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-rw-r--r--shell/hush.c205
1 files changed, 59 insertions, 146 deletions
diff --git a/shell/hush.c b/shell/hush.c
index bcccfb0bb..01690d9bc 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -493,8 +493,6 @@ struct globals {
char **traps; /* char *traps[NSIG] */
/* which signals have non-DFL handler (even with no traps set)? */
unsigned non_DFL_mask;
- /* which signals are known to be IGNed on entry to shell? */
- unsigned IGN_mask;
sigset_t blocked_set;
sigset_t inherited_set;
};
@@ -895,66 +893,71 @@ static void check_and_run_traps(void)
}
}
-/* The stuff below needs to be migrated to "Special action" above */
+#if ENABLE_HUSH_JOB
-/////* Signals are grouped, we handle them in batches */
-////static void set_misc_sighandler(void (*handler)(int))
-////{
-//// bb_signals(0
-//// + (1 << SIGINT)
-//// + (1 << SIGQUIT)
-//// + (1 << SIGTERM)
-//// , handler);
-////}
+/* Restores tty foreground process group, and exits.
+ * May be called as signal handler for fatal signal
+ * (will faithfully resend signal to itself, producing correct exit state)
+ * or called directly with -EXITCODE.
+ * We also call it if xfunc is exiting. */
+static void sigexit(int sig) NORETURN;
+static void sigexit(int sig)
+{
+ /* Disable all signals: job control, SIGPIPE, etc. */
+ sigprocmask_allsigs(SIG_BLOCK);
-#if ENABLE_HUSH_JOB
+#if ENABLE_HUSH_INTERACTIVE
+ /* Careful: we can end up here after [v]fork. Do not restore
+ * tty pgrp, only top-level shell process does that */
+ if (G.interactive_fd && getpid() == G.root_pid)
+ tcsetpgrp(G.interactive_fd, G.saved_tty_pgrp);
+#endif
+
+ /* Not a signal, just exit */
+ if (sig <= 0)
+ _exit(- sig);
+
+ kill_myself_with_sig(sig); /* does not return */
+}
/* helper */
-static unsigned maybe_set_sighandler(int sig, void (*handler)(int))
+static void maybe_set_sighandler(int sig)
{
+ void (*handler)(int);
/* non_DFL_mask'ed signals are, well, masked,
* no need to set handler for them.
- * IGN_mask'ed signals were found to be IGN on entry,
- * do not change that -> no need to set handler for them either
*/
- unsigned ign = ((G.IGN_mask|G.non_DFL_mask) >> sig) & 1;
- if (!ign) {
- handler = signal(sig, handler);
- ign = (handler == SIG_IGN);
- if (ign) /* restore back to IGN! */
+ if (!((G.non_DFL_mask >> sig) & 1)) {
+ handler = signal(sig, sigexit);
+ if (handler == SIG_IGN) /* restore back to IGN! */
signal(sig, handler);
}
- return ign << sig; /* pass back knowledge about SIG_IGN */
}
/* Used only to set handler to restore pgrp on exit, and to reset it to DFL */
-static void set_fatal_sighandler(void (*handler)(int))
+static void set_fatal_signals_to_sigexit(void)
{
- unsigned mask = 0;
-
if (HUSH_DEBUG) {
- mask |= maybe_set_sighandler(SIGILL , handler);
- mask |= maybe_set_sighandler(SIGFPE , handler);
- mask |= maybe_set_sighandler(SIGBUS , handler);
- mask |= maybe_set_sighandler(SIGSEGV, handler);
- mask |= maybe_set_sighandler(SIGTRAP, handler);
+ maybe_set_sighandler(SIGILL );
+ maybe_set_sighandler(SIGFPE );
+ maybe_set_sighandler(SIGBUS );
+ maybe_set_sighandler(SIGSEGV);
+ maybe_set_sighandler(SIGTRAP);
