This issue came up recently in a bug report[1]; without the error code,
users can barely guess why the function failed.
[1] <https://bugs.php.net/80812>
Closes GH-6745.
The `zend_system_id` is a (true global) system ID that fingerprints a process state. When extensions add engine hooks during MINIT/startup, entropy is added the system ID for each hook. This allows extensions to identify that changes have been made to the engine since the last PHP process restart.
Closes GH-5871
Instead of storing the mapping base address and the address of
`execute_ex()` in a separate file in the temporary folder, we store
them right at the beginning of the memory mapping.
This reverts commit e1f6ab3388, reversing
changes made to e0ebe56ebf.
There are obviously issues with running tests in parallel, maybe
related to the cache ID. This needs to be investigated. Revert for
now.
Instead of storing the mapping base address and the address of
`execute_ex()` in a separate file in the temporary folder, we store
them right at the beginning of the memory mapping.
We must not use the same shared memory OPcache instance for different
SAPIs, since their memory layout is different. To avoid this, we add
the SAPI name (truncated to at most 20 characters) to the names of the
memory base file, the mutex and the file mapping.
Opcache stores `opline->handler`s in shared memory. These pointers are
invalid, if the main PHP DLL is loaded at another base address due to
ASLR. We therefore store the address of `execute_ex` in the mmap base
file, and check on startup whether it matches its current address. If
not, we fall back on the file cache if enabled, and bail out otherwise.
This still does not address cases where the opline handler is located
inside of another DLL (e.g. for some profilers, debuggers), but there
seems to be no general solution for now.
(cherry picked from commit 8ba10b8fbc)
Formerly, there was at most a single OPcache instance per user and the
so called system ID (which is determined from the PHP version).
Sometimes multiple OPcaches might be desired, though, particularly for
unrelated CLI scripts, which may even be necessary (e.g. for our test
suite in parallel mode).
We therefore introduce a new INI directive `opcache.cache_id` which
allows to configure independent OPcache instances for the same user.
We also use `GetUserNameW()` instead of `php_win32_get_username()`,
because the latter retrieves the user name encoded in the
`default_charset`, which can obviously yield different results for
different charsets, leading to OPcache "incompatibilities". Slightly
worse, some characters may not even be encodeable in the
`default_charset` and would be replaced by question marks, which could
result in different users sharing the same OPcache.
We also refactor, and re-use existing APIs to avoid duplicated code.
Opcache stores `opline->handler`s in shared memory. These pointers are
invalid, if the main PHP DLL is loaded at another base address due to
ASLR. We therefore store the address of `execute_ex` in the mmap base
file, and check on startup whether it matches its current address. If
not, we fall back on the file cache if enabled, and bail out otherwise.
This still does not address cases where the opline handler is located
inside of another DLL (e.g. for some profilers, debuggers), but there
seems to be no general solution for now.
The FormatMessage API needs to LocalFree the delivered error messages.
In cases where messages are delivered in non ASCII compatible encoding,
the messages might be unreadable. This aligns the error message encoding
with the encoding settings in PHP, the focus is UTF-8 as default.
Initialize error buffer
Avoid code duplication
Since long the default PHP charset is UTF-8, however the Windows part is
out of step with this important point. The current implementation in PHP
doesn't technically permit to handle UTF-8 filepath and several other
things. Till now, only the ANSI compatible APIs are being used. Here is more
about it
dd317752%28v=vs.85%29.aspx
The patch fixes not only issues with multibyte filenames under
incompatible codepages, but indirectly also issues with some other multibyte
encodings like BIG5, Shift-JIS, etc. by providing a clean way to access
filenames in UTF-8. Below is a small list of issues from the bug tracker,
that are getting fixed:
https://bugs.php.net/63401https://bugs.php.net/41199https://bugs.php.net/50203https://bugs.php.net/71509https://bugs.php.net/64699https://bugs.php.net/64506https://bugs.php.net/30195https://bugs.php.net/65358https://bugs.php.net/61315https://bugs.php.net/70943https://bugs.php.net/70903https://bugs.php.net/63593https://bugs.php.net/54977https://bugs.php.net/54028https://bugs.php.net/43148https://bugs.php.net/30730https://bugs.php.net/33350https://bugs.php.net/35300https://bugs.php.net/46990https://bugs.php.net/61309https://bugs.php.net/69333https://bugs.php.net/45517https://bugs.php.net/70551https://bugs.php.net/50197https://bugs.php.net/72200https://bugs.php.net/37672
Yet more related tickets can for sure be found - on bugs.php.net, Stackoverflow
and Github. Some of the bugs are pretty recent, some descend to early
2000th, but the user comments in there last even till today. Just for example,
bug #30195 was opened in 2004, the latest comment in there was made in 2014. It
is certain, that these bugs descend not only to pure PHP use cases, but get also
redirected from the popular PHP based projects. Given the modern systems (and
those supported by PHP) are always based on NTFS, there is no excuse to keep
these issues unresolved.
