Re: [PATCH] kernel: add a kernel_wait helper

[Andrew Morton]

On Tue, 21 Jul 2020 15:04:49 +0200 Christoph Hellwig <hch@xxxxxx> wrote:

> Add a helper that waits for a pid and stores the status in the passed
> in kernel pointer.  Use it to fix the usage of kernel_wait4 in
> call_usermodehelper_exec_sync that only happens to work due to the
> implicit set_fs(KERNEL_DS) for kernel threads.

I guess it's cleaner, although it's a bit sad to be adding code to
address a non-problem.

Did you consider a simpler kernel_wait() which just wraps a
set_fs(KERNEL_DS) around a call to kernel_wait4()?