During triage of the syscall list, we found a few syscalls that are currently whitelisted (presumably B2G heritage) but where it's not clear why the content process would need those. Some preliminary testing shows Firefox is functional when they're blocked. We should try removing them and seeing if this causes breakage in the field (at which point we'll know what uses them).

The syscalls in question are: utimes umask wait4

Comment on attachment 8782472 [details] Bug 1296309 - Remove unused syscalls from the seccomp whitelist. https://reviewboard.mozilla.org/r/72638/#review70450 Ok let's see if this breaks anything. lgtm

Pushed by gpascutto@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/7239d050d65f Remove unused syscalls from the seccomp whitelist. r=tedd

I think we need to back this patch out, there have been crash reports coming in due to missing these system calls in the whitelist. PulseAudio is the main issue regarding sys_umask, apparently umask is called before mkdir, seen here [1] Regarding the other system calls, the crash reports stack trace doesn't look too promising. [1] https://github.com/pulseaudio/pulseaudio/blob/master/src/pulsecore/core-util.c#L275

https://hg.mozilla.org/integration/mozilla-inbound/rev/1a6361b000fcb97f941e4091001e88be0e46927f Bug 1296309 - Return umask (PulseAudio) and wait4 (threads) to the whitelist. r=tedd

r+ over IRC. utimes() only occured in a GMP, not content process, crash, so it can stay.