Messages in this thread | | | From | Olivier Brunel <> | Subject | [PATCH 0/2] Re: bpfilter causes a leftover kernel process | Date | Sat, 20 Oct 2018 19:39:55 +0200 |
| |
On Tue, 16 Oct 2018 16:38:56 +0000 Alexei Starovoitov <alexei.starovoitov@gmail.com> wrote:
> On Wed, Sep 5, 2018 at 5:05 PM Olivier Brunel <jjk@jjacky.com> wrote: > > > > You'll see in the end that systemd complains that it can't > > unmount /oldroot (EBUSY), aka the root fs; and that's because of the > > bpfilter helper, which wasn't killed because it's seen as a kernel > > thread due to its empty command line and therefore not signaled. > > thanks for tracking it down. > can somebody send a patch to give bpfilter non-empty cmdline? > I think that would be a better fix than tweaking all pid1s.
So I'm not a kernel dev and this would be my first atttempt at a kernel patch, but I did have a look and came up with the following patch(es) to fix this. Hopefully I did things right.
It adds a default command line ("usermodehelper") to such processes, so any & all such helpers will be seen as user process and not kernel threads, but there's also the possibility to specify a command line to use, here "bpfilter_umh"
Cheers,
Olivier Brunel (2): umh: Add command line to user mode helpers net: bpfilter: Set user mode helper's command line
include/linux/umh.h | 1 + kernel/umh.c | 16 ++++++++++++++-- net/bpfilter/bpfilter_kern.c | 1 + 3 files changed, 16 insertions(+), 2 deletions(-)
-- 2.19.0
| |