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convert #if to if -- let gcc optimize away dead code for us

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This commit is contained in:
Mike Frysinger 2007-12-25 04:30:14 +00:00
parent ec5631b6d6
commit bb50fdfe07
2 changed files with 109 additions and 133 deletions
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3
init/Config.in
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@ -37,10 +37,9 @@ config FEATURE_KILL_REMOVED
been removed. been removed.
config FEATURE_KILL_DELAY config FEATURE_KILL_DELAY
int "How long to wait between TERM and KILL (0 - send TERM only)" int "How long to wait between TERM and KILL (0 - send TERM only)" if FEATURE_KILL_REMOVED
range 0 1024 range 0 1024
default 0 default 0
depends on FEATURE_KILL_REMOVED
help help
With nonzero setting, init sends TERM, forks, child waits N With nonzero setting, init sends TERM, forks, child waits N
seconds, sends KILL and exits. Setting it too high is unwise seconds, sends KILL and exits. Setting it too high is unwise

91
init/init.c
View File

@ -12,16 +12,12 @@
#include "libbb.h" #include "libbb.h"
#include <paths.h> #include <paths.h>
#include <sys/reboot.h> #include <sys/reboot.h>
#if ENABLE_FEATURE_INIT_SYSLOG
#include <sys/syslog.h> #include <sys/syslog.h>
#endif
#define INIT_BUFFS_SIZE 256 #define INIT_BUFFS_SIZE 256
#define CONSOLE_NAME_SIZE 32 #define CONSOLE_NAME_SIZE 32
#define MAXENV 16 /* Number of env. vars */ #define MAXENV 16 /* Number of env. vars */
#if ENABLE_FEATURE_INIT_COREDUMPS
/* /*
* When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called * When a file named CORE_ENABLE_FLAG_FILE exists, setrlimit is called
* before processes are spawned to set core file size as unlimited. * before processes are spawned to set core file size as unlimited.
@ -30,7 +26,6 @@
*/ */
#define CORE_ENABLE_FLAG_FILE "/.init_enable_core" #define CORE_ENABLE_FLAG_FILE "/.init_enable_core"
#include <sys/resource.h> #include <sys/resource.h>
#endif
#define INITTAB "/etc/inittab" /* inittab file location */ #define INITTAB "/etc/inittab" /* inittab file location */
#ifndef INIT_SCRIPT #ifndef INIT_SCRIPT
@ -68,12 +63,8 @@ struct init_action {
/* Static variables */ /* Static variables */
static struct init_action *init_action_list = NULL; static struct init_action *init_action_list = NULL;
#if !ENABLE_FEATURE_INIT_SYSLOG
static const char *log_console = VC_5; static const char *log_console = VC_5;
#endif
#if !ENABLE_DEBUG_INIT
static sig_atomic_t got_cont = 0; static sig_atomic_t got_cont = 0;
#endif
enum { enum {
L_LOG = 0x1, L_LOG = 0x1,
@ -105,33 +96,22 @@ static const char *const environment[] = {
/* Function prototypes */ /* Function prototypes */
static void delete_init_action(struct init_action *a); static void delete_init_action(struct init_action *a);
static int waitfor(pid_t pid); static int waitfor(pid_t pid);
#if !ENABLE_DEBUG_INIT
static void shutdown_signal(int sig); static void shutdown_signal(int sig);
#endif
#if !ENABLE_DEBUG_INIT
static void loop_forever(void) static void loop_forever(void)
{ {
while (1) while (1)
sleep(1); sleep(1);
} }
#endif
/* Print a message to the specified device. /* Print a message to the specified device.
* Device may be bitwise-or'd from L_LOG | L_CONSOLE */ * Device may be bitwise-or'd from L_LOG | L_CONSOLE */
#if ENABLE_DEBUG_INIT #define messageD(...) do { if (ENABLE_DEBUG_INIT) message(__VA_ARGS__); } while (0)
#define messageD message
#else
#define messageD(...) do {} while (0)
#endif
static void message(int device, const char *fmt, ...) static void message(int device, const char *fmt, ...)
__attribute__ ((format(printf, 2, 3))); __attribute__ ((format(printf, 2, 3)));
static void message(int device, const char *fmt, ...) static void message(int device, const char *fmt, ...)
