hush: rework signal and trap handling. Some smaller bits are TODO,

expect minor breakage

function                                             old     new   delta
set_fatal_sighandler                                  12     186    +174
check_and_run_traps                                    -     122    +122
maybe_set_sighandler                                   -      76     +76
hush_main                                            831     887     +56
sigtimedwait                                           -      50     +50
__GI_sigtimedwait                                      -      50     +50
hush_exit                                             49      93     +44
set_mode                                             749     777     +28
pseudo_exec_argv                                     131     151     +20
static.zero_ts                                         -       8      +8
expand_variables                                    1962    1970      +8
builtin_wait                                         172     174      +2
set_misc_sighandler                                   12       -     -12
set_jobctrl_sighandler                                12       -     -12
handler_ctrl_c                                        16       -     -16
builtin_set_mode                                      28       -     -28
handle_trap                                           97       -     -97
handler_ctrl_z                                       107       -    -107
builtin_trap                                         545     438    -107
run_list                                            2149    2006    -143
------------------------------------------------------------------------------
(add/remove: 5/6 grow/shrink: 7/2 up/down: 638/-522)          Total: 116 bytes
This commit is contained in:
Denis Vlasenko 2009-03-31 11:22:57 +00:00
parent d690f68554
commit d5762932fb

View File

@ -460,13 +460,13 @@ struct globals {
int last_jobid;
struct pipe *job_list;
struct pipe *toplevel_list;
smallint ctrl_z_flag;
//// smallint ctrl_z_flag;
#endif
#if ENABLE_HUSH_LOOPS
smallint flag_break_continue;
#endif
smallint fake_mode;
/* these three support $?, $#, and $1 */
/* These four support $?, $#, and $1 */
smalluint last_return_code;
/* is global_argv and global_argv[1..n] malloced? (note: not [0]) */
smalluint global_args_malloced;
@ -489,10 +489,14 @@ struct globals {
#endif
unsigned char charmap[256];
char user_input_buf[ENABLE_FEATURE_EDITING ? BUFSIZ : 2];
struct {
char *cmd;
struct sigaction oact;
} *traps;
/* Signal and trap handling */
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;
};
#define G (*ptr_to_globals)
@ -521,11 +525,9 @@ static int builtin_help(char **argv);
static int builtin_pwd(char **argv);
static int builtin_read(char **argv);
static int builtin_test(char **argv);
static void handle_trap(int sig);
static int builtin_trap(char **argv);
static int builtin_true(char **argv);
static int builtin_set(char **argv);
static int builtin_set_mode(const char, const char);
static int builtin_shift(char **argv);
static int builtin_source(char **argv);
static int builtin_umask(char **argv);
@ -750,95 +752,270 @@ static void free_strings(char **strings)
}
/* Signals are grouped, we handle them in batches */
static void set_misc_sighandler(void (*handler)(int))
/* Basic theory of signal handling in shell
* ========================================
* This does not describe what hush does, rahter, it is current understanding
* what it _should_ do.
* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
*
* Signals are handled only after each pipe ("cmd | cmd | cmd" thing)
* is finished or backgrounded. It is the same in interactive and
* non-interactive shells, and is the same regardless of whether
* a user trap handler is installed or a default one is in effect.
* ^C or ^Z from keyboard seem to execute "at once" because it usually
* backgrounds (i.e. stops) or kills all members of currently running
* pipe.
*
* Wait builtin in interruptible by signals for which user trap is set
* or by SIGINT in interactive shell.
*
* Trap handlers will execute even within trap handlers. (right?)
*
* User trap handlers are forgotten when subshell is entered.
*
* If job control is off, backgrounded commands ("cmd &")
* have SIGINT, SIGQUIT set to SIG_IGN.
*
* Commands run in command substitution ("`cmd`")
* have SIGTTIN, SIGTTOU, SIGTSTP set to SIG_IGN.
*
* Ordinary commands have IGN/DFL set as inherited by the shell
* from its parent.
*
* Default handlers which differ from DFL action
* (note: subshell is not an interactive shell):
*
* SIGQUIT: ignore
* SIGTERM (interactive): ignore
* SUGHUP (interactive): send SIGCONT to stopped jobs,
* send SIGHUP to all jobs and exit
* SIGTTIN, SIGTTOU, SIGTSTP (if job control is on): ignore
* (note that ^Z is handled not by trapping SIGTSTP, but by seeing
* that all pipe members are stopped) (right?)
