1 files changed, 41 insertions, 39 deletions

diff --git a/arch/um/os-Linux/helper.c b/arch/um/os-Linux/helper.c
index 7a72dbb..f4bd349 100644
--- a/arch/um/os-Linux/helper.c
+++ b/arch/um/os-Linux/helper.c
@@ -1,22 +1,19 @@
 /*
- * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
+ * Copyright (C) 2002 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
  * Licensed under the GPL
  */
 
-#include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
 #include <errno.h>
 #include <sched.h>
-#include <limits.h>
-#include <sys/signal.h>
-#include <sys/wait.h>
 #include <sys/socket.h>
-#include "user.h"
+#include <sys/wait.h>
+#include "kern_constants.h"
 #include "kern_util.h"
 #include "os.h"
 #include "um_malloc.h"
-#include "kern_constants.h"
+#include "user.h"
 
 struct helper_data {
 	void (*pre_exec)(void*);
@@ -30,21 +27,19 @@ static int helper_child(void *arg)
 {
 	struct helper_data *data = arg;
 	char **argv = data->argv;
-	int errval;
+	int err;
 
 	if (data->pre_exec != NULL)
 		(*data->pre_exec)(data->pre_data);
-	errval = execvp_noalloc(data->buf, argv[0], argv);
-	printk("helper_child - execvp of '%s' failed - errno = %d\n", argv[0],
-	       -errval);
-	write(data->fd, &errval, sizeof(errval));
-	kill(os_getpid(), SIGKILL);
+	err = execvp_noalloc(data->buf, argv[0], argv);
+
+	/* If the exec succeeds, we don't get here */
+	write(data->fd, &err, sizeof(err));
+
 	return 0;
 }
 
-/* Returns either the pid of the child process we run or -E* on failure.
- * XXX The alloc_stack here breaks if this is called in the tracing thread, so
- * we need to receive a preallocated stack (a local buffer is ok). */
+/* Returns either the pid of the child process we run or -E* on failure. */
 int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
 {
 	struct helper_data data;
@@ -58,14 +53,15 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
 	ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fds);
 	if (ret < 0) {
 		ret = -errno;
-		printk("run_helper : pipe failed, errno = %d\n", errno);
+		printk(UM_KERN_ERR "run_helper : pipe failed, errno = %d\n",
+		       errno);
 		goto out_free;
 	}
 
 	ret = os_set_exec_close(fds[1]);
 	if (ret < 0) {
-		printk("run_helper : setting FD_CLOEXEC failed, ret = %d\n",
-		       -ret);
+		printk(UM_KERN_ERR "run_helper : setting FD_CLOEXEC failed, "
+		       "ret = %d\n", -ret);
 		goto out_close;
 	}
 
@@ -76,10 +72,11 @@ 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);
+		printk(UM_KERN_ERR "run_helper : clone failed, errno = %d\n",
+		       errno);
 		goto out_free2;
 	}
 
@@ -96,12 +93,11 @@ int run_helper(void (*pre_exec)(void *), void *pre_data, char **argv)
 	} else {
 		if (n < 0) {
 			n = -errno;
-			printk("run_helper : read on pipe failed, ret = %d\n",
-			       -n);
+			printk(UM_KERN_ERR "run_helper : read on pipe failed, "
+			       "ret = %d\n", -n);
 			ret = n;
-			kill(pid, SIGKILL);
 		}
-		CATCH_EINTR(waitpid(pid, NULL, 0));
+		CATCH_EINTR(waitpid(pid, NULL, __WCLONE));
 	}
 
 out_free2:
@@ -126,24 +122,24 @@ 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",
-		       errno);
+		printk(UM_KERN_ERR "run_helper_thread : clone failed, "
+		       "errno = %d\n", errno);
 		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",
-			       errno);
+			printk(UM_KERN_ERR "run_helper_thread - wait failed, "
+			       "errno = %d\n", errno);
 			pid = err;
 		}
 		if (!WIFEXITED(status) || (WEXITSTATUS(status) != 0))
-			printk("run_helper_thread - thread returned status "
-			       "0x%x\n", status);
+			printk(UM_KERN_ERR "run_helper_thread - thread "
+			       "returned status 0x%x\n", status);
 		free_stack(stack, 0);
 	} else
 		*stack_out = stack;
@@ -152,12 +148,18 @@ int run_helper_thread(int (*proc)(void *), void *arg, unsigned int flags,
 
 int helper_wait(int pid)
 {
-	int ret;
+	int ret, status;
+	int wflags = __WCLONE;
 
-	CATCH_EINTR(ret = waitpid(pid, NULL, WNOHANG));
+	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 "helper_wait : waitpid process %d failed, "
+		       "errno = %d\n", pid, errno);
+		return -errno;
+	} else if (!WIFEXITED(status) || WEXITSTATUS(status) != 0) {
+		printk(UM_KERN_ERR "helper_wait : process %d exited with "
+		       "status 0x%x\n", pid, status);
+		return -ECHILD;
+	} else
+		return 0;
 }