1 files changed, 130 insertions, 59 deletions

diff --git a/shell/ash.c b/shell/ash.c
index d6fd38849..e3f79fcd5 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -30,7 +30,7 @@
  */
 
 /*
- * The follow should be set to reflect the type of system you have:
+ * The following should be set to reflect the type of system you have:
  *      JOBS -> 1 if you have Berkeley job control, 0 otherwise.
  *      define SYSV if you are running under System V.
  *      define DEBUG=1 to compile in debugging ('set -o debug' to turn on)
@@ -40,6 +40,11 @@
  * a quit signal will generate a core dump.
  */
 #define DEBUG 0
+/* Tweak debug output verbosity here */
+#define DEBUG_TIME 0
+#define DEBUG_PID 1
+#define DEBUG_SIG 1
+
 #define PROFILE 0
 
 #define IFS_BROKEN
@@ -47,9 +52,9 @@
 #define JOBS ENABLE_ASH_JOB_CONTROL
 
 #if DEBUG
-#ifndef _GNU_SOURCE
-#define _GNU_SOURCE
-#endif
+# ifndef _GNU_SOURCE
+#  define _GNU_SOURCE
+# endif
 #endif
 
 #include "busybox.h" /* for applet_names */
@@ -57,15 +62,15 @@
 #include <setjmp.h>
 #include <fnmatch.h>
 #if JOBS || ENABLE_ASH_READ_NCHARS
-#include <termios.h>
+# include <termios.h>
 #endif
 
 #ifndef PIPE_BUF
-#define PIPE_BUF 4096           /* amount of buffering in a pipe */
+# define PIPE_BUF 4096           /* amount of buffering in a pipe */
 #endif
 
 #if defined(__uClinux__)
-#error "Do not even bother, ash will not run on uClinux"
+# error "Do not even bother, ash will not run on uClinux"
 #endif
 
 
@@ -76,14 +81,6 @@
 #define CMDTABLESIZE 31         /* should be prime */
 
 
-/* ============ Misc helpers */
-
-#define xbarrier() do { __asm__ __volatile__ ("": : :"memory"); } while (0)
-
-/* C99 say: "char" declaration may be signed or unsigned default */
-#define signed_char2int(sc) ((int)((signed char)sc))
-
-
 /* ============ Shell options */
 
 static const char *const optletters_optnames[] = {
@@ -245,7 +242,30 @@ extern struct globals_misc *const ash_ptr_to_globals_misc;
 } while (0)
 
 
+/* ============ DEBUG */
+#if DEBUG
+static void trace_printf(const char *fmt, ...);
+static void trace_vprintf(const char *fmt, va_list va);
+# define TRACE(param)    trace_printf param
+# define TRACEV(param)   trace_vprintf param
+# define close(f) do { \
+        int dfd = (f); \
+        if (close(dfd) < 0) \
+                bb_error_msg("bug on %d: closing %d(%x)", \
+                        __LINE__, dfd, dfd); \
+} while (0)
+#else
+# define TRACE(param)
+# define TRACEV(param)
+#endif
+
+
 /* ============ Utility functions */
+#define xbarrier() do { __asm__ __volatile__ ("": : :"memory"); } while (0)
+
+/* C99 say: "char" declaration may be signed or unsigned by default */
+#define signed_char2int(sc) ((int)(signed char)(sc))
+
 static int isdigit_str9(const char *str)
 {
         int maxlen = 9 + 1; /* max 9 digits: 999999999 */
@@ -284,6 +304,12 @@ raise_exception(int e)
         exception = e;
         longjmp(exception_handler->loc, 1);
 }
+#if DEBUG
+#define raise_exception(e) do { \
+        TRACE(("raising exception %d on line %d\n", (e), __LINE__)); \
+        raise_exception(e); \
+} while (0)
+#endif
 
