Closed Bug 1310286 Opened 3 years ago Closed 3 years ago

Ignore the SIG64 signal that the Linux sandboxing code triggers on older kernels

Categories

(Firefox Build System :: General, defect)

Unspecified
Linux
defect
Not set

Tracking

(firefox52 fixed)

RESOLVED FIXED
mozilla52
Tracking Status
firefox52 --- fixed

People

(Reporter: botond, Assigned: botond)

Details

Attachments

(1 file)

On Linux kernel versions that don't support seccomp tsync (such as the 3.16 that ships with current Debian stable), the sandboxing code [1] produces SIG64 signals in rapid succession near the child process's startup, which makes debugging with rr (and with regular gdb, if you're attached to the child process from the start of its lifetime) annoying. See [2] for the initial investigation where we discovered this.

I'd like to propose amending our .gdbinit file to ignore this signal.

[1] http://searchfox.org/mozilla-central/rev/d96317a351af8aa78ab9847e7feed964bbaac7d7/security/sandbox/linux/Sandbox.cpp#360
[2] https://github.com/mozilla/rr/issues/1832
Comment on attachment 8801211 [details]
Bug 1310286 - Instruct gdb to ignore certain signals for which it is not useful to stop.  DONTBUILD NPOTB

https://reviewboard.mozilla.org/r/85938/#review85314

::: .gdbinit:14
(Diff revision 1)
>  # Don't stop for the SIG32/33/etc signals that Flash produces
>  handle SIG32 noprint nostop pass
>  handle SIG33 noprint nostop pass
>  handle SIGPIPE noprint nostop pass
>  
> +# Don't stop for the SIG64 signals triggered by the Linux 

trailing whitespace

::: .gdbinit:16
(Diff revision 1)
>  handle SIG33 noprint nostop pass
>  handle SIGPIPE noprint nostop pass
>  
> +# Don't stop for the SIG64 signals triggered by the Linux 
> +# sandboxing code on older kernels.
> +handle SIG64 noprint nostop pass

While you're here, you might as well add SIG38. Not sure what's producing them, but they're happening all the time for me and a lot of people.
Attachment #8801211 - Flags: review?(mh+mozilla) → review+
Updated to address review comment.
Pushed by bballo@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/976afe660227
Instruct gdb to ignore certain signals for which it is not useful to stop. r=glandium DONTBUILD NPOTB
https://hg.mozilla.org/mozilla-central/rev/976afe660227
Status: NEW → RESOLVED
Closed: 3 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla52
Product: Core → Firefox Build System
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