svn commit: [26143] trunk/busybox/shell
vda at busybox.net
vda at busybox.net
Sat Apr 18 01:23:21 UTC 2009
Author: vda
Date: 2009-04-18 01:23:21 +0000 (Sat, 18 Apr 2009)
New Revision: 26143
Log:
hush: implement proper SIGHUP handling
function old new delta
check_and_run_traps 164 229 +65
insert_bg_job 376 366 -10
hush_main 937 927 -10
Modified:
trunk/busybox/shell/hush.c
Changeset:
Modified: trunk/busybox/shell/hush.c
===================================================================
--- trunk/busybox/shell/hush.c 2009-04-17 23:53:15 UTC (rev 26142)
+++ trunk/busybox/shell/hush.c 2009-04-18 01:23:21 UTC (rev 26143)
@@ -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 @@
* "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 @@
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 @@
// 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 @@
/* 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;
@@ -1201,7 +1154,66 @@
#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)
{
/* xrealloc_getcwd_or_warn(arg) calls free(arg),
@@ -2061,7 +2073,9 @@
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 @@
}
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 @@
}
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 @@
}
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 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;
+ for (job = G.job_list; job; job = job->next)
+ if (job->jobid >= pi->jobid)
+ pi->jobid = job->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;
- }
+ /* Add job to the list of running jobs */
+ jobp = &G.job_list;
+ while ((job = *jobp) != NULL)
+ jobp = &job->next;
+ job = *jobp = xmalloc(sizeof(*job));
- /* 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 */
+ *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 @@
* 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 @@
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 @@
/* 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 @@
#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 @@
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 @@
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 */
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