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authorGravatar Denis Vlasenko <vda.linux@googlemail.com>2008-02-19 14:13:20 +0000
committerGravatar Denis Vlasenko <vda.linux@googlemail.com>2008-02-19 14:13:20 +0000
commit671ca33aa1804c1c4e26bf83635206dce7ed2623 (patch)
tree4bf32b2810361b905bb7e8e1796b1cc22da0eb81 /init
parenta58a637bed06f6d794fcf822d08df926812ccd23 (diff)
downloadbusybox-671ca33aa1804c1c4e26bf83635206dce7ed2623.tar.gz
busybox-671ca33aa1804c1c4e26bf83635206dce7ed2623.tar.bz2
init: make it NOMMU-capable
httpd: trivial compile fix
Diffstat (limited to 'init')
-rw-r--r--init/init.c50
1 files changed, 31 insertions, 19 deletions
diff --git a/init/init.c b/init/init.c
index a82b45b7c..13410ac39 100644
--- a/init/init.c
+++ b/init/init.c
@@ -117,11 +117,13 @@ static void loop_forever(void)
}
/* Print a message to the specified device.
- * Device may be bitwise-or'd from L_LOG | L_CONSOLE */
+ * "where" may be bitwise-or'd from L_LOG | L_CONSOLE
+ * NB: careful, we can be called after vfork!
+ */
#define messageD(...) do { if (ENABLE_DEBUG_INIT) message(__VA_ARGS__); } while (0)
-static void message(int device, const char *fmt, ...)
+static void message(int where, const char *fmt, ...)
__attribute__ ((format(printf, 2, 3)));
-static void message(int device, const char *fmt, ...)
+static void message(int where, const char *fmt, ...)
{
static int log_fd = -1;
va_list arguments;
@@ -137,7 +139,7 @@ static void message(int device, const char *fmt, ...)
if (ENABLE_FEATURE_INIT_SYSLOG) {
/* Log the message to syslogd */
- if (device & L_LOG) {
+ if (where & L_LOG) {
/* don't out "\r" */
openlog(applet_name, 0, LOG_DAEMON);
syslog(LOG_INFO, "init: %s", msg + 1);
@@ -157,20 +159,20 @@ static void message(int device, const char *fmt, ...)
log_fd = device_open(log_console, O_WRONLY | O_NONBLOCK | O_NOCTTY);
if (log_fd < 0) {
bb_error_msg("can't log to %s", log_console);
- device = L_CONSOLE;
+ where = L_CONSOLE;
} else {
close_on_exec_on(log_fd);
}
}
}
- if (device & L_LOG) {
+ if (where & L_LOG) {
full_write(log_fd, msg, l);
if (log_fd == 2)
return; /* don't print dup messages */
}
}
- if (device & L_CONSOLE) {
+ if (where & L_CONSOLE) {
/* Send console messages to console so people will see them. */
full_write(2, msg, l);
}
@@ -233,7 +235,8 @@ static void console_init(void)
putenv((char*)"TERM=linux");
}
-/* Set terminal settings to reasonable defaults */
+/* Set terminal settings to reasonable defaults.
+ * NB: careful, we can be called after vfork! */
static void set_sane_term(void)
{
struct termios tty;
@@ -270,7 +273,8 @@ static void set_sane_term(void)
tcsetattr(STDIN_FILENO, TCSANOW, &tty);
}
-/* Open the new terminal device */
+/* Open the new terminal device.
+ * NB: careful, we can be called after vfork! */
static void open_stdio_to_tty(const char* tty_name, int exit_on_failure)
{
/* empty tty_name means "use init's tty", else... */
@@ -286,6 +290,8 @@ static void open_stdio_to_tty(const char* tty_name, int exit_on_failure)
_exit(1);
if (ENABLE_DEBUG_INIT)
_exit(2);
+ /* NB: we don't reach this if we were called after vfork.
+ * Thus halt_reboot_pwoff() itself need not be vfork-safe. */
halt_reboot_pwoff(SIGUSR1); /* halt the system */
}
dup2(0, 1);
@@ -294,22 +300,24 @@ static void open_stdio_to_tty(const char* tty_name, int exit_on_failure)
set_sane_term();
}
-/* wrapper around exec:
- * takes string (max COMMAND_SIZE chars)
- * runs [-]/bin/sh -c "exec ......." if '>' etc detected.
- * otherwise splits words on whitespace and deals with leading dash.
+/* Wrapper around exec:
+ * Takes string (max COMMAND_SIZE chars).
+ * If chars like '>' detected, execs '[-]/bin/sh -c "exec ......."'.
+ * Otherwise splits words on whitespace, deals with leading dash,
+ * and uses plain exec().
+ * NB: careful, we can be called after vfork!
*/
static void init_exec(const char *command)
{
char *cmd[COMMAND_SIZE / 2];
char buf[COMMAND_SIZE + 6]; /* COMMAND_SIZE+strlen("exec ")+1 */
- int dash = (command[0] == '-');
+ int dash = (command[0] == '-' /* maybe? && command[1] == '/' */);
/* See if any special /bin/sh requiring characters are present */
if (strpbrk(command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
strcpy(buf, "exec ");
strcpy(buf + 5, command + dash); /* excluding "-" */
- /* LIBBB_DEFAULT_LOGIN_SHELL has leading dash */
+ /* NB: LIBBB_DEFAULT_LOGIN_SHELL define has leading dash */
cmd[0] = (char*)(LIBBB_DEFAULT_LOGIN_SHELL + !dash);
cmd[1] = (char*)"-c";
cmd[2] = buf;
@@ -351,7 +359,7 @@ static pid_t run(const struct init_action *a)
sigemptyset(&nmask);
sigaddset(&nmask, SIGCHLD);
sigprocmask(SIG_BLOCK, &nmask, &omask);
- pid = fork();
+ pid = vfork();
sigprocmask(SIG_SETMASK, &omask, NULL);
if (pid < 0)
@@ -379,8 +387,9 @@ static pid_t run(const struct init_action *a)
setsid();
/* Open the new terminal device */
- open_stdio_to_tty(a->terminal, 1 /* - exit if open fails*/);
+ open_stdio_to_tty(a->terminal, 1 /* - exit if open fails */);
+// NB: do not enable unless you change vfork to fork above
#ifdef BUT_RUN_ACTIONS_ALREADY_DOES_WAITING
/* If the init Action requires us to wait, then force the
* supplied terminal to be the controlling tty. */
@@ -424,7 +433,9 @@ static pid_t run(const struct init_action *a)
/* Child - fall though to actually execute things */
}
#endif
- if (a->action_type & ASKFIRST) {
+
+ /* NB: on NOMMU we can't wait for input in child */
+ if (BB_MMU && (a->action_type & ASKFIRST)) {
static const char press_enter[] ALIGN1 =
#ifdef CUSTOMIZED_BANNER
#include CUSTOMIZED_BANNER
@@ -809,7 +820,8 @@ static void reload_signal(int sig ATTRIBUTE_UNUSED)
}
}
#if CONFIG_FEATURE_KILL_DELAY
- if (fork() == 0) { /* child */
+ /* NB: parent will wait in NOMMU case */
+ if ((BB_MMU ? fork() : vfork()) == 0) { /* child */
sleep(CONFIG_FEATURE_KILL_DELAY);
for (a = init_action_list; a; a = a->next) {
pid_t pid = a->pid;