hush: code shrink

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

1 files changed, 66 insertions, 59 deletions

diff --git a/shell/hush.c b/shell/hush.c
index 0b17b222d..71972f751 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -1379,6 +1379,11 @@ enum {
 #endif
 };
 
+static void sigprocmask_set(sigset_t *set)
+{
+        sigprocmask(SIG_SETMASK, set, NULL);
+}
+
 #if ENABLE_HUSH_FAST
 static void SIGCHLD_handler(int sig UNUSED_PARAM)
 {
@@ -5378,18 +5383,15 @@ static void reset_traps_to_defaults(void)
          * Stupid. It can be done with *single* &= op, but we can't use
          * the fact that G.blocked_set is implemented as a bitmask
          * in libc... */
-        mask = (SPECIAL_INTERACTIVE_SIGS >> 1);
-        sig = 1;
-        while (1) {
+        mask = SPECIAL_INTERACTIVE_SIGS;
+        sig = 0;
+        while ((mask >>= 1) != 0) {
+                sig++;
                 if (mask & 1) {
                         /* Careful. Only if no trap or trap is not "" */
                         if (!G.traps || !G.traps[sig] || G.traps[sig][0])
                                 sigdelset(&G.blocked_set, sig);
                 }
-                mask >>= 1;
-                if (!mask)
-                        break;
-                sig++;
         }
         /* Our homegrown sig mask is saner to work with :) */
         G.non_DFL_mask &= ~SPECIAL_INTERACTIVE_SIGS;
@@ -5411,7 +5413,7 @@ static void reset_traps_to_defaults(void)
                         continue;
                 sigdelset(&G.blocked_set, sig);
         }
-        sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
+        sigprocmask_set(&G.blocked_set);
 }
 
 #else /* !BB_MMU */
@@ -5541,7 +5543,7 @@ static void re_execute_shell(char ***to_free, const char *s,
 
  do_exec:
         debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
-        sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
+        sigprocmask_set(&G.inherited_set);
         execve(bb_busybox_exec_path, argv, pp);
         /* Fallback. Useful for init=/bin/hush usage etc */
         if (argv[0][0] == '/')
@@ -6195,7 +6197,7 @@ static void execvp_or_die(char **argv) NORETURN;
 static void execvp_or_die(char **argv)
 {
         debug_printf_exec("execing '%s'\n", argv[0]);
-        sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
+        sigprocmask_set(&G.inherited_set);
         execvp(argv[0], argv);
         bb_perror_msg("can't execute '%s'", argv[0]);
         _exit(127); /* bash compat */
@@ -6327,7 +6329,7 @@ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
 # endif
                         /* Re-exec ourselves */
                         debug_printf_exec("re-execing applet '%s'\n", argv[0]);
-                        sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
+                        sigprocmask_set(&G.inherited_set);
                         execv(bb_busybox_exec_path, argv);
                         /* If they called chroot or otherwise made the binary no longer
                          * executable, fall through */
@@ -7435,84 +7437,89 @@ static void init_sigmasks(void)
 {
         unsigned sig;
         unsigned mask;
-        sigset_t old_blocked_set;
 
+        /* POSIX allows shell to re-enable SIGCHLD
+         * even if it was SIG_IGN on entry */
+#if ENABLE_HUSH_FAST
+        G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
+#endif
         if (!G.inherited_set_is_saved) {
+#if ENABLE_HUSH_FAST
+                signal(SIGCHLD, SIGCHLD_handler);
+#else
+                signal(SIGCHLD, SIG_DFL);
+#endif
                 sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
                 G.inherited_set = G.blocked_set;
         }
-        old_blocked_set = G.blocked_set;
 
+        /* Which signals are shell-special? */
         mask = (1 << SIGQUIT);
         if (G_interactive_fd) {
-                mask = (1 << SIGQUIT) | SPECIAL_INTERACTIVE_SIGS;
+                mask |= SPECIAL_INTERACTIVE_SIGS;
                 if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
                         mask |= SPECIAL_JOB_SIGS;
         }
         G.non_DFL_mask = mask;
 
+        /* Block them. And unblock SIGCHLD */
         sig = 0;
-        while (mask) {
+        while ((mask >>= 1) != 0) {
+                sig++;
                 if (mask & 1)
                         sigaddset(&G.blocked_set, sig);
-                mask >>= 1;
-                sig++;
         }
         sigdelset(&G.blocked_set, SIGCHLD);
 
-        if (memcmp(&old_blocked_set, &G.blocked_set, sizeof(old_blocked_set)) != 0)
-                sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
-
-        /* POSIX allows shell to re-enable SIGCHLD
-         * even if it was SIG_IGN on entry */
-#if ENABLE_HUSH_FAST
-        G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
-        if (!G.inherited_set_is_saved)
-                signal(SIGCHLD, SIGCHLD_handler);
-#else
-        if (!G.inherited_set_is_saved)
-                signal(SIGCHLD, SIG_DFL);
-#endif
+        if (memcmp(&G.inherited_set, &G.blocked_set, sizeof(G.inherited_set)) != 0)
+                sigprocmask_set(&G.blocked_set);
 
