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8144343: [aix] Stack bottom should be page aligned

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On thread create or attach, ensure stack bottom is aligned to os::vm_page_size()

Reviewed-by: simonis, kvn
This commit is contained in:
Thomas Stuefe 2015-12-02 10:17:31 +01:00
parent 57b477e21a
commit f06c0a7041
1 changed files with 36 additions and 27 deletions
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63
hotspot/src/os/aix/vm/os_aix.cpp
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@ -2263,8 +2263,12 @@ void os::pd_commit_memory_or_exit(char* addr, size_t size, bool exec,
bool os::pd_commit_memory(char* addr, size_t size, bool exec) {
assert0(is_aligned_to(addr, os::vm_page_size()));
assert0(is_aligned_to(size, os::vm_page_size()));
assert(is_aligned_to(addr, os::vm_page_size()),
"addr " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
p2i(addr), os::vm_page_size());
assert(is_aligned_to(size, os::vm_page_size()),
"size " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
size, os::vm_page_size());
vmembk_t* const vmi = vmembk_find(addr);
assert0(vmi);
@ -2287,8 +2291,12 @@ void os::pd_commit_memory_or_exit(char* addr, size_t size,
}
bool os::pd_uncommit_memory(char* addr, size_t size) {
assert0(is_aligned_to(addr, os::vm_page_size()));
assert0(is_aligned_to(size, os::vm_page_size()));
assert(is_aligned_to(addr, os::vm_page_size()),
"addr " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
p2i(addr), os::vm_page_size());
assert(is_aligned_to(size, os::vm_page_size()),
"size " PTR_FORMAT " not aligned to vm_page_size (" PTR_FORMAT ")",
size, os::vm_page_size());
// Dynamically do different things for mmap/shmat.
const vmembk_t* const vmi = vmembk_find(addr);
@ -4299,7 +4307,7 @@ static bool query_stack_dimensions(address* p_stack_base, size_t* p_stack_size)
pthread_t tid = pthread_self();
struct __pthrdsinfo pinfo;
char dummy[1]; // We only need this to satisfy the api and to not get E.
char dummy[1]; // Just needed to satisfy pthread_getthrds_np.
int dummy_size = sizeof(dummy);
memset(&pinfo, 0, sizeof(pinfo));
@ -4320,38 +4328,39 @@ static bool query_stack_dimensions(address* p_stack_base, size_t* p_stack_size)
// Not sure what to do here - I feel inclined to forbid this use case completely.
guarantee0(pinfo.__pi_stacksize);
// Note: the pthread stack on AIX seems to look like this:
// Note: we get three values from pthread_getthrds_np:
// __pi_stackaddr, __pi_stacksize, __pi_stackend
//
// --------------------- real base ? at page border ?
// high addr ---------------------
//
// pthread internal data, like ~2K, see also
// http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.ibm.aix.prftungd/doc/prftungd/thread_supp_tun_params.htm
// | pthread internal data, like ~2K
// |
// | --------------------- __pi_stackend (usually not page aligned, (xxxxF890))
// |
// |
// |
// |
// |
// |
// | --------------------- (__pi_stackend - __pi_stacksize)
// |
// | padding to align the following AIX guard pages, if enabled.
// |
// V --------------------- __pi_stackaddr
//
// --------------------- __pi_stackend - not page aligned, (xxxxF890)
//
// stack
// ....
//
// stack
//
// --------------------- __pi_stackend - __pi_stacksize
//
// padding due to AIX guard pages (?) see AIXTHREAD_GUARDPAGES
// --------------------- __pi_stackaddr (page aligned if AIXTHREAD_GUARDPAGES > 0)
//
// AIX guard pages (?)
// low addr AIX guard pages, if enabled (AIXTHREAD_GUARDPAGES > 0)
//
// So, the safe thing to do is to use the area from __pi_stackend to __pi_stackaddr;
// __pi_stackend however is almost never page aligned.
//
address stack_base = (address)(pinfo.__pi_stackend);
address stack_low_addr = (address)align_ptr_up(pinfo.__pi_stackaddr, os::vm_page_size());
size_t stack_size = stack_base - stack_low_addr;
if (p_stack_base) {
(*p_stack_base) = (address) (pinfo.__pi_stackend);
*p_stack_base = stack_base;
}
if (p_stack_size) {
(*p_stack_size) = pinfo.__pi_stackend - pinfo.__pi_stackaddr;
*p_stack_size = stack_size;
}
return true;