The internalization approach on Windows is in many ways different from
UNIX and Linux, while it supports and is based on Unicode. It depends on the
current system code page, APIs used and exact kind how the binary was compiled
The locale doesn't affect the way Unicode or ANSI API work. PHP in particular
is being compiled without _UNICODE defined and this is conditioned by the
way we handle strings. Here is more about it
https://msdn.microsoft.com/en-us/library/tsbaswba.aspx
However, with any system code page ANSI functions automatically convert
paths to UTF-16. Paths in some encodings incompatible with the
current system code page, won't work correctly with ANSI APIs. PHP
till now only uses the ANSI Windows APIs.
For example, on a system with the current code page 1252, the paths
in cp1252 are supported and transparently converted to UTF-16 by the
ANSI functions. Once one wants to handle a filepath encoded with cp932 on
that particular system, an ANSI or a POSIX compatible function used in
PHP will produce an erroneous result. When trying to convert that cp932 path
to UTF-8 and passing to the ANSI functions, an ANSI function would
likely interpret the UTF-8 string as some string in the current code page and
create a filepath that represents every single byte of the UTF-8 string.
These behaviors are not only broken but also disregard the documented
INI settings.
This patch solves the issies with the multibyte paths on Windows by
intelligently enforcing the usage of the Unicode aware APIs. For
functions expect Unicode (fe CreateFileW, FindFirstFileW, etc.), arguments
will be converted to UTF-16 wide chars. For functions returning Unicode
aware data (fe GetCurrentDirectoryW, etc.), resulting wide string is
converted back to char's depending on the current PHP charset settings,
either to the current ANSI codepage (this is the behavior prior to this patch)
or to UTF-8 (the default behavior).
In a particular case, users might have to explicitly set
internal_encoding or default_charset, if filenames in ANSI codepage are
necessary. Current tests show no regressions and witness that this will be an
exotic case, the current default UTF-8 encoding is compatible with any
supported system. The dependency libraries are long switching to Unicode APIs,
so some tests were also added for extensions not directly related to streams.
At large, the patch brings over 150 related tests into the core. Those target
and was run on various environments with European, Asian, etc. codepages.
General PHP frameworks was tested and showed no regressions.
The impact on the current C code base is low, the most places affected
are the Windows only places in the three files tsrm_win32.c, zend_virtual_cwd.c
and plain_wrapper.c. The actual implementation of the most of the wide
char supporting functionality is in win32/ioutil.* and win32/codepage.*,
several low level functionsare extended in place to avoid reimplementation for
now. No performance impact was sighted. As previously mentioned, the ANSI APIs
used prior the patch perform Unicode conversions internally. Using the
Unicode APIs directly while doing custom conversions just retains the status
quo. The ways to optimize it are open (fe. by implementing caching for the
strings converted to wide variants).
The long path implementation is user transparent. If a path exceeds the
length of _MAX_PATH, it'll be automatically prefixed with \\?\. The MAXPATHLEN
is set to 2048 bytes.
Appreciation to Pierre Joye, Matt Ficken, @algo13 and others for tips, ideas
and testing.
Thanks.
which is essential as an attempt to fix the "failed to reattach"
error on Windows. If file_cache is enabled, Opcache will
automaticaly switch to file_cache_only mode in the case a process
failed to map the shared segment at the required address. The
important small part of the SHM will still be mapped, which
allows information exchange between normal processes using SHM
and those using the fallback mechanism.
This is based on Dmitry's, Matt's and mine ideas. So many thanks for
support!
