hush: fix NOMMU hangs in pseudo_exec_argv. Add forgotted setting
of signal mask. Reuse same help string in all shells.
function old new delta
builtin_exit 49 47 -2
pseudo_exec_argv 149 145 -4
builtin_help 74 63 -11
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/3 up/down: 0/-17) Total: -17 bytes
text data bss dec hex filename
825379 476 7616 833471 cb7bf busybox_old
825341 476 7616 833433 cb799 busybox_unstripped
diff --git a/shell/ash.c b/shell/ash.c
index 1cd2050..fe8c1be 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -12230,7 +12230,9 @@
unsigned col;
unsigned i;
- out1fmt("\nBuilt-in commands:\n-------------------\n");
+ out1fmt("\n"
+ "Built-in commands:\n"
+ "------------------\n");
for (col = 0, i = 0; i < ARRAY_SIZE(builtintab); i++) {
col += out1fmt("%c%s", ((col == 0) ? '\t' : ' '),
builtintab[i].name + 1);
diff --git a/shell/hush.c b/shell/hush.c
index 61db928..c384202 100644
--- a/shell/hush.c
+++ b/shell/hush.c
@@ -363,11 +363,13 @@
/* bitmask of FLAG_xxx, for figuring out valid reserved words */
int old_flag;
/* group we are enclosed in:
- * example 1: "{ { false; ..."
- * example 2: "if true; then { false; ..."
- * example 3: "if true; then if false; ..."
- * when we find closing "}" / "fi" / whatever, we move list_head
- * into stack->command->group and delete ourself.
+ * example: "if pipe1; pipe2; then pipe3; fi"
+ * when we see "if" or "then", we malloc and copy current context,
+ * and make ->stack point to it. then we parse pipeN.
+ * when closing "then" / fi" / whatever is found,
+ * we move list_head into ->stack->command->group,
+ * copy ->stack into current context, and delete ->stack.
+ * (parsing of { list } and ( list ) doesn't use this method)
*/
struct parse_context *stack;
#endif
@@ -532,7 +534,6 @@
static int builtin_break(char **argv);
static int builtin_continue(char **argv);
#endif
-//static int builtin_not_written(char **argv);
/* Table of built-in functions. They can be forked or not, depending on
* context: within pipes, they fork. As simple commands, they do not.
@@ -554,42 +555,44 @@
/* For now, echo and test are unconditionally enabled.
* Maybe make it configurable? */
static const struct built_in_command bltins[] = {
- BLTIN("." , builtin_source, "Run commands in a file"),
- BLTIN(":" , builtin_true, "No-op"),
- BLTIN("[" , builtin_test, "Test condition"),
+ BLTIN("." , builtin_source , "Run commands in a file"),
+ BLTIN(":" , builtin_true , "No-op"),
+ BLTIN("[" , builtin_test , "Test condition"),
#if ENABLE_HUSH_JOB
- BLTIN("bg" , builtin_fg_bg, "Resume a job in the background"),
+ BLTIN("bg" , builtin_fg_bg , "Resume a job in the background"),
#endif
#if ENABLE_HUSH_LOOPS
- BLTIN("break" , builtin_break, "Exit from a loop"),
+ BLTIN("break" , builtin_break , "Exit from a loop"),
#endif
- BLTIN("cd" , builtin_cd, "Change directory"),
+ BLTIN("cd" , builtin_cd , "Change directory"),
#if ENABLE_HUSH_LOOPS
BLTIN("continue", builtin_continue, "Start new loop iteration"),
#endif
- BLTIN("echo" , builtin_echo, "Write to stdout"),
- BLTIN("eval" , builtin_eval, "Construct and run shell command"),
- BLTIN("exec" , builtin_exec, "Execute command, don't return to shell"),
- BLTIN("exit" , builtin_exit, "Exit"),
- BLTIN("export", builtin_export, "Set environment variable"),
+ BLTIN("echo" , builtin_echo , "Write to stdout"),
+ BLTIN("eval" , builtin_eval , "Construct and run shell command"),
+ BLTIN("exec" , builtin_exec , "Execute command, don't return to shell"),
+ BLTIN("exit" , builtin_exit , "Exit"),
+ BLTIN("export" , builtin_export , "Set environment variable"),
#if ENABLE_HUSH_JOB