         G.inherited_set_is_saved = 1;
 }
 
 #if ENABLE_HUSH_JOB
 /* helper */
-static void maybe_set_to_sigexit(int sig)
+/* Set handlers to restore tty pgrp and exit */
+static void set_fatal_handlers_to_sigexit(void)
 {
         void (*handler)(int);
+        unsigned fatal_sigs, sig;
+
+        /* We will restore tty pgrp on these signals */
+        fatal_sigs = 0
+                + (1 << SIGILL ) * HUSH_DEBUG
+                + (1 << SIGFPE ) * HUSH_DEBUG
+                + (1 << SIGBUS ) * HUSH_DEBUG
+                + (1 << SIGSEGV) * HUSH_DEBUG
+                + (1 << SIGTRAP) * HUSH_DEBUG
+                + (1 << SIGABRT)
+        /* bash 3.2 seems to handle these just like 'fatal' ones */
+                + (1 << SIGPIPE)
+                + (1 << SIGALRM)
+        /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
+         * if we aren't interactive... but in this case
+         * we never want to restore pgrp on exit, and this fn is not called */
+                /*+ (1 << SIGHUP )*/
+                /*+ (1 << SIGTERM)*/
+                /*+ (1 << SIGINT )*/
+        ;
+
         /* non_DFL_mask'ed signals are, well, masked,
          * no need to set handler for them.
          */
-        if (!((G.non_DFL_mask >> sig) & 1)) {
+        fatal_sigs &= ~G.non_DFL_mask;
+
+        /* For each sig in fatal_sigs... */
+        sig = 0;
+        while ((fatal_sigs >>= 1) != 0) {
+                sig++;
+                if (!(fatal_sigs & 1))
+                        continue;
                 handler = signal(sig, sigexit);
                 if (handler == SIG_IGN) /* oops... restore back to IGN! */
                         signal(sig, handler);
         }
 }
-/* Set handlers to restore tty pgrp and exit */
-static void set_fatal_handlers(void)
-{
-        /* We _must_ restore tty pgrp on fatal signals */
-        if (HUSH_DEBUG) {
-                maybe_set_to_sigexit(SIGILL );
-                maybe_set_to_sigexit(SIGFPE );
-                maybe_set_to_sigexit(SIGBUS );
-                maybe_set_to_sigexit(SIGSEGV);
-                maybe_set_to_sigexit(SIGTRAP);
-        } /* else: hush is perfect. what SEGV? */
-        maybe_set_to_sigexit(SIGABRT);
-        /* bash 3.2 seems to handle these just like 'fatal' ones */
-        maybe_set_to_sigexit(SIGPIPE);
-        maybe_set_to_sigexit(SIGALRM);
-        /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
-         * if we aren't interactive... but in this case
-         * we never want to restore pgrp on exit, and this fn is not called */
-        /*maybe_set_to_sigexit(SIGHUP );*/
-        /*maybe_set_to_sigexit(SIGTERM);*/
-        /*maybe_set_to_sigexit(SIGINT );*/
-}
 #endif
 
 static int set_mode(int state, char mode, const char *o_opt)
@@ -7769,7 +7776,7 @@ int hush_main(int argc, char **argv)
                                                 sigaddset(&G.blocked_set, sig);
                                         }
                                 }
-                                sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
+                                sigprocmask_set(&G.blocked_set);
                         }
 # if ENABLE_HUSH_LOOPS
                         optarg++;
@@ -7910,7 +7917,7 @@ int hush_main(int argc, char **argv)
 
                 if (G_saved_tty_pgrp) {
                         /* Set other signals to restore saved_tty_pgrp */
-                        set_fatal_handlers();
+                        set_fatal_handlers_to_sigexit();
                         /* Put ourselves in our own process group
                          * (bash, too, does this only if ctty is available) */
                         bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
@@ -8301,7 +8308,7 @@ static int FAST_FUNC builtin_trap(char **argv)
                                 sigdelset(&G.blocked_set, sig);
                         }
                 }
-                sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
+                sigprocmask_set(&G.blocked_set);
                 return ret;
         }
 
@@ -8858,7 +8865,7 @@ static int FAST_FUNC builtin_wait(char **argv)
                  * $
                  */
                 sigaddset(&G.blocked_set, SIGCHLD);
-                sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
+                sigprocmask_set(&G.blocked_set);
                 while (1) {
                         checkjobs(NULL);
                         if (errno == ECHILD)
@@ -8875,7 +8882,7 @@ static int FAST_FUNC builtin_wait(char **argv)
                         }
                 }
                 sigdelset(&G.blocked_set, SIGCHLD);
-                sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
+                sigprocmask_set(&G.blocked_set);
                 return ret;
         }