libunwindstack: Add Memory::ReadTag() function for reading memory tags.
This uses an experimental Linux kernel API for reading the tags across
processes using ptrace.
Bug: 135772972
Test: Unit tests pass.
Change-Id: Ib1a09d9219166011de80cf250b756bb8a4bcdb0a
diff --git a/libunwindstack/Android.bp b/libunwindstack/Android.bp
index ab59a4b..57c4c2e 100644
--- a/libunwindstack/Android.bp
+++ b/libunwindstack/Android.bp
@@ -57,6 +57,7 @@
"MapInfo.cpp",
"Maps.cpp",
"Memory.cpp",
+ "MemoryMte.cpp",
"LocalUnwinder.cpp",
"Regs.cpp",
"RegsArm.cpp",
@@ -101,6 +102,16 @@
"liblog",
"liblzma",
],
+
+ header_libs: [
+ "bionic_libc_platform_headers",
+ ],
+
+ product_variables: {
+ experimental_mte: {
+ cflags: ["-DANDROID_EXPERIMENTAL_MTE"],
+ },
+ },
}
cc_library {
@@ -213,6 +224,7 @@
"tests/MemoryRangesTest.cpp",
"tests/MemoryRemoteTest.cpp",
"tests/MemoryTest.cpp",
+ "tests/MemoryMteTest.cpp",
"tests/RegsInfoTest.cpp",
"tests/RegsIterateTest.cpp",
"tests/RegsStepIfSignalHandlerTest.cpp",
@@ -268,6 +280,16 @@
"tests/files/offline/straddle_arm/*",
"tests/files/offline/straddle_arm64/*",
],
+
+ header_libs: [
+ "bionic_libc_platform_headers",
+ ],
+
+ product_variables: {
+ experimental_mte: {
+ cflags: ["-DANDROID_EXPERIMENTAL_MTE"],
+ },
+ },
}
cc_test {
diff --git a/libunwindstack/Memory.cpp b/libunwindstack/Memory.cpp
index 8de3d98..fac9085 100644
--- a/libunwindstack/Memory.cpp
+++ b/libunwindstack/Memory.cpp
@@ -324,6 +324,16 @@
return ProcessVmRead(getpid(), addr, dst, size);
}
+#if !defined(ANDROID_EXPERIMENTAL_MTE)
+long MemoryRemote::ReadTag(uint64_t) {
+ return -1;
+}
+
+long MemoryLocal::ReadTag(uint64_t) {
+ return -1;
+}
+#endif
+
MemoryRange::MemoryRange(const std::shared_ptr<Memory>& memory, uint64_t begin, uint64_t length,
uint64_t offset)
: memory_(memory), begin_(begin), length_(length), offset_(offset) {}
diff --git a/libunwindstack/MemoryCache.h b/libunwindstack/MemoryCache.h
index 769d907..d97640d 100644
--- a/libunwindstack/MemoryCache.h
+++ b/libunwindstack/MemoryCache.h
@@ -33,6 +33,7 @@
virtual ~MemoryCache() = default;
size_t Read(uint64_t addr, void* dst, size_t size) override;
+ long ReadTag(uint64_t addr) override { return impl_->ReadTag(addr); }
void Clear() override { cache_.clear(); }
diff --git a/libunwindstack/MemoryLocal.h b/libunwindstack/MemoryLocal.h
index 7e027cf..741f107 100644
--- a/libunwindstack/MemoryLocal.h
+++ b/libunwindstack/MemoryLocal.h
@@ -31,6 +31,7 @@
bool IsLocal() const override { return true; }
size_t Read(uint64_t addr, void* dst, size_t size) override;
+ long ReadTag(uint64_t addr) override;
};
} // namespace unwindstack
diff --git a/libunwindstack/MemoryMte.cpp b/libunwindstack/MemoryMte.cpp
new file mode 100644
index 0000000..d1d0ebc
--- /dev/null
+++ b/libunwindstack/MemoryMte.cpp
@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#if defined(ANDROID_EXPERIMENTAL_MTE)
+
+#include <sys/ptrace.h>
+
+#include <bionic/mte.h>
+#include <bionic/mte_kernel.h>
+
+#include "MemoryLocal.h"
+#include "MemoryRemote.h"
+
+namespace unwindstack {
+
+long MemoryRemote::ReadTag(uint64_t addr) {
+#if defined(__aarch64__)
+ return ptrace(PTRACE_PEEKTAG, pid_, (void*)addr, nullptr);
+#else
+ (void)addr;
+ return -1;
+#endif
+}
+
+long MemoryLocal::ReadTag(uint64_t addr) {
+#if defined(__aarch64__)
+ // Check that the memory is readable first. This is racy with the ldg but there's not much
+ // we can do about it.