 /*
  * Called from trap.c when a SIGINT is received.  (If the user specifies
@@ -316,6 +342,12 @@ raise_interrupt(void)
         raise_exception(i);
         /* NOTREACHED */
 }
+#if DEBUG
+#define raise_interrupt() do { \
+        TRACE(("raising interrupt on line %d\n", __LINE__)); \
+        raise_interrupt(); \
+} while (0)
+#endif
 
 #if ENABLE_ASH_OPTIMIZE_FOR_SIZE
 static void
@@ -334,7 +366,9 @@ force_int_on(void)
                 raise_interrupt();
 }
 #define FORCE_INT_ON force_int_on()
-#else
+
+#else /* !ASH_OPTIMIZE_FOR_SIZE */
+
 #define INT_ON do { \
         xbarrier(); \
         if (--suppressint == 0 && intpending) \
@@ -346,7 +380,7 @@ force_int_on(void)
         if (intpending) \
                 raise_interrupt(); \
 } while (0)
-#endif /* ASH_OPTIMIZE_FOR_SIZE */
+#endif /* !ASH_OPTIMIZE_FOR_SIZE */
 
 #define SAVE_INT(v) ((v) = suppressint)
 
@@ -376,7 +410,6 @@ static void
 onsig(int signo)
 {
         gotsig[signo - 1] = 1;
-        pendingsig = signo;
 
         if (/* exsig || */ (signo == SIGINT && !trap[SIGINT])) {
                 if (!suppressint) {
@@ -384,6 +417,8 @@ onsig(int signo)
                         raise_interrupt(); /* does not return */
                 }
                 intpending = 1;
+        } else {
+                pendingsig = signo;
         }
 }
 
@@ -684,6 +719,12 @@ trace_printf(const char *fmt, ...)
 
         if (debug != 1)
                 return;
+        if (DEBUG_TIME)
+                fprintf(tracefile, "%u ", (int) time(NULL));
+        if (DEBUG_PID)
+                fprintf(tracefile, "[%u] ", (int) getpid());
+        if (DEBUG_SIG)
+                fprintf(tracefile, "pending s:%d i:%d(supp:%d) ", pendingsig, intpending, suppressint);
         va_start(va, fmt);
         vfprintf(tracefile, fmt, va);
         va_end(va);
@@ -694,6 +735,12 @@ trace_vprintf(const char *fmt, va_list va)
 {
         if (debug != 1)
                 return;
+        if (DEBUG_TIME)
+                fprintf(tracefile, "%u ", (int) time(NULL));
+        if (DEBUG_PID)
+                fprintf(tracefile, "[%u] ", (int) getpid());
+        if (DEBUG_SIG)
+                fprintf(tracefile, "pending s:%d i:%d(supp:%d) ", pendingsig, intpending, suppressint);
         vfprintf(tracefile, fmt, va);
 }
 
@@ -998,14 +1045,6 @@ showtree(union node *n)
         shtree(n, 1, NULL, stdout);
 }
 
-#define TRACE(param)    trace_printf param
-#define TRACEV(param)   trace_vprintf param
-
-#else
-
-#define TRACE(param)
-#define TRACEV(param)
-
 #endif /* DEBUG */
 
 
@@ -3779,7 +3818,7 @@ dowait(int wait_flags, struct job *job)
          * NB: _not_ safe_waitpid, we need to detect EINTR */
         pid = waitpid(-1, &status,
                         (doing_jobctl ? (wait_flags | WUNTRACED) : wait_flags));
-        TRACE(("wait returns pid=%d, status=0x%x\n", pid, status));
+        TRACE(("wait returns pid=%d, status=0x%x, errno=%d(%s)\n", pid, status, errno, strerror(errno)));
 
         if (pid <= 0) {
                 /* If we were doing blocking wait and (probably) got EINTR,
@@ -5031,7 +5070,9 @@ redirect(union node *redir, int flags)
                 if (newfd < 0) {
                         /* NTOFD/NFROMFD: copy redir->ndup.dupfd to fd */
                         if (redir->ndup.dupfd < 0) { /* "fd>&-" */
-                                close(fd);
+                                /* Don't want to trigger debugging */
+                                if (fd != -1)
+                                        close(fd);
                         } else {
                                 copyfd(redir->ndup.dupfd, fd | COPYFD_EXACT);
                         }
@@ -5084,7 +5125,7 @@ popredir(int drop, int restore)
                                 /*close(fd);*/
                                 copyfd(copy, fd | COPYFD_EXACT);
                         }
-                        close(copy);
+                        close(copy & ~COPYFD_RESTORE);
                 }
         }
         redirlist = rp->next;
@@ -7871,20 +7912,30 @@ dotrap(void)
         pendingsig = 0;
         xbarrier();
 