* SIGINT (interactive): wait for last pipe, ignore the rest
* of the command line, show prompt. (check/expand this)
* Example 1: this waits 5 sec, but does not execute ls:
* "echo $$; sleep 5; ls -l" + "kill -INT <pid>"
* Example 2: this does not wait and does not execute ls:
* "echo $$; sleep 5 & wait; ls -l" + "kill -INT <pid>"
*
* (What happens to signals which are IGN on shell start?)
* (What happens with signal mask on shell start?)
*
* Implementation in hush
* ======================
* We use in-kernel pending signal mask to determine which signals were sent.
* We block all signals which we don't want to take action immediately,
* i.e. we block all signals which need to have special handling as described
* above, and all signals which have traps set.
* After each pipe execution, we extract any pending signals via sigtimedwait()
* and act on them.
*
* unsigned non_DFL_mask: a mask of such "special" signals
* sigset_t blocked_set: current blocked signal set
*
* "trap - SIGxxx": clear bit in blocked_set unless it is also in non_DFL
* "trap 'cmd' SIGxxx": set bit in blocked_set (even if 'cmd' is '')
* after [v]fork, if we plan to be a shell:
* nothing for {} subshell (say, "true | { true; true; } | true")
* unset all traps if () shell. [TODO]
* after [v]fork, if we plan to exec:
* POSIX says pending signal mask is cleared in child - no need to clear it.
* restore blocked signal set to one inherited by shell just prior to exec.
*
* Note: as a result, we do not use signal handlers much. The only use
* is to restore terminal pgrp on exit.
*
* TODO: check/fix wait builtin to be interruptible.
*/
/* called once at shell init */
static void init_signal_mask(void)
{
bb_signals(0
+ (1 << SIGINT)
+ (1 << SIGQUIT)
+ (1 << SIGTERM)
, handler);
unsigned sig;
unsigned mask = (1 << SIGQUIT);
#if ENABLE_HUSH_INTERACTIVE
if (G.interactive_fd) {
mask = 0
| (1 << SIGQUIT)
| (1 << SIGTERM)
| (1 << SIGHUP)
#if ENABLE_HUSH_JOB
| (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP)
#endif
| (1 << SIGINT)
;
}
#endif
G.non_DFL_mask = mask;
/*sigemptyset(&G.blocked_set); - already is */
sigprocmask(SIG_SETMASK, NULL, &G.blocked_set);
sig = 0;
while (mask) {
if (mask & 1)
sigaddset(&G.blocked_set, sig);
mask >>= 1;
sig++;
}
sigprocmask(SIG_SETMASK, &G.blocked_set, &G.inherited_set);
}
static void check_and_run_traps(void)
{
static const struct timespec zero_ts = { 0, 0 };
smalluint save_rcode;
int sig;
while (1) {
sig = sigtimedwait(&G.blocked_set, NULL, &zero_ts);
if (sig <= 0)
break;
if (G.traps && G.traps[sig]) {
if (G.traps[sig][0]) {
/* We have user-defined handler */
char *argv[] = { NULL, xstrdup(G.traps[sig]), NULL };
save_rcode = G.last_return_code;
builtin_eval(argv);
free(argv[1]);
G.last_return_code = save_rcode;
} /* else: "" trap, ignoring signal */
continue;
}
/* not a trap: special action */
#if 0 //TODO
switch (sig) {
case SIGHUP: ...
break;
case SIGINT: ...