+ char data;
+ if (!mte_supported() || !Read(addr, &data, 1)) {
+ return -1;
+ }
+
+ __asm__ __volatile__(".arch_extension mte; ldg %0, [%0]" : "+r"(addr) : : "memory");
+ return (addr >> 56) & 0xf;
+#else
+ (void)addr;
+ return -1;
+#endif
+}
+
+} // namespace unwindstack
+
+#endif
diff --git a/libunwindstack/MemoryRemote.h b/libunwindstack/MemoryRemote.h
index db367d6..dd09c88 100644
--- a/libunwindstack/MemoryRemote.h
+++ b/libunwindstack/MemoryRemote.h
@@ -32,6 +32,7 @@
virtual ~MemoryRemote() = default;
size_t Read(uint64_t addr, void* dst, size_t size) override;
+ long ReadTag(uint64_t addr) override;
pid_t pid() { return pid_; }
diff --git a/libunwindstack/include/unwindstack/Memory.h b/libunwindstack/include/unwindstack/Memory.h
index ecd908a..26252b6 100644
--- a/libunwindstack/include/unwindstack/Memory.h
+++ b/libunwindstack/include/unwindstack/Memory.h
@@ -44,6 +44,7 @@
virtual bool IsLocal() const { return false; }
virtual size_t Read(uint64_t addr, void* dst, size_t size) = 0;
+ virtual long ReadTag(uint64_t) { return -1; }
bool ReadFully(uint64_t addr, void* dst, size_t size);
diff --git a/libunwindstack/tests/MemoryMteTest.cpp b/libunwindstack/tests/MemoryMteTest.cpp
new file mode 100644
index 0000000..3ae322e
--- /dev/null
+++ b/libunwindstack/tests/MemoryMteTest.cpp
@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#if defined(ANDROID_EXPERIMENTAL_MTE)
+
+#include <sys/mman.h>
+#include <sys/types.h>
+
+#include <gtest/gtest.h>
+
+#include <bionic/mte.h>
+
+#include "MemoryLocal.h"
+#include "MemoryRemote.h"
+#include "TestUtils.h"
+
+namespace unwindstack {
+
+static uintptr_t CreateTagMapping() {
+ uintptr_t mapping =
+ reinterpret_cast<uintptr_t>(mmap(nullptr, getpagesize(), PROT_READ | PROT_WRITE | PROT_MTE,
+ MAP_PRIVATE | MAP_ANONYMOUS, -1, 0));
+ if (reinterpret_cast<void*>(mapping) == MAP_FAILED) {
+ return 0;
+ }
+#if defined(__aarch64__)
+ __asm__ __volatile__(".arch_extension mte; stg %0, [%0]"
+ :
+ : "r"(mapping + (1ULL << 56))
+ : "memory");
+#endif
+ return mapping;
+}
+
+TEST(MemoryMteTest, remote_read_tag) {
+#if !defined(__aarch64__)
+ GTEST_SKIP() << "Requires aarch64";
+#else
+ if (!mte_supported()) {
+ GTEST_SKIP() << "Requires MTE";
+ }
+#endif
+
+ uintptr_t mapping = CreateTagMapping();
+ ASSERT_NE(0U, mapping);
+
+ pid_t pid;
+ if ((pid = fork()) == 0) {
+ while (true)
+ ;
+ exit(1);
+ }
+ ASSERT_LT(0, pid);
+ TestScopedPidReaper reap(pid);
+
+ ASSERT_TRUE(TestAttach(pid));
+
+ MemoryRemote remote(pid);
+
+ EXPECT_EQ(1, remote.ReadTag(mapping));
+ EXPECT_EQ(0, remote.ReadTag(mapping + 16));
+
+ ASSERT_TRUE(TestDetach(pid));
+}
+
+TEST(MemoryMteTest, local_read_tag) {
+#if !defined(__aarch64__)
+ GTEST_SKIP() << "Requires aarch64";
+#else
+ if (!mte_supported()) {
+ GTEST_SKIP() << "Requires MTE";
+ }
+#endif
+
+ uintptr_t mapping = CreateTagMapping();
+ ASSERT_NE(0U, mapping);
+
+ MemoryLocal local;
+
+ EXPECT_EQ(1, local.ReadTag(mapping));
+ EXPECT_EQ(0, local.ReadTag(mapping + 16));
+}
+
+} // namespace unwindstack
+
+#endif
diff --git a/libunwindstack/tests/MemoryRemoteTest.cpp b/libunwindstack/tests/MemoryRemoteTest.cpp
index c90dedc..385078d 100644
--- a/libunwindstack/tests/MemoryRemoteTest.cpp