+        TRACE(("dotrap entered\n"));
         for (i = 1, q = gotsig; i < NSIG; i++, q++) {
                 if (!*q)
                         continue;
-                *q = '\0';
 
                 p = trap[i];
+                /* non-trapped SIGINT is handled separately by raise_interrupt,
+                 * don't upset it by resetting gotsig[SIGINT-1] */
+                if (i == SIGINT && !p)
+                        continue;
+
+                TRACE(("sig %d is active, will run handler '%s'\n", i, p));
+                *q = '\0';
                 if (!p)
                         continue;
                 skip = evalstring(p, SKIPEVAL);
                 exitstatus = savestatus;
-                if (skip)
+                if (skip) {
+                        TRACE(("dotrap returns %d\n", skip));
                         return skip;
+                }
         }
 
+        TRACE(("dotrap returns 0\n"));
         return 0;
 }
 
@@ -7906,28 +7957,32 @@ static void prehash(union node *);
 static void
 evaltree(union node *n, int flags)
 {
-
         struct jmploc *volatile savehandler = exception_handler;
         struct jmploc jmploc;
         int checkexit = 0;
         void (*evalfn)(union node *, int);
         int status;
+        int int_level;
+
+        SAVE_INT(int_level);
 
         if (n == NULL) {
                 TRACE(("evaltree(NULL) called\n"));
                 goto out1;
         }
-        TRACE(("pid %d, evaltree(%p: %d, %d) called\n",
-                        getpid(), n, n->type, flags));
+        TRACE(("evaltree(%p: %d, %d) called\n", n, n->type, flags));
 
         exception_handler = &jmploc;
         {
                 int err = setjmp(jmploc.loc);
                 if (err) {
                         /* if it was a signal, check for trap handlers */
-                        if (exception == EXSIG)
+                        if (exception == EXSIG) {
+                                TRACE(("exception %d (EXSIG) in evaltree, err=%d\n", exception, err));
                                 goto out;
+                        }
                         /* continue on the way out */
+                        TRACE(("exception %d in evaltree, propagating err=%d\n", exception, err));
                         exception_handler = savehandler;
                         longjmp(exception_handler->loc, err);
                 }
@@ -8010,7 +8065,8 @@ evaltree(union node *n, int flags)
                 if (exitstatus == 0) {
                         n = n->nif.ifpart;
                         goto evaln;
-                } else if (n->nif.elsepart) {
+                }
+                if (n->nif.elsepart) {
                         n = n->nif.elsepart;
                         goto evaln;
                 }
@@ -8036,6 +8092,9 @@ evaltree(union node *n, int flags)
  exexit:
                 raise_exception(EXEXIT);
         }
+
+        RESTORE_INT(int_level);
+        TRACE(("leaving evaltree (no interrupts)\n"));
 }
 
 #if !defined(__alpha__) || (defined(__GNUC__) && __GNUC__ >= 3)
@@ -8281,7 +8340,9 @@ evalpipe(union node *n, int flags)
                 if (prevfd >= 0)
                         close(prevfd);
                 prevfd = pip[0];
-                close(pip[1]);
+                /* Don't want to trigger debugging */
+                if (pip[1] != -1)
+                        close(pip[1]);
         }
         if (n->npipe.pipe_backgnd == 0) {
                 exitstatus = waitforjob(jp);
@@ -8913,6 +8974,7 @@ evalcommand(union node *cmd, int flags)
                         if (forkshell(jp, cmd, FORK_FG) != 0) {
                                 exitstatus = waitforjob(jp);
                                 INT_ON;
+                                TRACE(("forked child exited with %d\n", exitstatus));
                                 break;
                         }
                         FORCE_INT_ON;
@@ -12391,7 +12453,7 @@ readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 #endif
 
