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Merge pull request #10654 from poettering/srand-rdrand

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random-util.c mini-fixes
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Yu Watanabe 2018-11-07 02:03:09 +09:00 committed by GitHub
commit 49a060aca8
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1 changed files with 6 additions and 2 deletions
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8
src/basic/random-util.c
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@ -142,8 +142,9 @@ void initialize_srand(void) {
static bool srand_called = false; static bool srand_called = false;
unsigned x; unsigned x;
#if HAVE_SYS_AUXV_H #if HAVE_SYS_AUXV_H
void *auxv; const void *auxv;
#endif #endif
uint64_t k;
if (srand_called) if (srand_called)
return; return;
@ -153,7 +154,7 @@ void initialize_srand(void) {
* try to make use of that to seed the pseudo-random generator. It's * try to make use of that to seed the pseudo-random generator. It's
* better than nothing... */ * better than nothing... */
auxv = (void*) getauxval(AT_RANDOM); auxv = (const void*) getauxval(AT_RANDOM);
if (auxv) { if (auxv) {
assert_cc(sizeof(x) <= 16); assert_cc(sizeof(x) <= 16);
memcpy(&x, auxv, sizeof(x)); memcpy(&x, auxv, sizeof(x));
@ -164,6 +165,9 @@ void initialize_srand(void) {
x ^= (unsigned) now(CLOCK_REALTIME); x ^= (unsigned) now(CLOCK_REALTIME);
x ^= (unsigned) gettid(); x ^= (unsigned) gettid();
if (rdrand64(&k) >= 0)
x ^= (unsigned) k;
srand(x); srand(x);
srand_called = true; srand_called = true;
} }