{ {
#if !ENABLE_FEATURE_INIT_SYSLOG
static int log_fd = -1; static int log_fd = -1;
#endif
va_list arguments; va_list arguments;
int l; int l;
char msg[128]; char msg[128];
@ -143,7 +123,7 @@ static void message(int device, const char *fmt, ...)
msg[sizeof(msg) - 2] = '\0'; msg[sizeof(msg) - 2] = '\0';
l = strlen(msg); l = strlen(msg);
#if ENABLE_FEATURE_INIT_SYSLOG if (ENABLE_FEATURE_INIT_SYSLOG) {
/* Log the message to syslogd */ /* Log the message to syslogd */
if (device & L_LOG) { if (device & L_LOG) {
/* don't out "\r" */ /* don't out "\r" */
@ -153,7 +133,7 @@ static void message(int device, const char *fmt, ...)
} }
msg[l++] = '\n'; msg[l++] = '\n';
msg[l] = '\0'; msg[l] = '\0';
#else } else {
msg[l++] = '\n'; msg[l++] = '\n';
msg[l] = '\0'; msg[l] = '\0';
/* Take full control of the log tty, and never close it. /* Take full control of the log tty, and never close it.
@ -176,7 +156,7 @@ static void message(int device, const char *fmt, ...)
if (log_fd == 2) if (log_fd == 2)
return; /* don't print dup messages */ return; /* don't print dup messages */
} }
#endif }
if (device & L_CONSOLE) { if (device & L_CONSOLE) {
/* Send console messages to console so people will see them. */ /* Send console messages to console so people will see them. */
@ -235,9 +215,8 @@ static void console_init(void)
* if TERM is set to linux (the default) */ * if TERM is set to linux (the default) */
if (!s || strcmp(s, "linux") == 0) if (!s || strcmp(s, "linux") == 0)
putenv((char*)"TERM=vt102"); putenv((char*)"TERM=vt102");
#if !ENABLE_FEATURE_INIT_SYSLOG if (!ENABLE_FEATURE_INIT_SYSLOG)
log_console = NULL; log_console = NULL;
#endif
} else if (!s) } else if (!s)
putenv((char*)"TERM=linux"); putenv((char*)"TERM=linux");
} }
@ -290,11 +269,10 @@ static void open_stdio_to_tty(const char* tty_name, int fail)
tty_name, strerror(errno)); tty_name, strerror(errno));
if (fail) if (fail)
_exit(1); _exit(1);
#if !ENABLE_DEBUG_INIT if (!ENABLE_DEBUG_INIT)
shutdown_signal(SIGUSR1); shutdown_signal(SIGUSR1);
#else else
_exit(2); _exit(2);
#endif
} else { } else {
dup2(fd, 0); dup2(fd, 0);
dup2(fd, 1); dup2(fd, 1);
@ -348,9 +326,13 @@ static pid_t run(const struct init_action *a)
open_stdio_to_tty(a->terminal, 1 /* - exit if open fails*/); open_stdio_to_tty(a->terminal, 1 /* - exit if open fails*/);
#ifdef BUT_RUN_ACTIONS_ALREADY_DOES_WAITING #ifdef BUT_RUN_ACTIONS_ALREADY_DOES_WAITING
# define BRAADS 1
#else
# define BRAADS 0
#endif
/* If the init Action requires us to wait, then force the /* If the init Action requires us to wait, then force the
* supplied terminal to be the controlling tty. */ * supplied terminal to be the controlling tty. */
if (a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) { if (BRAADS && a->action & (SYSINIT | WAIT | CTRLALTDEL | SHUTDOWN | RESTART)) {
/* Now fork off another process to just hang around */ /* Now fork off another process to just hang around */
pid = fork(); pid = fork();
@ -388,7 +370,6 @@ static pid_t run(const struct init_action *a)
/* Child - fall though to actually execute things */ /* Child - fall though to actually execute things */
} }
#endif
/* See if any special /bin/sh requiring characters are present */ /* See if any special /bin/sh requiring characters are present */
if (strpbrk(a->command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) { if (strpbrk(a->command, "~`!$^&*()=|\\{}[];\"'<>?") != NULL) {
@ -422,6 +403,11 @@ static pid_t run(const struct init_action *a)
++cmdpath; ++cmdpath;
#ifdef WHY_WE_DO_THIS_SHELL_MUST_HANDLE_THIS_ITSELF #ifdef WHY_WE_DO_THIS_SHELL_MUST_HANDLE_THIS_ITSELF
# define WWDTSMHTI 1
#else
# define WWDTSMHTI 0
#endif
if (WWDTSMHTI) {
/* find the last component in the command pathname */ /* find the last component in the command pathname */
s = bb_get_last_path_component_nostrip(cmdpath); s = bb_get_last_path_component_nostrip(cmdpath);
/* make a new argv[0] */ /* make a new argv[0] */
@ -433,14 +419,13 @@ static pid_t run(const struct init_action *a)
cmd[0][0] = '-'; cmd[0][0] = '-';
strcpy(cmd[0] + 1, s); strcpy(cmd[0] + 1, s);
} }
#endif }
#if ENABLE_FEATURE_INIT_SCTTY
/* Establish this process as session leader and /* Establish this process as session leader and
* _attempt_ to make stdin a controlling tty. * _attempt_ to make stdin a controlling tty.
