tree 18545ad58e6e07d59651839c5eb1d531f12b2b4f
parent 9d985453dc072362dc57e0837d0c9cef214cd57e
author Kostya Kortchinsky <kostyak@google.com> 1632771119 -0700
committer Copybara-Service <copybara-worker@google.com> 1632776121 -0700

[gwp-asan] Initialize AllocatorVersionMagic at runtime

GWP-ASan's `AllocatorState` was recently extended with a
`AllocatorVersionMagic` structure required so that GWP-ASan bug reports
can be understood by tools at different versions.

On Fuchsia, this in included in the `scudo::Allocator` structure, and
by having non-zero initializers, this effectively moved the static
allocator structure from the `.bss` segment to the `.data` segment, thus
increasing (significantly) the size of the libc.

This CL proposes to initialize the structure with its magic numbers at
runtime, allowing for the allocator to go back into the `.bss` segment.

I will work on adding a test on the Scudo side to ensure that this type
of changes get detected early on. Additional work is also needed to
reduce the footprint of the (large) memory-tagging related structures
that are currently part of the allocator.

Differential Revision: https://reviews.llvm.org/D110575

GitOrigin-RevId: 04f5913395de23a5f6745156021ab10a4a0039de