From 4c253ed1cae8b4df72ce1353ee826a4fae399e25 Mon Sep 17 00:00:00 2001 From: Lennart Poettering Date: Fri, 22 Dec 2017 13:08:14 +0100 Subject: tree-wide: introduce new safe_fork() helper and port everything over MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This adds a new safe_fork() wrapper around fork() and makes use of it everywhere. The new wrapper does a couple of things we previously did manually and separately in a safer, more correct and automatic way: 1. Optionally resets signal handlers/mask in the child 2. Sets a name on all processes we fork off right after forking off (and the patch assigns useful names for all processes we fork off now, following a systematic naming scheme: always enclosed in () – in order to indicate that these are not proper, exec()ed processes, but only forked off children, and if the process is long-running with only our own code, without execve()'ing something else, it gets am "sd-" prefix.) 3. Optionally closes all file descriptors in the child 4. Optionally sets a PR_SET_DEATHSIG to SIGTERM in the child, in a safe way so that the parent dying before this happens being handled safely. 5. Optionally reopens the logs 6. Optionally connects stdin/stdout/stderr to /dev/null 7. Debug logs about the forked off processes. --- src/sulogin-shell/sulogin-shell.c | 15 +++++---------- 1 file changed, 5 insertions(+), 10 deletions(-) (limited to 'src/sulogin-shell') diff --git a/src/sulogin-shell/sulogin-shell.c b/src/sulogin-shell/sulogin-shell.c index 70659df417..a6e0e0476f 100644 --- a/src/sulogin-shell/sulogin-shell.c +++ b/src/sulogin-shell/sulogin-shell.c @@ -81,18 +81,13 @@ static int start_default_target(sd_bus *bus) { static int fork_wait(const char* const cmdline[]) { pid_t pid; + int r; - pid = fork(); - if (pid < 0) - return log_error_errno(errno, "fork(): %m"); - if (pid == 0) { - + r = safe_fork("(sulogin)", FORK_RESET_SIGNALS|FORK_DEATHSIG, &pid); + if (r < 0) + return log_error_errno(r, "fork(): %m"); + if (r == 0) { /* Child */ - - (void) reset_all_signal_handlers(); - (void) reset_signal_mask(); - assert_se(prctl(PR_SET_PDEATHSIG, SIGTERM) == 0); - execv(cmdline[0], (char**) cmdline); log_error_errno(errno, "Failed to execute %s: %m", cmdline[0]); _exit(EXIT_FAILURE); /* Operational error */ -- cgit v1.2.1