// Copyright 2018 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifdef UNSAFE_BUFFERS_BUILD
// TODO(crbug.com/40284755): Remove this and use spans.
#pragma allow_unsafe_buffers
#endif
#include "base/trace_event/cfi_backtrace_android.h"
#include "base/files/file_util.h"
#include "testing/gtest/include/gtest/gtest.h"
namespace base {
namespace trace_event {
namespace {
void* GetPC() {
return __builtin_return_address(0);
}
} // namespace
TEST(CFIBacktraceAndroidTest, TestUnwinding) {
auto* unwinder = CFIBacktraceAndroid::GetInitializedInstance();
EXPECT_TRUE(unwinder->can_unwind_stack_frames());
EXPECT_GT(unwinder->executable_start_addr(), 0u);
EXPECT_GT(unwinder->executable_end_addr(), unwinder->executable_start_addr());
EXPECT_GT(unwinder->cfi_mmap_->length(), 0u);
const size_t kMaxFrames = 100;
const void* frames[kMaxFrames];
size_t unwind_count = unwinder->Unwind(frames, kMaxFrames);
// Expect at least 2 frames in the result.
ASSERT_GT(unwind_count, 2u);
EXPECT_LE(unwind_count, kMaxFrames);
const size_t kMaxCurrentFuncCodeSize = 50;
const uintptr_t current_pc = reinterpret_cast<uintptr_t>(GetPC());
const uintptr_t actual_frame = reinterpret_cast<uintptr_t>(frames[2]);
EXPECT_NEAR(current_pc, actual_frame, kMaxCurrentFuncCodeSize);
for (size_t i = 0; i < unwind_count; ++i) {
EXPECT_GT(reinterpret_cast<uintptr_t>(frames[i]),
unwinder->executable_start_addr());
EXPECT_LT(reinterpret_cast<uintptr_t>(frames[i]),
unwinder->executable_end_addr());
}
}
// Flaky: https://bugs.chromium.org/p/chromium/issues/detail?id=829555
TEST(CFIBacktraceAndroidTest, DISABLED_TestFindCFIRow) {
auto* unwinder = CFIBacktraceAndroid::GetInitializedInstance();
/* Input is generated from the CFI file:
STACK CFI INIT 1000 500
STACK CFI 1002 .cfa: sp 272 + .ra: .cfa -4 + ^ r4: .cfa -16 +
STACK CFI 1008 .cfa: sp 544 + .r1: .cfa -0 + ^ r4: .cfa -16 + ^
STACK CFI 1040 .cfa: sp 816 + .r1: .cfa -0 + ^ r4: .cfa -16 + ^
STACK CFI 1050 .cfa: sp 816 + .ra: .cfa -8 + ^ r4: .cfa -16 + ^
STACK CFI 1080 .cfa: sp 544 + .r1: .cfa -0 + ^ r4: .cfa -16 + ^
STACK CFI INIT 2000 22
STACK CFI 2004 .cfa: sp 16 + .ra: .cfa -12 + ^ r4: .cfa -16 + ^
STACK CFI 2008 .cfa: sp 16 + .ra: .cfa -12 + ^ r4: .cfa -16 + ^
STACK CFI INIT 2024 100
STACK CFI 2030 .cfa: sp 48 + .ra: .cfa -12 + ^ r4: .cfa -16 + ^
STACK CFI 2100 .cfa: sp 64 + .r1: .cfa -0 + ^ r4: .cfa -16 + ^
STACK CFI INIT 2200 10
STACK CFI 2204 .cfa: sp 44 + .ra: .cfa -8 + ^ r4: .cfa -16 + ^
*/
uint16_t input[] = {// UNW_INDEX size
0x07, 0x0,
// UNW_INDEX address column (4 byte rows).
0x1000, 0x0, 0x1502, 0x0, 0x2000, 0x0, 0x2024, 0x0,
0x2126, 0x0, 0x2200, 0x0, 0x2212, 0x0,
// UNW_INDEX index column (2 byte rows).
0x0, 0xffff, 0xb, 0x10, 0xffff, 0x15, 0xffff,
// UNW_DATA table.
