diff options
Diffstat (limited to 'shell/hush.c')
| -rw-r--r-- | shell/hush.c | 404 |
1 files changed, 230 insertions, 174 deletions
diff --git a/shell/hush.c b/shell/hush.c index c80429d5c..1f8a3e607 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -44,6 +44,8 @@ * special variables (done: PWD, PPID, RANDOM) * tilde expansion * aliases + * kill %jobspec + * wait %jobspec * follow IFS rules more precisely, including update semantics * builtins mandated by standards we don't support: * [un]alias, command, fc, getopts, newgrp, readonly, times @@ -7041,16 +7043,134 @@ static void delete_finished_bg_job(struct pipe *pi) } #endif /* JOB */ -/* Check to see if any processes have exited -- if they - * have, figure out why and see if a job has completed */ -static int checkjobs(struct pipe *fg_pipe) +static int process_wait_result(struct pipe *fg_pipe, pid_t childpid, int status) { - int attributes; - int status; #if ENABLE_HUSH_JOB struct pipe *pi; #endif - pid_t childpid; + int i, dead; + + dead = WIFEXITED(status) || WIFSIGNALED(status); + +#if DEBUG_JOBS + if (WIFSTOPPED(status)) + debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n", + childpid, WSTOPSIG(status), WEXITSTATUS(status)); + if (WIFSIGNALED(status)) + debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n", + childpid, WTERMSIG(status), WEXITSTATUS(status)); + if (WIFEXITED(status)) + debug_printf_jobs("pid %d exited, exitcode %d\n", + childpid, WEXITSTATUS(status)); +#endif + /* Were we asked to wait for a fg pipe? */ + if (fg_pipe) { + i = fg_pipe->num_cmds; + while (--i >= 0) { + debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid); + if (fg_pipe->cmds[i].pid != childpid) + continue; + if (dead) { + int ex; + fg_pipe->cmds[i].pid = 0; + fg_pipe->alive_cmds--; + ex = WEXITSTATUS(status); + /* bash prints killer signal's name for *last* + * process in pipe (prints just newline for SIGINT/SIGPIPE). + * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT) + */ + if (WIFSIGNALED(status)) { + int sig = WTERMSIG(status); + if (i == fg_pipe->num_cmds-1) + /* TODO: use strsignal() instead for bash compat? but that's bloat... */ + puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig)); + /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */ + /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here? + * Maybe we need to use sig | 128? */ + ex = sig + 128; + } + fg_pipe->cmds[i].cmd_exitcode = ex; + } else { + fg_pipe->stopped_cmds++; + } + debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n", + fg_pipe->alive_cmds, fg_pipe->stopped_cmds); + if (fg_pipe->alive_cmds == fg_pipe->stopped_cmds) { + /* All processes in fg pipe have exited or stopped */ + int rcode = 0; + i = fg_pipe->num_cmds; + while (--i >= 0) { + rcode = fg_pipe->cmds[i].cmd_exitcode; + /* usually last process gives overall exitstatus, + * but with "set -o pipefail", last *failed* process does */ + if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0) + break; + } + IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;) +/* Note: *non-interactive* bash does not continue if all processes in fg pipe + * are stopped. Testcase: "cat | cat" in a script (not on command line!) + * and "killall -STOP cat" */ + if (G_interactive_fd) { +#if ENABLE_HUSH_JOB + if (fg_pipe->alive_cmds != 0) + insert_bg_job(fg_pipe); +#endif + return rcode; + } + if (fg_pipe->alive_cmds == 0) + return rcode; + } + /* There are still running processes in the fg_pipe */ + return -1; + } + /* It wasnt in fg_pipe, look for process in bg pipes */ + } + +#if ENABLE_HUSH_JOB + /* We were asked to wait for bg or orphaned children */ + /* No need to remember exitcode in this case */ + for (pi = G.job_list; pi; pi = pi->next) { + for (i = 0; i < pi->num_cmds; i++) { + if (pi->cmds[i].pid == childpid) + goto found_pi_and_prognum; + } + } + /* Happens when shell is used as init process (init=/bin/sh) */ + debug_printf("checkjobs: pid %d was not in our list!