diff options
Diffstat (limited to 'lib/libc/stdlib/rand.c')
| -rw-r--r-- | lib/libc/stdlib/rand.c | 20 |
1 files changed, 16 insertions, 4 deletions
diff --git a/lib/libc/stdlib/rand.c b/lib/libc/stdlib/rand.c index f9c9b56..676c95e 100644 --- a/lib/libc/stdlib/rand.c +++ b/lib/libc/stdlib/rand.c @@ -67,15 +67,15 @@ do_rand(unsigned long *ctx) */ long hi, lo, x; - /* Can't be initialized with 0, so use another value. */ - if (*ctx == 0) - *ctx = 123459876; + /* Must be in [1, 0x7ffffffe] range at this point. */ hi = *ctx / 127773; lo = *ctx % 127773; x = 16807 * lo - 2836 * hi; if (x < 0) x += 0x7fffffff; - return ((*ctx = x) % ((u_long)RAND_MAX + 1)); + *ctx = x; + /* Transform to [0, 0x7ffffffd] range. */ + return (x - 1); #endif /* !USE_WEAK_SEEDING */ } @@ -84,6 +84,10 @@ int rand_r(unsigned int *ctx) { u_long val = (u_long) *ctx; +#ifndef USE_WEAK_SEEDING + /* Transform to [1, 0x7ffffffe] range. */ + val = (val % 0x7ffffffe) + 1; +#endif int r = do_rand(&val); *ctx = (unsigned int) val; @@ -104,6 +108,10 @@ srand(seed) u_int seed; { next = seed; +#ifndef USE_WEAK_SEEDING + /* Transform to [1, 0x7ffffffe] range. */ + next = (next % 0x7ffffffe) + 1; +#endif } @@ -125,6 +133,10 @@ sranddev() mib[0] = CTL_KERN; mib[1] = KERN_ARND; sysctl(mib, 2, (void *)&next, &len, NULL, 0); +#ifndef USE_WEAK_SEEDING + /* Transform to [1, 0x7ffffffe] range. */ + next = (next % 0x7ffffffe) + 1; +#endif } |
