Bug 262100 - [GTK] webkit2gtk crashes at runtime when GDS mitigation is enabled
Summary: [GTK] webkit2gtk crashes at runtime when GDS mitigation is enabled
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: WebKit2 (show other bugs)
Version: Other
Hardware: PC Linux
: P2 Major
Assignee: Nobody
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2023-09-26 00:40 PDT by CodingCellist
Modified: 2023-09-26 00:42 PDT (History)
1 user (show)

See Also:

Attachments
systemd-logs of a crashing startup (GDS mitigation enabled) using builtins for avx(2) detection (behaviour is the same on unmodified install) (3.87 KB, text/x-log)
2023-09-26 00:40 PDT, CodingCellist 		no flags Details
Attempted, NON-FIXING patch (1.76 KB, patch)
2023-09-26 00:42 PDT, CodingCellist 		no flags Details | Formatted Diff | Diff
View All Add an attachment (proposed patch, testcase, etc.)

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Description CodingCellist 2023-09-26 00:40:22 PDT 
Created attachment 467871 [details]
systemd-logs of a crashing startup (GDS mitigation enabled) using builtins for avx(2) detection (behaviour is the same on unmodified install)

When the Gather Data Sampling (GDS) mitigation in the Linux kernel is enabled, webkit2gtk will crash due to incomplete AVX2 enumeration. The mitigation is known to cause problems in these cases [1].

I tried rebuilding webkit2gtk while using the `__builtin_cpu_supports` functions instead of the bitshift checks in `JavaScriptCore/assembler/MacroAssemblerX86Common.cpp:collectCPUFeatures`, but unfortunately this does not seem to be sufficient to fix the issue. There are some further logs and discussion on the Arch bug tracker [2].

[1]: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=553a5c03e90a6087e88f8ff878335ef0621536fb
[2]: https://bugs.archlinux.org/task/79444
Comment 1 CodingCellist 2023-09-26 00:42:51 PDT 
Created attachment 467872 [details]
Attempted, NON-FIXING patch