[llvm] r364105 - [ASan] Use dynamic shadow on 32-bit iOS and simulators

Julian Lettner via llvm-commits llvm-commits at lists.llvm.org
Fri Jun 21 14:01:41 PDT 2019


Author: yln
Date: Fri Jun 21 14:01:39 2019
New Revision: 364105

URL: http://llvm.org/viewvc/llvm-project?rev=364105&view=rev
Log:
[ASan] Use dynamic shadow on 32-bit iOS and simulators

The VM layout on iOS is not stable between releases. On 64-bit iOS and
its derivatives we use a dynamic shadow offset that enables ASan to
search for a valid location for the shadow heap on process launch rather
than hardcode it.

This commit extends that approach for 32-bit iOS plus derivatives and
their simulators.

rdar://50645192
rdar://51200372
rdar://51767702

Reviewed By: delcypher

Differential Revision: https://reviews.llvm.org/D63586

Added:
    llvm/trunk/test/Instrumentation/AddressSanitizer/dynamic-shadow-darwin.ll
Modified:
    llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp

Modified: llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp?rev=364105&r1=364104&r2=364105&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Instrumentation/AddressSanitizer.cpp Fri Jun 21 14:01:39 2019
@@ -94,9 +94,6 @@ static const uint64_t kDefaultShadowOffs
 static const uint64_t kDefaultShadowOffset64 = 1ULL << 44;
 static const uint64_t kDynamicShadowSentinel =
     std::numeric_limits<uint64_t>::max();
-static const uint64_t kIOSShadowOffset32 = 1ULL << 30;
-static const uint64_t kIOSSimShadowOffset32 = 1ULL << 30;
-static const uint64_t kIOSSimShadowOffset64 = kDefaultShadowOffset64;
 static const uint64_t kSmallX86_64ShadowOffsetBase = 0x7FFFFFFF;  // < 2G.
 static const uint64_t kSmallX86_64ShadowOffsetAlignMask = ~0xFFFULL;
 static const uint64_t kLinuxKasan_ShadowOffset64 = 0xdffffc0000000000;
@@ -428,7 +425,6 @@ static ShadowMapping getShadowMapping(Tr
   bool IsPPC64 = TargetTriple.getArch() == Triple::ppc64 ||
                  TargetTriple.getArch() == Triple::ppc64le;
   bool IsSystemZ = TargetTriple.getArch() == Triple::systemz;
-  bool IsX86 = TargetTriple.getArch() == Triple::x86;
   bool IsX86_64 = TargetTriple.getArch() == Triple::x86_64;
   bool IsMIPS32 = TargetTriple.isMIPS32();
   bool IsMIPS64 = TargetTriple.isMIPS64();
@@ -455,8 +451,7 @@ static ShadowMapping getShadowMapping(Tr
     else if (IsNetBSD)
       Mapping.Offset = kNetBSD_ShadowOffset32;
     else if (IsIOS)
-      // If we're targeting iOS and x86, the binary is built for iOS simulator.
-      Mapping.Offset = IsX86 ? kIOSSimShadowOffset32 : kIOSShadowOffset32;
+      Mapping.Offset = kDynamicShadowSentinel;
     else if (IsWindows)
       Mapping.Offset = kWindowsShadowOffset32;
     else if (IsMyriad) {
@@ -495,10 +490,7 @@ static ShadowMapping getShadowMapping(Tr
     } else if (IsMIPS64)
       Mapping.Offset = kMIPS64_ShadowOffset64;
     else if (IsIOS)
-      // If we're targeting iOS and x86, the binary is built for iOS simulator.
-      // We are using dynamic shadow offset on the 64-bit devices.
-      Mapping.Offset =
-        IsX86_64 ? kIOSSimShadowOffset64 : kDynamicShadowSentinel;
+      Mapping.Offset = kDynamicShadowSentinel;
     else if (IsAArch64)
       Mapping.Offset = kAArch64_ShadowOffset64;
     else

Added: llvm/trunk/test/Instrumentation/AddressSanitizer/dynamic-shadow-darwin.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Instrumentation/AddressSanitizer/dynamic-shadow-darwin.ll?rev=364105&view=auto
==============================================================================
--- llvm/trunk/test/Instrumentation/AddressSanitizer/dynamic-shadow-darwin.ll (added)
+++ llvm/trunk/test/Instrumentation/AddressSanitizer/dynamic-shadow-darwin.ll Fri Jun 21 14:01:39 2019
@@ -0,0 +1,28 @@
+; Test using dynamic shadow address on darwin
+;
+; RUN: opt -asan -asan-module -mtriple=arm64_32-apple-watchos --data-layout="e-m:o-p:32:32-i64:64-i128:128-n32:64-S128" -S < %s | FileCheck %s --check-prefixes=CHECK,CHECK-DYNAMIC -DPTR_SIZE=32
+; RUN: opt -asan -asan-module -mtriple=armv7k-apple-watchos --data-layout="e-m:o-p:32:32-Fi8-i64:64-a:0:32-n32-S128" -S < %s | FileCheck %s --check-prefixes=CHECK,CHECK-DYNAMIC -DPTR_SIZE=32
+; RUN: opt -asan -asan-module -mtriple=arm64-apple-ios --data-layout="e-m:o-i64:64-i128:128-n32:64-S128" -S < %s | FileCheck %s --check-prefixes=CHECK,CHECK-DYNAMIC -DPTR_SIZE=64
+; RUN: opt -asan -asan-module -mtriple=armv7s-apple-ios --data-layout="e-m:o-p:32:32-Fi8-f64:32:64-v64:32:64-v128:32:128-a:0:32-n32-S32" -S < %s | FileCheck %s --check-prefixes=CHECK,CHECK-DYNAMIC -DPTR_SIZE=32
+; RUN: opt -asan -asan-module -mtriple=i386-apple-watchos-simulator --data-layout="e-m:o-p:32:32-f64:32:64-f80:128-n8:16:32-S128" -S < %s | FileCheck %s --check-prefixes=CHECK,CHECK-DYNAMIC -DPTR_SIZE=32
+; RUN: opt -asan -asan-module -mtriple=i386-apple-ios-simulator --data-layout="e-m:o-p:32:32-f64:32:64-f80:128-n8:16:32-S128" -S < %s | FileCheck %s --check-prefixes=CHECK,CHECK-DYNAMIC -DPTR_SIZE=32
+; RUN: opt -asan -asan-module -mtriple=x86_64-apple-ios-simulator --data-layout="e-m:o-i64:64-f80:128-n8:16:32:64-S128" -S < %s | FileCheck %s --check-prefixes=CHECK,CHECK-DYNAMIC -DPTR_SIZE=64
+;
+; // macOS does not use dynamic shadow placement
+; RUN: opt -asan -asan-module -mtriple=x86_64-apple-macosx --data-layout="e-m:o-i64:64-f80:128-n8:16:32:64-S128" -S < %s | FileCheck %s --check-prefixes=CHECK,CHECK-NONDYNAMIC -DPTR_SIZE=64
+
+define i32 @test_load(i32* %a) sanitize_address {
+; First instrumentation in the function must be to load the dynamic shadow
+; address into a local variable.
+; CHECK-LABEL: @test_load
+; CHECK: entry:
+; CHECK-DYNAMIC-NEXT: %[[SHADOW:[^ ]*]] = load i[[PTR_SIZE]], i[[PTR_SIZE]]* @__asan_shadow_memory_dynamic_address
+; CHECK-NONDYNAMIC-NOT: __asan_shadow_memory_dynamic_address
+
+; Shadow address is loaded and added into the whole offset computation.
+; CHECK-DYNAMIC: add i[[PTR_SIZE]] %{{.*}}, %[[SHADOW]]
+
+entry:
+  %tmp1 = load i32, i32* %a, align 4
+  ret i32 %tmp1
+}




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