_termios);
+}
+
+/* Display usage information and command line options */
+static void usage(void)
+{
+	printf("Usage: delaytop [Options]\n"
+	"Options:\n"
+	"  -h, --help				Show this help message and exit\n"
+	"  -d, --delay=SECONDS	  Set refresh interval (default: 2 seconds, min: 1)\n"
+	"  -n, --iterations=COUNT	Set number of updates (default: 0 = infinite)\n"
+	"  -P, --processes=NUMBER	Set maximum number of processes to show (default: 20, max: 1000)\n"
+	"  -o, --once				Display once and exit\n"
+	"  -p, --pid=PID			Monitor only the specified PID\n"
+	"  -C, --container=PATH	 Monitor the container at specified cgroup path\n");
+	exit(0);
+}
+
+/* Parse command line arguments and set configuration */
+static void parse_args(int argc, char **argv)
+{
+	int c;
+	struct option long_options[] = {
+		{"help", no_argument, 0, 'h'},
+		{"delay", required_argument, 0, 'd'},
+		{"iterations", required_argument, 0, 'n'},
+		{"pid", required_argument, 0, 'p'},
+		{"once", no_argument, 0, 'o'},
+		{"processes", required_argument, 0, 'P'},
+		{"container", required_argument, 0, 'C'},
+		{0, 0, 0, 0}
+	};
+
+	/* Set defaults */
+	cfg.delay = 2;
+	cfg.iterations = 0;
+	cfg.max_processes = 20;
+	cfg.sort_field = 'c';	/* Default sort by CPU delay */
+	cfg.output_one_time = 0;
+	cfg.monitor_pid = 0;	/* 0 means monitor all PIDs */
+	cfg.container_path = NULL;
+
+	while (1) {
+		int option_index = 0;
+
+		c = getopt_long(argc, argv, "hd:n:p:oP:C:", long_options, &option_index);
+		if (c == -1)
+			break;
+
+		switch (c) {
+		case 'h':
+			usage();
+			break;
+		case 'd':
+			cfg.delay = atoi(optarg);
+			if (cfg.delay < 1) {
+				fprintf(stderr, "Error: delay must be >= 1.\n");
+				exit(1);
+			}
+			break;
+		case 'n':
+			cfg.iterations = atoi(optarg);
+			if (cfg.iterations < 0) {
+				fprintf(stderr, "Error: iterations must be >= 0.\n");
+				exit(1);
+			}
+			break;
+		case 'p':
+			cfg.monitor_pid = atoi(optarg);
+			if (cfg.monitor_pid < 1) {
+				fprintf(stderr, "Error: pid must be >= 1.\n");
+				exit(1);
+			}
+			break;
+		case 'o':
+			cfg.output_one_time = 1;
+			break;
+		case 'P':
+			cfg.max_processes = atoi(optarg);
+			if (cfg.max_processes < 1) {
+				fprintf(stderr, "Error: processes must be >= 1.\n");
+				exit(1);
+			}
+			if (cfg.max_processes > MAX_TASKS) {
+				fprintf(stderr, "Warning: processes capped to %d.\n",
+					MAX_TASKS);
+				cfg.max_processes = MAX_TASKS;
+			}
+			break;
+		case 'C':
+			cfg.container_path = strdup(optarg);
+			break;
+		default:
+			fprintf(stderr, "Try 'delaytop --help' for more information.\n");
+			exit(1);
+		}
+	}
+}
+
+/* Create a raw netlink socket and bind */
+static int create_nl_socket(void)
+{
+	int fd;
+	struct sockaddr_nl local;
+
+	fd = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC);
+	if (fd < 0)
+		return -1;
+
+	memset(&local, 0, sizeof(local));
+	local.nl_family = AF_NETLINK;
+
+	if (bind(fd, (struct sockaddr *) &local, sizeof(local)) < 0) {
+		fprintf(stderr, "Failed to bind socket when create nl_socket\n");
+		close(fd);
+		return -1;
+	}
+
+	return fd;
+}
+
+/* Send a command via netlink */
+static int send_cmd(int sd, __u16 nlmsg_type, __u32 nlmsg_pid,
+			 __u8 genl_cmd, __u16 nla_type,
+			 void *nla_data, int nla_len)
+{
+	struct sockaddr_nl nladdr;
+	struct nlattr *na;
+	int r, buflen;
+	char *buf;
+
+	struct {
+		struct nlmsghdr n;
+		struct genlmsghdr g;
+		char buf[MAX_MSG_SIZE];
