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hush: cmd and arithmetic also need the fix for FILE rewind

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Discovered by running testsuite with a newest glibc

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2016-08-19 20:15:26 +02:00
parent 215b0ca6e4
commit e9abe75fda
1 changed files with 39 additions and 32 deletions
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71
shell/hush.c
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@ -1477,19 +1477,50 @@ static sighandler_t install_sighandler(int sig, sighandler_t handler)
return old_sa.sa_handler;
}
static void hush_exit(int exitcode) NORETURN;
static void fflush_and__exit(void) NORETURN;
static void restore_ttypgrp_and__exit(void) NORETURN;
static void restore_ttypgrp_and__exit(void)
{
/* xfunc has failed! die die die */
/* no EXIT traps, this is an escape hatch! */
G.exiting = 1;
hush_exit(xfunc_error_retval);
}
/* Needed only on some libc:
* It was observed that on exit(), fgetc'ed buffered data
* gets "unwound" via lseek(fd, -NUM, SEEK_CUR).
* With the net effect that even after fork(), not vfork(),
* exit() in NOEXECed applet in "sh SCRIPT":
* noexec_applet_here
* echo END_OF_SCRIPT
* lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
* This makes "echo END_OF_SCRIPT" executed twice.
* Similar problems can be seen with die_if_script() -> xfunc_die()
* and in `cmd` handling.
* If set as die_func(), this makes xfunc_die() exit via _exit(), not exit():
*/
static void fflush_and__exit(void)
{
fflush_all();
_exit(xfunc_error_retval);
}
#if ENABLE_HUSH_JOB
static void xfunc_has_died(void);
/* After [v]fork, in child: do not restore tty pgrp on xfunc death */
# define disable_restore_tty_pgrp_on_exit() (die_func = NULL)
# define disable_restore_tty_pgrp_on_exit() (die_func = fflush_and__exit)
/* After [v]fork, in parent: restore tty pgrp on xfunc death */
# define enable_restore_tty_pgrp_on_exit() (die_func = xfunc_has_died)
# define enable_restore_tty_pgrp_on_exit() (die_func = restore_ttypgrp_and__exit)
/* Restores tty foreground process group, and exits.
* May be called as signal handler for fatal signal
* (will resend signal to itself, producing correct exit state)
* or called directly with -EXITCODE.
* We also call it if xfunc is exiting. */
* We also call it if xfunc is exiting.
*/
static void sigexit(int sig) NORETURN;
static void sigexit(int sig)
{
@ -1544,7 +1575,6 @@ static sighandler_t pick_sighandler(unsigned sig)
}
/* Restores tty foreground process group, and exits. */
static void hush_exit(int exitcode) NORETURN;
static void hush_exit(int exitcode)
{
#if ENABLE_FEATURE_EDITING_SAVE_ON_EXIT
@ -1588,15 +1618,6 @@ static void hush_exit(int exitcode)
#endif
}
static void xfunc_has_died(void) NORETURN;
static void xfunc_has_died(void)
{
/* xfunc has failed! die die die */
/* no EXIT traps, this is an escape hatch! */
G.exiting = 1;
hush_exit(xfunc_error_retval);
}
//TODO: return a mask of ALL handled sigs?
static int check_and_run_traps(void)
@ -5913,7 +5934,8 @@ static FILE *generate_stream_from_string(const char *s, pid_t *pid_p)
) {
static const char *const argv[] = { NULL, NULL };
builtin_trap((char**)argv);
exit(0); /* not _exit() - we need to fflush */
fflush_all(); /* important */
_exit(0);
}
# if BB_MMU
reset_traps_to_defaults();
@ -6467,22 +6489,7 @@ static void dump_cmd_in_x_mode(char **argv)
* Don't exit() here. If you don't exec, use _exit instead.
* The at_exit handlers apparently confuse the calling process,
* in particular stdin handling. Not sure why? -- because of vfork! (vda)
* Also, it was observed that on exit(), fgetc'ed buffered data
* gets "unwound" by some libcs, via lseek(fd, -NUM, SEEK_CUR).
* With the net effect that even after fork(), not vfork(),
* exit() in NOEXECed applet in "sh SCRIPT":
* noexec_applet_here
* echo END_OF_SCRIPT
* lseeks fd in input FILE object from EOF to "e" in "echo END_OF_SCRIPT".
* This makes "echo END_OF_SCRIPT" executed twice. exexit() is the fix.
*/
#if ENABLE_FEATURE_SH_STANDALONE
static void exexit(void)
{
fflush_all();
_exit(xfunc_error_retval);
}
#endif
static void pseudo_exec_argv(nommu_save_t *nommu_save,
char **argv, int assignment_cnt,
char **argv_expanded) NORETURN;
@ -6563,7 +6570,6 @@ static NOINLINE void pseudo_exec_argv(nommu_save_t *nommu_save,
# if BB_MMU /* see above why on NOMMU it is not allowed */
if (APPLET_IS_NOEXEC(a)) {
debug_printf_exec("running applet '%s'\n", argv[0]);
die_func = exexit;
run_applet_no_and_exit(a, argv);
}
# endif
@ -7804,6 +7810,7 @@ int hush_main(int argc, char **argv)
INIT_G();
if (EXIT_SUCCESS != 0) /* if EXIT_SUCCESS == 0, it is already done */
G.last_exitcode = EXIT_SUCCESS;
#if ENABLE_HUSH_FAST
G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
#endif
@ -7893,7 +7900,7 @@ int hush_main(int argc, char **argv)
/* Initialize some more globals to non-zero values */
cmdedit_update_prompt();
die_func = xfunc_has_died;
die_func = restore_ttypgrp_and__exit;
/* Shell is non-interactive at first. We need to call
* install_special_sighandlers() if we are going to execute "sh <script>",