From 44eb4d8b9b7b3b539bcd4e311e9d7c8e2acf8d80 Mon Sep 17 00:00:00 2001 From: Rich Felker Date: Thu, 18 Oct 2012 15:58:23 -0400 Subject: overhaul system() and popen() to use vfork; fix various related bugs since we target systems without overcommit, special care should be taken that system() and popen(), like posix_spawn(), do not fail in processes whose commit charges are too high to allow ordinary forking. this in turn requires special precautions to ensure that the parent process's signal handlers do not end up running in the shared-memory child, where they could corrupt the state of the parent process. popen has also been updated to use pipe2, so it does not have a fd-leak race in multi-threaded programs. since pipe2 is missing on older kernels, (non-atomic) emulation has been added. some silly bugs in the old code should be gone too. --- src/process/posix_spawn.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) (limited to 'src/process/posix_spawn.c') diff --git a/src/process/posix_spawn.c b/src/process/posix_spawn.c index 8a6ff6db..e8557487 100644 --- a/src/process/posix_spawn.c +++ b/src/process/posix_spawn.c @@ -4,6 +4,7 @@ #include #include #include "syscall.h" +#include "pthread_impl.h" #include "fdop.h" #include "libc.h" @@ -30,7 +31,7 @@ int __posix_spawnx(pid_t *restrict res, const char *restrict path, if (!attr) attr = &dummy_attr; - sigprocmask(SIG_BLOCK, (void *)(uint64_t []){-1}, &oldmask); + sigprocmask(SIG_BLOCK, SIGALL_SET, &oldmask); __acquire_ptc(); pid = __vfork(); @@ -43,14 +44,14 @@ int __posix_spawnx(pid_t *restrict res, const char *restrict path, return 0; } - for (i=1; i<=64; i++) { + for (i=1; i<=8*__SYSCALL_SSLEN; i++) { struct sigaction sa; - sigaction(i, 0, &sa); - if (sa.sa_handler!=SIG_IGN || + __libc_sigaction(i, 0, &sa); + if (sa.sa_handler!=SIG_DFL && (sa.sa_handler!=SIG_IGN || ((attr->__flags & POSIX_SPAWN_SETSIGDEF) - && sigismember(&attr->__def, i) )) { + && sigismember(&attr->__def, i) ))) { sa.sa_handler = SIG_DFL; - sigaction(i, &sa, 0); + __libc_sigaction(i, &sa, 0); } } -- cgit v1.2.1