This patch fixes a bug where child processes of launch_script() can
misbehave due to SIGCHLD being blocked. In the case of `sudo`, this
causes a permanent hang.
Previously a SIGCHLD handler was added to reap fork_exec()'d zombie
processes by calling waitpid(-1, ...). This required other
fork()/waitpid() callers to temporarilly block SIGCHILD to avoid
having the final wait status being intercepted by the SIGCHLD
handler:
7c3370d4fe3fa6cda8655f109e4659afc8ca4269
Since then, the qemu_add_child_watch() interface was added to allow
registration of such processes and reap only from that specific set
of PIDs:
4d54ec7898bd951007cb6122d5315584bd41d0c4
As a result, we can now avoid blocking SIGCHLD in launch_script(), so
drop that behavior.
Signed-off-by: Michael Roth <mdr...@linux.vnet.ibm.com>
---
net/tap.c | 5 -----
1 files changed, 0 insertions(+), 5 deletions(-)
diff --git a/net/tap.c b/net/tap.c
index 1f26dc9..2cf79e1 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -351,10 +351,6 @@ static int launch_script(const char *setup_script, const
char *ifname, int fd)
char *args[3];
char **parg;
- sigemptyset(&mask);
- sigaddset(&mask, SIGCHLD);
- sigprocmask(SIG_BLOCK, &mask, &oldmask);
-
/* try to launch network script */
pid = fork();
if (pid == 0) {
@@ -378,7 +374,6 @@ static int launch_script(const char *setup_script, const
char *ifname, int fd)
while (waitpid(pid, &status, 0) != pid) {
/* loop */
}
- sigprocmask(SIG_SETMASK, &oldmask, NULL);
if (WIFEXITED(status) && WEXITSTATUS(status) == 0) {
return 0;
--
1.7.4.1
