[git commit] hush: fix login shell's signal handling; add -l option so that it's easier to test
Denys Vlasenko
vda.linux at googlemail.com
Thu May 12 00:10:33 UTC 2011
commit: http://git.busybox.net/busybox/commit/?id=f58f705c5812cec5d5308ae29baceeb648d08e24
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master
function old new delta
hush_main 958 1001 +43
install_special_sighandlers 47 52 +5
packed_usage 28752 28741 -11
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 2/1 up/down: 48/-11) Total: 37 bytes
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
shell/hush.c | 67 ++++++++++++++++++++++++++++++---------------------------
1 files changed, 35 insertions(+), 32 deletions(-)
diff --git a/shell/hush.c b/shell/hush.c
index b2c3a75..cdd4be4 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -260,7 +260,7 @@ typedef void (*hush_sighandler_t)(int);
* therefore we don't show them either.
*/
//usage:#define hush_trivial_usage
-//usage: "[-nx] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
+//usage: "[-nxl] [-c 'SCRIPT' [ARG0 [ARGS]] / FILE [ARGS]]"
//usage:#define hush_full_usage "\n\n"
//usage: "Unix shell interpreter"
@@ -1493,8 +1493,8 @@ static sighandler_t pick_sighandler(unsigned sig)
handler = record_pending_signo;
/* TTIN/TTOU/TSTS can't be set to record_pending_signo
* in order to ignore them: they will be raised
- * in an endless loop then when we try to do some
- * terminal ioctls! We do nave to _ignore_ these.
+ * in an endless loop when we try to do some
+ * terminal ioctls! We do have to _ignore_ these.
*/
if (SPECIAL_JOBSTOP_SIGS & sigmask)
handler = SIG_IGN;
@@ -1508,9 +1508,6 @@ static void hush_exit(int exitcode)
{
fflush_all();
if (G.exiting <= 0 && G.traps && G.traps[0] && G.traps[0][0]) {
- /* Prevent recursion:
- * trap "echo Hi; exit" EXIT; exit
- */
char *argv[3];
/* argv[0] is unused */
argv[1] = G.traps[0];
@@ -5474,7 +5471,8 @@ static void reset_traps_to_defaults(void)
G_fatal_sig_mask = 0;
#endif
G.special_sig_mask &= ~SPECIAL_INTERACTIVE_SIGS;
- /* SIGQUIT and maybe SPECIAL_JOBSTOP_SIGS remain set in G.special_sig_mask */
+ /* SIGQUIT,SIGCHLD and maybe SPECIAL_JOBSTOP_SIGS
+ * remain set in G.special_sig_mask */
if (!G.traps)
return;
@@ -5537,7 +5535,6 @@ static void re_execute_shell(char ***to_free, const char *s,
for (sig = 1; sig < NSIG; sig++) {
if (G.traps[sig] && !G.traps[sig][0])
empty_trap_mask |= 1LL << sig;
-///vda: optimize
}
}
@@ -7540,9 +7537,6 @@ static void install_special_sighandlers(void)
{
unsigned mask;
- if (G.special_sig_mask != 0)
- return;
-
/* Which signals are shell-special? */
mask = (1 << SIGQUIT) | (1 << SIGCHLD);
if (G_interactive_fd) {
@@ -7550,9 +7544,12 @@ static void install_special_sighandlers(void)
if (G_saved_tty_pgrp) /* we have ctty, job control sigs work */
mask |= SPECIAL_JOBSTOP_SIGS;
}
- G.special_sig_mask = mask;
-
- install_sighandlers(mask);
+ /* Careful, do not re-install handlers we already installed */
+ if (G.special_sig_mask != mask) {
+ unsigned diff = mask & ~G.special_sig_mask;
+ G.special_sig_mask = mask;
+ install_sighandlers(diff);
+ }
}
#if ENABLE_HUSH_JOB
@@ -7573,17 +7570,14 @@ static void install_fatal_sighandlers(void)
/* bash 3.2 seems to handle these just like 'fatal' ones */
+ (1 << SIGPIPE)
+ (1 << SIGALRM)
- /* if we are interactive, SIGHUP, SIGTERM and SIGINT are masked.
+ /* if we are interactive, SIGHUP, SIGTERM and SIGINT are special sigs.
