On 12/07/2011 09:48 PM, Michael Roth wrote:
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>
Applied. Thanks.
Regards,
Anthony Liguori
---
net/tap.c | 6 ------
1 files changed, 0 insertions(+), 6 deletions(-)
diff --git a/net/tap.c b/net/tap.c
index 1f26dc9..6c27a94 100644
--- a/net/tap.c
+++ b/net/tap.c
@@ -346,15 +346,10 @@ static TAPState *net_tap_fd_init(VLANState *vlan,
static int launch_script(const char *setup_script, const char *ifname, int fd)
{
- sigset_t oldmask, mask;
int pid, status;
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 +373,6 @@ 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;