+++ b/libunwindstack/tests/MemoryRemoteTest.cpp
@@ -26,8 +26,10 @@
#include <vector>
-#include <android-base/test_utils.h>
#include <android-base/file.h>
+#include <android-base/test_utils.h>
+#include <bionic/mte.h>
+#include <bionic/mte_kernel.h>
#include <gtest/gtest.h>
#include "MemoryRemote.h"
@@ -37,24 +39,7 @@
namespace unwindstack {
-class MemoryRemoteTest : public ::testing::Test {
- protected:
- static bool Attach(pid_t pid) {
- if (ptrace(PTRACE_ATTACH, pid, 0, 0) == -1) {
- return false;
- }
-
- return TestQuiescePid(pid);
- }
-
- static bool Detach(pid_t pid) {
- return ptrace(PTRACE_DETACH, pid, 0, 0) == 0;
- }
-
- static constexpr size_t NS_PER_SEC = 1000000000ULL;
-};
-
-TEST_F(MemoryRemoteTest, read) {
+TEST(MemoryRemoteTest, read) {
std::vector<uint8_t> src(1024);
memset(src.data(), 0x4c, 1024);
@@ -66,7 +51,7 @@
ASSERT_LT(0, pid);
TestScopedPidReaper reap(pid);
- ASSERT_TRUE(Attach(pid));
+ ASSERT_TRUE(TestAttach(pid));
MemoryRemote remote(pid);
@@ -76,10 +61,10 @@
ASSERT_EQ(0x4cU, dst[i]) << "Failed at byte " << i;
}
- ASSERT_TRUE(Detach(pid));
+ ASSERT_TRUE(TestDetach(pid));
}
-TEST_F(MemoryRemoteTest, read_large) {
+TEST(MemoryRemoteTest, read_large) {
static constexpr size_t kTotalPages = 245;
std::vector<uint8_t> src(kTotalPages * getpagesize());
for (size_t i = 0; i < kTotalPages; i++) {
@@ -95,7 +80,7 @@
ASSERT_LT(0, pid);
TestScopedPidReaper reap(pid);
- ASSERT_TRUE(Attach(pid));
+ ASSERT_TRUE(TestAttach(pid));
MemoryRemote remote(pid);
@@ -105,10 +90,10 @@
ASSERT_EQ(i / getpagesize(), dst[i]) << "Failed at byte " << i;
}
- ASSERT_TRUE(Detach(pid));
+ ASSERT_TRUE(TestDetach(pid));
}
-TEST_F(MemoryRemoteTest, read_partial) {
+TEST(MemoryRemoteTest, read_partial) {
char* mapping = static_cast<char*>(
mmap(nullptr, 4 * getpagesize(), PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0));
ASSERT_NE(MAP_FAILED, mapping);
@@ -128,7 +113,7 @@
// Unmap from our process.
ASSERT_EQ(0, munmap(mapping, 3 * getpagesize()));
- ASSERT_TRUE(Attach(pid));
+ ASSERT_TRUE(TestAttach(pid));
MemoryRemote remote(pid);
@@ -149,10 +134,10 @@
ASSERT_EQ(0x4cU, dst[i]) << "Failed at byte " << i;
}
- ASSERT_TRUE(Detach(pid));
+ ASSERT_TRUE(TestDetach(pid));
}
-TEST_F(MemoryRemoteTest, read_fail) {
+TEST(MemoryRemoteTest, read_fail) {
int pagesize = getpagesize();
void* src = mmap(nullptr, pagesize * 2, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE,-1, 0);
memset(src, 0x4c, pagesize * 2);
@@ -169,7 +154,7 @@
ASSERT_LT(0, pid);
TestScopedPidReaper reap(pid);
- ASSERT_TRUE(Attach(pid));
+ ASSERT_TRUE(TestAttach(pid));
MemoryRemote remote(pid);
@@ -188,10 +173,10 @@
ASSERT_EQ(0, munmap(src, pagesize));
- ASSERT_TRUE(Detach(pid));
+ ASSERT_TRUE(TestDetach(pid));
}
-TEST_F(MemoryRemoteTest, read_overflow) {
+TEST(MemoryRemoteTest, read_overflow) {
pid_t pid;
if ((pid = fork()) == 0) {
while (true)
@@ -201,7 +186,7 @@
ASSERT_LT(0, pid);
TestScopedPidReaper reap(pid);
- ASSERT_TRUE(Attach(pid));
+ ASSERT_TRUE(TestAttach(pid));
MemoryRemote remote(pid);
@@ -209,10 +194,10 @@
std::vector<uint8_t> dst(200);
ASSERT_FALSE(remote.ReadFully(UINT64_MAX - 100, dst.data(), 200));
- ASSERT_TRUE(Detach(pid));
+ ASSERT_TRUE(TestDetach(pid));
}
-TEST_F(MemoryRemoteTest, read_illegal) {
