1 files changed, 27 insertions, 11 deletions

diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
index 7a72dbb61b0d..fba3f0fefeef 100644
--- a/arch/um/os-Linux/helper.c
+++ b/arch/um/os-Linux/helper.c
@@ -76,7 +76,7 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
         data.fd = fds[1];
         data.buf = __cant_sleep() ? kmalloc(PATH_MAX, UM_GFP_ATOMIC) :
                                         kmalloc(PATH_MAX, UM_GFP_KERNEL);
-        pid = clone(helper_child, (void *) sp, CLONE_VM | SIGCHLD, &data);
+        pid = clone(helper_child, (void *) sp, CLONE_VM, &data);
         if (pid < 0) {
                 ret = -errno;
                 printk("run_helper : clone failed, errno = %d\n", errno);
@@ -101,7 +101,7 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
                         ret = n;
                         kill(pid, SIGKILL);
                 }
-                CATCH_EINTR(waitpid(pid, NULL, 0));
+                CATCH_EINTR(waitpid(pid, NULL, __WCLONE));
         }
 
 out_free2:
@@ -126,7 +126,7 @@ int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
                 return -ENOMEM;
 
         sp = stack + UM_KERN_PAGE_SIZE - sizeof(void *);
-        pid = clone(proc, (void *) sp, flags | SIGCHLD, arg);
+        pid = clone(proc, (void *) sp, flags, arg);
         if (pid < 0) {
                 err = -errno;
                 printk("run_helper_thread : clone failed, errno = %d\n",
@@ -134,7 +134,7 @@ int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
                 return err;
         }
         if (stack_out == NULL) {
-                CATCH_EINTR(pid = waitpid(pid, &status, 0));
+                CATCH_EINTR(pid = waitpid(pid, &status, __WCLONE));
                 if (pid < 0) {
                         err = -errno;
                         printk("run_helper_thread - wait failed, errno = %d\n",
@@ -150,14 +150,30 @@ int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
         return pid;
 }
 
-int helper_wait(int pid)
+int helper_wait(int pid, int nohang, char *pname)
 {
-        int ret;
+        int ret, status;
+        int wflags = __WCLONE;
 
-        CATCH_EINTR(ret = waitpid(pid, NULL, WNOHANG));
+        if (nohang)
+                wflags |= WNOHANG;
+
+        if (!pname)
+                pname = "helper_wait";
+
+        CATCH_EINTR(ret = waitpid(pid, &status, wflags));
         if (ret < 0) {
-                ret = -errno;
-                printk("helper_wait : waitpid failed, errno = %d\n", errno);
-        }
-        return ret;
+                printk(UM_KERN_ERR "%s : waitpid process %d failed, "
+                       "errno = %d\n", pname, pid, errno);
+                return -errno;
+        } else if (nohang && ret == 0) {
+                printk(UM_KERN_ERR "%s : process %d has not exited\n",
+                       pname, pid);
+                return -ECHILD;
+        } else if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+                printk(UM_KERN_ERR "%s : process %d didn't exit with "
+                       "status 0\n", pname, pid);
+                return -ECHILD;
+        } else
+                return 0;
 }