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-rw-r--r--shell/ash.c118
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);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-26 20:41:33 +0000