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(__libc_stack_end): Mark hidden. (_dl_make_stack_executable): Add one more __builtin_expect.

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This commit is contained in:
Ulrich Drepper
2004-01-13 20:18:20 +00:00
parent d1fc817ea4
commit 760bafc5aa
1 changed files with 8 additions and 11 deletions
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19
sysdeps/unix/sysv/linux/dl-execstack.c
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@ -26,21 +26,21 @@
#include "kernel-features.h" #include "kernel-features.h"
extern void *__libc_stack_end; extern void *__libc_stack_end attribute_hidden;
int int
internal_function internal_function
_dl_make_stack_executable (void **stack_endp) _dl_make_stack_executable (void **stack_endp)
{ {
/* This gives us the highest/lowest page that needs to be changed. */
uintptr_t page = (uintptr_t) __libc_stack_end & -(intptr_t) GL(dl_pagesize);
/* Challenge the caller. */ /* Challenge the caller. */
if (*stack_endp != __libc_stack_end) if (__builtin_expect (*stack_endp != __libc_stack_end, 0))
return EPERM; return EPERM;
*stack_endp = NULL; *stack_endp = NULL;
#if _STACK_GROWS_DOWN #if _STACK_GROWS_DOWN
/* This gives us the highest page that needs to be changed. */
uintptr_t page = (uintptr_t) __libc_stack_end & -(intptr_t) GL(dl_pagesize);
/* Newer Linux kernels support a flag to make our job easy. */ /* Newer Linux kernels support a flag to make our job easy. */
# ifdef PROT_GROWSDOWN # ifdef PROT_GROWSDOWN
# if __ASSUME_PROT_GROWSUPDOWN == 0 # if __ASSUME_PROT_GROWSUPDOWN == 0
@ -48,8 +48,9 @@ _dl_make_stack_executable (void **stack_endp)
if (! no_growsdown) if (! no_growsdown)
# endif # endif
{ {
if (__mprotect ((void *) page, GL(dl_pagesize), if (__builtin_expect (__mprotect ((void *) page, GL(dl_pagesize),
PROT_READ|PROT_WRITE|PROT_EXEC|PROT_GROWSDOWN) == 0) PROT_READ|PROT_WRITE|PROT_EXEC
|PROT_GROWSDOWN) == 0, 1))
goto return_success; goto return_success;
# if __ASSUME_PROT_GROWSUPDOWN == 0 # if __ASSUME_PROT_GROWSUPDOWN == 0
if (errno == EINVAL) if (errno == EINVAL)
@ -95,10 +96,6 @@ _dl_make_stack_executable (void **stack_endp)
# endif # endif
#elif _STACK_GROWS_UP #elif _STACK_GROWS_UP
/* This gives us the lowest page that needs to be changed. */
uintptr_t page = (uintptr_t) __libc_stack_end & -(intptr_t) GL(dl_pagesize);
/* Newer Linux kernels support a flag to make our job easy. */ /* Newer Linux kernels support a flag to make our job easy. */
# ifdef PROT_GROWSUP # ifdef PROT_GROWSUP
# if __ASSUME_PROT_GROWSUPDOWN == 0 # if __ASSUME_PROT_GROWSUPDOWN == 0