CI: Work around a libasan bug seen on Ubuntu with the Linux 6.5 kernel

We are recently seeing SEGV crashes during the build (while running code generators) from within libasan itself. Turns out this is libasan bug seen with the Linux 6.5 kernel on Ubuntu.
Author: https://github.com/trflynn89 Commit: https://github.com/SerenityOS/serenity/commit/5713c2ffdd Pull-request: https://github.com/SerenityOS/serenity/pull/23567 Reviewed-by: https://github.com/ADKaster ✅
2024-03-12 19:53:15 -04:00 · 2024-03-12 19:53:15 -04:00 · 5713c2ffdd · 2024-07-17 01:53:23 +09:00
commit 5713c2ffdd
parent 4c15c87d0c
1 changed files with 9 additions and 0 deletions
--- a/Meta/Azure/Lagom.yml
+++ b/Meta/Azure/Lagom.yml
@ -58,6 +58,15 @@ jobs:
          ccache_version: 2
        serenity_ccache_size: '2G'

+    # On Ubuntu, with Linux kernel 6.5, ARCH_MMAP_RND_BITS was changed from ARCH_MMAP_RND_BITS_MIN (28 on x64) to
+    # ARCH_MMAP_RND_BITS_MAX (32 on x64). This breaks assumptions made by libasan's allocators, and we see a flaky
+    # crash from within libasan itself. Here, we restore the previous value until we have a version of GCC which fixes
+    # the issue in libasan (reportedly 13.2.1): https://stackoverflow.com/questions/77894856/possible-bug-in-gcc-sanitizers
+    - ${{ if eq(parameters.os, 'Linux') }}:
+      - script: |
+          sudo sysctl vm.mmap_rnd_bits=28
+        displayName: 'Work around libasan ASLR bug'
+
    - ${{ if eq(parameters.os, 'Android') }}:
      - script: |
          yes | $ANDROID_SDK_ROOT/tools/bin/sdkmanager "ndk;$(ndk_version)"