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7e754f12d

Denis Vlasenko
Denis Vlasenko
2007-04-09
FAILED Duration: 11s

Subject

Implement first instance of NOFORK applet - echo find: use NOFORK/NOEXEC; small -exec buglet also eliminated vfork_daemon_rexec: honor PREFER_APPLETS echo: small size improvements

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Architecture & Compiler Flags

Architecture: x86_64-linux-gnu Compiler: gcc (Ubuntu 11.4.0-1ubuntu1~22.04.3) 11.4.0

—

Build Log

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Commit Diff GitHub →

Config.in +2 -1coreutils/echo.c +38 -37findutils/find.c +23 -2include/applets.h +6 -1libbb/process_escape_sequence.c +3 -6libbb/vfork_daemon_rexec.c +5 -3
Config.in+2 -1
@@ -244,7 +244,8 @@ config FEATURE_EXEC_PREFER_APPLETS
help
This is an experimental option which directs applets about to
call 'exec' to try and find an applicable busybox applet before
- searching the executable path for a binary or symlink to execute.
+ searching the PATH. This may affect shell, find -exec, xargs and
+ similar programs.
config BUSYBOX_EXEC_PATH
string "Path to BusyBox executable"
coreutils/echo.c+38 -37
@@ -20,86 +20,85 @@
* 1) In handling '\c' escape, the previous version only suppressed the
* trailing newline. SUSv3 specifies _no_ output after '\c'.
* 2) SUSv3 specifies that octal escapes are of the form \0{#{#{#}}}.
- * The previous version version did not allow 4-digit octals.
+ * The previous version did not allow 4-digit octals.
*/
-
-#include <stdio.h>
-#include <string.h>
-#include <stdlib.h>
#include "busybox.h"
int bb_echo(char **argv)
{
-#ifndef CONFIG_FEATURE_FANCY_ECHO
+ const char *arg;
+#if !ENABLE_FEATURE_FANCY_ECHO
#define eflag '\\'
++argv;
#else
const char *p;
- int nflag = 1;
- int eflag = 0;
+ char nflag = 1;
+ char eflag = 0;
+
+ while (1) {
+ arg = *++argv;
+ if (!arg)
+ goto ret;
+ if (*arg != '-')
+ break;
- while (*++argv && (**argv == '-')) {
/* If it appears that we are handling options, then make sure
* that all of the options specified are actually valid.
* Otherwise, the string should just be echoed.
*/
-
- if (!*(p = *argv + 1)) { /* A single '-', so echo it. */
+ p = arg + 1;
+ if (!*p) /* A single '-', so echo it. */
goto just_echo;
- }
do {
- if (strrchr("neE", *p) == 0) {
+ if (!strrchr("neE", *p))
goto just_echo;
- }
} while (*++p);
/* All of the options in this arg are valid, so handle them. */
- p = *argv + 1;
+ p = arg + 1;
do {
- if (*p == 'n') {
+ if (*p == 'n')
nflag = 0;
- } else if (*p == 'e') {
+ if (*p == 'e')
eflag = '\\';
- } else {
- eflag = 0;
- }
} while (*++p);
}
-
-just_echo:
+ just_echo:
#endif
- while (*argv) {
+ while (1) {
+ /* arg is already = *argv and isn't NULL */
int c;
- while ((c = *(*argv)++)) {
+ while ((c = *arg++)) {
if (c == eflag) { /* Check for escape seq. */
- if (**argv == 'c') {
+ if (*arg == 'c') {
/* '\c' means cancel newline and