*/ */
if (ENABLE_FEATURE_INIT_SCTTY)
ioctl(0, TIOCSCTTY, 0 /*only try, don't steal*/); ioctl(0, TIOCSCTTY, 0 /*only try, don't steal*/);
#endif
} }
if (a->action & ASKFIRST) { if (a->action & ASKFIRST) {
@ -470,8 +455,7 @@ static pid_t run(const struct init_action *a)
message(L_LOG, "starting pid %d, tty '%s': '%s'", message(L_LOG, "starting pid %d, tty '%s': '%s'",
getpid(), a->terminal, cmdpath); getpid(), a->terminal, cmdpath);
#if ENABLE_FEATURE_INIT_COREDUMPS if (ENABLE_FEATURE_INIT_COREDUMPS) {
{
struct stat sb; struct stat sb;
if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) { if (stat(CORE_ENABLE_FLAG_FILE, &sb) == 0) {
struct rlimit limit; struct rlimit limit;
@ -481,7 +465,7 @@ static pid_t run(const struct init_action *a)
setrlimit(RLIMIT_CORE, &limit); setrlimit(RLIMIT_CORE, &limit);
} }
} }
#endif
/* Now run it. The new program will take over this PID, /* Now run it. The new program will take over this PID,
* so nothing further in init.c should be run. */ * so nothing further in init.c should be run. */
BB_EXECVP(cmdpath, cmd); BB_EXECVP(cmdpath, cmd);
@ -536,7 +520,6 @@ static void run_actions(int action)
} }
} }
#if !ENABLE_DEBUG_INIT
static void init_reboot(unsigned long magic) static void init_reboot(unsigned long magic)
{ {
pid_t pid; pid_t pid;
@ -676,8 +659,6 @@ static void cont_handler(int sig ATTRIBUTE_UNUSED)
got_cont = 1; got_cont = 1;
} }
#endif /* !ENABLE_DEBUG_INIT */
static void new_init_action(uint8_t action, const char *command, const char *cons) static void new_init_action(uint8_t action, const char *command, const char *cons)
{ {
struct init_action *new_action, *a, *last; struct init_action *new_action, *a, *last;
@ -737,14 +718,16 @@ static void delete_init_action(struct init_action *action)
*/ */
static void parse_inittab(void) static void parse_inittab(void)
{ {
#if ENABLE_FEATURE_USE_INITTAB
FILE *file; FILE *file;
char buf[INIT_BUFFS_SIZE]; char buf[INIT_BUFFS_SIZE];
if (ENABLE_FEATURE_USE_INITTAB)
file = fopen(INITTAB, "r"); file = fopen(INITTAB, "r");
if (file == NULL) { else
file = NULL;
/* No inittab file -- set up some default behavior */ /* No inittab file -- set up some default behavior */
#endif if (file == NULL) {
/* Reboot on Ctrl-Alt-Del */ /* Reboot on Ctrl-Alt-Del */
new_init_action(CTRLALTDEL, "reboot", ""); new_init_action(CTRLALTDEL, "reboot", "");
/* Umount all filesystems on halt/reboot */ /* Umount all filesystems on halt/reboot */
@ -763,7 +746,6 @@ static void parse_inittab(void)
new_init_action(SYSINIT, INIT_SCRIPT, ""); new_init_action(SYSINIT, INIT_SCRIPT, "");
return; return;
#if ENABLE_FEATURE_USE_INITTAB
} }
while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) { while (fgets(buf, INIT_BUFFS_SIZE, file) != NULL) {
@ -823,10 +805,8 @@ static void parse_inittab(void)
next_line: ; next_line: ;
} }
fclose(file); fclose(file);
#endif /* FEATURE_USE_INITTAB */
} }
#if ENABLE_FEATURE_USE_INITTAB
static void reload_signal(int sig ATTRIBUTE_UNUSED) static void reload_signal(int sig ATTRIBUTE_UNUSED)