+	} msg;
+
+	msg.n.nlmsg_len = NLMSG_LENGTH(GENL_HDRLEN);
+	msg.n.nlmsg_type = nlmsg_type;
+	msg.n.nlmsg_flags = NLM_F_REQUEST;
+	msg.n.nlmsg_seq = 0;
+	msg.n.nlmsg_pid = nlmsg_pid;
+	msg.g.cmd = genl_cmd;
+	msg.g.version = 0x1;
+	na = (struct nlattr *) GENLMSG_DATA(&msg);
+	na->nla_type = nla_type;
+	na->nla_len = nla_len + NLA_HDRLEN;
+	memcpy(NLA_DATA(na), nla_data, nla_len);
+	msg.n.nlmsg_len += NLMSG_ALIGN(na->nla_len);
+
+	buf = (char *) &msg;
+	buflen = msg.n.nlmsg_len;
+	memset(&nladdr, 0, sizeof(nladdr));
+	nladdr.nl_family = AF_NETLINK;
+	while ((r = sendto(sd, buf, buflen, 0, (struct sockaddr *) &nladdr,
+					sizeof(nladdr))) < buflen) {
+		if (r > 0) {
+			buf += r;
+			buflen -= r;
+		} else if (errno != EAGAIN)
+			return -1;
+	}
+	return 0;
+}
+
+/* Get family ID for taskstats via netlink */
+static int get_family_id(int sd)
+{
+	struct {
+		struct nlmsghdr n;
+		struct genlmsghdr g;
+		char buf[256];
+	} ans;
+
+	int id = 0, rc;
+	struct nlattr *na;
+	int rep_len;
+	char name[100];
+
+	strncpy(name, TASKSTATS_GENL_NAME, sizeof(name) - 1);
+	name[sizeof(name) - 1] = '\0';
+	rc = send_cmd(sd, GENL_ID_CTRL, getpid(), CTRL_CMD_GETFAMILY,
+			CTRL_ATTR_FAMILY_NAME, (void *)name,
+			strlen(TASKSTATS_GENL_NAME)+1);
+	if (rc < 0) {
+		fprintf(stderr, "Failed to send cmd for family id\n");
+		return 0;
+	}
+
+	rep_len = recv(sd, &ans, sizeof(ans), 0);
+	if (ans.n.nlmsg_type == NLMSG_ERROR ||
+		(rep_len < 0) || !NLMSG_OK((&ans.n), rep_len)) {
+		fprintf(stderr, "Failed to receive response for family id\n");
+		return 0;
+	}
+
+	na = (struct nlattr *) GENLMSG_DATA(&ans);
+	na = (struct nlattr *) ((char *) na + NLA_ALIGN(na->nla_len));
+	if (na->nla_type == CTRL_ATTR_FAMILY_ID)
+		id = *(__u16 *) NLA_DATA(na);
+	return id;
+}
+
+static void read_psi_stats(void)
+{
+	FILE *fp;
+	char line[256];
+	int ret = 0;
+	/* Zero all fields */
+	memset(&psi, 0, sizeof(psi));
+	/* CPU pressure */
+	fp = fopen(PSI_CPU_SOME, "r");
+	if (fp) {
+		while (fgets(line, sizeof(line), fp)) {
+			if (strncmp(line, "some", 4) == 0) {
+				ret = sscanf(line, "some avg10=%lf avg60=%lf avg300=%lf total=%llu",
+							&psi.cpu_some_avg10, &psi.cpu_some_avg60,
+							&psi.cpu_some_avg300, &psi.cpu_some_total);
+				if (ret != 4)
+					fprintf(stderr, "Failed to parse CPU some PSI data\n");
+			} else if (strncmp(line, "full", 4) == 0) {
+				ret = sscanf(line, "full avg10=%lf avg60=%lf avg300=%lf total=%llu",
+						&psi.cpu_full_avg10, &psi.cpu_full_avg60,
+						&psi.cpu_full_avg300, &psi.cpu_full_total);
+				if (ret != 4)
+					fprintf(stderr, "Failed to parse CPU full PSI data\n");
+			}
+		}
+		fclose(fp);
+	}
+	/* Memory pressure */
+	fp = fopen(PSI_MEMORY_SOME, "r");
+	if (fp) {
+		while (fgets(line, sizeof(line), fp)) {
+			if (strncmp(line, "some", 4) == 0) {
+				ret = sscanf(line, "some avg10=%lf avg60=%lf avg300=%lf total=%llu",
+						&psi.memory_some_avg10, &psi.memory_some_avg60,
+						&psi.memory_some_avg300, &psi.memory_some_total);
+				if (ret != 4)
+					fprintf(stderr, "Failed to parse Memory some PSI data\n");
+			} else if (strncmp(line, "full", 4) == 0) {
+				ret = sscanf(line, "full avg10=%lf avg60=%lf avg300=%lf total=%llu",
+						&psi.memory_full_avg10, &psi.memory_full_avg60,
+						&psi.memory_full_avg300, &psi.memory_full_total);
+			}
+				if (ret != 4)
+					fprintf(stderr, "Failed to parse Memory full PSI data\n");
+		}
