[PATCH] fix osf_wait4() breakage

[PATCH] fix osf_wait4() breakage

[Al Viro]

kernel_wait4() expects a userland address for status - it's only
rusage that goes as a kernel one (and needs a copyout afterwards)

Fixes: "osf_wait4: switch to kernel_wait4()"
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
diff --git a/arch/alpha/kernel/osf_sys.c b/arch/alpha/kernel/osf_sys.c
index 6e921754c8fc..c210a25dd6da 100644
--- a/arch/alpha/kernel/osf_sys.c
+++ b/arch/alpha/kernel/osf_sys.c
@@ -1180,13 +1180,10 @@ SYSCALL_DEFINE2(osf_getrusage, int, who, struct rusage32 __user *, ru)
 SYSCALL_DEFINE4(osf_wait4, pid_t, pid, int __user *, ustatus, int, options,
 		struct rusage32 __user *, ur)
 {
-	unsigned int status = 0;
 	struct rusage r;
-	long err = kernel_wait4(pid, &status, options, &r);
+	long err = kernel_wait4(pid, ustatus, options, &r);
 	if (err <= 0)
 		return err;
-	if (put_user(status, ustatus))
-		return -EFAULT;
 	if (!ur)
 		return err;
 	if (put_tv_to_tv32(&ur->ru_utime, &r.ru_utime))

Re: [PATCH] fix osf_wait4() breakage

[Linus Torvalds]

Applied.

Just a note:

On Sun, Jul 22, 2018 at 7:07 AM Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> Fixes: "osf_wait4: switch to kernel_wait4()"

Please put the actual commit ID there too, because that's what people
with automation check.

> Cc: stable@vger.kernel.org # v4.12+

.. and when you do that, you'll see that it wasn't actually in 4.12,
but got merged during the 4.13 merge window:

    $ git name-rev 92ebce5ac55d
    92ebce5ac55d tags/v4.13-rc1~154^2

(unless it was backported, but I don't think it was).

Also, the prototype for kernel_wait4() (in <linux/sched/task.h>) is
wrong, and doesn't have the __user annotation.

                Linus