Re: [GIT PULL] Please pull proc and exec work for 5.7-rc1

From: Linus Torvalds
Date: Thu Apr 30 2020 - 09:48:06 EST


On Thu, Apr 30, 2020 at 6:39 AM Bernd Edlinger
<bernd.edlinger@xxxxxxxxxx> wrote:
>
> Excuse me, but what in my /proc folder there is no attr/something
> is there a procfs equivalent of pthread_attach ?
>
> What exactly is "attr/something" ?

Anything that uses that proc_pid_attr_write().

Which you should have realized, since you wrote the patch that changed
that function to return -EAGAIN.

That's

/proc/<pid>/attr/{current,exec,fscreate,keycreate,prev,sockcreate}

and some smack files.

Your patch definitely made them return -EINVAL if they happen in that
execve() black hole, instead of waiting for the execve() to just
complete and then just work.

Dropping a lock really is broken. It';s broken even if you then set a
flag saying "I dropped the lock, now you can't use it".

Linus