break;
default: /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */
}
#endif
}
}
/* The stuff below needs to be migrated to "Special action" above */
/////* 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);
////}
#if ENABLE_HUSH_JOB
/* helper */
static unsigned 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! */
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))
{
bb_signals(0
+ (1 << SIGILL)
+ (1 << SIGTRAP)
+ (1 << SIGABRT)
+ (1 << SIGFPE)
+ (1 << SIGBUS)
+ (1 << SIGSEGV)
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);
} /* else: hush is perfect. what SEGV? */
mask |= maybe_set_sighandler(SIGABRT, handler);
/* bash 3.2 seems to handle these just like 'fatal' ones */
+ (1 << SIGHUP)
+ (1 << SIGPIPE)
+ (1 << SIGALRM)
, handler);
mask |= maybe_set_sighandler(SIGPIPE, handler);
mask |= maybe_set_sighandler(SIGALRM, handler);
mask |= maybe_set_sighandler(SIGHUP , handler);
/* 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;
}
static void set_jobctrl_sighandler(void (*handler)(int))
/* Used only to suppress ^Z in `cmd` */
static void IGN_jobctrl_signals(void)
{
bb_signals(0
+ (1 << SIGTSTP)
+ (1 << SIGTTIN)
+ (1 << SIGTTOU)
, handler);
, 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 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_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);
}
////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
@ -865,8 +1042,8 @@ static void sigexit(int sig)
#else /* !JOB */
#define set_fatal_sighandler(handler) ((void)0)
#define set_jobctrl_sighandler(handler) ((void)0)
#define set_fatal_sighandler(handler) ((void)0)
#define IGN_jobctrl_signals(handler) ((void)0)
#endif /* JOB */
@ -874,8 +1051,11 @@ static void sigexit(int sig)
static void hush_exit(int exitcode) NORETURN;
static void hush_exit(int exitcode)
{
if (G.traps && G.traps[0].cmd)
handle_trap(0);
if (G.traps && G.traps[0] && G.traps[0][0]) {
char *argv[] = { NULL, xstrdup(G.traps[0]), NULL };
builtin_eval(argv);
free(argv[1]);
}
if (ENABLE_HUSH_JOB) {
fflush(NULL); /* flush all streams */
@ -2052,6 +2232,8 @@ static void pseudo_exec_argv(nommu_save_t *nommu_save, char **argv, int assignme
}
#endif
sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
debug_printf_exec("execing '%s'\n", argv[0]);
execvp(argv[0], argv);
bb_perror_msg("can't exec '%s'", argv[0]);
@ -2200,6 +2382,8 @@ static int checkjobs(struct pipe* fg_pipe)
pid_t childpid;
int rcode = 0;
debug_printf_jobs("checkjobs %p\n", fg_pipe);
attributes = WUNTRACED;
if (fg_pipe == NULL)
attributes |= WNOHANG;
@ -2459,7 +2643,7 @@ static int run_pipe(struct pipe *pi)
/* Disable job control signals for shell (parent) and
* for initial child code after fork */
set_jobctrl_sighandler(SIG_IGN);
//// set_jobctrl_sighandler(SIG_IGN);
/* Going to fork a child per each pipe member */
pi->alive_cmds = 0;
@ -2486,9 +2670,9 @@ static int run_pipe(struct pipe *pi)
command->pid = BB_MMU ? fork() : vfork();
if (!command->pid) { /* child */
if (ENABLE_HUSH_JOB)
die_sleep = 0; /* let nofork's xfuncs die */
#if ENABLE_HUSH_JOB
die_sleep = 0; /* let nofork's xfuncs die */
/* Every child adds itself to new process group
* with pgid == pid_of_first_child_in_pipe */
if (G.run_list_level == 1 && G.interactive_fd) {
@ -2514,9 +2698,9 @@ 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);
//// set_jobctrl_sighandler(SIG_DFL);
//// set_misc_sighandler(SIG_DFL);
//// signal(SIGCHLD, SIG_DFL);
/* Stores to nommu_save list of env vars putenv'ed
* (NOMMU, on MMU we don't need that) */
/* cast away volatility... */
@ -2693,6 +2877,8 @@ 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
#if ENABLE_HUSH_JOB
/* Example of nested list: "while true; do { sleep 1 | exit 2; } done".
* We are saving state before entering outermost list ("while...done")
@ -2713,27 +2899,27 @@ static int run_list(struct pipe *pi)
restore_nofork_data(&G.nofork_save);
}
#endif
if (G.ctrl_z_flag) {
/* ctrl-Z has forked and stored pid of the child in pi->pid.
* Remember this child as background job */
insert_bg_job(pi);
} else {
//// if (G.ctrl_z_flag) {
//// /* ctrl-Z has forked and stored pid of the child in pi->pid.
