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Update.

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2004-03-26  Ulrich Drepper  <drepper@redhat.com>

	* elf/dl-caller.c: New file.
	* include/caller.h: New file.
	* Makefile (distribute): Add include/caller.h.
	* elf/Makefile (dl-routines): Add dl-caller.
	* elf/dl-load.c (_dl_map_object_from_fd): Record l_text_end.
	* elf/dl-open.c (check_libc_caller): Removed.
	(dl_open_worker): Use __check_caller instead.
	* elf/rtld.c (_rtld_global_ro): Initialize _dl_check_caller.
	(_dl_start_final): Record l_text_end for ld.so map.
	(dl_main): Record l_text_end for main object and vdso.
	* include/link.h (struct link_map): Add l_text_end field.
	* sysdeps/generic/ldsodefs.h (struct rtld_global_ro): Add
	_dl_check_caller field.
	Define enum allowmask.  Add declaration of _dl_check_caller.
	* sysdeps/unix/sysv/linux/dl-execstack.c: Also use __check_caller test.
This commit is contained in:
Ulrich Drepper
2004-03-27 03:40:33 +00:00
parent 17c263876b
commit eec8b6cae5
12 changed files with 159 additions and 79 deletions
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12
sysdeps/unix/sysv/linux/dl-execstack.c
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@ -20,8 +20,10 @@
#include <ldsodefs.h>
#include <sys/mman.h>
#include <errno.h>
#include <libintl.h>
#include <stdbool.h>
#include <stackinfo.h>
#include <caller.h>
#include "kernel-features.h"
@ -31,13 +33,14 @@ internal_function
_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
uintptr_t page = ((uintptr_t) *stack_endp
& -(intptr_t) GLRO(dl_pagesize));
/* Challenge the caller. */
if (__builtin_expect (*stack_endp != __libc_stack_end, 0))
if (__builtin_expect (__check_caller (__builtin_return_address (0),
allow_ldso|allow_libpthread) != 0, 0)
|| __builtin_expect (*stack_endp != __libc_stack_end, 0))
return EPERM;
*stack_endp = NULL;
#if _STACK_GROWS_DOWN
/* Newer Linux kernels support a flag to make our job easy. */
@ -151,6 +154,9 @@ _dl_make_stack_executable (void **stack_endp)
#endif
return_success:
/* Clear the address. */
*stack_endp = NULL;
/* Remember that we changed the permission. */
GL(dl_stack_flags) |= PF_X;