- BLTIN("fg" , builtin_fg_bg, "Bring job into the foreground"),
- BLTIN("jobs" , builtin_jobs, "List active jobs"),
+ BLTIN("fg" , builtin_fg_bg , "Bring job into the foreground"),
#endif
- BLTIN("pwd" , builtin_pwd, "Print current directory"),
- BLTIN("read" , builtin_read, "Input environment variable"),
-// BLTIN("return", builtin_not_written, "Return from a function"),
- BLTIN("set" , builtin_set, "Set/unset shell local variables"),
- BLTIN("shift" , builtin_shift, "Shift positional parameters"),
- BLTIN("test" , builtin_test, "Test condition"),
- BLTIN("trap" , builtin_trap, "Trap signals"),
-// BLTIN("ulimit", builtin_not_written, "Control resource limits"),
- BLTIN("umask" , builtin_umask, "Set file creation mask"),
- BLTIN("unset" , builtin_unset, "Unset environment variable"),
- BLTIN("wait" , builtin_wait, "Wait for process"),
#if ENABLE_HUSH_HELP
- BLTIN("help" , builtin_help, "List shell built-in commands"),
+ BLTIN("help" , builtin_help , "List shell built-in commands"),
#endif
+#if ENABLE_HUSH_JOB
+ BLTIN("jobs" , builtin_jobs , "List active jobs"),
+#endif
+ BLTIN("pwd" , builtin_pwd , "Print current directory"),
+ BLTIN("read" , builtin_read , "Input environment variable"),
+// BLTIN("return" , builtin_return , "Return from a function"),
+ BLTIN("set" , builtin_set , "Set/unset shell local variables"),
+ BLTIN("shift" , builtin_shift , "Shift positional parameters"),
+ BLTIN("test" , builtin_test , "Test condition"),
+ BLTIN("trap" , builtin_trap , "Trap signals"),
+// BLTIN("ulimit" , builtin_return , "Control resource limits"),
+ BLTIN("umask" , builtin_umask , "Set file creation mask"),
+ BLTIN("unset" , builtin_unset , "Unset environment variable"),
+ BLTIN("wait" , builtin_wait , "Wait for process"),
};
@@ -2117,7 +2120,7 @@
#endif
static void free_pipe_list(struct pipe *head, int indent);
-/* return code is the exit status of the pipe */
+/* Return code is the exit status of the pipe */
static void free_pipe(struct pipe *pi, int indent)
{
char **p;
@@ -2125,7 +2128,7 @@
struct redir_struct *r, *rnext;
int a, i;
- if (pi->stopped_cmds > 0)
+ if (pi->stopped_cmds > 0) /* why? */
return;
debug_printf_clean("%s run pipe: (pid %d)\n", indenter(indent), getpid());
for (i = 0; i < pi->num_cmds; i++) {
@@ -2216,9 +2219,7 @@
char **new_env;
const struct built_in_command *x;
- /* If a variable is assigned in a forest, and nobody listens,
- * was it ever really set?
- */
+ /* Case when we are here: ... | var=val | ... */
if (!argv[assignment_cnt])
_exit(EXIT_SUCCESS);
@@ -2239,8 +2240,13 @@
#endif
}
- /*
- * Check if the command matches any of the builtins.
+ /* On NOMMU, we must never block!
+ * Example: { sleep 99999 | read line } & echo Ok
+ * read builtin will block on read syscall, leaving parent blocked
+ * in vfork. Therefore we can't do this:
+ */
+#if BB_MMU
+ /* Check if the command matches any of the builtins.
* Depending on context, this might be redundant. But it's
* easier to waste a few CPU cycles than it is to figure out
* if this is one of those cases.
@@ -2249,33 +2255,35 @@
if (strcmp(argv[0], x->cmd) == 0) {
debug_printf_exec("running builtin '%s'\n", argv[0]);
rcode = x->function(argv);
- fflush(stdout);
+ fflush(NULL);
_exit(rcode);
}
}
+#endif
- /* Check if the command matches any busybox applets */
#if ENABLE_FEATURE_SH_STANDALONE
+ /* Check if the command matches any busybox applets */
if (strchr(argv[0], '/') == NULL) {
int a = find_applet_by_name(argv[0]);
if (a >= 0) {
+#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]);
-// is it ok that run_applet_no_and_exit() does exit(), not _exit()?