* ignore all subsequent chars. */
- return 0;
+ goto ret;
}
-#ifndef CONFIG_FEATURE_FANCY_ECHO
+#if !ENABLE_FEATURE_FANCY_ECHO
/* SUSv3 specifies that octal escapes must begin with '0'. */
- if (((unsigned int)(**argv - '1')) >= 7)
+ if ( (((unsigned char)*arg) - '1') >= 7)
#endif
{
/* Since SUSv3 mandates a first digit of 0, 4-digit octals
* of the form \0### are accepted. */
- if ((**argv == '0') && (((unsigned int)(argv[0][1] - '0')) < 8)) {
- (*argv)++;
+ if (*arg == '0' && ((unsigned char)(arg[1]) - '0') < 8) {
+ arg++;
}
/* bb_process_escape_sequence can handle nul correctly */
- c = bb_process_escape_sequence((const char **) argv);
+ c = bb_process_escape_sequence(&arg);
}
}
putchar(c);
}
- if (*++argv) {
- putchar(' ');
- }
+ arg = *++argv;
+ if (!arg)
+ break;
+ putchar(' ');
}
#ifdef CONFIG_FEATURE_FANCY_ECHO
@@ -109,14 +108,16 @@ just_echo:
#else
putchar('\n');
#endif
- return 0;
+ ret:
+ return fflush(stdout);
}
+/* This is a NOFORK applet. Be very careful! */
+
int echo_main(int argc, char** argv);
int echo_main(int argc, char** argv)
{
- (void)bb_echo(argv);
- fflush_stdout_and_exit(EXIT_SUCCESS);
+ return bb_echo(argv);
}
/*-
findutils/find.c+23 -2
@@ -242,9 +242,30 @@ ACTF(exec)
for (i = 0; i < ap->exec_argc; i++)
argv[i] = subst(ap->exec_argv[i], ap->subst_count[i], fileName);
argv[i] = NULL; /* terminate the list */
- rc = wait4pid(spawn(argv));
- if (rc)
+
+ if (ENABLE_FEATURE_EXEC_PREFER_APPLETS) {
+ const struct BB_applet *a = find_applet_by_name(argv[0]);
+ if (a) {
+ if (a->nofork) {
+ rc = a->main(ap->exec_argc, argv);
+ goto f;
+ }
+#ifndef BB_NOMMU
+ if (a->noexec) {
+ rc = fork();
+ if (rc) goto w;
+ current_applet = a;
+ run_current_applet_and_exit(ap->exec_argc, argv);
+ }
+#endif
+ }
+ }
+ rc = spawn(argv);
+ w:
+ rc = wait4pid(rc);
+ if (rc < 0)
bb_perror_msg("%s", argv[0]);
+ f:
for (i = 0; i < ap->exec_argc; i++)
free(argv[i]);
return rc == 0; /* return 1 if success */
include/applets.h+6 -1
@@ -28,24 +28,28 @@ s - suid type:
# define APPLET_NOUSAGE(name,main,l,s) int main##_main(int argc, char **argv);
# define APPLET_ODDNAME(name,main,l,s,name2) int main##_main(int argc, char **argv);
# define APPLET_NOEXEC(name,main,l,s,name2) int main##_main(int argc, char **argv);
+# define APPLET_NOFORK(name,main,l,s,name2) int main##_main(int argc, char **argv);
#elif defined(MAKE_USAGE) && ENABLE_FEATURE_VERBOSE_USAGE
# define APPLET(name,l,s) name##_trivial_usage "\n\n" name##_full_usage "\0"
# define APPLET_NOUSAGE(name,main,l,s) "\b\0"
# define APPLET_ODDNAME(name,main,l,s,name2) name2##_trivial_usage "\n\n" name2##_full_usage "\0"
# define APPLET_NOEXEC(name,main,l,s,name2) name2##_trivial_usage "\n\n" name2##_full_usage "\0"
+# define APPLET_NOFORK(name,main,l,s,name2) name2##_trivial_usage "\n\n" name2##_full_usage "\0"
#elif defined(MAKE_USAGE) && !ENABLE_FEATURE_VERBOSE_USAGE
