diff options
| -rw-r--r-- | shell/ash.c | 118 |
1 files changed, 66 insertions, 52 deletions
diff --git a/shell/ash.c b/shell/ash.c index 4a3d2d48e..8c99e30ef 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -201,6 +201,14 @@ struct globals_misc { /* indicates specified signal received */ char gotsig[NSIG - 1]; 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; #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 exsig (G_misc.exsig ) #define pendingsig (G_misc.pendingsig ) -#define isloginsh (G_misc.isloginsh) -#define nullstr (G_misc.nullstr ) -#define optlist (G_misc.optlist ) -#define sigmode (G_misc.sigmode ) -#define gotsig (G_misc.gotsig ) -#define trap (G_misc.trap ) +#define isloginsh (G_misc.isloginsh ) +#define nullstr (G_misc.nullstr ) +#define optlist (G_misc.optlist ) +#define sigmode (G_misc.sigmode ) +#define gotsig (G_misc.gotsig ) +#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 { \ (*(struct globals_misc**)&ash_ptr_to_globals_misc) = xzalloc(sizeof(G_misc)); \ barrier(); \ @@ -1006,12 +1018,12 @@ struct parsefile { 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 int startlinno; /* line # where last token started */ static char *commandname; /* currently executing 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 */ @@ -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 */ /* @@ -1694,7 +1683,7 @@ struct localvar { #define VNOFUNC 0x40 /* don't call the callback function */ #define VNOSET 0x80 /* do not set variable - just readonly test */ #define VNOSAVE 0x100 /* when text is on the heap before setvareq */ -#ifdef DYNAMIC_VAR +#if ENABLE_ASH_RANDOM_SUPPORT # define VDYNAMIC 0x200 /* dynamic variable */ #else # define VDYNAMIC 0 @@ -1966,7 +1955,7 @@ lookupvar(const char *name) v = *findvar(hashvar(name), name); if (v) { -#ifdef DYNAMIC_VAR +#if ENABLE_ASH_RANDOM_SUPPORT /* * Dynamic variables are implemented roughly the same way they are * in bash. Namely, they're "special" so long as they aren't unset. @@ -2127,7 +2116,7 @@ unsetvar(const char *s) retval = 1; if (flags & VREADONLY) goto out; -#ifdef DYNAMIC_VAR +#if ENABLE_ASH_RANDOM_SUPPORT vp->flags &= ~VDYNAMIC; #endif if (flags & VUNSET) @@ -3243,9 +3232,6 @@ struct 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); #if !JOBS #define forkshell(job, node, mode) forkshell(job, mode) @@ -3257,7 +3243,7 @@ static int waitforjob(struct job *); enum { doing_jobctl = 0 }; #define setjobctl(on) do {} while (0) #else -static smallint doing_jobctl; +static smallint doing_jobctl; //references:8 static void setjobctl(int); #endif @@ -3356,17 +3342,17 @@ setsignal(int signo) #if JOBS /* pgrp of shell on invocation */ -static int initialpgrp; -static int ttyfd = -1; +static int initialpgrp; //references:2 +static int ttyfd = -1; //5 #endif /* array of jobs */ -static struct job *jobtab; +static struct job *jobtab; //5 /* size of array */ -static unsigned njobs; +static unsigned njobs; //4 /* current job */ -static struct job *curjob; +static struct job *curjob; //lots /* number of presumed living untracked jobs */ -static int jobless; +static int jobless; //4 static void 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. */ +#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 */ @@ -5358,7 +5357,7 @@ struct backcmd { /* result of evalbackcmd */ }; /* 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 */ static void evaltree(union node *, int); @@ -9619,18 +9618,33 @@ setcmd(int argc ATTRIBUTE_UNUSED, char **argv ATTRIBUTE_UNUSED) static void 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) { /* "get", generate */ - char buf[16]; - - rseed = rseed * 1103515245 + 12345; - sprintf(buf, "%d", (unsigned int)((rseed & 32767))); + uint32_t t; + + /* LCG has period of 2^32 and alternating lowest bit */ + 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 */ - setvar(vrandom.text, buf, VNOFUNC); + setvar(vrandom.text, utoa(t), VNOFUNC); vrandom.flags &= ~VNOFUNC; } else { /* set/reset */ - rseed = strtoul(value, (char **)NULL, 10); + random_galois_LFSR = random_LCG = strtoul(value, (char **)NULL, 10); } } #endif @@ -13417,7 +13431,7 @@ int ash_main(int argc ATTRIBUTE_UNUSED, char **argv) rootpid = getpid(); #if ENABLE_ASH_RANDOM_SUPPORT - rseed = rootpid + time(NULL); + random_galois_LFSR = random_LCG = rootpid + time(NULL); #endif init(); setstackmark(&smark); |