e9abe75fd
Denys Vlasenko
2016-08-19
Subject
hush: `cmd` and arithmetic also need the fix for FILE rewind
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Commit Diff GitHub →
shell/hush.c+39 -32
| @@ -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>", | |