From d0006fa784a7de881db187756770d2492c75df5d Mon Sep 17 00:00:00 2001 From: Paul Holzinger Date: Wed, 5 Feb 2025 14:00:41 +0100 Subject: treewide: use _exit() over exit() In the podman CI I noticed many seccomp denials in our logs even though tests passed: comm="pasta.avx2" exe="/usr/bin/pasta.avx2" sig=31 arch=c000003e syscall=202 compat=0 ip=0x7fb3d31f69db code=0x80000000 Which is futex being called and blocked by the pasta profile. After a few tries I managed to reproduce locally with this loop in ~20 min: while :; do podman run -d --network bridge quay.io/libpod/testimage:20241011 \ sleep 100 && \ sleep 10 && \ podman rm -fa -t0 done And using a pasta version with prctl(PR_SET_DUMPABLE, 1); set I got the following stack trace: Stack trace of thread 1: #0 0x00007fc95e6de91b __lll_lock_wait_private (libc.so.6 + 0x9491b) #1 0x00007fc95e68d6de __run_exit_handlers (libc.so.6 + 0x436de) #2 0x00007fc95e68d70e exit (libc.so.6 + 0x4370e) #3 0x000055f31b78c50b n/a (n/a + 0x0) #4 0x00007fc95e68d70e exit (libc.so.6 + 0x4370e) #5 0x000055f31b78d5a2 n/a (n/a + 0x0) Pasta got killed in exit(), it seems glibc is trying to use a lock when running exit handlers even though no exit handlers are defined. Given no exit handlers are needed we can call _exit() instead. This skips exit handlers and does not flush stdio streams compared to exit() which should be fine for the use here. Based on the input from Stefano I did not change the test/doc programs or qrap as they do not use seccomp filters. Signed-off-by: Paul Holzinger Signed-off-by: Stefano Brivio --- util.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'util.c') diff --git a/util.c b/util.c index 800c6b5..4d51e04 100644 --- a/util.c +++ b/util.c @@ -405,7 +405,7 @@ void pidfile_write(int fd, pid_t pid) if (write(fd, pid_buf, n) < 0) { perror("PID file write"); - exit(EXIT_FAILURE); + _exit(EXIT_FAILURE); } close(fd); @@ -441,12 +441,12 @@ int __daemon(int pidfile_fd, int devnull_fd) if (pid == -1) { perror("fork"); - exit(EXIT_FAILURE); + _exit(EXIT_FAILURE); } if (pid) { pidfile_write(pidfile_fd, pid); - exit(EXIT_SUCCESS); + _exit(EXIT_SUCCESS); } if (setsid() < 0 || @@ -454,7 +454,7 @@ int __daemon(int pidfile_fd, int devnull_fd) dup2(devnull_fd, STDOUT_FILENO) < 0 || dup2(devnull_fd, STDERR_FILENO) < 0 || close(devnull_fd)) - exit(EXIT_FAILURE); + _exit(EXIT_FAILURE); return 0; } -- cgit v1.2.3