+		fclose(fp);
+	}
+	/* IO pressure */
+	fp = fopen(PSI_IO_SOME, "r");
+	if (fp) {
+		while (fgets(line, sizeof(line), fp)) {
+			if (strncmp(line, "some", 4) == 0) {
+				ret = sscanf(line, "some avg10=%lf avg60=%lf avg300=%lf total=%llu",
+						&psi.io_some_avg10, &psi.io_some_avg60,
+						&psi.io_some_avg300, &psi.io_some_total);
+				if (ret != 4)
+					fprintf(stderr, "Failed to parse IO some PSI data\n");
+			} else if (strncmp(line, "full", 4) == 0) {
+				ret = sscanf(line, "full avg10=%lf avg60=%lf avg300=%lf total=%llu",
+						&psi.io_full_avg10, &psi.io_full_avg60,
+						&psi.io_full_avg300, &psi.io_full_total);
+				if (ret != 4)
+					fprintf(stderr, "Failed to parse IO full PSI data\n");
+			}
+		}
+		fclose(fp);
+	}
+	/* IRQ pressure (only full) */
+	fp = fopen(PSI_IRQ_FULL, "r");
+	if (fp) {
+		while (fgets(line, sizeof(line), fp)) {
+			if (strncmp(line, "full", 4) == 0) {
+				ret = sscanf(line, "full avg10=%lf avg60=%lf avg300=%lf total=%llu",
+						&psi.irq_full_avg10, &psi.irq_full_avg60,
+						&psi.irq_full_avg300, &psi.irq_full_total);
+				if (ret != 4)
+					fprintf(stderr, "Failed to parse IRQ full PSI data\n");
+			}
+		}
+		fclose(fp);
+	}
+}
+
+static int read_comm(int pid, char *comm_buf, size_t buf_size)
+{
+	char path[64];
+	int ret = -1;
+	size_t len;
+	FILE *fp;
+
+	snprintf(path, sizeof(path), "/proc/%d/comm", pid);
+	fp = fopen(path, "r");
+	if (!fp) {
+		fprintf(stderr, "Failed to open comm file /proc/%d/comm\n", pid);
+		return ret;
+	}
+
+	if (fgets(comm_buf, buf_size, fp)) {
+		len = strlen(comm_buf);
+		if (len > 0 && comm_buf[len - 1] == '\n')
+			comm_buf[len - 1] = '\0';
+		ret = 0;
+	}
+
+	fclose(fp);
+
+	return ret;
+}
+
+static void fetch_and_fill_task_info(int pid, const char *comm)
+{
+	struct {
+		struct nlmsghdr n;
+		struct genlmsghdr g;
+		char buf[MAX_MSG_SIZE];
+	} resp;
+	struct taskstats stats;
+	struct nlattr *nested;
+	struct nlattr *na;
+	int nested_len;
+	int nl_len;
+	int rc;
+
+	/* Send request for task stats */
+	if (send_cmd(nl_sd, family_id, getpid(), TASKSTATS_CMD_GET,
+				 TASKSTATS_CMD_ATTR_PID, &pid, sizeof(pid)) < 0) {
+		fprintf(stderr, "Failed to send request for task stats\n");
+		return;
+	}
+
+	/* Receive response */
+	rc = recv(nl_sd, &resp, sizeof(resp), 0);
+	if (rc < 0 || resp.n.nlmsg_type == NLMSG_ERROR) {
+		fprintf(stderr, "Failed to receive response for task stats\n");
+		return;
+	}
+
+	/* Parse response */
+	nl_len = GENLMSG_PAYLOAD(&resp.n);
+	na = (struct nlattr *) GENLMSG_DATA(&resp);
+	while (nl_len > 0) {
+		if (na->nla_type == TASKSTATS_TYPE_AGGR_PID) {
+			nested = (struct nlattr *) NLA_DATA(na);
+			nested_len = NLA_PAYLOAD(na->nla_len);
+			while (nested_len > 0) {
+				if (nested->nla_type == TASKSTATS_TYPE_STATS) {
+					memcpy(&stats, NLA_DATA(nested), sizeof(stats));
+					if (task_count < MAX_TASKS) {
+						tasks[task_count].pid = pid;
+						tasks[task_count].tgid = pid;
+						strncpy(tasks[task_count].command, comm,
+							TASK_COMM_LEN - 1);
+						tasks[task_count].command[TASK_COMM_LEN - 1] = '\0';
+						SET_TASK_STAT(task_count, cpu_count);
+						SET_TASK_STAT(task_count, cpu_delay_total);
+						SET_TASK_STAT(task_count, blkio_count);
+						SET_TASK_STAT(task_count, blkio_delay_total);
+						SET_TASK_STAT(task_count, swapin_count);
+						SET_TASK_STAT(task_count, swapin_delay_total);
+						SET_TASK_STAT(task_count, freepages_count);
