tree 8956d33c52a9d5d962fd00be63f35d33cf31da02
parent 313545f85af72f954820e54f4110cda591a6cf7b
author Kyle Farnung <kfarnung@microsoft.com> 1773874131 -0700
committer swiftshader-scoped@luci-project-accounts.iam.gserviceaccount.com <swiftshader-scoped@luci-project-accounts.iam.gserviceaccount.com> 1773945931 -0700

Backport macOS ARM64 ASAN dynamic shadow offset from LLVM 12+

LLVM 10's AddressSanitizer pass uses the Linux ARM64 static shadow
offset (0x1000000000) for ALL ARM64 targets, including macOS ARM64.
However, macOS ARM64 requires a dynamic shadow offset because the ASAN
runtime maps shadow memory at a different address (0x7000020000).

This mismatch causes JIT-compiled shader code to compute wrong shadow
addresses, hitting protected memory and crashing with SIGBUS
(KERN_PROTECTION_FAILURE).

Backport the fix from LLVM 12+ which adds an IsMacOS && IsAArch64 check
to use kDynamicShadowSentinel (dynamic shadow offset) on macOS ARM64,
matching what the ASAN runtime expects.

LLVM change:
https://github.com/llvm/llvm-project/commit/176a6e7abe33d58a65ce9cfac15fe320962e7b6e

Bug: 493957482
Change-Id: I4d48bc41f89728d508d1937a1d767ea5a1576e6b
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/77208
Reviewed-by: Shahbaz Youssefi <syoussefi@google.com>
Reviewed-by: Geoff Lang <geofflang@google.com>
Commit-Queue: Shahbaz Youssefi <syoussefi@google.com>
Tested-by: Shahbaz Youssefi <syoussefi@google.com>