//// * Remember this child as background job */
//// insert_bg_job(pi);
//// } else {
/* ctrl-C. We just stop doing whatever we were doing */
bb_putchar('\n');
}
//// }
USE_HUSH_LOOPS(loop_top = NULL;)
USE_HUSH_LOOPS(G.depth_of_loop = 0;)
rcode = 0;
goto ret;
}
/* ctrl-Z handler will store pid etc in pi */
G.toplevel_list = pi;
G.ctrl_z_flag = 0;
#if ENABLE_FEATURE_SH_STANDALONE
G.nofork_save.saved = 0; /* in case we will run a nofork later */
#endif
signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
signal(SIGINT, handler_ctrl_c);
//// /* ctrl-Z handler will store pid etc in pi */
//// G.toplevel_list = pi;
//// G.ctrl_z_flag = 0;
////#if ENABLE_FEATURE_SH_STANDALONE
//// G.nofork_save.saved = 0; /* in case we will run a nofork later */
////#endif
//// signal_SA_RESTART_empty_mask(SIGTSTP, handler_ctrl_z);
//// signal(SIGINT, handler_ctrl_c);
}
#endif /* JOB */
@ -2854,11 +3040,17 @@ static int run_list(struct pipe *pi)
continue; /* not matched yet, skip this pipe */
}
#endif
if (pi->num_cmds == 0)
goto check_jobs_and_continue;
/* Just pressing <enter> in shell should check for jobs.
* OTOH, in non-interactive shell this is useless
* and only leads to extra job checks */
if (pi->num_cmds == 0) {
if (G.interactive_fd)
goto check_jobs_and_continue;
continue;
}
/* After analyzing all keywords and conditions, we decided
* to execute this pipe. NB: has to do checkjobs(NULL)
* to execute this pipe. NB: have to do checkjobs(NULL)
* after run_pipe() to collect any background children,
* even if list execution is to be stopped. */
debug_printf_exec(": run_pipe with %d members\n", pi->num_cmds);
@ -2871,6 +3063,7 @@ static int run_list(struct pipe *pi)
if (r != -1) {
/* we only ran a builtin: rcode is already known
* and we don't need to wait for anything. */
check_and_run_traps();
#if ENABLE_HUSH_LOOPS
/* was it "break" or "continue"? */
if (G.flag_break_continue) {
@ -2895,6 +3088,7 @@ static int run_list(struct pipe *pi)
/* even bash 3.2 doesn't do that well with nested bg:
* try "{ { sleep 10; echo DEEP; } & echo HERE; } &".
* I'm NOT treating inner &'s as jobs */
check_and_run_traps();
#if ENABLE_HUSH_JOB
if (G.run_list_level == 1)
insert_bg_job(pi);
@ -2905,11 +3099,13 @@ static int run_list(struct pipe *pi)
if (G.run_list_level == 1 && G.interactive_fd) {
/* waits for completion, then fg's main shell */
rcode = checkjobs_and_fg_shell(pi);
check_and_run_traps();
debug_printf_exec(": checkjobs_and_fg_shell returned %d\n", rcode);
} else
#endif
{ /* this one just waits for completion */
rcode = checkjobs(pi);
check_and_run_traps();
debug_printf_exec(": checkjobs returned %d\n", rcode);
}
}
@ -2948,17 +3144,18 @@ static int run_list(struct pipe *pi)
} /* for (pi) */
#if ENABLE_HUSH_JOB
if (G.ctrl_z_flag) {
/* ctrl-Z forked somewhere in the past, we are the child,
* and now we completed running the list. Exit. */
//TODO: _exit?
exit(rcode);
}
//// if (G.ctrl_z_flag) {
//// /* ctrl-Z forked somewhere in the past, we are the child,
//// * and now we completed running the list. Exit. */
//////TODO: _exit?
