Re: [PATCH 05/14] umh: Separate the user mode driver and the user mode helper support
flat view
From: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Date: 2020-06-26 16:23:23
Also in:
bpf, linux-fsdevel
Possibly related (same subject, not in this thread)
- 2020-06-27 · Re: [PATCH 05/14] umh: Separate the user mode driver and the user mode helper support · Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
- 2020-06-27 · Re: [PATCH 05/14] umh: Separate the user mode driver and the user mode helper support · Eric W. Biederman <hidden>
- 2020-06-27 · Re: [PATCH 05/14] umh: Separate the user mode driver and the user mode helper support · Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
- 2020-06-26 · Re: [PATCH 05/14] umh: Separate the user mode driver and the user mode helper support · Eric W. Biederman <hidden>
On 2020/06/26 21:55, Eric W. Biederman wrote:
quoted hunk ↗ jump to hunk
+static void umd_cleanup(struct subprocess_info *info) +{ + struct umh_info *umh_info = info->data; + + /* cleanup if umh_pipe_setup() was successful but exec failed */
s/umh_pipe_setup/umd_setup/
quoted hunk ↗ jump to hunk
+ if (info->retval) { + fput(umh_info->pipe_to_umh); + fput(umh_info->pipe_from_umh); + } +}
After this cleanup, I expect adding some protections/isolation which kernel threads have (e.g. excluded from ptrace(), excluded from OOM victim selection, excluded from SysRq-i, won't be terminated by SIGKILL from usermode processes, won't be stopped by SIGSTOP from usermode processes, what else?). Doing it means giving up Alexei's It's nice to be able to compile that blob with -g and be able to 'gdb -p' into it. That works and very convenient when it comes to debugging. Compare that to debugging a kernel module! but I think doing it is essential for keeping usermode blob processes as secure/robust as kernel threads.