diff options
| -rw-r--r-- | shell/hush.c | 203 |
1 files changed, 108 insertions, 95 deletions
diff --git a/shell/hush.c b/shell/hush.c index f9757a7..72589fd 100644 --- a/shell/hush.c +++ b/shell/hush.c @@ -52,11 +52,10 @@ * grep for "TODO" and fix (some of them are easy) * change { and } from special chars to reserved words * $var refs in function do not pick up values set by "var=val func" - * builtins: return, ulimit + * builtins: ulimit * follow IFS rules more precisely, including update semantics * figure out what to do with backslash-newline * continuation lines, both explicit and implicit - done? - * SIGHUP handling * separate job control from interactiveness * (testcase: booting with init=/bin/hush does not show prompt (2009-04)) * @@ -1070,8 +1069,9 @@ static void restore_G_args(save_arg_t *sv, char **argv) * "trap 'cmd' SIGxxx": * set bit in blocked_set (even if 'cmd' is '') * after [v]fork, if we plan to be a shell: - * nothing for {} child shell (say, "true | { true; true; } | true") - * unset all traps if () shell. + * unblock signals with special interactive handling + * (child shell is not interactive), + * unset all traps (note: regardless of child shell's type - {}, (), etc) * 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. @@ -1084,9 +1084,9 @@ enum { SPECIAL_INTERACTIVE_SIGS = 0 #if ENABLE_HUSH_JOB | (1 << SIGTTIN) | (1 << SIGTTOU) | (1 << SIGTSTP) + | (1 << SIGHUP) #endif | (1 << SIGTERM) -//TODO | (1 << SIGHUP) | (1 << SIGINT) }; @@ -1095,53 +1095,6 @@ enum { // G.count_SIGCHLD++; //} -static int check_and_run_traps(int sig) -{ - static const struct timespec zero_timespec = { 0, 0 }; - smalluint save_rcode; - int last_sig = 0; - - if (sig) - goto jump_in; - while (1) { - sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec); - if (sig <= 0) - break; - jump_in: - last_sig = sig; - 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_exitcode; - builtin_eval(argv); - free(argv[1]); - G.last_exitcode = save_rcode; - } /* else: "" trap, ignoring signal */ - continue; - } - /* not a trap: special action */ - switch (sig) { -// case SIGCHLD: -// G.count_SIGCHLD++; -// break; - case SIGINT: -//TODO: add putchar('\n') also when we detect that child was killed (sleep 5 + ^C) - /* Builtin was ^C'ed, make it look prettier: */ - bb_putchar('\n'); - G.flag_SIGINT = 1; - break; -//TODO -// case SIGHUP: ... -// break; - default: /* ignored: */ - /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */ - break; - } - } - return last_sig; -} - #if ENABLE_HUSH_JOB /* After [v]fork, in child: do not restore tty pgrp on xfunc death */ @@ -1151,7 +1104,7 @@ static int check_and_run_traps(int sig) /* 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) + * (will 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; @@ -1201,6 +1154,65 @@ static void hush_exit(int exitcode) #endif } +static int check_and_run_traps(int sig) +{ + static const struct timespec zero_timespec = { 0, 0 }; + smalluint save_rcode; + int last_sig = 0; + + if (sig) + goto jump_in; + while (1) { + sig = sigtimedwait(&G.blocked_set, NULL, &zero_timespec); + if (sig <= 0) + break; + jump_in: + last_sig = sig; + 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_exitcode; + builtin_eval(argv); + free(argv[1]); + G.last_exitcode = save_rcode; + } /* else: "" trap, ignoring signal */ + continue; + } + /* not a trap: special action */ + switch (sig) { +// case SIGCHLD: +// G.count_SIGCHLD++; +// break; + case SIGINT: +//TODO: add putchar('\n') also when we detect that child was killed (sleep 5 + ^C) + /* Builtin was ^C'ed, make it look prettier: */ + bb_putchar('\n'); + G.flag_SIGINT = 1; + break; +#if ENABLE_HUSH_JOB + case SIGHUP: { + struct pipe *job; + /* bash is observed to signal whole process groups, + * not individual processes */ + for (job = G.job_list; job; job = job->next) { + if (job->pgrp <= 0) + continue; + debug_printf_exec("HUPing pgrp %d\n", job->pgrp); + if (kill(- job->pgrp, SIGHUP) == 0) + kill(- job->pgrp, SIGCONT); + } + sigexit(SIGHUP); + } +#endif + default: /* ignored: */ + /* SIGTERM, SIGQUIT, SIGTTIN, SIGTTOU, SIGTSTP */ + break; + } + } + return last_sig; +} + static const char *set_cwd(void) { @@ -2061,7 +2073,9 @@ static int expand_vars_to_list(o_string *output, int n, char *arg, char or_mask) case '`': /* <SPECIAL_VAR_SYMBOL>`cmd<SPECIAL_VAR_SYMBOL> */ *p = '\0'; arg++; -//TODO: can we just stuff it into "output" directly? + /* Can't just stuff it into output o_string, + * expanded result may need to be globbed + * and $IFS-splitted */ debug_printf_subst("SUBST '%s' first_ch %x\n", arg, first_ch); process_command_subs(&subst_result, arg); debug_printf_subst("SUBST RES '%s'\n", subst_result.data); @@ -2777,7 +2791,8 @@ static const struct function *find_function(const char *name) } funcp = funcp->next; } - debug_printf_exec("found function '%s'\n", name); + if (funcp) + debug_printf_exec("found function '%s'\n", name); return funcp; } @@ -2819,7 +2834,7 @@ static struct function *new_function(char *name) } goto skip; } - debug_printf_exec("remembering new function '%s'\n", command->argv[0]); + debug_printf_exec("remembering new function '%s'\n", name); funcp = *funcpp = xzalloc(sizeof(*funcp)); /*funcp->next = NULL;*/ skip: @@ -3059,8 +3074,11 @@ static const char *get_cmdtext(struct pipe *pi) } len = 0; - do len += strlen(*argv) + 1; while (*++argv); - pi->cmdtext = p = xmalloc(len); + do { + len += strlen(*argv) + 1; + } while (*++argv); + p = xmalloc(len); + pi->cmdtext = p;// = xmalloc(len); argv = pi->cmds[0].argv; do { len = strlen(*argv); @@ -3074,44 +3092,36 @@ static const char *get_cmdtext(struct pipe *pi) static void insert_bg_job(struct pipe *pi) { - struct pipe *thejob; + struct pipe *job, **jobp; int i; /* Linear search for the ID of the job to use */ pi->jobid = 1; - for (thejob = G.job_list; thejob; thejob = thejob->next) - if (thejob->jobid >= pi->jobid) - pi->jobid = thejob->jobid + 1; - - /* Add thejob to the list of running jobs */ - if (!G.job_list) { - thejob = G.job_list = xmalloc(sizeof(*thejob)); - } else { - for (thejob = G.job_list; thejob->next; thejob = thejob->next) - continue; - thejob->next = xmalloc(sizeof(*thejob)); - thejob = thejob->next; - } - - /* Physically copy the struct job */ - memcpy(thejob, pi, sizeof(struct pipe)); - thejob->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds); - /* We cannot copy entire pi->cmds[] vector! Double free()s will happen */ + for (job = G.job_list; job; job = job->next) + if (job->jobid >= pi->jobid) + pi->jobid = job->jobid + 1; + + /* Add job to the list of running jobs */ + jobp = &G.job_list; + while ((job = *jobp) != NULL) + jobp = &job->next; + job = *jobp = xmalloc(sizeof(*job)); + + *job = *pi; /* physical copy */ + job->next = NULL; + job->cmds = xzalloc(sizeof(pi->cmds[0]) * pi->num_cmds); + /* Cannot copy entire pi->cmds[] vector! This causes double frees */ for (i = 0; i < pi->num_cmds; i++) { -// TODO: do we really need to have so many fields which are just dead weight -// at execution stage? - thejob->cmds[i].pid = pi->cmds[i].pid; + job->cmds[i].pid = pi->cmds[i].pid; /* all other fields are not used and stay zero */ } - thejob->next = NULL; - thejob->cmdtext = xstrdup(get_cmdtext(pi)); + job->cmdtext = xstrdup(get_cmdtext(pi)); - /* We don't wait for background thejobs to return -- append it - to the list of backgrounded thejobs and leave it alone */ if (G_interactive_fd) - printf("[%d] %d %s\n", thejob->jobid, thejob->cmds[0].pid, thejob->cmdtext); - G.last_bg_pid = thejob->cmds[0].pid; - G.last_jobid = thejob->jobid; + printf("[%d] %d %s\n", job->jobid, job->cmds[0].pid, job->cmdtext); + /* Last command's pid goes to $! */ + G.last_bg_pid = job->cmds[job->num_cmds - 1].pid; + G.last_jobid = job->jobid; } static void remove_bg_job(struct pipe *pi) @@ -3306,7 +3316,7 @@ static int checkjobs_and_fg_shell(struct pipe* fg_pipe) * cmd || ... { list } || ... * If it is, then we can run cmd as a builtin, NOFORK [do we do this?], * or (if SH_STANDALONE) an applet, and we can run the { list } - * with run_list(). If it isn't one of these, we fork and exec cmd. + * with run_list. If it isn't one of these, we fork and exec cmd. * * Cases when we must fork: * non-single: cmd | cmd @@ -3942,7 +3952,11 @@ static int run_list(struct pipe *pi) check_and_run_traps(0); #if ENABLE_HUSH_JOB if (G.run_list_level == 1) +{ +debug_printf_exec("insert_bg_job1\n"); insert_bg_job(pi); +debug_printf_exec("insert_bg_job2\n"); +} #endif G.last_exitcode = rcode = EXIT_SUCCESS; debug_printf_exec(": cmd&: exitcode EXIT_SUCCESS\n"); @@ -5853,11 +5867,10 @@ static void set_fatal_handlers(void) /* bash 3.2 seems to handle these just like 'fatal' ones */ maybe_set_to_sigexit(SIGPIPE); maybe_set_to_sigexit(SIGALRM); -//TODO: disable and move down when proper SIGHUP handling is added - maybe_set_to_sigexit(SIGHUP ); - /* if we are interactive, [SIGHUP,] SIGTERM and SIGINT are masked. + /* 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 );*/ } @@ -6350,7 +6363,7 @@ static int builtin_exec(char **argv) #if !BB_MMU nommu_save_t dummy; #endif -// TODO: if exec fails, bash does NOT exit! We do... + /* TODO: if exec fails, bash does NOT exit! We do... */ pseudo_exec_argv(&dummy, argv, 0, NULL); /* never returns */ } @@ -6472,8 +6485,8 @@ static int builtin_fg_bg(char **argv) bb_error_msg("%s: %d: no such job", argv[0], jobnum); return EXIT_FAILURE; found: - // TODO: bash prints a string representation - // of job being foregrounded (like "sleep 1 | cat") + /* TODO: bash prints a string representation + * of job being foregrounded (like "sleep 1 | cat") */ if (argv[0][0] == 'f') { /* Put the job into the foreground. */ tcsetpgrp(G_interactive_fd, pi->pgrp); @@ -6705,7 +6718,7 @@ static int builtin_source(char **argv) if (*++argv == NULL) return EXIT_FAILURE; - /* TODO: search through $PATH is missing */ +// TODO: search through $PATH is missing input = fopen_or_warn(*argv, "r"); if (!input) { /* bb_perror_msg("%s", *argv); - done by fopen_or_warn */ |