//// exit(rcode);
//// }
ret:
if (!--G.run_list_level && G.interactive_fd) {
signal(SIGTSTP, SIG_IGN);
signal(SIGINT, SIG_IGN);
}
G.run_list_level--;
//// if (!G.run_list_level && G.interactive_fd) {
//// signal(SIGTSTP, SIG_IGN);
//// signal(SIGINT, SIG_IGN);
//// }
#endif
debug_printf_exec("run_list lvl %d return %d\n", G.run_list_level + 1, rcode);
#if ENABLE_HUSH_LOOPS
@ -3478,10 +3675,10 @@ static FILE *generate_stream_from_list(struct pipe *head)
/* 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. */
/*set_jobctrl_sighandler(SIG_IGN);*/
set_misc_sighandler(SIG_DFL);
//// /* 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. */
_exit(run_list(head));
}
@ -4287,7 +4484,6 @@ static void setup_job_control(void)
pid_t shell_pgrp;
shell_pgrp = getpgrp();
close_on_exec_on(G.interactive_fd);
/* If we were ran as 'hush &',
* sleep until we are in the foreground. */
@ -4298,8 +4494,8 @@ static void setup_job_control(void)
}
/* Ignore job-control and misc signals. */
set_jobctrl_sighandler(SIG_IGN);
set_misc_sighandler(SIG_IGN);
//// set_jobctrl_sighandler(SIG_IGN);
//// set_misc_sighandler(SIG_IGN);
//huh? signal(SIGCHLD, SIG_IGN);
/* We _must_ restore tty pgrp on fatal signals */
@ -4312,6 +4508,16 @@ static void setup_job_control(void)
}
#endif
static int set_mode(const char cstate, const char mode)
{
int state = (cstate == '-' ? 1 : 0);
switch (mode) {
case 'n': G.fake_mode = state; break;
case 'x': /*G.debug_mode = state;*/ break;
default: return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int hush_main(int argc, char **argv)
@ -4408,7 +4614,7 @@ int hush_main(int argc, char **argv)
break;
case 'n':
case 'x':
if (!builtin_set_mode('-', opt))
if (!set_mode('-', opt))
break;
default:
#ifndef BB_VER
@ -4447,6 +4653,7 @@ int hush_main(int argc, char **argv)
// to (inadvertently) close/redirect it
}
}
init_signal_mask();
debug_printf("G.interactive_fd=%d\n", G.interactive_fd);
if (G.interactive_fd) {
fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
@ -4475,9 +4682,10 @@ int hush_main(int argc, char **argv)
}
if (G.interactive_fd) {
fcntl(G.interactive_fd, F_SETFD, FD_CLOEXEC);
set_misc_sighandler(SIG_IGN);
//// set_misc_sighandler(SIG_IGN);
}
}
init_signal_mask();
#endif
#if ENABLE_HUSH_INTERACTIVE && !ENABLE_FEATURE_SH_EXTRA_QUIET
@ -4530,93 +4738,63 @@ int lash_main(int argc, char **argv)
/*
* Built-ins
*/
/* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#trap
*
* Traps are also evaluated immediately instead of being delayed properly:
* http://www.opengroup.org/onlinepubs/9699919799/utilities/V3_chap02.html#tag_18_11
* Example: hush -c 'trap "echo hi" 31; sleep 10; echo moo' & sleep 1; kill -31 $!
* "hi" should not be displayed until the sleep finishes
* This will have to get fixed ...
*/
static void handle_trap(int sig)
{
int save_errno, save_rcode;
char *argv[] = { NULL, G.traps[sig].cmd, NULL };
/* Race! We transitioned from handled to ignore/default, but
* the signal came in after updating .cmd but before we could
* register the new signal handler.
*/
if (!argv[1] || argv[1][0] == '\0')
return;
/* need to save/restore errno/$? across traps */
save_errno = errno;
save_rcode = G.last_return_code;
builtin_eval(argv);
errno = save_errno;
G.last_return_code = save_rcode;
}
static int builtin_trap(char **argv)
{
size_t i;
int i;
int sig;
bool ign = false;
char *new_cmd = NULL;
char *new_cmd;
if (!G.traps)
G.traps = xzalloc(sizeof(*G.traps) * NSIG);
G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
if (!argv[1]) {
/* No args: print all trapped. This isn't 100% correct as we should
* be escaping the cmd so that it can be pasted back in ...
*/
for (i = 0; i < NSIG; ++i)
if (G.traps[i].cmd)
printf("trap -- '%s' %s\n", G.traps[i].cmd, get_signame(i));
if (G.traps[i])
printf("trap -- '%s' %s\n", G.traps[i], get_signame(i));
return EXIT_SUCCESS;
}
/* first arg is decimal: reset all specified */
sig = bb_strtou(argv[1], NULL, 10);
new_cmd = NULL;
i = 0;
/* if first arg is decimal: reset all specified */
sig = bb_strtou(*++argv, NULL, 10);
if (errno == 0) {
int ret;
i = 0;
set_all:
ret = EXIT_SUCCESS;
while (argv[++i]) {
char *old_cmd;
sig = get_signum(argv[i]);
while (*argv) {
sig = get_signum(*argv++);
if (sig < 0 || sig >= NSIG) {
ret = EXIT_FAILURE;
/* mimic bash message exactly */
bb_perror_msg("trap: %s: invalid signal specification", argv[i]);
continue;
}
/* Make sure .cmd is always a valid command list since
* signals can occur at any time ...
