hush: pass $! thru re-execution; try harder on re-exec; give error

msg if re-exec didn't work; other tweaks in main()

function                                             old     new   delta
hush_main                                           1144    1199     +55
re_execute_shell                                     237     286     +49
file_get                                             240     260     +20
clean_up_after_re_execute                             58      66      +8
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 4/0 up/down: 132/0)             Total: 132 bytes
This commit is contained in:
Denis Vlasenko 2009-04-05 10:39:03 +00:00
parent 232be3e79b
commit 46f9b6db80

View File

@ -487,7 +487,8 @@ struct globals {
int global_argc;
char **global_argv;
#if !BB_MMU
char **argv_for_re_execing;
char *argv0_for_re_execing;
char **argv_from_re_execing;
#endif
#if ENABLE_HUSH_LOOPS
unsigned depth_break_continue;
@ -2356,18 +2357,19 @@ static void re_execute_shell(const char *s)
char **argv, **pp, **pp2;
unsigned cnt;
/* 1:hush 2:-$<pid> 3:-?<exitcode> 4:-D<depth> <vars...>
* 5:-c 6:<cmd> <argN...> 7:NULL
/* 1:hush 2:-$<pid> 3:-!<pid> 4:-?<exitcode> 5:-D<depth> <vars...>
* 6:-c 7:<cmd> <argN...> 8:NULL
*/
cnt = 7 + G.global_argc;
cnt = 8 + G.global_argc;
for (cur = G.top_var; cur; cur = cur->next) {
if (!cur->flg_export || cur->flg_read_only)
cnt += 2;
}
G.argv_for_re_execing = pp = xzalloc(sizeof(argv[0]) * cnt);
*pp++ = (char *) applet_name;
*pp++ = xasprintf("-$%u", G.root_pid);
*pp++ = xasprintf("-?%u", G.last_return_code);
G.argv_from_re_execing = pp = xzalloc(sizeof(argv[0]) * cnt);
*pp++ = (char *) G.argv0_for_re_execing;
*pp++ = xasprintf("-$%u", (unsigned) G.root_pid);
*pp++ = xasprintf("-!%u", (unsigned) G.last_bg_pid);
*pp++ = xasprintf("-?%u", (unsigned) G.last_return_code);
#if ENABLE_HUSH_LOOPS
*pp++ = xasprintf("-D%u", G.depth_of_loop);
#endif
@ -2392,23 +2394,27 @@ static void re_execute_shell(const char *s)
debug_printf_exec("re_execute_shell pid:%d cmd:'%s'\n", getpid(), s);
sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
execv(bb_busybox_exec_path, G.argv_for_re_execing);
//TODO: fallback for init=/bin/hush?
_exit(127);
execv(bb_busybox_exec_path, G.argv_from_re_execing);
/* Fallback. Useful for init=/bin/hush usage etc */
if (G.argv0_for_re_execing[0] == '/')
execv(G.argv0_for_re_execing, G.argv_from_re_execing);
xfunc_error_retval = 127;
bb_error_msg_and_die("can't re-execute the shell");
}
static void clean_up_after_re_execute(void)
{
char **pp = G.argv_for_re_execing;
char **pp = G.argv_from_re_execing;
if (pp) {
/* Must match re_execute_shell's allocations */
free(pp[1]);
free(pp[2]);
#if ENABLE_HUSH_LOOPS
free(pp[3]);
#if ENABLE_HUSH_LOOPS
free(pp[4]);
#endif
free(pp);
G.argv_for_re_execing = NULL;
G.argv_from_re_execing = NULL;
}
}
#else
@ -3001,8 +3007,8 @@ static void debug_print_tree(struct pipe *pi, int lvl)
[RES_SNTX ] = "SNTX" ,
};
static const char *const GRPTYPE[] = {
"()",
"{}",
"()",
#if ENABLE_HUSH_FUNCTIONS
"func()",
#endif
@ -4990,14 +4996,15 @@ int hush_main(int argc, char **argv)
};
int opt;
FILE *input;
char **e;
struct variable *cur_var;
INIT_G();
G.root_pid = getpid();
if (EXIT_SUCCESS) /* if EXIT_SUCCESS == 0, is already done */
G.last_return_code = EXIT_SUCCESS;
#if !BB_MMU
G.argv0_for_re_execing = argv[0];
#endif
/* Deal with HUSH_VERSION */
G.shell_ver = const_shell_ver; /* copying struct here */
G.top_var = &G.shell_ver;
@ -5020,11 +5027,9 @@ int hush_main(int argc, char **argv)
}
debug_printf_env("putenv '%s'\n", hush_version_str);
putenv((char *)hush_version_str); /* reinstate HUSH_VERSION */
#if ENABLE_FEATURE_EDITING
G.line_input_state = new_line_input_t(FOR_SHELL);