# define APPLET(name,l,s) name##_trivial_usage "\0"
# define APPLET_NOUSAGE(name,main,l,s) "\b\0"
# define APPLET_ODDNAME(name,main,l,s,name2) name2##_trivial_usage "\0"
# define APPLET_NOEXEC(name,main,l,s,name2) name2##_trivial_usage "\0"
+# define APPLET_NOFORK(name,main,l,s,name2) name2##_trivial_usage "\0"
#elif defined(MAKE_LINKS)
# define APPLET(name,l,c) LINK l name
# define APPLET_NOUSAGE(name,main,l,s) LINK l name
# define APPLET_ODDNAME(name,main,l,s,name2) LINK l name
# define APPLET_NOEXEC(name,main,l,s,name2) LINK l name
+# define APPLET_NOFORK(name,main,l,s,name2) LINK l name
#else
const struct BB_applet applets[] = { /* name,main,location,need_suid */
@@ -53,6 +57,7 @@ s - suid type:
# define APPLET_NOUSAGE(name,main,l,s) {#name,main##_main,l,s},
# define APPLET_ODDNAME(name,main,l,s,name2) {#name,main##_main,l,s},
# define APPLET_NOEXEC(name,main,l,s,name2) {#name,main##_main,l,s,1},
+# define APPLET_NOFORK(name,main,l,s,name2) {#name,main##_main,l,s,1,1},
#endif
#if ENABLE_INSTALL_NO_USR
@@ -118,7 +123,7 @@ USE_DUMPKMAP(APPLET(dumpkmap, _BB_DIR_BIN, _BB_SUID_NEVER))
USE_APP_DUMPLEASES(APPLET(dumpleases, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
//USE_E2FSCK(APPLET(e2fsck, _BB_DIR_SBIN, _BB_SUID_NEVER))
//USE_E2LABEL(APPLET_NOUSAGE(e2label, tune2fs, _BB_DIR_SBIN, _BB_SUID_NEVER))
-USE_ECHO(APPLET_NOEXEC(echo, echo, _BB_DIR_BIN, _BB_SUID_NEVER, echo))
+USE_ECHO(APPLET_NOFORK(echo, echo, _BB_DIR_BIN, _BB_SUID_NEVER, echo))
USE_ED(APPLET(ed, _BB_DIR_BIN, _BB_SUID_NEVER))
USE_FEATURE_GREP_EGREP_ALIAS(APPLET_NOUSAGE(egrep, grep, _BB_DIR_BIN, _BB_SUID_NEVER))
USE_EJECT(APPLET(eject, _BB_DIR_USR_BIN, _BB_SUID_NEVER))
libbb/process_escape_sequence.c+3 -6
@@ -8,9 +8,6 @@
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
*/
-#include <stdio.h>
-#include <limits.h>
-#include <ctype.h>
#include "libbb.h"
#define WANT_HEX_ESCAPES 1
@@ -46,10 +43,10 @@ char bb_process_escape_sequence(const char **ptr)
#endif
do {
- d = (unsigned int)(*q - '0');
+ d = (unsigned char)(*q) - '0';
#ifdef WANT_HEX_ESCAPES
if (d >= 10) {
- d = ((unsigned int)(_tolower(*q) - 'a')) + 10;
+ d = (unsigned char)(_tolower(*q)) - 'a' + 10;
}
#endif
@@ -80,7 +77,7 @@ char bb_process_escape_sequence(const char **ptr)
break;
}
} while (*++p);
- n = *(p+(sizeof(charmap)/2));
+ n = *(p + (sizeof(charmap)/2));
}
*ptr = q;
libbb/vfork_daemon_rexec.c+5 -3
@@ -26,14 +26,16 @@ pid_t spawn(char **argv)
volatile int failed;
pid_t pid;
- // Be nice to nommu machines.
+// Ain't it a good place to fflush(NULL)?
+
+ /* Be nice to nommu machines. */
failed = 0;
pid = vfork();
if (pid < 0) /* error */
return pid;
if (!pid) { /* child */
- /* Don't use BB_EXECVP tricks here! */
- execvp(argv[0], argv);
+ /* This macro is ok - it doesn't do NOEXEC/NOFORK tricks */
+ BB_EXECVP(argv[0], argv);
/* We are (maybe) sharing a stack with blocked parent,
* let parent know we failed and then exit to unblock parent