[hackers] [sbase] Don't return but _exit after failed exec*() and fork() || FRIGN

From: <git_AT_suckless.org>
Date: Mon, 9 Mar 2015 15:51:40 +0100 (CET)

commit 86540324c4da4bd8279d213b2a7fc3b52a0cfad5
Author: FRIGN <dev_AT_frign.de>
Date: Mon Mar 9 01:04:34 2015 +0100

    Don't return but _exit after failed exec*() and fork()
    
    Quoting POSIX[0]:
    "Care should be taken, also, to call _exit() rather than exit() if exec cannot be used, since
    exit() flushes and closes standard I/O channels, thereby damaging the parent process' standard
    I/O data structures. (Even with fork(), it is wrong to call exit(), since buffered data would
    then be flushed twice.)"
    
    [0]: http://pubs.opengroup.org/onlinepubs/009695399/functions/vfork.html

diff --git a/chroot.c b/chroot.c
index 5048c78..beec628 100644
--- a/chroot.c
+++ b/chroot.c
_AT_@ -36,15 +36,14 @@ main(int argc, char *argv[])
 
         if (argc == 1) {
                 cmd = *shell;
- execvp(*shell, shell);
+ execvp(cmd, shell);
         } else {
                 cmd = argv[1];
- execvp(argv[1], argv + 1);
+ execvp(cmd, argv + 1);
         }
 
         savederrno = errno;
         weprintf("execvp %s:", cmd);
- _exit(126 + (savederrno == ENOENT));
 
- return 0; /* not reached */
+ _exit(126 + (savederrno == ENOENT));
 }
diff --git a/env.c b/env.c
index 971514b..5af93e0 100644
--- a/env.c
+++ b/env.c
_AT_@ -18,6 +18,8 @@ usage(void)
 int
 main(int argc, char *argv[])
 {
+ int savederrno;
+
         ARGBEGIN {
         case 'i':
                 if (environ)
_AT_@ -35,7 +37,9 @@ main(int argc, char *argv[])
 
         if (*argv) {
                 execvp(*argv, argv);
- enprintf(126 + (errno == EEXIST), "execvp: %s:", *argv);
+ savederrno = errno;
+ weprintf("execvp %s:", *argv);
+ _exit(126 + (savederrno == EEXIST));
         }
 
         for (; environ && *environ; environ++)
diff --git a/nice.c b/nice.c
index 70a5c2d..d9985fa 100644
--- a/nice.c
+++ b/nice.c
_AT_@ -44,5 +44,5 @@ main(int argc, char *argv[])
         savederrno = errno;
         weprintf("execvp %s:", argv[0]);
 
- return 126 + (savederrno == ENOENT);
+ _exit(126 + (savederrno == ENOENT));
 }
diff --git a/nohup.c b/nohup.c
index 6c7b933..59970cb 100644
--- a/nohup.c
+++ b/nohup.c
_AT_@ -42,8 +42,7 @@ main(int argc, char *argv[])
 
         execvp(argv[0], argv);
         savederrno = errno;
- weprintf("exec %s:", argv[0]);
- _exit(126 + (savederrno == ENOENT));
+ weprintf("execvp %s:", argv[0]);
 
- return 0; /* not reached */
+ _exit(126 + (savederrno == ENOENT));
 }
diff --git a/setsid.c b/setsid.c
index 73c2ae8..212100b 100644
--- a/setsid.c
+++ b/setsid.c
_AT_@ -26,7 +26,8 @@ main(int argc, char *argv[])
         if (getpgrp() == getpid()) {
                 switch (fork()) {
                 case -1:
- eprintf("fork:");
+ weprintf("fork:");
+ _exit(1);
                 case 0:
                         break;
                 default:
_AT_@ -39,5 +40,5 @@ main(int argc, char *argv[])
         savederrno = errno;
         weprintf("execvp %s:", argv[0]);
 
- return 126 + (savederrno == ENOENT);
+ _exit(126 + (savederrno == ENOENT));
 }
diff --git a/tar.c b/tar.c
index e0e6240..d847c9d 100644
--- a/tar.c
+++ b/tar.c
_AT_@ -55,7 +55,8 @@ decomp(FILE *fp)
 
         pid = fork();
         if (pid < 0) {
- eprintf("fork:");
+ weprintf("fork:");
+ _exit(1);
         } else if (!pid) {
                 dup2(fileno(fp), 0);
                 dup2(fds[1], 1);
_AT_@ -64,12 +65,13 @@ decomp(FILE *fp)
 
                 switch (filtermode) {
                 case 'j':
- execlp("bzip2", "bzip2", "-cd", (char *)0);
- eprintf("execlp bzip2:");
+ execlp("bzip2", "bzip2", "-cd", NULL);
+ weprintf("execlp bzip2:");
+ _exit(1);
                 case 'z':
- execlp("gzip", "gzip", "-cd", (char *)0);
- eprintf("execlp gzip:");
- break;
+ execlp("gzip", "gzip", "-cd", NULL);
+ weprintf("execlp gzip:");
+ _exit(1);
                 }
         }
         close(fds[1]);
diff --git a/time.c b/time.c
index 0b8e607..3ff25ac 100644
--- a/time.c
+++ b/time.c
_AT_@ -41,11 +41,12 @@ main(int argc, char *argv[])
 
         switch ((pid = fork())) {
         case -1:
- eprintf("fork:");
+ weprintf("fork:");
+ _exit(1);
         case 0:
                 execvp(argv[0], argv);
                 savederrno = errno;
- weprintf("exec %s:", argv[0]);
+ weprintf("execvp %s:", argv[0]);
                 _exit(126 + (savederrno == ENOENT));
         default:
                 break;
diff --git a/xargs.c b/xargs.c
index 9245627..983eeb2 100644
--- a/xargs.c
+++ b/xargs.c
_AT_@ -168,13 +168,15 @@ spawn(void)
         int savederrno;
 
         pid = fork();
- if (pid < 0)
- eprintf("fork:");
+ if (pid < 0) {
+ weprintf("fork:");
+ _exit(1);
+ }
         if (pid == 0) {
                 execvp(*cmd, cmd);
                 savederrno = errno;
                 weprintf("execvp %s:", *cmd);
- _exit(savederrno == ENOENT ? 127 : 126);
+ _exit(126 + (savederrno == ENOENT));
         }
         waitchld();
 }
Received on Mon Mar 09 2015 - 15:51:40 CET