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Better description for jit-sealloc option and early check for executable memory.

This commit is contained in:
Zoltán Herczeg 2019-10-01 13:46:41 +00:00
parent 3787601f81
commit 70b0debf10
4 changed files with 28 additions and 5 deletions
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2
CMakeLists.txt
View File

@ -178,7 +178,7 @@ SET(PCRE2_SUPPORT_JIT OFF CACHE BOOL
"Enable support for Just-in-time compiling.")
SET(PCRE2_SUPPORT_JIT_SEALLOC OFF CACHE BOOL
"Enable SELinux compatible execmem allocator in JIT.")
"Enable SELinux compatible execmem allocator in JIT (experimental).")
SET(PCRE2GREP_SUPPORT_JIT ON CACHE BOOL
"Enable use of Just-in-time compiling in pcre2grep.")

8
README
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@ -164,9 +164,11 @@ library. They are also documented in the pcre2build man page.
will be a compile time error. If in doubt, use --enable-jit=auto, which
enables JIT only if the current hardware is supported.
. If you are enabling JIT under SELinux you may also want to add
--enable-jit-sealloc, which enables the use of an execmem allocator in JIT
that is compatible with SELinux. This has no effect if JIT is not enabled.
. If you are enabling JIT under SELinux environment you may also want to add
--enable-jit-sealloc, which enables the use of an executable memory allocator
that is compatible with SELinux. Warning: this allocator is experimental!
It does not support fork() operation and may crash when no disk space is
available. This option has no effect if JIT is disabled.
. If you do not want to make use of the default support for UTF-8 Unicode
character strings in the 8-bit library, UTF-16 Unicode character strings in

2
configure.ac
View File

@ -161,7 +161,7 @@ fi
# Handle --enable-jit-sealloc (disabled by default)
AC_ARG_ENABLE(jit-sealloc,
AS_HELP_STRING([--enable-jit-sealloc],
[enable SELinux compatible execmem allocator in JIT]),
[enable SELinux compatible execmem allocator in JIT (experimental)]),
, enable_jit_sealloc=no)
# Handle --disable-pcre2grep-jit (enabled by default)

21
src/pcre2_jit_compile.c
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@ -13740,12 +13740,33 @@ Returns: 0: success or (*NOJIT) was used
PCRE2_EXP_DEFN int PCRE2_CALL_CONVENTION
pcre2_jit_compile(pcre2_code *code, uint32_t options)
{
static int executable_allocator_is_working = 0;
pcre2_real_code *re = (pcre2_real_code *)code;
#ifdef SUPPORT_JIT
executable_functions *functions = (executable_functions *)re->executable_jit;
#endif
if (executable_allocator_is_working == 0)
{
/* Checks whether the executable allocator is working. This check
might run multiple times in multi-threaded environments, but the result
should not be affected by it. */
void *ptr = SLJIT_MALLOC_EXEC(32);
executable_allocator_is_working = -1;
if (ptr != NULL)
{
SLJIT_FREE_EXEC(((sljit_u8*)(ptr)) + SLJIT_EXEC_OFFSET(ptr));
executable_allocator_is_working = 1;
}
}
if (executable_allocator_is_working < 0)
return PCRE2_ERROR_NOMEMORY;
if (code == NULL)
return PCRE2_ERROR_NULL;