\n", childpid); + return -1; /* this wasn't a process from fg_pipe */ + + found_pi_and_prognum: + if (dead) { + /* child exited */ + pi->cmds[i].pid = 0; + pi->cmds[i].cmd_exitcode = WEXITSTATUS(status); + if (WIFSIGNALED(status)) + pi->cmds[i].cmd_exitcode = 128 + WTERMSIG(status); + pi->alive_cmds--; + if (!pi->alive_cmds) { + if (G_interactive_fd) + printf(JOB_STATUS_FORMAT, pi->jobid, + "Done", pi->cmdtext); + delete_finished_bg_job(pi); + } + } else { + /* child stopped */ + pi->stopped_cmds++; + } +#endif + return -1; /* this wasn't a process from fg_pipe */ +} + +/* Check to see if any processes have exited -- if they have, + * figure out why and see if a job has completed. + * Alternatively (fg_pipe == NULL, waitfor_pid != 0), + * wait for a specific pid to complete, return exitcode+1 + * (this allows to distinguish zero as "no children exited" result). + */ +static int checkjobs(struct pipe *fg_pipe, pid_t waitfor_pid) +{ + int attributes; + int status; int rcode = 0; debug_printf_jobs("checkjobs %p\n", fg_pipe); @@ -7087,12 +7207,10 @@ static int checkjobs(struct pipe *fg_pipe) * 1 <========== bg pipe is not fully done, but exitcode is already known! * [hush 1.14.0: yes we do it right] */ - wait_more: while (1) { - int i; - int dead; - + pid_t childpid; #if ENABLE_HUSH_FAST + int i; i = G.count_SIGCHLD; #endif childpid = waitpid(-1, &status, attributes); @@ -7106,112 +7224,24 @@ static int checkjobs(struct pipe *fg_pipe) //bb_error_msg("[%d] checkjobs: waitpid returned <= 0, G.count_SIGCHLD:%d G.handled_SIGCHLD:%d", getpid(), G.count_SIGCHLD, G.handled_SIGCHLD); } #endif + /* ECHILD (no children), or 0 (no change in children status) */ + rcode = childpid; break; } - dead = WIFEXITED(status) || WIFSIGNALED(status); - -#if DEBUG_JOBS - if (WIFSTOPPED(status)) - debug_printf_jobs("pid %d stopped by sig %d (exitcode %d)\n", - childpid, WSTOPSIG(status), WEXITSTATUS(status)); - if (WIFSIGNALED(status)) - debug_printf_jobs("pid %d killed by sig %d (exitcode %d)\n", - childpid, WTERMSIG(status), WEXITSTATUS(status)); - if (WIFEXITED(status)) - debug_printf_jobs("pid %d exited, exitcode %d\n", - childpid, WEXITSTATUS(status)); -#endif - /* Were we asked to wait for fg pipe? */ - if (fg_pipe) { - i = fg_pipe->num_cmds; - while (--i >= 0) { - debug_printf_jobs("check pid %d\n", fg_pipe->cmds[i].pid); - if (fg_pipe->cmds[i].pid != childpid) - continue; - if (dead) { - int ex; - fg_pipe->cmds[i].pid = 0; - fg_pipe->alive_cmds--; - ex = WEXITSTATUS(status); - /* bash prints killer signal's name for *last* - * process in pipe (prints just newline for SIGINT/SIGPIPE). - * Mimic this. Example: "sleep 5" + (^\ or kill -QUIT) - */ - if (WIFSIGNALED(status)) { - int sig = WTERMSIG(status); - if (i == fg_pipe->num_cmds-1) - /* TODO: use strsignal() instead for bash compat? but that's bloat... */ - puts(sig == SIGINT || sig == SIGPIPE ? "" : get_signame(sig)); - /* TODO: if (WCOREDUMP(status)) + " (core dumped)"; */ - /* TODO: MIPS has 128 sigs (1..128), what if sig==128 here? - * Maybe we need to use sig | 128? */ - ex = sig + 128; - } - fg_pipe->cmds[i].cmd_exitcode = ex; - } else { - fg_pipe->stopped_cmds++; - } - debug_printf_jobs("fg_pipe: alive_cmds %d stopped_cmds %d\n", - fg_pipe->alive_cmds, fg_pipe->stopped_cmds); - if (fg_pipe->alive_cmds == fg_pipe->stopped_cmds) { - /* All processes in fg pipe have exited or stopped */ - i = fg_pipe->num_cmds; - while (--i >= 0) { - rcode = fg_pipe->cmds[i].cmd_exitcode; - /* usually last process gives overall exitstatus, - * but with "set -o pipefail", last *failed* process does */ - if (G.o_opt[OPT_O_PIPEFAIL] == 0 || rcode != 0) - break; - } - IF_HAS_KEYWORDS(if (fg_pipe->pi_inverted) rcode = !rcode;) -/* Note: *non-interactive* bash does not continue if all processes in fg pipe - * are stopped. Testcase: "cat | cat" in a script (not on command line!) - * and "killall -STOP cat" */ - if (G_interactive_fd) { -#if ENABLE_HUSH_JOB - if (fg_pipe->alive_cmds != 0) - insert_bg_job(fg_pipe); -#endif - return rcode; - } - if (fg_pipe->alive_cmds == 0) - return rcode; - } - /* There are still running processes in the fg pipe */ - goto wait_more; /* do waitpid again */ - } - /* it wasnt fg_pipe, look for process in bg pipes */ - } - -#if ENABLE_HUSH_JOB - /* We asked to wait for bg or orphaned children */ - /* No need to remember exitcode in this case */ - for (pi = G.job_list; pi; pi = pi->next) { - for (i = 0; i < pi->num_cmds; i++) { - if (pi->cmds[i].pid == childpid) - goto found_pi_and_prognum; - } + rcode = process_wait_result(fg_pipe, childpid, status); + if (rcode >= 0) { + /* fg_pipe exited or stopped */ + break; } - /* Happens when shell is used as init process (init=/bin/sh) */ - debug_printf("checkjobs: pid %d was not in our list!\n", childpid); - continue; /* do waitpid again */ - - found_pi_and_prognum: - if (dead) { - /* child exited */ - pi->cmds[i].pid = 0; - pi->alive_cmds--; - if (!pi->alive_cmds) { - if (G_interactive_fd) - printf(JOB_STATUS_FORMAT, pi->jobid, - "Done", pi->cmdtext); - delete_finished_bg_job(pi); - } - } else { - /* child stopped */ - pi->stopped_cmds++; + if (childpid == waitfor_pid) { + rcode = WEXITSTATUS(status); + if (WIFSIGNALED(status)) + rcode = 128 + WTERMSIG(status); + rcode++; + break; /* "wait PID" called us, give it exitcode+1 */ } -#endif + /* This wasn't one of our processes, or */ + /* fg_pipe still has running processes, do waitpid again */ } /* while (waitpid succeeds)... */ return rcode; @@ -7221,7 +7251,7 @@ static int checkjobs(struct pipe *fg_pipe) static int checkjobs_and_fg_shell(struct pipe *fg_pipe) { pid_t p; - int rcode = checkjobs(fg_pipe); + int rcode = checkjobs(fg_pipe, 0 /*(no pid to wait for)*/); if (G_saved_tty_pgrp) { /* Job finished, move the shell to the foreground */ p = getpgrp(); /* our process group id */ @@ -7893,7 +7923,7 @@ static int run_list(struct pipe *pi) /* else: e.g. "continue 2" should *break* once, *then* continue */ } /* else: "while... do... { we are here (innermost list is not a loop!) };...done" */ if (G.depth_break_continue != 0 || fbc == BC_BREAK) { - checkjobs(NULL); + checkjobs(NULL, 0 /*(no pid to wait for)*/); break; } /* "continue": simulate end of loop */ @@ -7902,7 +7932,7 @@ static int run_list(struct pipe *pi) } #endif if (G_flag_return_in_progress == 1) { - checkjobs(NULL); + checkjobs(NULL, 0 /*(no pid to wait for)*/); break; } } else if (pi->followup == PIPE_BG) { @@ -7929,7 +7959,7 @@ static int run_list(struct pipe *pi) } else #endif { /* This one just waits for completion */ - rcode = checkjobs(pi); + rcode = checkjobs(pi, 0 /*(no pid to wait for)*/); debug_printf_exec(": checkjobs exitcode %d\n", rcode); check_and_run_traps(); } @@ -7943,7 +7973,7 @@ static int run_list(struct pipe *pi) cond_code = rcode; #endif check_jobs_and_continue: - checkjobs(NULL); + checkjobs(NULL, 0 /*(no pid to wait for)*/); dont_check_jobs_but_continue: ; #if ENABLE_HUSH_LOOPS /* Beware of "while false; true; do ..."