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| author | Denys Vlasenko <vda.linux@googlemail.com> | 2013-08-16 11:48:48 +0200 |
|---|---|---|
| committer | Denys Vlasenko <vda.linux@googlemail.com> | 2013-08-16 11:48:48 +0200 |
| commit | d2e07bc16cbd68bc2771f9f163e610e4e327c67c (patch) | |
| tree | 737d5309821fd44427754223965ec596bfa1fcf8 /init | |
| parent | 73fbe9dc86df6c7db425c2c3939ff98c8c44974e (diff) | |
| download | busybox-w32-d2e07bc16cbd68bc2771f9f163e610e4e327c67c.tar.gz busybox-w32-d2e07bc16cbd68bc2771f9f163e610e4e327c67c.tar.bz2 busybox-w32-d2e07bc16cbd68bc2771f9f163e610e4e327c67c.zip | |
init: don't use fixed size buffer for command
We store init actions forever. 256 bytes per action means that
a typical inittab of ~10 commands uses 2.5k just to remember
command strings - which are usually _much_ shorter than 256 bytes.
At a cost of a bit more code, it's possible to allocate
only actually needed amount.
function old new delta
init_exec 224 248 +24
new_init_action 140 142 +2
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'init')
| -rw-r--r-- | init/init.c | 22 |
1 files changed, 13 insertions, 9 deletions
diff --git a/init/init.c b/init/init.c index f3a35d532..05ed4f7a7 100644 --- a/init/init.c +++ b/init/init.c | |||
| @@ -140,7 +140,6 @@ | |||
| 140 | * not fully functional init by switching it on! */ | 140 | * not fully functional init by switching it on! */ |
| 141 | #define DEBUG_INIT 0 | 141 | #define DEBUG_INIT 0 |
| 142 | 142 | ||
| 143 | #define COMMAND_SIZE 256 | ||
| 144 | #define CONSOLE_NAME_SIZE 32 | 143 | #define CONSOLE_NAME_SIZE 32 |
| 145 | 144 | ||
| 146 | /* Default sysinit script. */ | 145 | /* Default sysinit script. */ |
| @@ -195,7 +194,7 @@ struct init_action { | |||
| 195 | pid_t pid; | 194 | pid_t pid; |
| 196 | uint8_t action_type; | 195 | uint8_t action_type; |
| 197 | char terminal[CONSOLE_NAME_SIZE]; | 196 | char terminal[CONSOLE_NAME_SIZE]; |
| 198 | char command[COMMAND_SIZE]; | 197 | char command[1]; |
| 199 | }; | 198 | }; |
| 200 | 199 | ||
| 201 | static struct init_action *init_action_list = NULL; | 200 | static struct init_action *init_action_list = NULL; |
| @@ -398,7 +397,7 @@ static void reset_sighandlers_and_unblock_sigs(void) | |||
| 398 | } | 397 | } |
| 399 | 398 | ||
| 400 | /* Wrapper around exec: | 399 | /* Wrapper around exec: |
| 401 | * Takes string (max COMMAND_SIZE chars). | 400 | * Takes string. |
| 402 | * If chars like '>' detected, execs '[-]/bin/sh -c "exec ......."'. | 401 | * If chars like '>' detected, execs '[-]/bin/sh -c "exec ......."'. |
| 403 | * Otherwise splits words on whitespace, deals with leading dash, | 402 | * Otherwise splits words on whitespace, deals with leading dash, |
| 404 | * and uses plain exec(). | 403 | * and uses plain exec(). |
| @@ -406,10 +405,15 @@ static void reset_sighandlers_and_unblock_sigs(void) | |||
| 406 | */ | 405 | */ |
| 407 | static void init_exec(const char *command) | 406 | static void init_exec(const char *command) |
| 408 | { | 407 | { |
| 409 | char *cmd[COMMAND_SIZE / 2]; | 408 | /* +8 allows to write VLA sizes below more efficiently: */ |
| 410 | char buf[COMMAND_SIZE + 6]; /* COMMAND_SIZE+strlen("exec ")+1 */ | 409 | unsigned command_size = strlen(command) + 8; |
| 411 | int dash = (command[0] == '-' /* maybe? && command[1] == '/' */); | 410 | /* strlen(command) + strlen("exec ")+1: */ |
| 412 | 411 | char buf[command_size]; | |
| 412 | /* strlen(command) / 2 + 4: */ | ||
| 413 | char *cmd[command_size / 2]; | ||
| 414 | int dash; | ||
| 415 | |||
| 416 | dash = (command[0] == '-' /* maybe? && command[1] == '/' */); | ||
| 413 | command += dash; | 417 | command += dash; |
| 414 | 418 | ||
| 415 | /* See if any special /bin/sh requiring characters are present */ | 419 | /* See if any special /bin/sh requiring characters are present */ |
| @@ -626,13 +630,13 @@ static void new_init_action(uint8_t action_type, const char *command, const char | |||
| 626 | nextp = &a->next; | 630 | nextp = &a->next; |
| 627 | } | 631 | } |
| 628 | 632 | ||
| 629 | a = xzalloc(sizeof(*a)); | 633 | a = xzalloc(sizeof(*a) + strlen(command)); |
| 630 | 634 | ||
| 631 | /* Append to the end of the list */ | 635 | /* Append to the end of the list */ |
| 632 | append: | 636 | append: |
| 633 | *nextp = a; | 637 | *nextp = a; |
| 634 | a->action_type = action_type; | 638 | a->action_type = action_type; |
| 635 | safe_strncpy(a->command, command, sizeof(a->command)); | 639 | strcpy(a->command, command); |
| 636 | safe_strncpy(a->terminal, cons, sizeof(a->terminal)); | 640 | safe_strncpy(a->terminal, cons, sizeof(a->terminal)); |
| 637 | dbg_message(L_LOG | L_CONSOLE, "command='%s' action=%d tty='%s'\n", | 641 | dbg_message(L_LOG | L_CONSOLE, "command='%s' action=%d tty='%s'\n", |
| 638 | a->command, a->action_type, a->terminal); | 642 | a->command, a->action_type, a->terminal); |