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authorJoseph Myers <joseph@codesourcery.com>2014-06-20 20:02:34 +0000
committerJoseph Myers <joseph@codesourcery.com>2014-06-20 20:02:34 +0000
commit4a103975c4c4929455d60224101013888640cd2f (patch)
treeb4dd6d80368a78ae0b0a70e8486067487461329c
parenta2a76afe9127dc7b3e7c526bdf0088c1cc17c33d (diff)
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Remove __ASSUME_AT_RANDOM.
This patch removes __ASSUME_AT_RANDOM now it can be assumed to be true unconditionally. Tested x86_64 that the disassembly of installed shared libraries is unchanged by this patch. * sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_AT_RANDOM): Remove macro. * sysdeps/unix/sysv/linux/dl-osinfo.h (_dl_setup_stack_chk_guard) [!__ASSUME_AT_RANDOM]: Remove conditional code. (_dl_setup_pointer_guard) [!__ASSUME_AT_RANDOM]: Likewise.
-rw-r--r--ChangeLog6
-rw-r--r--sysdeps/unix/sysv/linux/dl-osinfo.h48
-rw-r--r--sysdeps/unix/sysv/linux/kernel-features.h3
3 files changed, 13 insertions, 44 deletions
diff --git a/ChangeLog b/ChangeLog
index a87a2d0..beea12c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
2014-06-20 Joseph Myers <joseph@codesourcery.com>
+ * sysdeps/unix/sysv/linux/kernel-features.h (__ASSUME_AT_RANDOM):
+ Remove macro.
+ * sysdeps/unix/sysv/linux/dl-osinfo.h (_dl_setup_stack_chk_guard)
+ [!__ASSUME_AT_RANDOM]: Remove conditional code.
+ (_dl_setup_pointer_guard) [!__ASSUME_AT_RANDOM]: Likewise.
+
* sysdeps/unix/sysv/linux/kernel-features.h
(__ASSUME_ADJ_OFFSET_SS_READ): Remove macro.
* sysdeps/unix/sysv/linux/adjtime.c (ADJTIME)
diff --git a/sysdeps/unix/sysv/linux/dl-osinfo.h b/sysdeps/unix/sysv/linux/dl-osinfo.h
index af13438..fd82287 100644
--- a/sysdeps/unix/sysv/linux/dl-osinfo.h
+++ b/sysdeps/unix/sysv/linux/dl-osinfo.h
@@ -57,39 +57,17 @@ _dl_setup_stack_chk_guard (void *dl_random)
unsigned char bytes[sizeof (uintptr_t)];
} ret;
-#ifndef __ASSUME_AT_RANDOM
- if (__glibc_unlikely (dl_random == NULL))
- {
- const size_t filllen = sizeof (ret.bytes) - 1;
- ret.num = 0;
-# ifdef ENABLE_STACKGUARD_RANDOMIZE
- int fd = open_not_cancel_2 ("/dev/urandom", O_RDONLY);
- if (fd >= 0)
- {
- ssize_t reslen = read_not_cancel (fd, ret.bytes + 1, filllen);
- close_not_cancel_no_status (fd);
- if (reslen == (ssize_t) filllen)
- return ret.num;
- }
-# endif
- ret.bytes[filllen] = 255;
- ret.bytes[filllen - 1] = '\n';
- }
- else
-#endif
- {
- /* We need in the moment only 8 bytes on 32-bit platforms and 16
- bytes on 64-bit platforms. Therefore we can use the data
- directly and not use the kernel-provided data to seed a PRNG. */
- memcpy (ret.bytes, dl_random, sizeof (ret));
+ /* We need in the moment only 8 bytes on 32-bit platforms and 16
+ bytes on 64-bit platforms. Therefore we can use the data
+ directly and not use the kernel-provided data to seed a PRNG. */
+ memcpy (ret.bytes, dl_random, sizeof (ret));
#if BYTE_ORDER == LITTLE_ENDIAN
- ret.num &= ~(uintptr_t) 0xff;
+ ret.num &= ~(uintptr_t) 0xff;
#elif BYTE_ORDER == BIG_ENDIAN
- ret.num &= ~((uintptr_t) 0xff << (8 * (sizeof (ret) - 1)));
+ ret.num &= ~((uintptr_t) 0xff << (8 * (sizeof (ret) - 1)));
#else
# error "BYTE_ORDER unknown"
#endif
- }
return ret.num;
}
@@ -97,18 +75,6 @@ static inline uintptr_t __attribute__ ((always_inline))
_dl_setup_pointer_guard (void *dl_random, uintptr_t stack_chk_guard)
{
uintptr_t ret;
-#ifndef __ASSUME_AT_RANDOM
- if (dl_random == NULL)
- {
- ret = stack_chk_guard;
-# ifndef HP_TIMING_NONAVAIL
- hp_timing_t now;
- HP_TIMING_NOW (now);
- ret ^= now;
-# endif
- }
- else
-#endif
- memcpy (&ret, (char *) dl_random + sizeof (ret), sizeof (ret));
+ memcpy (&ret, (char *) dl_random + sizeof (ret), sizeof (ret));
return ret;
}
diff --git a/sysdeps/unix/sysv/linux/kernel-features.h b/sysdeps/unix/sysv/linux/kernel-features.h
index d067321..80655e0 100644
--- a/sysdeps/unix/sysv/linux/kernel-features.h
+++ b/sysdeps/unix/sysv/linux/kernel-features.h
@@ -162,9 +162,6 @@
/* Support for the FUTEX_CLOCK_REALTIME flag was added in 2.6.29. */
#define __ASSUME_FUTEX_CLOCK_REALTIME 1
-/* Support for the AT_RANDOM auxiliary vector entry was added in 2.6.29. */
-#define __ASSUME_AT_RANDOM 1
-
/* Support for preadv and pwritev was added in 2.6.30. */
#define __ASSUME_PREADV 1
#define __ASSUME_PWRITEV 1