+						SET_TASK_STAT(task_count, freepages_delay_total);
+						SET_TASK_STAT(task_count, thrashing_count);
+						SET_TASK_STAT(task_count, thrashing_delay_total);
+						SET_TASK_STAT(task_count, compact_count);
+						SET_TASK_STAT(task_count, compact_delay_total);
+						SET_TASK_STAT(task_count, wpcopy_count);
+						SET_TASK_STAT(task_count, wpcopy_delay_total);
+						SET_TASK_STAT(task_count, irq_count);
+						SET_TASK_STAT(task_count, irq_delay_total);
+						task_count++;
+					}
+					break;
+				}
+				nested_len -= NLA_ALIGN(nested->nla_len);
+				nested = NLA_NEXT(nested);
+			}
+		}
+		nl_len -= NLA_ALIGN(na->nla_len);
+		na = NLA_NEXT(na);
+	}
+	return;
+}
+
+static void get_task_delays(void)
+{
+	char comm[TASK_COMM_LEN];
+	struct dirent *entry;
+	DIR *dir;
+	int pid;
+
+	task_count = 0;
+	if (cfg.monitor_pid > 0) {
+		if (read_comm(cfg.monitor_pid, comm, sizeof(comm)) == 0)
+			fetch_and_fill_task_info(cfg.monitor_pid, comm);
+		return;
+	}
+
+	dir = opendir("/proc");
+	if (!dir) {
+		fprintf(stderr, "Error opening /proc directory\n");
+		return;
+	}
+
+	while ((entry = readdir(dir)) != NULL && task_count < MAX_TASKS) {
+		if (!isdigit(entry->d_name[0]))
+			continue;
+		pid = atoi(entry->d_name);
+		if (pid == 0)
+			continue;
+		if (read_comm(pid, comm, sizeof(comm)) != 0)
+			continue;
+		fetch_and_fill_task_info(pid, comm);
+	}
+	closedir(dir);
+}
+
+/* Calculate average delay in milliseconds */
+static double average_ms(unsigned long long total, unsigned long long count)
+{
+	if (count == 0)
+		return 0;
+	return (double)total / 1000000.0 / count;
+}
+
+/* Comparison function for sorting tasks */
+static int compare_tasks(const void *a, const void *b)
+{
+	const struct task_info *t1 = (const struct task_info *)a;
+	const struct task_info *t2 = (const struct task_info *)b;
+	double avg1, avg2;
+
+	switch (cfg.sort_field) {
+	case 'c': /* CPU */
+		avg1 = average_ms(t1->cpu_delay_total, t1->cpu_count);
+		avg2 = average_ms(t2->cpu_delay_total, t2->cpu_count);
+		if (avg1 != avg2)
+			return avg2 > avg1 ? 1 : -1;
+		return t2->cpu_delay_total > t1->cpu_delay_total ? 1 : -1;
+
+	default:
+		return t2->cpu_delay_total > t1->cpu_delay_total ? 1 : -1;
+	}
+}
+
+/* Sort tasks by selected field */
+static void sort_tasks(void)
+{
+	if (task_count > 0)
+		qsort(tasks, task_count, sizeof(struct task_info), compare_tasks);
+}
+
+/* Get container statistics via cgroupstats */
+static void get_container_stats(void)
+{
+	int rc, cfd;
+	struct {
+		struct nlmsghdr n;
+		struct genlmsghdr g;
+		char buf[MAX_MSG_SIZE];
+	} req, resp;
+	struct nlattr *na;
+	int nl_len;
+	struct cgroupstats stats;
+
+	/* Check if container path is set */
+	if (!cfg.container_path)
+		return;
+
+	/* Open container cgroup */
+	cfd = open(cfg.container_path, O_RDONLY);
+	if (cfd < 0) {
+		fprintf(stderr, "Error opening container path: %s\n", cfg.container_path);
+		return;
+	}
+
+	/* Send request for container stats */
+	if (send_cmd(nl_sd, family_id, getpid(), CGROUPSTATS_CMD_GET,
+				CGROUPSTATS_CMD_ATTR_FD, &cfd, sizeof(__u32)) < 0) {
+		fprintf(stderr, "Failed to send request for container stats\n");
+		close(cfd);
+		return;
+	}
+
+	/* Receive response */
+	rc = recv(nl_sd, &resp, sizeof(resp), 0);
+	if (rc < 0 || resp.n.nlmsg_type == NLMSG_ERROR) {
+		fprintf(stderr, "Failed to receive response for container stats\n");
+		close(cfd);
+		return;
+	}
+
+	/* Parse response */
+	nl_len = GENLMSG_PAYLOAD(&resp.n);
+	na = (struct nlattr *) GENLMSG_DATA(&resp);
+	while (nl_len > 0) {
+		if (na->nla_type == CGROUPSTATS_TYPE_CGROUP_STATS) {
+			/* Get the cgroupstats structure */
+			memcpy(&stats, NLA_DATA(na), sizeof(stats));
+
+			/* Fill container stats */
+			container_stats.nr_sleeping = stats.nr_sleeping;
+			container_stats.nr_running = stats.nr_running;
+			container_stats.nr_stopped = stats.nr_stopped;
+			container_stats.nr_uninterruptible = stats.nr_uninterruptible;
+			container_stats.nr_io_wait = stats.nr_io_wait;
+			break;
+		}
+		nl_len -= NLA_ALIGN(na->nla_len);
+		na = (struct nlattr *) ((char *) na + NLA_ALIGN(na->nla_len));
+	}
+
+	close(cfd);
+}
+
+/* Display results to stdout or log file */
+static void display_results(void)
+{
+	time_t now = time(NULL);
+	struct tm *tm_now = localtime(&now);
+	FILE *out = stdout;
+	char timestamp[32];
+	bool suc = true;
+	int i, count;
+
+	/* Clear terminal screen */
+	suc &= BOOL_FPRINT(out, "\033[H\033[J");
+
+	/* PSI output (one-line, no cat style) */
+	suc &= BOOL_FPRINT(out, "System Pressure Information: (avg10/avg60/avg300/total)\n");
+	suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
+		"CPU some:",
+		psi.cpu_some_avg10,
+		psi.cpu_some_avg60,
+		psi.cpu_some_avg300,
+		psi.cpu_some_total / 1000);
+	suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
+		"CPU full:",
+		psi.cpu_full_avg10,
+		psi.cpu_full_avg60,
+		psi.cpu_full_avg300,
+		psi.cpu_full_total / 1000);
+	suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
+		"Memory full:",
+		psi.memory_full_avg10,
+		psi.memory_full_avg60,
+		psi.memory_full_avg300,
+		psi.memory_full_total / 1000);
+	suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
+		"Memory some:",
+		psi.memory_some_avg10,
+		psi.memory_some_avg60,
+		psi.memory_some_avg300,
+		psi.memory_some_total / 1000);
+	suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
+		"IO full:",
+		psi.io_full_avg10,
+		psi.io_full_avg60,
+		psi.io_full_avg300,
+		psi.io_full_total / 1000);
+	suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
+		"IO some:",
+		psi.io_some_avg10,
+		psi.io_some_avg60,
+		psi.io_some_avg300,
+		psi.io_some_total / 1000);
+	suc &= BOOL_FPRINT(out, PSI_LINE_FORMAT,
+		"IRQ full:",
+		psi.irq_full_avg10,
+		psi.irq_full_avg60,
+		psi.irq_full_avg300,
+		psi.irq_full_total / 1000);
+
+	if (cfg.container_path) {
+		suc &= BOOL_FPRINT(out, "Container Information (%s):\n", cfg.container_path);
+		suc &= BOOL_FPRINT(out, "Processes: running=%d, sleeping=%d, ",
+			container_stats.nr_running, container_stats.nr_sleeping);
+		suc &= BOOL_FPRINT(out, "stopped=%d, uninterruptible=%d, io_wait=%d\n\n",
+			container_stats.nr_stopped, container_stats.nr_uninterruptible,
+			container_stats.nr_io_wait);
+	}
+	suc &= BOOL_FPRINT(out, "Top %d processes (sorted by CPU delay):\n",
+			cfg.max_processes);
+	suc &= BOOL_FPRINT(out, "%5s  %5s  %-17s", "PID", "TGID", "COMMAND");
+	suc &= BOOL_FPRINT(out, "%7s %7s %7s %7s %7s %7s %7s %7s\n",
+		"CPU(ms)", "IO(ms)", "SWAP(ms)", "RCL(ms)",
+		"THR(ms)", "CMP(ms)", "WP(ms)", "IRQ(ms)");
+
+	suc &= BOOL_FPRINT(out, "-----------------------------------------------");
+	suc &= BOOL_FPRINT(out, "----------------------------------------------\n");
+	count = task_count < cfg.max_processes ? task_count : cfg.max_processes;
+
+	for (i = 0; i < count; i++) {
