diff options
Diffstat (limited to 'shell')
| -rw-r--r-- | shell/ash.c | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/shell/ash.c b/shell/ash.c index 9c3216243..85064d5af 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -9615,7 +9615,6 @@ setcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED) } #if ENABLE_ASH_RANDOM_SUPPORT -/* Roughly copied from bash.. */ static void change_random(const char *value) { @@ -9636,10 +9635,11 @@ change_random(const char *value) if (random_galois_LFSR < 0) /* if we just shifted 1 out of msb... */ t ^= MASK; random_galois_LFSR = t; - /* Both are weak, xoring them gives better randomness + /* Both are weak, combining them gives better randomness * and ~2^64 period. & 0x7fff is probably bash compat - * for $RANDOM range. */ - t = (t ^ random_LCG) & 0x7fff; + * for $RANDOM range. Combining with subtraction is + * just for fun. + and ^ would work equally well. */ + t = (t - random_LCG) & 0x7fff; /* set without recursion */ setvar(vrandom.text, utoa(t), VNOFUNC); vrandom.flags &= ~VNOFUNC; @@ -13432,7 +13432,9 @@ int ash_main(int argc ATTRIBUTE_UNUSED, char **argv) rootpid = getpid(); #if ENABLE_ASH_RANDOM_SUPPORT - random_galois_LFSR = random_LCG = rootpid + time(NULL); + /* Can use monotonic_ns() for better randomness but for now it is + * not used anywhere else in busybox... so avoid bloat */ + random_galois_LFSR = random_LCG = rootpid + monotonic_us(); #endif init(); setstackmark(&smark); |