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* shrink MKSH_SMALL even further by removing functionality like

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some GNU bash extensions (suggested by cnuke@) and bind macros
* make the random cache more efficient (and the code potentially
  smaller, although we have a new implementation of the oaat hash
  function, alongside the old one, now) and pushb only if needed
  (i.e. state has changed or user has set $RANDOM, but not onfork)
This commit is contained in:
tg
2009-09-23 18:04:58 +00:00
parent 1ea1096a4e
commit 1a28786229
10 changed files with 194 additions and 62 deletions
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70
var.c
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@ -22,7 +22,7 @@
#include "sh.h"
__RCSID("$MirOS: src/bin/mksh/var.c,v 1.89 2009/09/20 13:29:18 tg Exp $");
__RCSID("$MirOS: src/bin/mksh/var.c,v 1.90 2009/09/23 18:04:58 tg Exp $");
/*
* Variables
@ -973,13 +973,18 @@ makenv(void)
#if HAVE_ARC4RANDOM && !defined(MKSH_SMALL)
static uint32_t rnd_cache[2];
static unsigned char rnd_lastflag = 2;
#if HAVE_ARC4RANDOM_PUSHB
static bool rnd_wpush = false;
#define rnd_mix(v,w) rnd_cmix(v,w)
#else
#define rnd_mix(v,w) rnd_cmix(v)
#endif
static void rnd_cachemix(unsigned long);
static void rnd_mix(unsigned long, bool);
static void
rnd_cachemix(unsigned long newval)
rnd_mix(unsigned long newval, bool wantpush)
{
size_t i;
struct {
union {
int rval;
@ -988,31 +993,26 @@ rnd_cachemix(unsigned long newval)
uint32_t v1;
uint32_t v2;
unsigned long v3;
#if HAVE_ARC4RANDOM_PUSHB
bool neededpush;
bool wantingpush;
#endif
} v;
unsigned char buf[sizeof(v) * 2 + 1], *cp, num;
#if HAVE_ARC4RANDOM_PUSHB
v.neededpush = rnd_wpush;
v.wantingpush = wantpush;
rnd_wpush = v.neededpush || v.wantingpush;
#endif
v.v0.rval = rand();
v.v1 = rnd_cache[0];
v.v2 = rnd_cache[1];
v.v3 = newval;
num = 0;
loop:
cp = (void *)&v;
i = 0;
while (i < 2 * sizeof(v)) {
buf[i++] = digits_uc[*cp >> 4];
buf[i++] = digits_lc[*cp & 0x0F];
++cp;
}
buf[i] = 0;
rnd_cache[num] = hash(buf);
if (num == 0) {
++num;
v.v0.arval = arc4random();
goto loop;
}
rnd_cache[0] = hashmem(&v, sizeof(v));
v.v0.arval = arc4random();
rnd_cache[1] = hashmem(&v, sizeof(v));
}
#endif
@ -1032,17 +1032,21 @@ rnd_get(void)
srand(arc4random() & 0x7FFF);
else if (rnd_lastflag == 0)
/* transition from 0: addrandom */
rnd_cachemix(rand());
rnd_mix(rand(), true);
rnd_lastflag = Flag(FARC4RANDOM);
}
if (Flag(FARC4RANDOM)) {
if (rnd_cache[0] || rnd_cache[1])
if (rnd_cache[0] || rnd_cache[1]) {
#if HAVE_ARC4RANDOM_PUSHB
rv = arc4random_pushb(rnd_cache, sizeof(rnd_cache));
#else
if (rnd_wpush) {
rv = arc4random_pushb(rnd_cache,
sizeof(rnd_cache));
rnd_wpush = false;
} else
#endif
arc4random_addrandom((void *)rnd_cache,
sizeof(rnd_cache));
#endif
}
rnd_cache[0] = rnd_cache[1] = 0;
return ((
#if HAVE_ARC4RANDOM_PUSHB
@ -1066,7 +1070,7 @@ rnd_set(unsigned long newval)
#endif
#else
#if HAVE_ARC4RANDOM
rnd_cachemix(newval);
rnd_mix(newval, true);
if (Flag(FARC4RANDOM) == 1)
return;
if (Flag(FARC4RANDOM) == 2)
@ -1080,9 +1084,9 @@ rnd_set(unsigned long newval)
#if !HAVE_ARC4RANDOM || !defined(MKSH_SMALL)
/*
* Called after a fork in parent to bump the random number generator.
* Called after a fork to bump the random number generator.
* Done to ensure children will not get the same random number sequence
* if the parent doesn't use $RANDOM.
* as the parent processes.
*/
void
change_random(unsigned long newval)
@ -1091,7 +1095,7 @@ change_random(unsigned long newval)
#if HAVE_ARC4RANDOM
if (Flag(FARC4RANDOM)) {
rnd_cachemix(newval);
rnd_mix(newval, false);
return;
}
#endif
@ -1413,7 +1417,9 @@ set_array(const char *var, bool reset, const char **vals)
struct tbl *vp, *vq;
mksh_uari_t i, n;
const char *ccp;
#ifndef MKSH_SMALL
char *cp;
#endif
/* to get local array, use "typeset foo; set -A foo" */
vp = global(var);
@ -1430,6 +1436,7 @@ set_array(const char *var, bool reset, const char **vals)
* evaluation of some of vals[] may fail...
*/
for (n = i = 0; (ccp = vals[i]); n = ++i) {
#ifndef MKSH_SMALL
if (*ccp == '[') {
int level = 0;
@ -1449,6 +1456,7 @@ set_array(const char *var, bool reset, const char **vals)
} else
ccp = vals[i];
}
#endif
vq = arraysearch(vp, n);
/* would be nice to deal with errors here... (see above) */