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authorUlrich Drepper <drepper@redhat.com>2004-09-21 02:30:50 +0000
committerUlrich Drepper <drepper@redhat.com>2004-09-21 02:30:50 +0000
commit1658cb803650b8a08e708f2b8b73613769732c7a (patch)
tree3216f0b94159cde522c7f8c189b68d3f679c9f47 /sysdeps/unix
parent3c12b91ade6e271cb17ecaae526d959bc7e40098 (diff)
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Update.
* sysdeps/unix/sysv/linux/dl-execstack.c (_dl_make_stack_executable): Remove some duplication.
Diffstat (limited to 'sysdeps/unix')
-rw-r--r--sysdeps/unix/sysv/linux/dl-execstack.c63
1 files changed, 17 insertions, 46 deletions
diff --git a/sysdeps/unix/sysv/linux/dl-execstack.c b/sysdeps/unix/sysv/linux/dl-execstack.c
index 97ff5d0e62..6ef9679045 100644
--- a/sysdeps/unix/sysv/linux/dl-execstack.c
+++ b/sysdeps/unix/sysv/linux/dl-execstack.c
@@ -45,25 +45,24 @@ _dl_make_stack_executable (void **stack_endp)
|| __builtin_expect (*stack_endp != __libc_stack_end, 0))
return EPERM;
-#if _STACK_GROWS_DOWN
/* Newer Linux kernels support a flag to make our job easy. */
-# ifdef PROT_GROWSDOWN
-# if __ASSUME_PROT_GROWSUPDOWN == 0
- static bool no_growsdown;
- if (! no_growsdown)
-# endif
+#if defined PROT_GROWSDOWN || defined PROT_GROWSUP
+# if __ASSUME_PROT_GROWSUPDOWN == 0
+ static bool no_growsupdown;
+ if (! no_growsupdown)
+# endif
{
if (__builtin_expect (__mprotect ((void *) page, GLRO(dl_pagesize),
__stack_prot) == 0, 1))
goto return_success;
-# if __ASSUME_PROT_GROWSUPDOWN == 0
+# if __ASSUME_PROT_GROWSUPDOWN == 0
if (errno == EINVAL)
- no_growsdown = true;
+ no_growsupdown = true;
else
-# endif
+# endif
return errno;
}
-# endif
+#endif
/* There is always a hole in the address space below the bottom of the
stack. So when we make an mprotect call that starts below the bottom
@@ -72,8 +71,10 @@ _dl_make_stack_executable (void **stack_endp)
We start with a random guess at how deep the stack might have gotten
so as to have extended the GROWSDOWN mapping to lower pages. */
-# if __ASSUME_PROT_GROWSUPDOWN == 0
+#if __ASSUME_PROT_GROWSUPDOWN == 0
size_t size = GLRO(dl_pagesize) * 8;
+
+# if _STACK_GROWS_DOWN
page = page + GLRO(dl_pagesize) - size;
while (1)
{
@@ -97,41 +98,11 @@ _dl_make_stack_executable (void **stack_endp)
page += size;
}
}
-# endif
-#elif _STACK_GROWS_UP
- /* Newer Linux kernels support a flag to make our job easy. */
-# ifdef PROT_GROWSUP
-# if __ASSUME_PROT_GROWSUPDOWN == 0
- static bool no_growsup;
- if (! no_growsup)
-# endif
- {
- if (__mprotect ((void *) page, GLRO(dl_pagesize),
- PROT_READ|PROT_WRITE|PROT_EXEC|PROT_GROWSUP) == 0)
- goto return_success;
-# if __ASSUME_PROT_GROWSUPDOWN == 0
- if (errno == EINVAL)
- no_growsup = true;
- else
-# endif
- return errno;
- }
-# endif
-
- /* There is always a hole in the address space above the top of the
- stack. So when we make an mprotect call that spans past the top
- of the stack, it will include the hole and fail with ENOMEM.
-
- We start with a random guess at how deep the stack might have gotten
- so as to have extended the GROWSUP mapping to higher pages. */
-
-# if __ASSUME_PROT_GROWSUPDOWN == 0
- size_t size = GLRO(dl_pagesize) * 8;
+# elif _STACK_GROWS_UP
while (1)
{
- if (__mprotect ((void *) page, size,
- PROT_READ|PROT_WRITE|PROT_EXEC) == 0)
+ if (__mprotect ((void *) page, size, __stack_prot & ~PROT_GROWSUP) == 0)
/* We got this chunk changed; loop to do another chunk below. */
page += size;
else
@@ -149,10 +120,10 @@ _dl_make_stack_executable (void **stack_endp)
size /= 2;
}
}
-# endif
-#else
-# error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP"
+# else
+# error "Define either _STACK_GROWS_DOWN or _STACK_GROWS_UP"
+# endif
#endif
return_success: