mirror of
https://github.com/archlinuxarm/PKGBUILDs.git
synced 2024-11-08 22:45:43 +00:00
60 lines
2.8 KiB
Diff
60 lines
2.8 KiB
Diff
From fb77ca05ffb4f8e666878f2f6718a9fb4d686839 Mon Sep 17 00:00:00 2001
|
|
From: Thurston Dang <thurston@google.com>
|
|
Date: Thu, 13 Apr 2023 23:55:01 +0000
|
|
Subject: [PATCH] Re-land 'ASan: move allocator base to avoid conflict with
|
|
high-entropy ASLR for x86-64 Linux'
|
|
|
|
D147984 was reverted because it broke lit tests on Mac. This revision is based on D147984
|
|
but maintains the old behavior for Apple.
|
|
|
|
Note that, per the follow-up discussion with MaskRay in D147984, this patch excludes Apple
|
|
but includes other platforms (e.g., aarch64, MIPS64) and OSes (e.g., FreeBSD, S390X), not just
|
|
x86-64 Linux.
|
|
|
|
Original commit message from D147984:
|
|
|
|
Users have discovered [*] that when CONFIG_ARCH_MMAP_RND_BITS == 32,
|
|
it will frequently conflict with ASan's allocator on x86-64 Linux, because the
|
|
PIE program segment base address of 0x555555555554 plus an ASLR shift of up to
|
|
((2**32) * 4K == 0x100000000000) will sometimes exceed ASan's hardcoded
|
|
base address of 0x600000000000. We fix this by simply moving the allocator base
|
|
to 0x500000000000, which is below the PIE program segment base address. This is
|
|
cleaner than trying to move it to another location that is sandwiched between
|
|
the PIE program and library segments, because if either of those grow too large,
|
|
it will collide with the allocator region.
|
|
|
|
Note that we will never need to change this base address again (unless we want to increase
|
|
the size of the allocator), because ASLR cannot be set above 32-bits for x86-64 Linux (the
|
|
PIE program segment and library segments would collide with each other; see also
|
|
ARCH_MMAP_RND_BITS_MAX in https://github.com/torvalds/linux/blob/master/arch/x86/Kconfig).
|
|
|
|
[*] see https://b.corp.google.com/issues/276925478
|
|
and https://groups.google.com/a/google.com/g/chrome-os-gardeners/c/BbfzCP3dEeo/m/h3C_vVUxCQAJ
|
|
|
|
Differential Revision: https://reviews.llvm.org/D148280
|
|
---
|
|
compiler-rt/lib/asan/asan_allocator.h | 8 ++++++--
|
|
1 file changed, 6 insertions(+), 2 deletions(-)
|
|
|
|
diff --git a/compiler-rt/lib/asan/asan_allocator.h b/compiler-rt/lib/asan/asan_allocator.h
|
|
index 0b4dbf03bb9d5..6a12a6c602528 100644
|
|
--- a/compiler-rt/lib/asan/asan_allocator.h
|
|
+++ b/compiler-rt/lib/asan/asan_allocator.h
|
|
@@ -143,11 +143,15 @@ typedef DefaultSizeClassMap SizeClassMap;
|
|
const uptr kAllocatorSpace = ~(uptr)0;
|
|
const uptr kAllocatorSize = 0x8000000000ULL; // 500G
|
|
typedef DefaultSizeClassMap SizeClassMap;
|
|
-# else
|
|
+# elif SANITIZER_APPLE
|
|
const uptr kAllocatorSpace = 0x600000000000ULL;
|
|
const uptr kAllocatorSize = 0x40000000000ULL; // 4T.
|
|
typedef DefaultSizeClassMap SizeClassMap;
|
|
-# endif
|
|
+# else
|
|
+const uptr kAllocatorSpace = 0x500000000000ULL;
|
|
+const uptr kAllocatorSize = 0x40000000000ULL; // 4T.
|
|
+typedef DefaultSizeClassMap SizeClassMap;
|
|
+# endif
|
|
template <typename AddressSpaceViewTy>
|
|
struct AP64 { // Allocator64 parameters. Deliberately using a short name.
|
|
static const uptr kSpaceBeg = kAllocatorSpace;
|