} /* else: hush is perfect. what SEGV? */
- mask |= maybe_set_sighandler(SIGABRT, handler);
+ maybe_set_sighandler(SIGABRT);
/* bash 3.2 seems to handle these just like 'fatal' ones */
- mask |= maybe_set_sighandler(SIGPIPE, handler);
- mask |= maybe_set_sighandler(SIGALRM, handler);
- mask |= maybe_set_sighandler(SIGHUP , handler);
+ maybe_set_sighandler(SIGPIPE);
+ maybe_set_sighandler(SIGALRM);
+ maybe_set_sighandler(SIGHUP );
/* if we aren't interactive... but in this case
* we never want to restore pgrp on exit, and this fn is not called */
- /*mask |= maybe_set_sighandler(SIGTERM, handler); */
- /*mask |= maybe_set_sighandler(SIGINT , handler); */
-
- G.IGN_mask = mask;
+ /*maybe_set_sighandler(SIGTERM);*/
+ /*maybe_set_sighandler(SIGINT );*/
}
/* Used only to suppress ^Z in `cmd` */
-static void IGN_jobctrl_signals(void)
+static void set_jobctrl_signals_to_IGN(void)
{
bb_signals(0
+ (1 << SIGTSTP)
@@ -962,88 +965,11 @@ static void IGN_jobctrl_signals(void)
+ (1 << SIGTTOU)
, SIG_IGN);
}
-/* SIGCHLD is special and handled separately */
-
-////static void set_every_sighandler(void (*handler)(int))
-////{
-//// set_fatal_sighandler(handler);
-//// set_jobctrl_sighandler(handler);
-//// set_misc_sighandler(handler);
-//// signal(SIGCHLD, handler);
-////}
-
-////static void handler_ctrl_c(int sig UNUSED_PARAM)
-////{
-//// debug_printf_jobs("got sig %d\n", sig);
-////// as usual we can have all kinds of nasty problems with leaked malloc data here
-//// siglongjmp(G.toplevel_jb, 1);
-////}
-
-////static void handler_ctrl_z(int sig UNUSED_PARAM)
-////{
-//// pid_t pid;
-////
-//// debug_printf_jobs("got tty sig %d in pid %d\n", sig, getpid());
-////
-//// if (!BB_MMU) {
-//// fputs("Sorry, backgrounding (CTRL+Z) of foreground scripts not supported on nommu\n", stderr);
-//// return;
-//// }
-////
-//// pid = fork();
-//// if (pid < 0) /* can't fork. Pretend there was no ctrl-Z */
-//// return;
-//// G.ctrl_z_flag = 1;
-//// if (!pid) { /* child */
-//// if (ENABLE_HUSH_JOB)
-//// die_sleep = 0; /* let nofork's xfuncs die */
-//// bb_setpgrp();
-//// debug_printf_jobs("set pgrp for child %d ok\n", getpid());
-//////// set_every_sighandler(SIG_DFL);
-//// raise(SIGTSTP); /* resend TSTP so that child will be stopped */
-//// debug_printf_jobs("returning in child\n");
-//// /* return to nofork, it will eventually exit now,
-//// * not return back to shell */
-//// return;
-//// }
-//// /* parent */
-//// /* finish filling up pipe info */
-//// G.toplevel_list->pgrp = pid; /* child is in its own pgrp */
-//// G.toplevel_list->cmds[0].pid = pid;
-//// /* parent needs to longjmp out of running nofork.
-//// * we will "return" exitcode 0, with child put in background */
-////// as usual we can have all kinds of nasty problems with leaked malloc data here
-//// debug_printf_jobs("siglongjmp in parent\n");
-//// siglongjmp(G.toplevel_jb, 1);
-////}
-
-/* Restores tty foreground process group, and exits.
- * May be called as signal handler for fatal signal
- * (will faithfully resend signal to itself, producing correct exit state)
- * or called directly with -EXITCODE.
