diff options
author | Andi Kleen <ak@linux.intel.com> | 2011-09-29 13:15:13 +0000 |
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committer | Andi Kleen <ak@linux.intel.com> | 2011-09-29 13:15:13 +0000 |
commit | 37ad400cf317c869551743a0acfbef928e422a6b (patch) | |
tree | 036cb4380d2a3505ae1768b759e006e030596b0d /gcc/toplev.c | |
parent | f99b40cb2e6b839afb5b9330aa53fb6a7ef615b6 (diff) |
Use urandom to get random seed
When available use /dev/urandom to get the random seem. This will lower the probability
of collisions.
On other systems it will fallback to the old methods.
Passes bootstrap + testsuite on x86_64. Ok?
gcc/:
2011-09-26 Andi Kleen <ak@linux.intel.com>
* toplev.c (init_local_tick): Try reading random seed from /dev/urandom
git-svn-id: https://gcc.gnu.org/svn/gcc/trunk@179348 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/toplev.c')
-rw-r--r-- | gcc/toplev.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/gcc/toplev.c b/gcc/toplev.c index 78583fc52a6..ab6b5a41837 100644 --- a/gcc/toplev.c +++ b/gcc/toplev.c @@ -262,7 +262,17 @@ init_local_tick (void) { if (!flag_random_seed) { - /* Get some more or less random data. */ + /* Try urandom first. Time of day is too likely to collide. + In case of any error we just use the local tick. */ + + int fd = open ("/dev/urandom", O_RDONLY); + if (fd >= 0) + { + read (fd, &random_seed, sizeof (random_seed)); + close (fd); + } + + /* Now get the tick anyways */ #ifdef HAVE_GETTIMEOFDAY { struct timeval tv; |