+		suc &= BOOL_FPRINT(out, "%5d  %5d  %-15s",
+			tasks[i].pid, tasks[i].tgid, tasks[i].command);
+		suc &= BOOL_FPRINT(out, "%7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f %7.2f\n",
+			average_ms(tasks[i].cpu_delay_total, tasks[i].cpu_count),
+			average_ms(tasks[i].blkio_delay_total, tasks[i].blkio_count),
+			average_ms(tasks[i].swapin_delay_total, tasks[i].swapin_count),
+			average_ms(tasks[i].freepages_delay_total, tasks[i].freepages_count),
+			average_ms(tasks[i].thrashing_delay_total, tasks[i].thrashing_count),
+			average_ms(tasks[i].compact_delay_total, tasks[i].compact_count),
+			average_ms(tasks[i].wpcopy_delay_total, tasks[i].wpcopy_count),
+			average_ms(tasks[i].irq_delay_total, tasks[i].irq_count));
+	}
+
+	suc &= BOOL_FPRINT(out, "\n");
+
+	if (!suc)
+		perror("Error writing to output");
+}
+
+/* Main function */
+int main(int argc, char **argv)
+{
+	int iterations = 0;
+	int use_q_quit = 0;
+
+	/* Parse command line arguments */
+	parse_args(argc, argv);
+
+	/* Setup netlink socket */
+	nl_sd = create_nl_socket();
+	if (nl_sd < 0) {
+		fprintf(stderr, "Error creating netlink socket\n");
+		exit(1);
+	}
+
+	/* Get family ID for taskstats via netlink */
+	family_id = get_family_id(nl_sd);
+	if (!family_id) {
+		fprintf(stderr, "Error getting taskstats family ID\n");
+		close(nl_sd);
+		exit(1);
+	}
+
+	if (!cfg.output_one_time) {
+		use_q_quit = 1;
+		enable_raw_mode();
+		printf("Press 'q' to quit.\n");
+		fflush(stdout);
+	}
+
+	/* Main loop */
+	while (running) {
+		/* Read PSI statistics */
+		read_psi_stats();
+
+		/* Get container stats if container path provided */
+		if (cfg.container_path)
+			get_container_stats();
+
+		/* Get task delays */
+		get_task_delays();
+
+		/* Sort tasks */
+		sort_tasks();
+
+		/* Display results to stdout or log file */
+		display_results();
+
+		/* Check for iterations */
+		if (cfg.iterations > 0 && ++iterations >= cfg.iterations)
+			break;
+
+		/* Exit if output_one_time is set */
+		if (cfg.output_one_time)
+			break;
+
+		/* Check for 'q' key to quit */
+		if (use_q_quit) {
+			struct timeval tv = {cfg.delay, 0};
+			fd_set readfds;
+
+			FD_ZERO(&readfds);
+			FD_SET(STDIN_FILENO, &readfds);
+			int r = select(STDIN_FILENO+1, &readfds, NULL, NULL, &tv);
+
+			if (r > 0 && FD_ISSET(STDIN_FILENO, &readfds)) {
+				char ch = 0;
+
+				read(STDIN_FILENO, &ch, 1);
+				if (ch == 'q' || ch == 'Q') {
+					running = 0;
+					break;
+				}
+			}
+		} else {
+			sleep(cfg.delay);
+		}
+	}
+
+	/* Restore terminal mode */
+	if (use_q_quit)
+		disable_raw_mode();
+
+	/* Cleanup */
+	close(nl_sd);
+	if (cfg.container_path)
+		free(cfg.container_path);
+
+	return 0;
+}

tools/accounting/getdelays.c

@@ -194,75 +194,108 @@ static int get_family_id(int sd)
 #define average_ms(t, c) (t / 1000000ULL / (c ? c : 1))
 #define delay_ms(t) (t / 1000000ULL)
 
+/*
+ * Version compatibility note:
+ * Field availability depends on taskstats version (t->version),
+ * corresponding to TASKSTATS_VERSION in kernel headers
+ * see include/uapi/linux/taskstats.h
+ *
+ * Version feature mapping:
+ * version >= 11  - supports COMPACT statistics
+ * version >= 13  - supports WPCOPY statistics
+ * version >= 14  - supports IRQ statistics
+ * version >= 16  - supports *_max and *_min delay statistics
+ *
+ * Always verify version before accessing version-dependent fields
+ * to maintain backward compatibility.
+ */
+#define PRINT_CPU_DELAY(version, t) \
+	do { \
+		if (version >= 16) { \
+			printf("%-10s%15s%15s%15s%15s%15s%15s%15s\n", \
+				"CPU", "count", "real total", "virtual total", \
+				"delay total", "delay average", "delay max", "delay min"); \
+			printf("          %15llu%15llu%15llu%15llu%15.3fms%13.6fms%13.6fms\n", \
+				(unsigned long long)(t)->cpu_count, \
+				(unsigned long long)(t)->cpu_run_real_total, \
+				(unsigned long long)(t)->cpu_run_virtual_total, \
+				(unsigned long long)(t)->cpu_delay_total, \
+				average_ms((double)(t)->cpu_delay_total, (t)->cpu_count), \
+				delay_ms((double)(t)->cpu_delay_max), \
+				delay_ms((double)(t)->cpu_delay_min)); \
+		} else { \
+			printf("%-10s%15s%15s%15s%15s%15s\n", \
+				"CPU", "count", "real total", "virtual total", \
+				"delay total", "delay average"); \
+			printf("          %15llu%15llu%15llu%15llu%15.3fms\n", \
+				(unsigned long long)(t)->cpu_count, \
+				(unsigned long long)(t)->cpu_run_real_total, \
+				(unsigned long long)(t)->cpu_run_virtual_total, \
+				(unsigned long long)(t)->cpu_delay_total, \
+				average_ms((double)(t)->cpu_delay_total, (t)->cpu_count)); \
+		} \
+	} while (0)
+#define PRINT_FILED_DELAY(name, version, t, count, total, max, min) \
+	do { \
+		if (version >= 16) { \
+			printf("%-10s%15s%15s%15s%15s%15s\n", \
+				name, "count", "delay total", "delay average", \
+				"delay max", "delay min"); \
+			printf("          %15llu%15llu%15.3fms%13.6fms%13.6fms\n", \
+				(unsigned long long)(t)->count, \
+				(unsigned long long)(t)->total, \
+				average_ms((double)(t)->total, (t)->count), \
+				delay_ms((double)(t)->max), \
+				delay_ms((double)(t)->min)); \
+		} else { \
+			printf("%-10s%15s%15s%15s\n", \
+				name, "count", "delay total", "delay average"); \
+			printf("          %15llu%15llu%15.3fms\n", \
+				(unsigned long long)(t)->count, \
+				(unsigned long long)(t)->total, \
+				average_ms((double)(t)->total, (t)->count)); \
+		} \
+	} while (0)
+
 static void print_delayacct(struct taskstats *t)
 {
-	printf("\n\nCPU   %15s%15s%15s%15s%15s%15s%15s\n"
+	printf("\n\n");
-	       "      %15llu%15llu%15llu%15llu%15.3fms%13.6fms%13.6fms\n"
+
-	       "IO    %15s%15s%15s%15s%15s\n"
+	PRINT_CPU_DELAY(t->version, t);
-	       "      %15llu%15llu%15.3fms%13.6fms%13.6fms\n"
+
-	       "SWAP  %15s%15s%15s%15s%15s\n"
+	PRINT_FILED_DELAY("IO", t->version, t,
-	       "      %15llu%15llu%15.3fms%13.6fms%13.6fms\n"
+		blkio_count, blkio_delay_total,
-	       "RECLAIM  %12s%15s%15s%15s%15s\n"
+		blkio_delay_max, blkio_delay_min);
-	       "      %15llu%15llu%15.3fms%13.6fms%13.6fms\n"
+
-	       "THRASHING%12s%15s%15s%15s%15s\n"
+	PRINT_FILED_DELAY("SWAP", t->version, t,
-	       "      %15llu%15llu%15.3fms%13.6fms%13.6fms\n"
+		swapin_count, swapin_delay_total,
-	       "COMPACT  %12s%15s%15s%15s%15s\n"
+		swapin_delay_max, swapin_delay_min);
-	       "      %15llu%15llu%15.3fms%13.6fms%13.6fms\n"
+
-	       "WPCOPY   %12s%15s%15s%15s%15s\n"
+	PRINT_FILED_DELAY("RECLAIM", t->version, t,
-	       "      %15llu%15llu%15.3fms%13.6fms%13.6fms\n"
+		freepages_count, freepages_delay_total,
-	       "IRQ   %15s%15s%15s%15s%15s\n"
+		freepages_delay_max, freepages_delay_min);
-	       "      %15llu%15llu%15.3fms%13.6fms%13.6fms\n",
+
-	       "count", "real total", "virtual total",
+	PRINT_FILED_DELAY("THRASHING", t->version, t,