{ {
struct init_action *a, *tmp; struct init_action *a, *tmp;
@ -840,22 +820,21 @@ static void reload_signal(int sig ATTRIBUTE_UNUSED)
parse_inittab(); parse_inittab();
#if ENABLE_FEATURE_KILL_REMOVED if (ENABLE_FEATURE_KILL_REMOVED) {
for (a = init_action_list; a; a = a->next) { for (a = init_action_list; a; a = a->next) {
pid_t pid = a->pid; pid_t pid = a->pid;
if ((a->action & ONCE) && pid != 0) { if ((a->action & ONCE) && pid != 0) {
/* Be nice and send SIGTERM first */ /* Be nice and send SIGTERM first */
kill(pid, SIGTERM); kill(pid, SIGTERM);
#if CONFIG_FEATURE_KILL_DELAY if (CONFIG_FEATURE_KILL_DELAY)
if (fork() == 0) { /* child */ if (fork() == 0) { /* child */
sleep(CONFIG_FEATURE_KILL_DELAY); sleep(CONFIG_FEATURE_KILL_DELAY);
kill(pid, SIGKILL); kill(pid, SIGKILL);
_exit(0); _exit(0);
} }
#endif
} }
} }
#endif /* FEATURE_KILL_REMOVED */ }
/* remove unused entrys */ /* remove unused entrys */
for (a = init_action_list; a; a = tmp) { for (a = init_action_list; a; a = tmp) {
@ -866,7 +845,6 @@ static void reload_signal(int sig ATTRIBUTE_UNUSED)
} }
run_actions(RESPAWN); run_actions(RESPAWN);
} }
#endif /* FEATURE_USE_INITTAB */
int init_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; int init_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int init_main(int argc, char **argv) int init_main(int argc, char **argv)
@ -879,7 +857,8 @@ int init_main(int argc, char **argv)
if (argc > 1 && !strcmp(argv[1], "-q")) { if (argc > 1 && !strcmp(argv[1], "-q")) {
return kill(1, SIGHUP); return kill(1, SIGHUP);
} }
#if !ENABLE_DEBUG_INIT
if (!ENABLE_DEBUG_INIT) {
/* Expect to be invoked as init with PID=1 or be invoked as linuxrc */ /* Expect to be invoked as init with PID=1 or be invoked as linuxrc */
if (getpid() != 1 if (getpid() != 1
&& (!ENABLE_FEATURE_INITRD || !strstr(applet_name, "linuxrc")) && (!ENABLE_FEATURE_INITRD || !strstr(applet_name, "linuxrc"))
@ -901,8 +880,7 @@ int init_main(int argc, char **argv)
/* Turn off rebooting via CTL-ALT-DEL -- we get a /* Turn off rebooting via CTL-ALT-DEL -- we get a
* SIGINT on CAD so we can shut things down gracefully... */ * SIGINT on CAD so we can shut things down gracefully... */
init_reboot(RB_DISABLE_CAD); init_reboot(RB_DISABLE_CAD);
#endif }
/* Figure out where the default console should be */ /* Figure out where the default console should be */
console_init(); console_init();
@ -986,12 +964,11 @@ int init_main(int argc, char **argv)
/* Next run anything to be run only once */ /* Next run anything to be run only once */
run_actions(ONCE); run_actions(ONCE);
#if ENABLE_FEATURE_USE_INITTAB
/* Redefine SIGHUP to reread /etc/inittab */ /* Redefine SIGHUP to reread /etc/inittab */
if (ENABLE_FEATURE_USE_INITTAB)
signal(SIGHUP, reload_signal); signal(SIGHUP, reload_signal);
#else else
signal(SIGHUP, SIG_IGN); signal(SIGHUP, SIG_IGN);
#endif /* FEATURE_USE_INITTAB */
/* Now run the looping stuff for the rest of forever */ /* Now run the looping stuff for the rest of forever */
while (1) { while (1) {