From 6b1873371cea13036171d03a7c1e3e59158b4505 Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Sun, 9 Aug 2015 21:49:07 +0200 Subject: [PATCH] um: Fix waitpid() usage in helper code 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 Signed-off-by: Richard Weinberger --- 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 e3ee4a51ef63..3f02d4232812 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) {