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Improve STANDALONE_SHELL. "safe" applets are renamed NOEXEC applets

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and now this fact is recorded in applets.h, not ash.c.

Several fixes to "--help + STANDALONE_SHELL" scenarios.

function                                             old     new   delta
run_current_applet_and_exit                            -     355    +355
arith                                               2064    2073      +9
refresh                                             1148    1156      +8
getopt32                                            1068    1073      +5
telnet_main                                         1510    1514      +4
md5_sha1_sum_main                                    565     566      +1
xstrtoul_range_sfx                                   255     251      -4
packed_usage                                       22523   22514      -9
tryexec                                              255     203     -52
static.safe_applets                                  152       -    -152
.rodata                                           131320  131128    -192
run_applet_by_name                                   869     506    -363
------------------------------------------------------------------------------
(add/remove: 1/1 grow/shrink: 5/5 up/down: 382/-772)         Total: -390 bytes

./busybox ash -c 'i=20000; while test $i != 0; do touch z; i=$((i-1)); done'
runs more than twice as fast with STANDALONE_SHELL versus without.
This commit is contained in:
Denis Vlasenko
2007-04-09 03:11:58 +00:00
parent 95cb3263ae
commit c44ab01b75
5 changed files with 65 additions and 93 deletions
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59
shell/ash.c
View File

@ -6468,43 +6468,6 @@ casematch(union node *pattern, char *val)
/* ============ find_command */
#if ENABLE_FEATURE_SH_STANDALONE_SHELL
static int
is_safe_applet(char *name)
{
/* It isn't a bug to have non-existent applet here... */
/* ...just a waste of space... */
static const char safe_applets[][8] = {
"["
USE_AWK (, "awk" )
USE_CAT (, "cat" )
USE_CHMOD (, "chmod" )
USE_CHOWN (, "chown" )
USE_CP (, "cp" )
USE_CUT (, "cut" )
USE_DD (, "dd" )
USE_ECHO (, "echo" )
USE_FIND (, "find" )
USE_HEXDUMP(, "hexdump")
USE_LN (, "ln" )
USE_LS (, "ls" )
USE_MKDIR (, "mkdir" )
USE_RM (, "rm" )
USE_SORT (, "sort" )
USE_TEST (, "test" )
USE_TOUCH (, "touch" )
USE_XARGS (, "xargs" )
};
int n = sizeof(safe_applets) / sizeof(safe_applets[0]);
int i;
for (i = 0; i < n; i++)
if (strcmp(safe_applets[i], name) == 0)
return 1;
return 0;
}
#endif
struct builtincmd {
const char *name;
int (*builtin)(int, char **);
@ -6570,17 +6533,15 @@ tryexec(char *cmd, char **argv, char **envp)
#if ENABLE_FEATURE_SH_STANDALONE_SHELL
if (strchr(cmd, '/') == NULL) {
struct BB_applet *a;
char **c;
const struct BB_applet *a;
a = find_applet_by_name(cmd);
if (a) {
if (is_safe_applet(cmd)) {
c = argv;
while (*c)
c++;
applet_name = cmd;
exit(a->main(c - argv, argv));
if (a->noexec) {
char **c = argv;
while (*c) c++;
current_applet = a;
run_current_applet_and_exit(c - argv, argv);
}
/* re-exec ourselves with the new arguments */
execve(CONFIG_BUSYBOX_EXEC_PATH, argv, envp);
@ -6608,7 +6569,7 @@ tryexec(char *cmd, char **argv, char **envp)
;
ap = new = ckmalloc((ap - argv + 2) * sizeof(char *));
ap[1] = cmd;
*ap = cmd = (char *)DEFAULT_SHELL;
ap[0] = cmd = (char *)DEFAULT_SHELL;
ap += 2;
argv++;
while ((*ap++ = *argv++))
@ -11161,12 +11122,6 @@ find_command(char *name, struct cmdentry *entry, int act, const char *path)
entry->u.index = -1;
return;
}
/* Already caught above
if (is_safe_applet(name)) {
entry->cmdtype = CMDNORMAL;
entry->u.index = -1;
return;
}*/
#endif
updatetbl = (path == pathval());