[systemd-devel] systemd failing to close unwanted file descriptors & FDS spawning and crashing
Christopher Obbard
chris.obbard at collabora.com
Fri Mar 4 09:26:37 UTC 2022
Hi Mantas,
On 03/03/2022 20:30, Mantas Mikulėnas wrote:
> Ah, right, I forgot – since this is done in the service child (right
> before exec) and not in the main process, you probably need to add the
> -f option to make strace follow forks...
>
> On Thu, Mar 3, 2022, 22:08 Christopher Obbard
> <chris.obbard at collabora.com <mailto:chris.obbard at collabora.com>> wrote:
>
> Hi Mantas,
>
> On 03/03/2022 19:18, Mantas Mikulėnas wrote:
> > On Thu, Mar 3, 2022 at 9:09 PM Christopher Obbard
> > <chris.obbard at collabora.com <mailto:chris.obbard at collabora.com>
> <mailto:chris.obbard at collabora.com
> <mailto:chris.obbard at collabora.com>>> wrote:
> >
> > Hi systemd experts!
> >
> > I am using systemd-247 and systemd-250 on debian system, which is
> > running a minimal downstream 5.4 kernel for a Qualcomm board.
> >
> > systemd 241 in debian buster works fine, but systemd 247 (debian
> > bullseye) and systemd 250 (debian unstable) seem to get upset
> about
> > file
> > descriptors on services. These errors are consistant and the
> board
> > boots
> > just fine with init=/bin/sh
> >
> > I've got the required kernel config from README in my kernel,
> I am
> > using
> > a heavily patched downstream kernel, but from the following
> log can you
> > suggest anything I can do to debug this (other than throwing
> the board
> > out of the window) ?
> >
> >
> > From the message, it looks like the error is returned by
> > close_all_fds() in src/basic/fd-util.c, where the only major
> change is
> > that it has been ported to call close_range() if that's available...
> >
> > I would boot with init=/bin/sh, then run `exec strace -D -o
> > /var/log/systemd.trace /lib/systemd/systemd` to get a trace, and
> see if
> > the EINVAL actually comes from calling close_range() or from
> something else.
> >
> > --
> > Mantas Mikulėnas
>
> Thanks for your reply. It reproduced nicely with the command you gave.
>
> Seems like nothing related to close_range returning EINVAL, only the
> following calls returned EINVAL:
>
> cat systemd-failing.trace | grep EINVAL
> prctl(PR_CAPBSET_READ, 0x30 /* CAP_??? */) = -1 EINVAL (Invalid
> argument)
> prctl(PR_CAPBSET_READ, CAP_CHECKPOINT_RESTORE) = -1 EINVAL (Invalid
> argument)
> prctl(PR_CAPBSET_READ, CAP_PERFMON) = -1 EINVAL (Invalid argument)
> read(4, 0x55675a75b0, 4095) = -1 EINVAL (Invalid argument)
> mount("cgroup2", "/proc/self/fd/4", "cgroup2",
> MS_NOSUID|MS_NODEV|MS_NOEXEC, "nsdelegate,memory_recursiveprot") = -1
> EINVAL (Invalid argument)
>
>
> I have attached the full strace output, in case that would be useful?
>
> Thanks
> Chris
>
Right, so it looks like the call to close_range fails. This is a 5.4
kernel which doesn;t have close_range - so this is understandable.
For a quick fix, I set have_close_range to false - see the patch
attached. It seemed to work well.
Since my 5.4 kernel is a heavily modified downstream one - next I will
check if that syscall was implemented by someone else, and also I will
check if vanilla systemd works on vanilla 5.4 (there is no reason why it
shouldn't, right?).