run_applet_no_and_exit(a, argv);
}
- /* re-exec ourselves with the new arguments */
+#endif
+ /* Re-exec ourselves */
debug_printf_exec("re-execing applet '%s'\n", argv[0]);
- execvp(bb_busybox_exec_path, argv);
+ sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
+ execv(bb_busybox_exec_path, argv);
/* If they called chroot or otherwise made the binary no longer
* executable, fall through */
}
}
#endif
- sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
-
debug_printf_exec("execing '%s'\n", argv[0]);
+ sigprocmask(SIG_SETMASK, &G.inherited_set, NULL);
execvp(argv[0], argv);
bb_perror_msg("can't exec '%s'", argv[0]);
_exit(EXIT_FAILURE);
@@ -2317,8 +2325,8 @@
#endif
}
- /* Can happen. See what bash does with ">foo" by itself. */
- debug_printf("pseudo_exec'ed null command\n");
+ /* Case when we are here: ... | >file */
+ debug_printf_exec("pseudo_exec'ed null command\n");
_exit(EXIT_SUCCESS);
}
@@ -2569,8 +2577,8 @@
}
#endif
-/* run_pipe() starts all the jobs, but doesn't wait for anything
- * to finish. See checkjobs().
+/* Start all the jobs, but don't wait for anything to finish.
+ * See checkjobs().
*
* Return code is normally -1, when the caller has to wait for children
* to finish to determine the exit status of the pipe. If the pipe
@@ -2588,7 +2596,7 @@
* 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(). Otherwise, 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
@@ -3771,7 +3779,7 @@
* echo OK
*/
//TODO: pass non-exported variables, traps, and functions
- execl(CONFIG_BUSYBOX_EXEC_PATH, "hush", "-c", s, NULL);
+ execl(bb_busybox_exec_path, "hush", "-c", s, NULL);
_exit(127);
#endif
}
@@ -5144,7 +5152,7 @@
found:
// TODO: bash prints a string representation
// of job being foregrounded (like "sleep 1 | cat")
- if (*argv[0] == 'f') {
+ if (argv[0][0] == 'f') {
/* Put the job into the foreground. */
tcsetpgrp(G_interactive_fd, pi->pgrp);
}
@@ -5162,12 +5170,11 @@
if (errno == ESRCH) {
delete_finished_bg_job(pi);
return EXIT_SUCCESS;
- } else {
- bb_perror_msg("kill (SIGCONT)");
}
+ bb_perror_msg("kill (SIGCONT)");
}
- if (*argv[0] == 'f') {
+ if (argv[0][0] == 'f') {
remove_bg_job(pi);
return checkjobs_and_fg_shell(pi);
}
@@ -5180,8 +5187,9 @@
{
const struct built_in_command *x;
- printf("\nBuilt-in commands:\n");
- printf("-------------------\n");
+ printf("\n"
+ "Built-in commands:\n"
+ "------------------\n");
for (x = bltins; x != &bltins[ARRAY_SIZE(bltins)]; x++) {
printf("%s\t%s\n", x->cmd, x->descr);
}
diff --git a/shell/lash_unused.c b/shell/lash_unused.c
index 90b1f56..21ea547 100644
--- a/shell/lash_unused.c
+++ b/shell/lash_unused.c
@@ -312,8 +312,9 @@
{
const struct built_in_command *x;
- printf("\nBuilt-in commands:\n"
- "-------------------\n");
+ printf("\n"
+ "Built-in commands:\n"
+ "------------------\n");
for (x = bltins; x <= &VEC_LAST(bltins); x++) {
if (x->descr == NULL)
continue;
diff --git a/shell/msh.c b/shell/msh.c
index 5f8c90e..da1dc35 100644
--- a/shell/msh.c
+++ b/shell/msh.c
@@ -35,7 +35,6 @@
# include <assert.h>
# define bb_dev_null "/dev/null"
# define DEFAULT_SHELL "/proc/self/exe"
-# define CONFIG_BUSYBOX_EXEC_PATH "/proc/self/exe"
# define bb_banner "busybox standalone"
# define ENABLE_FEATURE_SH_STANDALONE 0
# define bb_msg_memory_exhausted "memory exhausted"
@@ -3176,8 +3175,9 @@
int col;
const struct builtincmd *x;
- puts("\nBuilt-in commands:\n"
- "-------------------");
+ printf("\n"
+ "Built-in commands:\n"
+ "------------------\n");
col = 0;
x = builtincmds;