         status = 0;
-        startword = 1;
+        startword = 2;
         backslash = 0;
 #if ENABLE_ASH_READ_TIMEOUT
         if (timeout) /* NB: ensuring end_ms is nonzero */
@@ -12399,6 +12461,8 @@ readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 #endif
         STARTSTACKSTR(p);
         do {
+                const char *is_ifs;
+
 #if ENABLE_ASH_READ_TIMEOUT
                 if (end_ms) {
                         struct pollfd pfd[1];
@@ -12428,25 +12492,34 @@ readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
                         continue;
                 }
                 if (!rflag && c == '\\') {
-                        backslash++;
+                        backslash = 1;
                         continue;
                 }
                 if (c == '\n')
                         break;
-                if (startword && *ifs == ' ' && strchr(ifs, c)) {
-                        continue;
+                is_ifs = strchr(ifs, c);
+                if (startword && is_ifs) {
+                        if (isspace(c))
+                                continue;
+                        /* non-space ifs char */
+                        startword--;
+                        if (startword == 1) /* first one? */
+                                continue;
                 }
                 startword = 0;
-                if (ap[1] != NULL && strchr(ifs, c) != NULL) {
+                if (ap[1] != NULL && is_ifs) {
+                        const char *beg;
                         STACKSTRNUL(p);
-                        setvar(*ap, stackblock(), 0);
+                        beg = stackblock();
+                        setvar(*ap, beg, 0);
                         ap++;
-                        startword = 1;
+                        /* can we skip one non-space ifs? (2: yes) */
+                        startword = isspace(c) ? 2 : 1;
                         STARTSTACKSTR(p);
-                } else {
- put:
-                        STPUTC(c, p);
+                        continue;
                 }
+ put:
+                STPUTC(c, p);
         }
 /* end of do {} while: */
 #if ENABLE_ASH_READ_NCHARS
@@ -12460,8 +12533,8 @@ readcmd(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
 #endif
 
         STACKSTRNUL(p);
-        /* Remove trailing blanks */
-        while ((char *)stackblock() <= --p && strchr(ifs, *p) != NULL)
+        /* Remove trailing space ifs chars */
+        while ((char *)stackblock() <= --p && isspace(*p) && strchr(ifs, *p) != NULL)
                 *p = '\0';
         setvar(*ap, stackblock(), 0);
         while (*++ap != NULL)
@@ -13640,7 +13713,7 @@ int ash_main(int argc UNUSED_PARAM, char **argv)
         exception_handler = &jmploc;
 #if DEBUG
         opentrace();
-        trace_puts("Shell args: ");
+        TRACE(("Shell args: "));
         trace_puts_args(argv);
 #endif
         rootpid = getpid();
@@ -13692,8 +13765,14 @@ int ash_main(int argc UNUSED_PARAM, char **argv)
         }
  state3:
         state = 4;
-        if (minusc)
+        if (minusc) {
+                /* evalstring pushes parsefile stack.
+                 * Ensure we don't falsely claim that 0 (stdin)
+                 * is one of stacked source fds */
+                if (!sflag)
+                        g_parsefile->fd = -1;
                 evalstring(minusc, 0);
+        }
 
         if (sflag || minusc == NULL) {
 #if ENABLE_FEATURE_EDITING_SAVEHISTORY
@@ -13720,14 +13799,6 @@ int ash_main(int argc UNUSED_PARAM, char **argv)
         /* NOTREACHED */
 }
 
-#if DEBUG
-const char *applet_name = "debug stuff usage";
-int main(int argc, char **argv)
-{
-        return ash_main(argc, argv);
-}
-#endif
-
 
 /*-
  * Copyright (c) 1989, 1991, 1993, 1994