rsundahl created this revision.
rsundahl added reviewers: yln, kubamracek, rjmccall, dcoughlin, delcypher,
aralisza, thetruestblue, wrotki.
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Herald added projects: clang, Sanitizers.
Herald added subscribers: Sanitizers, cfe-commits.
Hooks into the address sanitizer that support array cookie poisoning and
validation were being generated for x86_64 but not for ARM. (amended)
In addition to the ItaniumCXXABI array cookie of a single size_t element
containing the number of elements in the allocated array, the ARMCXXABI adds
a second size_t element containing the sizeof(element). This difference in
cookie size created the need to override the methods ::InitializeArrayCookie()
and ::readArrayCookieImpl(). Later, in support of ASAN poison array cookies,
calls to __asan_poison_cxx_array_cookie() and __asan_load_cxx_array_cookie()
were added to each method respectively. However, these "hooks" were only
implemented for the ItaniumCXXABI. This commit adds the same functionality
to the overridden ARMCXXABI methods.
rdar://92765369
Repository:
rG LLVM Github Monorepo
https://reviews.llvm.org/D125195
Files:
clang/lib/CodeGen/ItaniumCXXABI.cpp
compiler-rt/lib/asan/asan_poisoning.cpp
compiler-rt/test/asan/TestCases/Posix/new_array_cookie_test.cpp
compiler-rt/test/asan/TestCases/Posix/new_array_cookie_uaf_test.cpp
Index: compiler-rt/test/asan/TestCases/Posix/new_array_cookie_uaf_test.cpp
===================================================================
--- compiler-rt/test/asan/TestCases/Posix/new_array_cookie_uaf_test.cpp
+++ compiler-rt/test/asan/TestCases/Posix/new_array_cookie_uaf_test.cpp
@@ -3,17 +3,12 @@
// RUN: %env_asan_opts=poison_array_cookie=1 not %run %t 2>&1 | FileCheck %s --check-prefix=COOKIE
// RUN: %env_asan_opts=poison_array_cookie=0 not %run %t 2>&1 | FileCheck %s --check-prefix=NO_COOKIE
-// UNSUPPORTED: ios
-
-// Added to allow enabling of tests but needs investigation (rdar://91448627)
-// XFAIL: (darwin && (arm64-target-arch || arm64e-target-arch))
-
#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
int dtor_counter;
struct C {
- int x;
+ size_t x;
~C() {
dtor_counter++;
fprintf(stderr, "DTOR %d\n", dtor_counter);
@@ -22,7 +17,7 @@
__attribute__((noinline)) void Delete(C *c) { delete[] c; }
__attribute__((no_sanitize_address)) void Write42ToCookie(C *c) {
- long *p = reinterpret_cast<long*>(c);
+ size_t *p = reinterpret_cast<size_t*>(c);
p[-1] = 42;
}
Index: compiler-rt/test/asan/TestCases/Posix/new_array_cookie_test.cpp
===================================================================
--- compiler-rt/test/asan/TestCases/Posix/new_array_cookie_test.cpp
+++ compiler-rt/test/asan/TestCases/Posix/new_array_cookie_test.cpp
@@ -1,18 +1,13 @@
// REQUIRES: asan-64-bits
// RUN: %clangxx_asan -O3 %s -o %t
-// RUN: not %run %t 2>&1 | FileCheck %s
+// RUN: not %run %t 2>&1 | FileCheck %s
// RUN: %env_asan_opts=poison_array_cookie=1 not %run %t 2>&1 | FileCheck %s
// RUN: %env_asan_opts=poison_array_cookie=0 not %run %t 2>&1 | FileCheck %s --check-prefix=NO_COOKIE
-// UNSUPPORTED: ios
-
-// Added to allow enabling of tests but needs investigation (rdar://91448627)
-// XFAIL: (darwin && (arm64-target-arch || arm64e-target-arch))
-
#include <stdio.h>
#include <stdlib.h>
struct C {
- int x;
+ size_t x;
~C() {
fprintf(stderr, "ZZZZZZZZ\n");
exit(1);
@@ -21,10 +16,10 @@
int main(int argc, char **argv) {
C *buffer = new C[argc];
- buffer[-2].x = 10;
+ buffer[-1].x = 10;
// CHECK: AddressSanitizer: heap-buffer-overflow