*/
old_cmd = G.traps[sig].cmd;
G.traps[sig].cmd = xstrdup(new_cmd);
free(old_cmd);
free(G.traps[sig]);
G.traps[sig] = xstrdup(new_cmd);
debug_printf("trap: setting SIG%s (%i) to: %s",
get_signame(sig), sig, G.traps[sig].cmd);
debug_printf("trap: setting SIG%s (%i) to '%s'",
get_signame(sig), sig, G.traps[sig]);
/* There is no signal for 0 (EXIT) */
if (sig == 0)
continue;
if (new_cmd) {
/* add/update a handler */
struct sigaction act = {
.sa_handler = ign ? SIG_IGN : handle_trap,
.sa_flags = SA_RESTART,
};
sigemptyset(&act.sa_mask);
sigaction(sig, &act, old_cmd ? NULL : &G.traps[sig].oact);
} else if (old_cmd && !new_cmd)
/* there was a handler, and we are removing it */
sigaction_set(sig, &G.traps[sig].oact);
sigaddset(&G.blocked_set, sig);
} else {
/* there was a trap handler, we are removing it
* (if sig has non-DFL handling,
* we don't need to do anything) */
if (sig < 32 && (G.non_DFL_mask & (1 << sig)))
continue;
sigdelset(&G.blocked_set, sig);
}
sigprocmask(SIG_SETMASK, &G.blocked_set, NULL);
}
return ret;
}
@ -4624,17 +4802,15 @@ static int builtin_trap(char **argv)
/* first arg is "-": reset all specified to default */
/* first arg is "": ignore all specified */
/* everything else: execute first arg upon signal */
if (!argv[2]) {
if (!argv[1]) {
bb_error_msg("trap: invalid arguments");
return EXIT_FAILURE;
}
if (LONE_DASH(argv[1]))
if (LONE_DASH(*argv))
/* nothing! */;
else
new_cmd = argv[1];
if (argv[1][0] == '\0')
ign = true;
i = 1;
new_cmd = *argv;
argv++;
goto set_all;
}
@ -4891,16 +5067,6 @@ static int builtin_read(char **argv)
*
* So far, we only support "set -- [argument...]" and some of the short names.
*/
static int builtin_set_mode(const char cstate, const char mode)
{
int state = (cstate == '-' ? 1 : 0);
switch (mode) {
case 'n': G.fake_mode = state; break;
case 'x': /*G.debug_mode = state;*/ break;
default: return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}
static int builtin_set(char **argv)
{
int n;
@ -4922,7 +5088,7 @@ static int builtin_set(char **argv)
if (arg[0] == '+' || arg[0] == '-') {
for (n = 1; arg[n]; ++n)
if (builtin_set_mode(arg[0], arg[n]))
if (set_mode(arg[0], arg[n]))
goto error;
continue;
}
@ -5068,27 +5234,29 @@ static int builtin_wait(char **argv)
int ret = EXIT_SUCCESS;
int status;
if (argv[1] == NULL)
if (*++argv == NULL)
/* don't care about exit status */
wait(&status);
wait(NULL);
while (argv[1]) {
pid_t pid = bb_strtou(argv[1], NULL, 10);
while (*argv) {
pid_t pid = bb_strtou(*argv, NULL, 10);
if (errno) {
bb_perror_msg("wait %s", argv[1]);
/* mimic bash message */
bb_error_msg("wait: '%s': not a pid or valid job spec", *argv);
return EXIT_FAILURE;
} else if (waitpid(pid, &status, 0) == pid) {
}
if (waitpid(pid, &status, 0) == pid) {
if (WIFSIGNALED(status))
ret = 128 + WTERMSIG(status);
else if (WIFEXITED(status))
ret = WEXITSTATUS(status);
else
else /* wtf? */
ret = EXIT_FAILURE;
} else {
bb_perror_msg("wait %s", argv[1]);
bb_perror_msg("wait %s", *argv);
ret = 127;
}
++argv;
argv++;
}
return ret;