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ash: fix very weak $RANDOM generator; and move even more things

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out of data/bss

   text    data     bss     dec     hex filename
 807935     611    6884  815430   c7146 busybox_old
 808035     611    6868  815514   c719a busybox_unstripped
This commit is contained in:
Denis Vlasenko 2008-06-27 00:24:11 +00:00
parent 843cbd54d1
commit 448d30ee17
1 changed files with 65 additions and 51 deletions
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116
shell/ash.c
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@ -201,6 +201,14 @@ struct globals_misc {
/* indicates specified signal received */ /* indicates specified signal received */
char gotsig[NSIG - 1]; char gotsig[NSIG - 1];
char *trap[NSIG]; char *trap[NSIG];
/* Rarely referenced stuff */
#if ENABLE_ASH_RANDOM_SUPPORT
int32_t random_galois_LFSR; /* Galois LFSR (fast but weak) */
uint32_t random_LCG; /* LCG1 (fast but weak) */
#endif
pid_t backgndpid; /* pid of last background process */
smallint job_warning; /* user was warned about stopped jobs (can be 2, 1 or 0). */
}; };
extern struct globals_misc *const ash_ptr_to_globals_misc; extern struct globals_misc *const ash_ptr_to_globals_misc;
#define G_misc (*ash_ptr_to_globals_misc) #define G_misc (*ash_ptr_to_globals_misc)
@ -216,12 +224,16 @@ extern struct globals_misc *const ash_ptr_to_globals_misc;
#define intpending (G_misc.intpending ) #define intpending (G_misc.intpending )
//#define exsig (G_misc.exsig ) //#define exsig (G_misc.exsig )
#define pendingsig (G_misc.pendingsig ) #define pendingsig (G_misc.pendingsig )
#define isloginsh (G_misc.isloginsh) #define isloginsh (G_misc.isloginsh )
#define nullstr (G_misc.nullstr ) #define nullstr (G_misc.nullstr )
#define optlist (G_misc.optlist ) #define optlist (G_misc.optlist )
#define sigmode (G_misc.sigmode ) #define sigmode (G_misc.sigmode )
#define gotsig (G_misc.gotsig ) #define gotsig (G_misc.gotsig )
#define trap (G_misc.trap ) #define trap (G_misc.trap )
#define random_galois_LFSR (G_misc.random_galois_LFSR)
#define random_LCG (G_misc.random_LCG )
#define backgndpid (G_misc.backgndpid )
#define job_warning (G_misc.job_warning)
#define INIT_G_misc() do { \ #define INIT_G_misc() do { \
(*(struct globals_misc**)&ash_ptr_to_globals_misc) = xzalloc(sizeof(G_misc)); \ (*(struct globals_misc**)&ash_ptr_to_globals_misc) = xzalloc(sizeof(G_misc)); \
barrier(); \ barrier(); \
@ -1006,12 +1018,12 @@ struct parsefile {
struct strpush basestrpush; /* so pushing one is fast */ struct strpush basestrpush; /* so pushing one is fast */
}; };
static struct parsefile basepf; /* top level input file */ static struct parsefile basepf; /* top level input file */
static struct parsefile *g_parsefile = &basepf; /* current input file */ static struct parsefile *g_parsefile = &basepf; /* current input file */
static int startlinno; /* line # where last token started */ static int startlinno; /* line # where last token started */
static char *commandname; /* currently executing command */ static char *commandname; /* currently executing command */
static struct strlist *cmdenviron; /* environment for builtin command */ static struct strlist *cmdenviron; /* environment for builtin command */
static int exitstatus; /* exit status of last command */ static uint8_t exitstatus; /* exit status of last command */
/* ============ Message printing */ /* ============ Message printing */
@ -1605,29 +1617,6 @@ nextopt(const char *optstring)
} }
/* ============ Math support definitions */
#if ENABLE_ASH_MATH_SUPPORT_64
typedef int64_t arith_t;
#define arith_t_type long long
#else
typedef long arith_t;
#define arith_t_type long
#endif
#if ENABLE_ASH_MATH_SUPPORT
static arith_t dash_arith(const char *);
static arith_t arith(const char *expr, int *perrcode);
#endif
#if ENABLE_ASH_RANDOM_SUPPORT
static unsigned long rseed;
#ifndef DYNAMIC_VAR
#define DYNAMIC_VAR
#endif
#endif
/* ============ Shell variables */ /* ============ Shell variables */
/* /*
@ -1694,7 +1683,7 @@ struct localvar {
#define VNOFUNC 0x40 /* don't call the callback function */ #define VNOFUNC 0x40 /* don't call the callback function */
#define VNOSET 0x80 /* do not set variable - just readonly test */ #define VNOSET 0x80 /* do not set variable - just readonly test */
#define VNOSAVE 0x100 /* when text is on the heap before setvareq */ #define VNOSAVE 0x100 /* when text is on the heap before setvareq */
#ifdef DYNAMIC_VAR #if ENABLE_ASH_RANDOM_SUPPORT
# define VDYNAMIC 0x200 /* dynamic variable */ # define VDYNAMIC 0x200 /* dynamic variable */
#else #else
# define VDYNAMIC 0 # define VDYNAMIC 0
@ -1966,7 +1955,7 @@ lookupvar(const char *name)
v = *findvar(hashvar(name), name); v = *findvar(hashvar(name), name);
if (v) { if (v) {
#ifdef DYNAMIC_VAR #if ENABLE_ASH_RANDOM_SUPPORT
/* /*
* Dynamic variables are implemented roughly the same way they are * Dynamic variables are implemented roughly the same way they are
* in bash. Namely, they're "special" so long as they aren't unset. * in bash. Namely, they're "special" so long as they aren't unset.
