If UML is executing a helper program it is using
waitpid() with the __WCLONE flag to wait for the program
as the helper is executed from a clone()'ed thread.
While using __WCLONE is perfectly fine for clone()'ed
childs it won't detect terminated childs if the helper
has issued an execve().
We have to use __WALL to wait for both clone()'ed and
regular childs to detect the termination before and
after an execve().
Reported-and-tested-by: Thomas Meyer <tho...@m3y3r.de>
Signed-off-by: Richard Weinberger <rich...@nod.at>
---
arch/um/os-Linux/helper.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
index e3ee4a5..3f02d42 100644
--- a/arch/um/os-Linux/helper.c
+++ b/arch/um/os-Linux/helper.c
@@ -96,7 +96,7 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char
**argv)
"ret = %d\n", -n);
ret = n;
}
- CATCH_EINTR(waitpid(pid, NULL, __WCLONE));
+ CATCH_EINTR(waitpid(pid, NULL, __WALL));
}
out_free2:
@@ -129,7 +129,7 @@ int run_helper_thread(int (*proc)(void *), void *arg,
unsigned int flags,
return err;
}
if (stack_out == NULL) {
- CATCH_EINTR(pid = waitpid(pid, &status, __WCLONE));
+ CATCH_EINTR(pid = waitpid(pid, &status, __WALL));
if (pid < 0) {
err = -errno;
printk(UM_KERN_ERR "run_helper_thread - wait failed, "
@@ -148,7 +148,7 @@ int run_helper_thread(int (*proc)(void *), void *arg,
unsigned int flags,
int helper_wait(int pid)
{
int ret, status;
- int wflags = __WCLONE;
+ int wflags = __WALL;
CATCH_EINTR(ret = waitpid(pid, &status, wflags));
if (ret < 0) {
--
1.8.4.5
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