From 875cd44ff6d471315c29c9dda43d1814c7909168 Mon Sep 17 00:00:00 2001
From: Mitch Phillips <31459023+hctim@users.noreply.github.com>
Date: Mon, 10 May 2021 12:19:19 -0700
Subject: [Scudo] Use GWP-ASan's aligned allocations and fixup postalloc hooks.

This patch does a few cleanup things:
 1. The non-standalone scudo has a problem where GWP-ASan allocations
 may not meet alignment requirements where Scudo was requested to have
 alignment >= 16. Use the new GWP-ASan API to fix this.
 2. The standalone variant loses some debugging information inside of
 GWP-ASan because we ask GWP-ASan to allocate an aligned size in the
 frontend. This means reports end up with 'UaF on a 16-byte allocation'
 for a 1-byte allocation with 16-byte alignment. Also use the new API to
 fix this.
 3. Add post-alloc hooks for GWP-ASan intercepted allocations, and add
 stats tracking for GWP-ASan allocations.
 4. Add a small test that checks the alignment of the frontend
 allocator, so that it can be used under GWP-ASan torture mode.
 5. Add GWP-ASan torture mode as a testing configuration to catch these
 regressions.

Depends on D94830, D95889.

Reviewed By: cryptoad

Differential Revision: https://reviews.llvm.org/D95884

GitOrigin-RevId: e78b64df98878d1da56275e0c272ed58364da3ad
Change-Id: I9b7f7503e1b1fc3a57788e84231714588d796b5c
---
 gwp_asan/common.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/gwp_asan/common.h b/gwp_asan/common.h
index ee8f9d1..7ce367e 100644
--- a/gwp_asan/common.h
+++ b/gwp_asan/common.h
@@ -83,6 +83,8 @@ struct AllocationMetadata {
 // crash handler. This, in conjunction with the Metadata array, forms the entire
 // set of information required for understanding a GWP-ASan crash.
 struct AllocatorState {
+  constexpr AllocatorState() {}
+
   // Returns whether the provided pointer is a current sampled allocation that
   // is owned by this pool.
   GWP_ASAN_ALWAYS_INLINE bool pointerIsMine(const void *Ptr) const {
-- 
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