* mm_release()->clear_child_tid() from writing to a user-controlled
* kernel address.
*/
- set_fs(USER_DS);
+ force_uaccess_begin();
if (unlikely(in_atomic())) {
pr_info("note: %s[%d] exited with preempt_count %d\n",
return retval;
}
-static struct pid *pidfd_get_pid(unsigned int fd)
+static struct pid *pidfd_get_pid(unsigned int fd, unsigned int *flags)
{
struct fd f;
struct pid *pid;
return ERR_PTR(-EBADF);
pid = pidfd_pid(f.file);
- if (!IS_ERR(pid))
+ if (!IS_ERR(pid)) {
get_pid(pid);
+ *flags = f.file->f_flags;
+ }
fdput(f);
return pid;
struct pid *pid = NULL;
enum pid_type type;
long ret;
+ unsigned int f_flags = 0;
if (options & ~(WNOHANG|WNOWAIT|WEXITED|WSTOPPED|WCONTINUED|
__WNOTHREAD|__WCLONE|__WALL))
if (upid < 0)
return -EINVAL;
- pid = pidfd_get_pid(upid);
+ pid = pidfd_get_pid(upid, &f_flags);
if (IS_ERR(pid))
return PTR_ERR(pid);
+
break;
default:
return -EINVAL;
wo.wo_flags = options;
wo.wo_info = infop;
wo.wo_rusage = ru;
+ if (f_flags & O_NONBLOCK)
+ wo.wo_flags |= WNOHANG;
+
ret = do_wait(&wo);
+ if (!ret && !(options & WNOHANG) && (f_flags & O_NONBLOCK))
+ ret = -EAGAIN;
put_pid(pid);
return ret;
return ret;
}
+int kernel_wait(pid_t pid, int *stat)
+{
+ struct wait_opts wo = {
+ .wo_type = PIDTYPE_PID,
+ .wo_pid = find_get_pid(pid),
+ .wo_flags = WEXITED,
+ };
+ int ret;
+
+ ret = do_wait(&wo);
+ if (ret > 0 && wo.wo_stat)
+ *stat = wo.wo_stat;
+ put_pid(wo.wo_pid);
+ return ret;
+}
+
SYSCALL_DEFINE4(wait4, pid_t, upid, int __user *, stat_addr,
int, options, struct rusage __user *, ru)
{