#endif
/* XXX what should these be while sourcing /etc/profile? */
G.global_argc = argc;
G.global_argv = argv;
/* Initialize some more globals to non-zero values */
@ -5035,31 +5040,19 @@ int hush_main(int argc, char **argv)
G.PS2 = "> ";
#endif
if (EXIT_SUCCESS) /* otherwise is already done */
G.last_return_code = EXIT_SUCCESS;
if (argv[0] && argv[0][0] == '-') {
debug_printf("sourcing /etc/profile\n");
input = fopen_for_read("/etc/profile");
if (input != NULL) {
close_on_exec_on(fileno(input));
parse_and_run_file(input);
fclose(input);
}
}
input = stdin;
/* http://www.opengroup.org/onlinepubs/9699919799/utilities/sh.html */
while (1) {
opt = getopt(argc, argv, "c:xins"
#if !BB_MMU
"$:?:D:R:V:"
"$:!:?:D:R:V:"
#endif
);
if (opt <= 0)
break;
switch (opt) {
case 'c':
if (!G.root_pid)
G.root_pid = getpid();
G.global_argv = argv + optind;
if (!argv[optind]) {
/* -c 'script' (no params): prevent empty $0 */
@ -5082,6 +5075,9 @@ int hush_main(int argc, char **argv)
case '$':
G.root_pid = xatoi_u(optarg);
break;
case '!':
G.last_bg_pid = xatoi_u(optarg);
break;
case '?':
G.last_return_code = xatoi_u(optarg);
break;
@ -5109,6 +5105,21 @@ int hush_main(int argc, char **argv)
#endif
}
}
if (!G.root_pid)
G.root_pid = getpid();
if (argv[0] && argv[0][0] == '-') {
FILE *input;
/* XXX what should argv be while sourcing /etc/profile? */
debug_printf("sourcing /etc/profile\n");
input = fopen_for_read("/etc/profile");
if (input != NULL) {
close_on_exec_on(fileno(input));
parse_and_run_file(input);
fclose(input);
}
}
#if ENABLE_HUSH_JOB
/* A shell is interactive if the '-i' flag was given, or if all of
* the following conditions are met:
@ -5117,7 +5128,7 @@ int hush_main(int argc, char **argv)
* standard input is a terminal
* standard output is a terminal
* Refer to Posix.2, the description of the 'sh' utility. */
if (argv[optind] == NULL && input == stdin
if (argv[optind] == NULL
&& isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
) {
G.saved_tty_pgrp = tcgetpgrp(STDIN_FILENO);
@ -5132,8 +5143,8 @@ int hush_main(int argc, char **argv)
/* give up */
G_interactive_fd = 0;
}
// TODO: track & disallow any attempts of user
// to (inadvertently) close/redirect it
// TODO: track & disallow any attempts of user
// to (inadvertently) close/redirect it
}
}
init_signal_mask(); /* note: ensures SIGCHLD is not masked */
@ -5152,7 +5163,7 @@ int hush_main(int argc, char **argv)
}
#elif ENABLE_HUSH_INTERACTIVE
/* no job control compiled, only prompt/line editing */
if (argv[optind] == NULL && input == stdin
if (argv[optind] == NULL
&& isatty(STDIN_FILENO) && isatty(STDOUT_FILENO)
) {
G_interactive_fd = fcntl(STDIN_FILENO, F_DUPFD, 255);
@ -5169,10 +5180,12 @@ int hush_main(int argc, char **argv)
}
init_signal_mask(); /* note: ensures SIGCHLD is not masked */
#else
//TODO: we didn't do it for -c or /etc/profile! Shouldn't we?
init_signal_mask();
#endif
/* POSIX allows shell to re-enable SIGCHLD
* even if it was SIG_IGN on entry */
//TODO: we didn't do it for -c or /etc/profile! Shouldn't we?
// G.count_SIGCHLD++; /* ensure it is != G.handled_SIGCHLD */
signal(SIGCHLD, SIG_DFL); // SIGCHLD_handler);
@ -5186,18 +5199,21 @@ int hush_main(int argc, char **argv)
if (argv[optind] == NULL) {
parse_and_run_file(stdin);
} else {
FILE *input;
debug_printf("\nrunning script '%s'\n", argv[optind]);
G.global_argv = argv + optind;
G.global_argc = argc - optind;
input = xfopen_for_read(argv[optind]);
fcntl(fileno(input), F_SETFD, FD_CLOEXEC);
parse_and_run_file(input);
#if ENABLE_FEATURE_CLEAN_UP
fclose(input);
#endif
}
final_return:
#if ENABLE_FEATURE_CLEAN_UP
fclose(input);
if (G.cwd != bb_msg_unknown)
free((char*)G.cwd);
cur_var = G.top_var->next;