Re: lib/58154: aarch64: firefox-124.0.2 crashes very frequently on NetBSD/aarch64 10.0, likely related to thread-local storage

[Taylor R Campbell <riastradh%NetBSD.org@localhost>]

The following reply was made to PR lib/58154; it has been noted by GNATS.

From: Taylor R Campbell <riastradh%NetBSD.org@localhost>
To: Tobias Nygren <tnn%NetBSD.org@localhost>
Cc: gnats-bugs%NetBSD.org@localhost, netbsd-bugs%NetBSD.org@localhost, PHO <pho%cielonegro.org@localhost>
Subject: Re: lib/58154: aarch64: firefox-124.0.2 crashes very frequently on
	NetBSD/aarch64 10.0, likely related to thread-local storage
Date: Mon, 1 Jul 2024 16:32:01 +0000

 > Date: Mon, 1 Jul 2024 17:55:27 +0200
 > From: Tobias Nygren <tnn%NetBSD.org@localhost>
 >=20
 > On Tue, 14 May 2024 12:05:01 +0000 (UTC)
 > PHO <pho%cielonegro.org@localhost> wrote:
 >=20
 > >  https://github.com/NetBSD/src/commit/e50ac3613df8e5365faebd39e0d7983f3=
 1446204
 > >  https://github.com/NetBSD/src/commit/ee895c8f3880c6542c1c7db4c7f77235c=
 fac88d1
 > >  https://github.com/NetBSD/src/commit/b00640999a436897bc5be86efac494305=
 6d255a6
 > > =20
 > >  Can anybody review these? The second one is the bugfix. With these=20
 > >  patches Firefox completely stopped crashing even without my workaround.
 >=20
 > These patches also stop kicad from segfaulting.
 > I think we should commit them, with a netbsd-10 pullup.
 > Changes look good to me.
 
 The changes look good to me, but do you have an example that will at
 least exercise the branch?  I.e., a program that exercises the case
 tlsdesc->td_tlsindex > DTV_MAX_INDEX(dtv)?
 
 I would like to commit an automatic test so that, even if it doesn't
 deterministically crash while we have the bug, we keep the code path
 exercised in-tree.
 
 
 The first commit
 https://github.com/NetBSD/src/commit/e50ac3613df8e5365faebd39e0d7983f314462=
 04
 is fine without any tests, go ahead and commit that now.
 
 The third commit
 https://github.com/NetBSD/src/commit/b00640999a436897bc5be86efac4943056d255=
 a6
 sounds fine, but is there a reference for the interpretation of the
 DTV_MAX_INDEX quantity?  Like a page number that you can cite in the
 Drepper ELF TLS doc https://akkadia.org/drepper/tls.pdf?  If so, can
 you add a citation as a comment here?