-	       "delay total", "delay average", "delay max", "delay min",
+		thrashing_count, thrashing_delay_total,
-	       (unsigned long long)t->cpu_count,
+		thrashing_delay_max, thrashing_delay_min);
-	       (unsigned long long)t->cpu_run_real_total,
+
-	       (unsigned long long)t->cpu_run_virtual_total,
+	if (t->version >= 11) {
-	       (unsigned long long)t->cpu_delay_total,
+		PRINT_FILED_DELAY("COMPACT", t->version, t,
-	       average_ms((double)t->cpu_delay_total, t->cpu_count),
+			compact_count, compact_delay_total,
-	       delay_ms((double)t->cpu_delay_max),
+			compact_delay_max, compact_delay_min);
-	       delay_ms((double)t->cpu_delay_min),
+	}
-	       "count", "delay total", "delay average", "delay max", "delay min",
+
-	       (unsigned long long)t->blkio_count,
+	if (t->version >= 13) {
-	       (unsigned long long)t->blkio_delay_total,
+		PRINT_FILED_DELAY("WPCOPY", t->version, t,
-	       average_ms((double)t->blkio_delay_total, t->blkio_count),
+			wpcopy_count, wpcopy_delay_total,
-	       delay_ms((double)t->blkio_delay_max),
+			wpcopy_delay_max, wpcopy_delay_min);
-	       delay_ms((double)t->blkio_delay_min),
+	}
-	       "count", "delay total", "delay average", "delay max", "delay min",
+
-	       (unsigned long long)t->swapin_count,
+	if (t->version >= 14) {
-	       (unsigned long long)t->swapin_delay_total,
+		PRINT_FILED_DELAY("IRQ", t->version, t,
-	       average_ms((double)t->swapin_delay_total, t->swapin_count),
+			irq_count, irq_delay_total,
-	       delay_ms((double)t->swapin_delay_max),
+			irq_delay_max, irq_delay_min);
-	       delay_ms((double)t->swapin_delay_min),
+	}
-	       "count", "delay total", "delay average", "delay max", "delay min",
-	       (unsigned long long)t->freepages_count,
-	       (unsigned long long)t->freepages_delay_total,
-	       average_ms((double)t->freepages_delay_total, t->freepages_count),
-	       delay_ms((double)t->freepages_delay_max),
-	       delay_ms((double)t->freepages_delay_min),
-	       "count", "delay total", "delay average", "delay max", "delay min",
-	       (unsigned long long)t->thrashing_count,
-	       (unsigned long long)t->thrashing_delay_total,
-	       average_ms((double)t->thrashing_delay_total, t->thrashing_count),
-	       delay_ms((double)t->thrashing_delay_max),
-	       delay_ms((double)t->thrashing_delay_min),
-	       "count", "delay total", "delay average", "delay max", "delay min",
-	       (unsigned long long)t->compact_count,
-	       (unsigned long long)t->compact_delay_total,
-	       average_ms((double)t->compact_delay_total, t->compact_count),
-	       delay_ms((double)t->compact_delay_max),
-	       delay_ms((double)t->compact_delay_min),
-	       "count", "delay total", "delay average", "delay max", "delay min",
-	       (unsigned long long)t->wpcopy_count,
-	       (unsigned long long)t->wpcopy_delay_total,
-	       average_ms((double)t->wpcopy_delay_total, t->wpcopy_count),
-	       delay_ms((double)t->wpcopy_delay_max),
-	       delay_ms((double)t->wpcopy_delay_min),
-	       "count", "delay total", "delay average", "delay max", "delay min",
-	       (unsigned long long)t->irq_count,
-	       (unsigned long long)t->irq_delay_total,
-	       average_ms((double)t->irq_delay_total, t->irq_count),
-	       delay_ms((double)t->irq_delay_max),
-	       delay_ms((double)t->irq_delay_min));
 }
 
 static void task_context_switch_counts(struct taskstats *t)