0x5, 0x2, 0x111, 0x8, 0x220, 0x40, 0x330, 0x50, 0x332,
0x80, 0x220, 0x2, 0x4, 0x13, 0x8, 0x13, 0x2, 0xc, 0x33,
0xdc, 0x40, 0x1, 0x4, 0x2e};
FilePath temp_path;
CreateTemporaryFile(&temp_path);
EXPECT_TRUE(WriteFile(temp_path, base::as_bytes(base::make_span(input))));
unwinder->cfi_mmap_.reset(new MemoryMappedFile());
ASSERT_TRUE(unwinder->cfi_mmap_->Initialize(temp_path));
unwinder->ParseCFITables();
CFIBacktraceAndroid::CFIRow cfi_row = {0};
EXPECT_FALSE(unwinder->FindCFIRowForPC(0x01, &cfi_row));
EXPECT_FALSE(unwinder->FindCFIRowForPC(0x100, &cfi_row));
EXPECT_FALSE(unwinder->FindCFIRowForPC(0x1502, &cfi_row));
EXPECT_FALSE(unwinder->FindCFIRowForPC(0x3000, &cfi_row));
EXPECT_FALSE(unwinder->FindCFIRowForPC(0x2024, &cfi_row));
EXPECT_FALSE(unwinder->FindCFIRowForPC(0x2212, &cfi_row));
const CFIBacktraceAndroid::CFIRow kRow1 = {0x110, 0x4};
const CFIBacktraceAndroid::CFIRow kRow2 = {0x220, 0x4};
const CFIBacktraceAndroid::CFIRow kRow3 = {0x220, 0x8};
const CFIBacktraceAndroid::CFIRow kRow4 = {0x30, 0xc};
const CFIBacktraceAndroid::CFIRow kRow5 = {0x2c, 0x8};
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1002, &cfi_row));
EXPECT_EQ(kRow1, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1003, &cfi_row));
EXPECT_EQ(kRow1, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1008, &cfi_row));
EXPECT_EQ(kRow2, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1009, &cfi_row));
EXPECT_EQ(kRow2, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1039, &cfi_row));
EXPECT_EQ(kRow2, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1080, &cfi_row));
EXPECT_EQ(kRow3, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1100, &cfi_row));
EXPECT_EQ(kRow3, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x2050, &cfi_row));
EXPECT_EQ(kRow4, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x2208, &cfi_row));
EXPECT_EQ(kRow5, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x2210, &cfi_row));
EXPECT_EQ(kRow5, cfi_row);
// Test if cache is used on the future calls to Find, all addresses should
// have different hash. Resetting the memory map to make sure it is never
// accessed in Find().
unwinder->cfi_mmap_.reset(new MemoryMappedFile());
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1002, &cfi_row));
EXPECT_EQ(kRow1, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1003, &cfi_row));
EXPECT_EQ(kRow1, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1008, &cfi_row));
EXPECT_EQ(kRow2, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1009, &cfi_row));
EXPECT_EQ(kRow2, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1039, &cfi_row));
EXPECT_EQ(kRow2, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1080, &cfi_row));
EXPECT_EQ(kRow3, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x1100, &cfi_row));
EXPECT_EQ(kRow3, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x2050, &cfi_row));
EXPECT_EQ(kRow4, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x2208, &cfi_row));
EXPECT_EQ(kRow5, cfi_row);
EXPECT_TRUE(unwinder->FindCFIRowForPC(0x2210, &cfi_row));
EXPECT_EQ(kRow5, cfi_row);
}
TEST(CFIBacktraceAndroidTest, TestCFICache) {
// Use ASSERT macros in this function since they are in loop and using EXPECT
// prints too many failures.
CFIBacktraceAndroid::CFICache cache;
CFIBacktraceAndroid::CFIRow cfi;
// Empty cache should not find anything.
EXPECT_FALSE(cache.Find(1, &cfi));
// Insert 1 - 2*kLimit
for (uintptr_t i = 1; i <= 2 * cache.kLimit; ++i) {
CFIBacktraceAndroid::CFIRow val = {static_cast<uint16_t>(4 * i),
static_cast<uint16_t>(2 * i)};
cache.Add(i, val);
ASSERT_TRUE(cache.Find(i, &cfi));
ASSERT_EQ(cfi, val);
// Inserting more than kLimit items evicts |i - cache.kLimit| from cache.
if (i >= cache.kLimit)
ASSERT_FALSE(cache.Find(i - cache.kLimit, &cfi));
}
// Cache contains kLimit+1 - 2*kLimit.
// Check that 1 - kLimit cannot be found.
for (uintptr_t i = 1; i <= cache.kLimit; ++i) {
ASSERT_FALSE(cache.Find(i, &cfi));
}
// Check if kLimit+1 - 2*kLimit still exists in cache.
for (uintptr_t i = cache.kLimit + 1; i <= 2 * cache.kLimit; ++i) {
CFIBacktraceAndroid::CFIRow val = {static_cast<uint16_t>(4 * i),
static_cast<uint16_t>(2 * i)};
ASSERT_TRUE(cache.Find(i, &cfi));
ASSERT_EQ(cfi, val);
}
// Insert 2*kLimit+1, will evict kLimit.
cfi = {1, 1};
cache.Add(2 * cache.kLimit + 1, cfi);
EXPECT_TRUE(cache.Find(2 * cache.kLimit + 1, &cfi));
EXPECT_FALSE(cache.Find(cache.kLimit + 1, &cfi));
// Cache contains kLimit+1 - 2*kLimit.
}
} // namespace trace_event
} // namespace base
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