* if we aren't interactive... but in this case
- * we never want to restore pgrp on exit, and this fn is not called */
+ * we never want to restore pgrp on exit, and this fn is not called
+ */
/*+ (1 << SIGHUP )*/
/*+ (1 << SIGTERM)*/
/*+ (1 << SIGINT )*/
;
- /* special_sig_mask'ed signals are set to record_pending_signo
- * no need to set handler for them.
- */
- /*mask &= ~G.special_sig_mask; - they never overlap */
G_fatal_sig_mask = mask;
install_sighandlers(mask);
@@ -7632,6 +7626,10 @@ static int set_mode(int state, char mode, const char *o_opt)
int hush_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int hush_main(int argc, char **argv)
{
+ enum {
+ OPT_login = (1 << 0),
+ };
+ unsigned flags;
int opt;
unsigned builtin_argc;
char **e;
@@ -7735,8 +7733,6 @@ int hush_main(int argc, char **argv)
# endif
#endif
- G.global_argc = argc;
- G.global_argv = argv;
/* Initialize some more globals to non-zero values */
cmdedit_update_prompt();
@@ -7752,14 +7748,14 @@ int hush_main(int argc, char **argv)
* "sh -c <cmds>" or login shell's /etc/profile and friends.
* If we later decide that we are interactive, we run install_special_sighandlers()
* in order to intercept (more) signals.
-//FIXME: re-running is currently most likely broken, it's a no-op.
*/
/* Parse options */
/* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
+ flags = (argv[0] && argv[0][0] == '-') ? OPT_login : 0;
builtin_argc = 0;
while (1) {
- opt = getopt(argc, argv, "+c:xins"
+ opt = getopt(argc, argv, "+c:xinsl"
#if !BB_MMU
"<:$:R:V:"
# if ENABLE_HUSH_FUNCTIONS
@@ -7820,6 +7816,9 @@ int hush_main(int argc, char **argv)
/* "-s" means "read from stdin", but this is how we always
* operate, so simply do nothing here. */
break;
+ case 'l':
+ flags |= OPT_login;
+ break;
#if !BB_MMU
case '<': /* "big heredoc" support */
full_write1_str(optarg);
@@ -7843,7 +7842,6 @@ int hush_main(int argc, char **argv)
install_special_sighandlers();
G.traps = xzalloc(sizeof(G.traps[0]) * NSIG);
for (sig = 1; sig < NSIG; sig++) {
-///vda: fixme: more efficient code
if (empty_trap_mask & (1LL << sig)) {
G.traps[sig] = xzalloc(1); /* == xstrdup(""); */
signal(sig, SIG_IGN);
@@ -7886,13 +7884,18 @@ int hush_main(int argc, char **argv)
}
} /* option parsing loop */
+ /* Skip options. Try "hush -l": $1 should not be "-l"! */
+ G.global_argc = argc - (optind - 1);
+ G.global_argv = argv + (optind - 1);
+ G.global_argv[0] = argv[0];
+
if (!G.root_pid) {
G.root_pid = getpid();
G.root_ppid = getppid();
}
/* If we are login shell... */
- if (argv[0] && argv[0][0] == '-') {
+ if (flags & OPT_login) {
FILE *input;
debug_printf("sourcing /etc/profile\n");
input = fopen_for_read("/etc/profile");
@@ -7911,17 +7914,17 @@ int hush_main(int argc, char **argv)
*/
}
- if (argv[optind]) {
+ if (G.global_argv[1]) {
FILE *input;
/*
* "bash <script>" (which is never interactive (unless -i?))
* sources $BASH_ENV here (without scanning $PATH).
* If called as sh, does the same but with $ENV.
*/
- debug_printf("running script '%s'\n", argv[optind]);
- G.global_argv = argv + optind;
- G.global_argc = argc - optind;
- input = xfopen_for_read(argv[optind]);
+ G.global_argc--;
+ G.global_argv++;
+ debug_printf("running script '%s'\n", G.global_argv[0]);
+ input = xfopen_for_read(G.global_argv[0]);
close_on_exec_on(fileno(input));
install_special_sighandlers();
parse_and_run_file(input);
@@ -7984,7 +7987,7 @@ int hush_main(int argc, char **argv)
}
}
- /* Block some signals */
+ /* Install more signal handlers */
install_special_sighandlers();
if (G_saved_tty_pgrp) {
--
1.7.3.4
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