// CHECK: in main {{.*}}new_array_cookie_test.cpp:[[@LINE-2]]
-// CHECK: is located 0 bytes inside of 12-byte region
+// CHECK: is located {{0 bytes inside of 12|8 bytes inside of 24}}-byte region
// NO_COOKIE: ZZZZZZZZ
delete [] buffer;
}
Index: compiler-rt/lib/asan/asan_poisoning.cpp
===================================================================
--- compiler-rt/lib/asan/asan_poisoning.cpp
+++ compiler-rt/lib/asan/asan_poisoning.cpp
@@ -259,6 +259,10 @@
if (!flags()->poison_array_cookie) return;
uptr s = MEM_TO_SHADOW(p);
*reinterpret_cast<u8*>(s) = kAsanArrayCookieMagic;
+ // The ARM64 cookie has a second "elementSize" entry so poison it as well
+ #if SANITIZER_ARM64
+ *(reinterpret_cast<u8*>(s)-1) = kAsanArrayCookieMagic;
+ #endif
}
extern "C" SANITIZER_INTERFACE_ATTRIBUTE
Index: clang/lib/CodeGen/ItaniumCXXABI.cpp
===================================================================
--- clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -2424,6 +2424,8 @@
QualType elementType) {
assert(requiresArrayCookie(expr));
+ unsigned AS = newPtr.getAddressSpace();
+
// The cookie is always at the start of the buffer.
Address cookie = newPtr;
@@ -2435,7 +2437,20 @@
// The second element is the element count.
cookie = CGF.Builder.CreateConstInBoundsGEP(cookie, 1);
- CGF.Builder.CreateStore(numElements, cookie);
+ llvm::Instruction *SI = CGF.Builder.CreateStore(numElements, cookie);
+
+ // Handle poisoning the array cookie in asan
+ if (CGM.getLangOpts().Sanitize.has(SanitizerKind::Address) && AS == 0 &&
+ (expr->getOperatorNew()->isReplaceableGlobalAllocationFunction() ||
+ CGM.getCodeGenOpts().SanitizeAddressPoisonCustomArrayCookie)) {
+ // The store to the CookiePtr does not need to be instrumented.
+ CGM.getSanitizerMetadata()->disableSanitizerForInstruction(SI);
+ llvm::FunctionType *FTy =
+ llvm::FunctionType::get(CGM.VoidTy, cookie.getType(), false);
+ llvm::FunctionCallee F =
+ CGM.CreateRuntimeFunction(FTy, "__asan_poison_cxx_array_cookie");
+ CGF.Builder.CreateCall(F, cookie.getRawPointer(CGF));
+ }
// Finally, compute a pointer to the actual data buffer by skipping
// over the cookie completely.
@@ -2446,13 +2461,28 @@
llvm::Value *ARMCXXABI::readArrayCookieImpl(CodeGenFunction &CGF,
Address allocPtr,
CharUnits cookieSize) {
+ unsigned AS = allocPtr.getAddressSpace();
+
// The number of elements is at offset sizeof(size_t) relative to
// the allocated pointer.
Address numElementsPtr
= CGF.Builder.CreateConstInBoundsByteGEP(allocPtr, CGF.getSizeSize());
numElementsPtr = CGF.Builder.CreateElementBitCast(numElementsPtr, CGF.SizeTy);
- return CGF.Builder.CreateLoad(numElementsPtr);
+
+ if (!CGM.getLangOpts().Sanitize.has(SanitizerKind::Address) || AS != 0)
+ return CGF.Builder.CreateLoad(numElementsPtr);
+
+ // In asan mode emit a function call instead of a regular load and let the
+ // run-time deal with it: if the shadow is properly poisoned return the
+ // cookie, otherwise return 0 to avoid an infinite loop calling DTORs.
+ // We can't simply ignore this load using nosanitize metadata because
+ // the metadata may be lost.
+ llvm::FunctionType *FTy =
+ llvm::FunctionType::get(CGF.SizeTy, CGF.SizeTy->getPointerTo(0), false);
+ llvm::FunctionCallee F =
+ CGM.CreateRuntimeFunction(FTy, "__asan_load_cxx_array_cookie");
+ return CGF.Builder.CreateCall(F, numElementsPtr.getRawPointer(CGF));
}
/*********************** Static local initialization **************************/
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