Add BB_EXEC[LV]P() which encapsulate FEATURE_EXEC_PREFER_APPLETS

(patch from Gabriel L. Somlo <somlo@cmu.edu>)

3 files changed, 14 insertions, 19 deletions

diff --git a/include/libbb.h b/include/libbb.h
index ed1c41a02..85afdf20a 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -551,6 +551,16 @@ int execable_file(const char *name);
 char *find_execable(const char *filename);
 int exists_execable(const char *filename);
 
+#ifdef ENABLE_FEATURE_EXEC_PREFER_APPLETS
+#define BB_EXECVP(prog,cmd) \
+        execvp((find_applet_by_name(prog)) ? CONFIG_BUSYBOX_EXEC_PATH : prog, cmd)
+#define BB_EXECLP(prog,cmd,...) \
+        execlp((find_applet_by_name(prog)) ? CONFIG_BUSYBOX_EXEC_PATH : prog, cmd, __VA_ARGS__)
+#else
+#define BB_EXECVP(prog,cmd) execvp(prog,cmd)
+#define BB_EXECLP(prog,cmd,...) execvp(prog,cmd, __VA_ARGS__) 
+#endif
+
 USE_DESKTOP(long long) int uncompress(int fd_in, int fd_out);
 int inflate(int in, int out);
 
diff --git a/init/init.c b/init/init.c
index cb314003e..110af8566 100644
--- a/init/init.c
+++ b/init/init.c
@@ -389,7 +389,6 @@ static pid_t run(const struct init_action *a)
 #include CUSTOMIZED_BANNER
 #endif
                 "\nPlease press Enter to activate this console. ";
-        const char *prog;
 
         /* Block sigchild while forking.  */
         sigemptyset(&nmask);
@@ -561,10 +560,7 @@ static pid_t run(const struct init_action *a)
 
                 /* Now run it.  The new program will take over this PID,
                  * so nothing further in init.c should be run. */
-                prog = cmdpath;
-                if (ENABLE_FEATURE_EXEC_PREFER_APPLETS && find_applet_by_name(prog))
-                        prog = CONFIG_BUSYBOX_EXEC_PATH;
-                execvp(prog, cmd);
+                BB_EXECVP(cmdpath, cmd);
 
                 /* We're still here?  Some error happened. */
                 message(LOG | CONSOLE, "Bummer, cannot run '%s': %m", cmdpath);
@@ -682,7 +678,6 @@ static void exec_signal(int sig ATTRIBUTE_UNUSED)
 {
         struct init_action *a, *tmp;
         sigset_t unblock_signals;
-        char *prog;
 
         for (a = init_action_list; a; a = tmp) {
                 tmp = a->next;
@@ -718,10 +713,7 @@ static void exec_signal(int sig ATTRIBUTE_UNUSED)
                         dup(0);
 
                         messageD(CONSOLE | LOG, "Trying to re-exec %s", a->command);
-                        prog = a->command;
-                        if (ENABLE_FEATURE_EXEC_PREFER_APPLETS && find_applet_by_name(prog))
-                                prog = CONFIG_BUSYBOX_EXEC_PATH;
-                        execlp(prog, a->command, NULL);
+                        BB_EXECLP(a->command, a->command, NULL);
 
                         message(CONSOLE | LOG, "exec of '%s' failed: %m",
                                         a->command);
@@ -1076,10 +1068,7 @@ int init_main(int argc, char **argv)
 
                 putenv("SELINUX_INIT=YES");
                 if (selinux_init_load_policy(&enforce) == 0) {
-                        char *prog = argv[0];
-                        if (ENABLE_FEATURE_EXEC_PREFER_APPLETS && find_applet_by_name(prog))
-                                prog = CONFIG_BUSYBOX_EXEC_PATH;
-                        execvp(prog, argv);
+                        BB_EXECVP(argv[0], argv);
                 } else if (enforce > 0) {
                         /* SELinux in enforcing mode but load_policy failed */
                         /* At this point, we probably can't open /dev/console, so log() won't work */
diff --git a/libbb/xfuncs.c b/libbb/xfuncs.c
index 601ff3f7e..3cbb0d3eb 100644
--- a/libbb/xfuncs.c
+++ b/libbb/xfuncs.c
@@ -184,17 +184,13 @@ pid_t spawn(char **argv)
         /* Why static? */
         static int failed;
         pid_t pid;
-        const char *prog;
 
         // Be nice to nommu machines.
         failed = 0;
         pid = vfork();
         if (pid < 0) return pid;
         if (!pid) {
-                prog = argv[0];
-                if (ENABLE_FEATURE_EXEC_PREFER_APPLETS && find_applet_by_name(prog))
-                        prog = CONFIG_BUSYBOX_EXEC_PATH;
-                execvp(prog, argv);
+                BB_EXECVP(argv[0], argv);
 
                 // We're sharing a stack with blocked parent, let parent know we failed
                 // and then exit to unblock parent (but don't run atexit() stuff, which