On Fri, Jun 26, 2020 at 07:22:34AM +0200, Christian Borntraeger wrote:

On 26.06.20 04:54, Luis Chamberlain wrote:

quoted

On Wed, Jun 24, 2020 at 08:37:55PM +0200, Christian Borntraeger wrote:

quoted

On 24.06.20 20:32, Christian Borntraeger wrote:
[...]> 

quoted

So the translations look correct. But your change is actually a sematic change
if(ret) will only trigger if there is an error
if (KWIFEXITED(ret)) will always trigger when the process ends. So we will always overwrite -ECHILD
and we did not do it before. 

So the right fix is

diff --git a/kernel/umh.c b/kernel/umh.c
index f81e8698e36e..a3a3196e84d1 100644
--- a/kernel/umh.c
+++ b/kernel/umh.c

@@ -154,7 +154,7 @@ static void call_usermodehelper_exec_sync(struct subprocess_info *sub_info)
                 * the real error code is already in sub_info->retval or
                 * sub_info->retval is 0 anyway, so don't mess with it then.
                 */
-               if (KWIFEXITED(ret))
+               if (KWEXITSTATUS(ret))
                        sub_info->retval = KWEXITSTATUS(ret);
        }
 

I think.

Nope, the right form is to check for WIFEXITED() before using WEXITSTATUS().

But this IS a change over the previous code, no?
I will test next week as I am travelling right now. 

I'm all for reverting back to the previous behavior.  If someone wants
a behavior change it should be a separate patch.  And out of pure self
interest I'd like to see that change after my addition of the
kernel_wait helper to replace the kernel_wait4 abuse :)