RNDEBUG showed that using the pushb_fast will have much fewer syscalls

This commit is contained in:
tg 2010-09-19 19:21:20 +00:00
parent 915b30adfe
commit b0b03a5a75

41
var.c
View File

@ -26,7 +26,7 @@
#include <sys/sysctl.h> #include <sys/sysctl.h>
#endif #endif
__RCSID("$MirOS: src/bin/mksh/var.c,v 1.113 2010/09/14 21:26:19 tg Exp $"); __RCSID("$MirOS: src/bin/mksh/var.c,v 1.114 2010/09/19 19:21:20 tg Exp $");
/* /*
* Variables * Variables
@ -1029,10 +1029,8 @@ void
change_random(const void *vp, size_t n) change_random(const void *vp, size_t n)
{ {
register uint32_t h = 0x100; register uint32_t h = 0x100;
#if defined(__OpenBSD__) #if defined(arc4random_pushb_fast) || defined(MKSH_A4PB)
int mib[2]; uint32_t i;
uint8_t k[3];
size_t klen;
#endif #endif
kshstate_v.cr_dp = vp; kshstate_v.cr_dp = vp;
@ -1042,26 +1040,21 @@ change_random(const void *vp, size_t n)
sizeof(kshstate_v)), vp, n); sizeof(kshstate_v)), vp, n);
kshstate_v.lcg_state_ = oaathash_finalise(h); kshstate_v.lcg_state_ = oaathash_finalise(h);
#if defined(__OpenBSD__) #if defined(arc4random_pushb_fast) || defined(MKSH_A4PB)
/* OpenBSD, MirBSD: proper kernel entropy comes at zero cost */ /*
* either we have very check entropy get and push available,
mib[0] = CTL_KERN; * with malloc() pulling in this code already anyway, or the
mib[1] = KERN_ARND; * user requested us to use the old functions
klen = sizeof(k); */
sysctl(mib, 2, k, &klen, &kshstate_v.lcg_state_, #if defined(arc4random_pushb_fast)
arc4random_pushb_fast(&kshstate_v.lcg_state_,
sizeof(kshstate_v.lcg_state_)); sizeof(kshstate_v.lcg_state_));
/* we ignore failures and take in k anyway */ i = arc4random();
h = oaathash_update(h, k, sizeof(k)); #else
kshstate_v.lcg_state_ = oaathash_finalise(h); i = arc4random_pushb(&kshstate_v.lcg_state_,
#elif defined(MKSH_A4PB) sizeof(kshstate_v.lcg_state_));
/* forced by the user to use arc4random_pushb(3) - Cygwin? */ #endif
{ h = oaathash_update(h, (void *)&i, sizeof(i));
uint32_t prv;
prv = arc4random_pushb(&kshstate_v.lcg_state_,
sizeof(kshstate_v.lcg_state_));
h = oaathash_update(h, &prv, sizeof(prv));
}
kshstate_v.lcg_state_ = oaathash_finalise(h); kshstate_v.lcg_state_ = oaathash_finalise(h);
#endif #endif
} }