$ cat /mnt/systemd.trace | grep EINVAL
1 prctl(PR_CAPBSET_READ, 0x30 /* CAP_??? */) = -1 EINVAL (Invalid
argument)
1 prctl(PR_CAPBSET_READ, CAP_CHECKPOINT_RESTORE) = -1 EINVAL
(Invalid argument)
1 prctl(PR_CAPBSET_READ, CAP_PERFMON) = -1 EINVAL (Invalid argument)
1 read(4, 0x556968b5b0, 4095) = -1 EINVAL (Invalid argument)
1 mount("cgroup2", "/proc/self/fd/4", "cgroup2",
MS_NOSUID|MS_NODEV|MS_NOEXEC, "nsdelegate,memory_recursiveprot") = -1
EINVAL (Invalid argument)
364 <... prctl resumed>) = -1 EINVAL (Invalid argument)
364 <... prctl resumed>) = -1 EINVAL (Invalid argument)
365 <... prctl resumed>) = -1 EINVAL (Invalid argument)
364 <... prctl resumed>) = -1 EINVAL (Invalid argument)
365 <... prctl resumed>) = -1 EINVAL (Invalid argument)
366 <... prctl resumed>) = -1 EINVAL (Invalid argument)
366 <... prctl resumed>) = -1 EINVAL (Invalid argument)
365 <... prctl resumed>) = -1 EINVAL (Invalid argument)
361 <... prctl resumed>) = -1 EINVAL (Invalid argument)
366 <... prctl resumed>) = -1 EINVAL (Invalid argument)
370 <... prctl resumed>) = -1 EINVAL (Invalid argument)
368 <... prctl resumed>) = -1 EINVAL (Invalid argument)
361 <... prctl resumed>) = -1 EINVAL (Invalid argument)
370 <... prctl resumed>) = -1 EINVAL (Invalid argument)
368 <... prctl resumed>) = -1 EINVAL (Invalid argument)
361 <... prctl resumed>) = -1 EINVAL (Invalid argument)
370 <... prctl resumed>) = -1 EINVAL (Invalid argument)
368 <... prctl resumed>) = -1 EINVAL (Invalid argument)
367 <... prctl resumed>) = -1 EINVAL (Invalid argument)
362 <... prctl resumed>) = -1 EINVAL (Invalid argument)
367 <... prctl resumed>) = -1 EINVAL (Invalid argument)
362 <... prctl resumed>) = -1 EINVAL (Invalid argument)
367 <... prctl resumed>) = -1 EINVAL (Invalid argument)
362 <... prctl resumed>) = -1 EINVAL (Invalid argument)
363 <... prctl resumed>) = -1 EINVAL (Invalid argument)
360 <... prctl resumed>) = -1 EINVAL (Invalid argument)
363 <... prctl resumed>) = -1 EINVAL (Invalid argument)
360 <... prctl resumed>) = -1 EINVAL (Invalid argument)
363 <... prctl resumed>) = -1 EINVAL (Invalid argument)
360 <... prctl resumed>) = -1 EINVAL (Invalid argument)
369 <... prctl resumed>) = -1 EINVAL (Invalid argument)
369 <... prctl resumed>) = -1 EINVAL (Invalid argument)
369 <... prctl resumed>) = -1 EINVAL (Invalid argument)
359 <... prctl resumed>) = -1 EINVAL (Invalid argument)
359 <... prctl resumed>) = -1 EINVAL (Invalid argument)
359 <... prctl resumed>) = -1 EINVAL (Invalid argument)
364 <... ioctl resumed>, 0) = -1 EINVAL (Invalid argument)
373 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
374 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
375 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
376 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
377 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
378 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
379 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
380 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
381 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
382 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
384 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
385 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
386 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
387 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
388 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
389 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
391 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
392 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
393 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
395 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
397 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
398 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
399 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
400 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
401 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
402 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
403 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
404 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
405 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
406 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
407 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
408 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
409 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
410 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
411 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
412 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
413 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
414 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
415 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
416 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
418 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
419 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
420 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
421 <... close_range resumed>) = -1 EINVAL (Invalid argument)
422 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
423 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
424 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
417 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
425 close_range(3, 17, 0) = -1 EINVAL (Invalid argument)
Thanks
Chris
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