@ -2127,7 +2116,7 @@ unsetvar(const char *s)
retval = 1; retval = 1;
if (flags & VREADONLY) if (flags & VREADONLY)
goto out; goto out;
#ifdef DYNAMIC_VAR #if ENABLE_ASH_RANDOM_SUPPORT
vp->flags &= ~VDYNAMIC; vp->flags &= ~VDYNAMIC;
#endif #endif
if (flags & VUNSET) if (flags & VUNSET)
@ -3243,9 +3232,6 @@ struct job {
struct job *prev_job; /* previous job */ struct job *prev_job; /* previous job */
}; };
static pid_t backgndpid; /* pid of last background process */
static smallint job_warning; /* user was warned about stopped jobs (can be 2, 1 or 0). */
static struct job *makejob(/*union node *,*/ int); static struct job *makejob(/*union node *,*/ int);
#if !JOBS #if !JOBS
#define forkshell(job, node, mode) forkshell(job, mode) #define forkshell(job, node, mode) forkshell(job, mode)
@ -3257,7 +3243,7 @@ static int waitforjob(struct job *);
enum { doing_jobctl = 0 }; enum { doing_jobctl = 0 };
#define setjobctl(on) do {} while (0) #define setjobctl(on) do {} while (0)
#else #else
static smallint doing_jobctl; static smallint doing_jobctl; //references:8
static void setjobctl(int); static void setjobctl(int);
#endif #endif
@ -3356,17 +3342,17 @@ setsignal(int signo)
#if JOBS #if JOBS
/* pgrp of shell on invocation */ /* pgrp of shell on invocation */
static int initialpgrp; static int initialpgrp; //references:2
static int ttyfd = -1; static int ttyfd = -1; //5
#endif #endif
/* array of jobs */ /* array of jobs */
static struct job *jobtab; static struct job *jobtab; //5
/* size of array */ /* size of array */
static unsigned njobs; static unsigned njobs; //4
/* current job */ /* current job */
static struct job *curjob; static struct job *curjob; //lots
/* number of presumed living untracked jobs */ /* number of presumed living untracked jobs */
static int jobless; static int jobless; //4
static void static void
set_curjob(struct job *jp, unsigned mode) set_curjob(struct job *jp, unsigned mode)
@ -5041,6 +5027,19 @@ redirectsafe(union node *redir, int flags)
* We have to deal with backquotes, shell variables, and file metacharacters. * We have to deal with backquotes, shell variables, and file metacharacters.
*/ */
#if ENABLE_ASH_MATH_SUPPORT_64
typedef int64_t arith_t;
#define arith_t_type long long
#else
typedef long arith_t;
#define arith_t_type long
#endif
#if ENABLE_ASH_MATH_SUPPORT
static arith_t dash_arith(const char *);
static arith_t arith(const char *expr, int *perrcode);
#endif
/* /*
* expandarg flags * expandarg flags
*/ */
@ -5358,7 +5357,7 @@ struct backcmd { /* result of evalbackcmd */
}; };
/* These forward decls are needed to use "eval" code for backticks handling: */ /* These forward decls are needed to use "eval" code for backticks handling: */
static smalluint back_exitstatus; /* exit status of backquoted command */ static uint8_t back_exitstatus; /* exit status of backquoted command */
#define EV_EXIT 01 /* exit after evaluating tree */ #define EV_EXIT 01 /* exit after evaluating tree */
static void evaltree(union node *, int); static void evaltree(union node *, int);
@ -9619,18 +9618,33 @@ setcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED)
static void static void
change_random(const char *value) change_random(const char *value)
{ {
/* Galois LFSR parameter */
/* Taps at 32 31 29 1: */
enum { MASK = 0x8000000b };
/* Another example - taps at 32 31 30 10: */
/* MASK = 0x00400007 */
if (value == NULL) { if (value == NULL) {
/* "get", generate */ /* "get", generate */
char buf[16]; uint32_t t;
rseed = rseed * 1103515245 + 12345; /* LCG has period of 2^32 and alternating lowest bit */
sprintf(buf, "%d", (unsigned int)((rseed & 32767))); random_LCG = 1664525 * random_LCG + 1013904223;
/* Galois LFSR has period of 2^32-1 = 3 * 5 * 17 * 257 * 65537 */
t = (random_galois_LFSR << 1);
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
* and ~2^64 period. & 0x7fff is probably bash compat
* for $RANDOM range. */
t = (t ^ random_LCG) & 0x7fff;
/* set without recursion */ /* set without recursion */
setvar(vrandom.text, buf, VNOFUNC); setvar(vrandom.text, utoa(t), VNOFUNC);
vrandom.flags &= ~VNOFUNC; vrandom.flags &= ~VNOFUNC;
} else { } else {
/* set/reset */ /* set/reset */
rseed = strtoul(value, (char **)NULL, 10); random_galois_LFSR = random_LCG = strtoul(value, (char **)NULL, 10);
} }
} }
#endif #endif
@ -13417,7 +13431,7 @@ int ash_main(int argc ATTRIBUTE_UNUSED, char **argv)
rootpid = getpid(); rootpid = getpid();
#if ENABLE_ASH_RANDOM_SUPPORT #if ENABLE_ASH_RANDOM_SUPPORT
rseed = rootpid + time(NULL); random_galois_LFSR = random_LCG = rootpid + time(NULL);
#endif #endif
init(); init();
setstackmark(&smark); setstackmark(&smark);