+TEST(MemoryRemoteTest, read_illegal) {
pid_t pid;
if ((pid = fork()) == 0) {
while (true);
@@ -221,7 +206,7 @@
ASSERT_LT(0, pid);
TestScopedPidReaper reap(pid);
- ASSERT_TRUE(Attach(pid));
+ ASSERT_TRUE(TestAttach(pid));
MemoryRemote remote(pid);
@@ -229,10 +214,10 @@
ASSERT_FALSE(remote.ReadFully(0, dst.data(), 1));
ASSERT_FALSE(remote.ReadFully(0, dst.data(), 100));
- ASSERT_TRUE(Detach(pid));
+ ASSERT_TRUE(TestDetach(pid));
}
-TEST_F(MemoryRemoteTest, read_mprotect_hole) {
+TEST(MemoryRemoteTest, read_mprotect_hole) {
size_t page_size = getpagesize();
void* mapping =
mmap(nullptr, 3 * getpagesize(), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
@@ -250,7 +235,7 @@
ASSERT_EQ(0, munmap(mapping, 3 * page_size));
- ASSERT_TRUE(Attach(pid));
+ ASSERT_TRUE(TestAttach(pid));
MemoryRemote remote(pid);
std::vector<uint8_t> dst(getpagesize() * 4, 0xCC);
@@ -263,9 +248,11 @@
for (size_t i = read_size; i < dst.size(); ++i) {
ASSERT_EQ(0xCC, dst[i]);
}
+
+ ASSERT_TRUE(TestDetach(pid));
}
-TEST_F(MemoryRemoteTest, read_munmap_hole) {
+TEST(MemoryRemoteTest, read_munmap_hole) {
size_t page_size = getpagesize();
void* mapping =
mmap(nullptr, 3 * getpagesize(), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
@@ -285,7 +272,7 @@
ASSERT_EQ(0, munmap(mapping, page_size));
ASSERT_EQ(0, munmap(static_cast<char*>(mapping) + 2 * page_size, page_size));
- ASSERT_TRUE(Attach(pid));
+ ASSERT_TRUE(TestAttach(pid));
MemoryRemote remote(pid);
std::vector<uint8_t> dst(getpagesize() * 4, 0xCC);
@@ -297,11 +284,13 @@
for (size_t i = read_size; i < dst.size(); ++i) {
ASSERT_EQ(0xCC, dst[i]);
}
+
+ ASSERT_TRUE(TestDetach(pid));
}
// Verify that the memory remote object chooses a memory read function
// properly. Either process_vm_readv or ptrace.
-TEST_F(MemoryRemoteTest, read_choose_correctly) {
+TEST(MemoryRemoteTest, read_choose_correctly) {
size_t page_size = getpagesize();
void* mapping =
mmap(nullptr, 2 * getpagesize(), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
@@ -320,7 +309,7 @@
ASSERT_EQ(0, munmap(mapping, 2 * page_size));
- ASSERT_TRUE(Attach(pid));
+ ASSERT_TRUE(TestAttach(pid));
// We know that process_vm_readv of a mprotect'd PROT_NONE region will fail.
// Read from the PROT_NONE area first to force the choice of ptrace.
@@ -348,6 +337,8 @@
bytes = remote_readv.Read(reinterpret_cast<uint64_t>(mapping) + page_size, &value, sizeof(value));
ASSERT_EQ(sizeof(value), bytes);
ASSERT_EQ(0xfcfcfcfcU, value);
+
+ ASSERT_TRUE(TestDetach(pid));
}
} // namespace unwindstack
diff --git a/libunwindstack/tests/TestUtils.h b/libunwindstack/tests/TestUtils.h
index a4d7b9b..0685006 100644
--- a/libunwindstack/tests/TestUtils.h
+++ b/libunwindstack/tests/TestUtils.h
@@ -21,6 +21,7 @@
#include <sys/ptrace.h>
#include <sys/types.h>
#include <sys/wait.h>
+#include <unistd.h>
namespace unwindstack {
@@ -50,6 +51,18 @@
return ready;
}
+inline bool TestAttach(pid_t pid) {
+ if (ptrace(PTRACE_ATTACH, pid, 0, 0) == -1) {
+ return false;
+ }
+
+ return TestQuiescePid(pid);
+}
+
+inline bool TestDetach(pid_t pid) {
+ return ptrace(PTRACE_DETACH, pid, 0, 0) == 0;
+}
+
void TestCheckForLeaks(void (*unwind_func)(void*), void* data);
} // namespace unwindstack