From: Rusty Russell <rusty@rustcorp.com.au>
Milton Miller <miltonm@bga.com> and Junfeng Yang <yjf@stanford.edu> point
out that we hand a kernel address to sys_wait4 for the status pointer.
This is true, but since we don't have a SIGCHLD handler, it never gets that
far. Use NULL, and document the fact.
kernel/kmod.c | 12 +++++++-----
1 files changed, 7 insertions(+), 5 deletions(-)
diff -puN kernel/kmod.c~keventd-thread-cleanup kernel/kmod.c
--- 25/kernel/kmod.c~keventd-thread-cleanup 2003-06-16 01:39:34.000000000 -0700
+++ 25-akpm/kernel/kmod.c 2003-06-16 01:39:34.000000000 -0700
@@ -183,12 +183,15 @@ static int wait_for_helper(void *data)
struct subprocess_info *sub_info = data;
pid_t pid;
- pid = kernel_thread(____call_usermodehelper, sub_info,
- CLONE_VFORK | SIGCHLD);
+ sub_info->retval = 0;
+ pid = kernel_thread(____call_usermodehelper, sub_info, SIGCHLD);
if (pid < 0)
sub_info->retval = pid;
else
- sys_wait4(pid, (unsigned int *)&sub_info->retval, 0, NULL);
+ /* We don't have a SIGCHLD signal handler, so this
+ * always returns -ECHILD, but the important thing is
+ * that it blocks. */
+ sys_wait4(pid, NULL, 0, NULL);
complete(sub_info->complete);
return 0;
@@ -231,8 +234,7 @@ static void __call_usermodehelper(void *
* (ie. it runs with full root capabilities).
*
* Must be called from process context. Returns a negative error code
- * if program was not execed successfully, or (exitcode << 8 + signal)
- * of the application (0 if wait is not set).
+ * if program was not execed successfully, or 0.
*/
int call_usermodehelper(char *path, char **argv, char **envp, int wait)
{
_