- * We also call it if xfunc is exiting. */
-static void sigexit(int sig) NORETURN;
-static void sigexit(int sig)
-{
- /* Disable all signals: job control, SIGPIPE, etc. */
- sigprocmask_allsigs(SIG_BLOCK);
-
-#if ENABLE_HUSH_INTERACTIVE
- if (G.interactive_fd)
- tcsetpgrp(G.interactive_fd, G.saved_tty_pgrp);
-#endif
-
- /* Not a signal, just exit */
- if (sig <= 0)
- _exit(- sig);
-
- kill_myself_with_sig(sig); /* does not return */
-}
#else /* !JOB */
-#define set_fatal_sighandler(handler) ((void)0)
-#define IGN_jobctrl_signals(handler) ((void)0)
+#define set_fatal_signals_to_sigexit(handler) ((void)0)
+#define set_jobctrl_signals_to_IGN(handler) ((void)0)
#endif /* JOB */
@@ -1057,11 +983,12 @@ static void hush_exit(int exitcode)
free(argv[1]);
}
- if (ENABLE_HUSH_JOB) {
- fflush(NULL); /* flush all streams */
- sigexit(- (exitcode & 0xff));
- } else
- exit(exitcode);
+#if ENABLE_HUSH_JOB
+ fflush(NULL); /* flush all streams */
+ sigexit(- (exitcode & 0xff));
+#else
+ exit(exitcode);
+#endif
}
@@ -2641,10 +2568,6 @@ static int run_pipe(struct pipe *pi)
* might include `cmd` runs! Do not rerun it! We *must*
* use argv_expanded if it's non-NULL */
- /* Disable job control signals for shell (parent) and
- * for initial child code after fork */
-//// set_jobctrl_sighandler(SIG_IGN);
-
/* Going to fork a child per each pipe member */
pi->alive_cmds = 0;
nextin = 0;
@@ -2677,8 +2600,6 @@ static int run_pipe(struct pipe *pi)
* with pgid == pid_of_first_child_in_pipe */
if (G.run_list_level == 1 && G.interactive_fd) {
pid_t pgrp;
- /* Don't do pgrp restore anymore on fatal signals */
- set_fatal_sighandler(SIG_DFL);
pgrp = pi->pgrp;
if (pgrp < 0) /* true for 1st process only */
pgrp = getpid();
@@ -2698,9 +2619,8 @@ static int run_pipe(struct pipe *pi)
setup_redirects(command, NULL);
/* Restore default handlers just prior to exec */
-//// set_jobctrl_sighandler(SIG_DFL);
-//// set_misc_sighandler(SIG_DFL);
-//// signal(SIGCHLD, SIG_DFL);
+ /*signal(SIGCHLD, SIG_DFL); - so far we don't have any handlers */
+
/* Stores to nommu_save list of env vars putenv'ed
* (NOMMU, on MMU we don't need that) */
/* cast away volatility... */
@@ -2877,7 +2797,7 @@ static int run_list(struct pipe *pi)
* in order to return, no direct "return" statements please.
* This helps to ensure that no memory is leaked. */
-//TODO: needs re-thinking
+////TODO: ctrl-Z handling needs re-thinking and re-testing
#if ENABLE_HUSH_JOB
/* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
@@ -3674,12 +3594,11 @@ static FILE *generate_stream_from_list(struct pipe *head)
#endif
/* Process substitution is not considered to be usual
* 'command execution'.
- * SUSv3 says ctrl-Z should be ignored, ctrl-C should not. */
-//// /* Not needed, we are relying on it being disabled
-//// * everywhere outside actual command execution. */
- IGN_jobctrl_signals();
-//// set_misc_sighandler(SIG_DFL);
- /* Freeing 'head' here would break NOMMU. */
+ * SUSv3 says ctrl-Z should be ignored, ctrl-C should not.
+ */
+ set_jobctrl_signals_to_IGN();
+
+ /* Note: freeing 'head' here would break NOMMU. */
_exit(run_list(head));
}
close(channel[1]);
@@ -4493,13 +4412,8 @@ static void setup_job_control(void)
shell_pgrp = getpgrp();
}
- /* Ignore job-control and misc signals. */
-//// set_jobctrl_sighandler(SIG_IGN);
-//// set_misc_sighandler(SIG_IGN);
-//huh? signal(SIGCHLD, SIG_IGN);
-
/* We _must_ restore tty pgrp on fatal signals */
- set_fatal_sighandler(sigexit);
+ set_fatal_signals_to_sigexit();
/* Put ourselves in our own process group. */
bb_setpgrp(); /* is the same as setpgid(our_pid, our_pid); */
@@ -4682,7 +4596,6 @@ int hush_main(int argc, char **argv)
}
if (G.interactive_fd) {
fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
-//// set_misc_sighandler(SIG_IGN);
}
}
init_signal_mask();