Bug 895752 – www-client/firefox-110.0: SANDBOX ACCESS VIOLATION with USE="pgo"

• Product: Gentoo Linux
• Status: RESOLVED FIXED

[Description sqrtd 2023-02-21 20:29:39 UTC]

When updating Firefox I came across a SANDBOX ACCESS VIOLATION when building with pgo.

Steps to reproduce:
 1. Build Firefox with USE="pgo"

# /var/tmp/notmpfs/portage/www-client/firefox-110.0/temp/sandbox.log
VERSION 1.0
FORMAT: F - Function called
FORMAT: S - Access Status
FORMAT: P - Path as passed to function
FORMAT: A - Absolute Path (not canonical)
FORMAT: R - Canonical Path
FORMAT: C - Command Line

F: open_wr
S: deny
P: /dev/snd/seq
A: /dev/snd/seq
R: /dev/snd/seq
C: /var/tmp/notmpfs/portage/www-client/firefox-110.0/work/firefox_build/instrumented/dist/firefox/firefox http://localhost:8888/index.html -profile /var/tmp/notmpfs/portage/www-client/firefox-110.0/temp/tmpxxeq4vfh

F: open_wr
S: deny
P: /dev/snd/seq
A: /dev/snd/seq
R: /dev/snd/seq
C: /var/tmp/notmpfs/portage/www-client/firefox-110.0/work/firefox_build/instrumented/dist/firefox/firefox http://localhost:8888/index.html -profile /var/tmp/notmpfs/portage/www-client/firefox-110.0/temp/tmpxxeq4vfh

[Comment 1 sqrtd 2023-02-21 20:33:45 UTC]

Created attachment 853522 [details]
emerge --info output

[Comment 2 Joonas Niilola 2023-02-22 07:50:34 UTC]

Could you upload the full build.log please? You can use "xz -9" to compress it.

[Comment 3 sqrtd 2023-02-22 13:31:42 UTC]

Created attachment 853888 [details]
full build.log

[Comment 4 Joonas Niilola 2023-02-23 06:27:03 UTC]

So I was able to build firefox with your use flags on a normal glibc system. Then I spent a day setting up a musl container... just to realize pgo is use.masked for firefox in musl. So by that definition pgo won't work with musl.

However your error doesn't seem to be related to musl, but I'd rather blame -dbus and your system overall instead. If you want to try, add:

  addpredict /dev/snd

to line 552 in the ebuild. To clarify, you want to edit this:


  # May need a wider addpredict when using wayland+pgo.
  addpredict /dev/dri


into this:


  # May need a wider addpredict when using wayland+pgo.
  addpredict /dev/dri
  addpredict /dev/snd


(Again, I was able to compile firefox with -dbus +pgo +lto so just guessing here)

[Comment 5 sqrtd 2023-02-23 21:53:16 UTC]

I've just compiled Firefox with your suggested fix with both PGO & clang on musl which are masked, and it built successfully, so is there any reason for it to still be masked? I've had both unmasked for 1–2 months without even noticing until this issue came up and like you said it doesn't seem related to musl, and Alpine also seems to use PGO (not sure about clang) when building Firefox on amd64 (https://git.alpinelinux.org/aports/tree/community/firefox/APKBUILD#n614).

Thank you very much for your help and suggested fix and sorry if I wasted any of your time.

[Comment 6 Sam James 2023-02-23 22:28:56 UTC]

The issue was/is that building with clang[-default-libcxx] (or otherwise not passing -stdlib=libc++ or whatever it is) would fail. I haven't verified that now works.

[Comment 7 David Carlos Manuelda 2024-02-12 01:34:07 UTC]

(In reply to sqrtd from comment #5)
> I've just compiled Firefox with your suggested fix with both PGO & clang on
> musl which are masked, and it built successfully, so is there any reason for
> it to still be masked? I've had both unmasked for 1–2 months without even
> noticing until this issue came up and like you said it doesn't seem related
> to musl, and Alpine also seems to use PGO (not sure about clang) when
> building Firefox on amd64
> (https://git.alpinelinux.org/aports/tree/community/firefox/APKBUILD#n614).
> 
> Thank you very much for your help and suggested fix and sorry if I wasted
> any of your time.

Just for the record, they use also clang/clang++ to compile: https://git.alpinelinux.org/aports/tree/community/firefox/APKBUILD#n639

[Comment 8 Joonas Niilola 2024-02-12 05:45:28 UTC]

While this bug may not be fixed (relate to -dbus), pgo is now available on musl with commit d48fc6e32f86ef142c73c7c546d23d607334319e

[Comment 9 Joonas Niilola 2024-09-04 09:04:10 UTC]

Our "current" versions should have pretty wide sandbox relaxation when using pgo. 115esr may not work, but it's probably having its last version bump this week so I'm not going to spend time relaxing the sandbox paths there. 128esr and 130rapid should be okay, even in musl.