diff options
| -rw-r--r-- | shell/hush.c | 125 |
1 files changed, 66 insertions, 59 deletions
diff --git a/shell/hush.c b/shell/hush.c index 0b17b22..71972f7 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; } |