! */ @@ -9408,9 +9438,68 @@ static int FAST_FUNC builtin_umask(char **argv) } /* http://www.opengroup.org/onlinepubs/9699919799/utilities/wait.html */ +static int wait_for_child_or_signal(pid_t waitfor_pid) +{ + int ret = 0; + for (;;) { + int sig; + sigset_t oldset, allsigs; + + /* waitpid is not interruptible by SA_RESTARTed + * signals which we use. Thus, this ugly dance: + */ + + /* Make sure possible SIGCHLD is stored in kernel's + * pending signal mask before we call waitpid. + * Or else we may race with SIGCHLD, lose it, + * and get stuck in sigwaitinfo... + */ + sigfillset(&allsigs); + sigprocmask(SIG_SETMASK, &allsigs, &oldset); + + if (!sigisemptyset(&G.pending_set)) { + /* Crap! we raced with some signal! */ + // sig = 0; + goto restore; + } + + /*errno = 0; - checkjobs does this */ + ret = checkjobs(NULL, waitfor_pid); /* waitpid(WNOHANG) inside */ + /* if ECHILD, there are no children (ret is -1 or 0) */ + /* if ret == 0, no children changed state */ + /* if ret != 0, it's exitcode+1 of exited waitfor_pid child */ + if (errno == ECHILD || ret--) { + if (ret < 0) /* if ECHILD, may need to fix */ + ret = 0; + sigprocmask(SIG_SETMASK, &oldset, NULL); + break; + } + + /* Wait for SIGCHLD or any other signal */ + //sig = sigwaitinfo(&allsigs, NULL); + /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */ + /* Note: sigsuspend invokes signal handler */ + sigsuspend(&oldset); + restore: + sigprocmask(SIG_SETMASK, &oldset, NULL); + + /* So, did we get a signal? */ + //if (sig > 0) + // raise(sig); /* run handler */ + sig = check_and_run_traps(); + if (sig /*&& sig != SIGCHLD - always true */) { + /* see note 2 */ + ret = 128 + sig; + break; + } + /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */ + } + return ret; +} + static int FAST_FUNC builtin_wait(char **argv) { - int ret = EXIT_SUCCESS; + int ret; int status; argv = skip_dash_dash(argv); @@ -9431,74 +9520,41 @@ static int FAST_FUNC builtin_wait(char **argv) * ^C <-- after ~4 sec from keyboard * $ */ - while (1) { - int sig; - sigset_t oldset, allsigs; - - /* waitpid is not interruptible by SA_RESTARTed - * signals which we use. Thus, this ugly dance: - */ - - /* Make sure possible SIGCHLD is stored in kernel's - * pending signal mask before we call waitpid. - * Or else we may race with SIGCHLD, lose it, - * and get stuck in sigwaitinfo... - */ - sigfillset(&allsigs); - sigprocmask(SIG_SETMASK, &allsigs, &oldset); - - if (!sigisemptyset(&G.pending_set)) { - /* Crap! we raced with some signal! */ - // sig = 0; - goto restore; - } - - checkjobs(NULL); /* waitpid(WNOHANG) inside */ - if (errno == ECHILD) { - sigprocmask(SIG_SETMASK, &oldset, NULL); - break; - } - - /* Wait for SIGCHLD or any other signal */ - //sig = sigwaitinfo(&allsigs, NULL); - /* It is vitally important for sigsuspend that SIGCHLD has non-DFL handler! */ - /* Note: sigsuspend invokes signal handler */ - sigsuspend(&oldset); - restore: - sigprocmask(SIG_SETMASK, &oldset, NULL); - - /* So, did we get a signal? */ - //if (sig > 0) - // raise(sig); /* run handler */ - sig = check_and_run_traps(); - if (sig /*&& sig != SIGCHLD - always true */) { - /* see note 2 */ - ret = 128 + sig; - break; - } - /* SIGCHLD, or no signal, or ignored one, such as SIGQUIT. Repeat */ - } - return ret; + return wait_for_child_or_signal(0 /*(no pid to wait for)*/); } - /* This is probably buggy wrt interruptible-ness */ - while (*argv) { + /* TODO: support "wait %jobspec" */ + do { pid_t pid = bb_strtou(*argv, NULL, 10); - if (errno) { + if (errno || pid <= 0) { /* mimic bash message */ bb_error_msg("wait: '%s': not a pid or valid job spec", *argv); return EXIT_FAILURE; } - if (waitpid(pid, &status, 0) == pid) { + /* Do we have such child? */ + ret = waitpid(pid, &status, WNOHANG); + if (ret < 0) { + /* No */ + if (errno == ECHILD) { + /* Example: "wait 1". mimic bash message */ + bb_error_msg("wait: pid %d is not a child of this shell", (int)pid); + } else { + /* ??? */ + bb_perror_msg("wait %s", *argv); + } + ret = 127; + } else if (ret == 0) { + /* Yes, and it still runs */ + ret = wait_for_child_or_signal(pid); + } else { + /* Yes, and it just exited */ + process_wait_result(NULL, pid, status); ret = WEXITSTATUS(status); if (WIFSIGNALED(status)) ret = 128 + WTERMSIG(status); - } else { - bb_perror_msg("wait %s", *argv); - ret = 127; } argv++; - } + } while (*argv); return ret; } |