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Diffstat (limited to 'third_party/abseil_cpp/absl/debugging/symbolize_test.cc')
| -rw-r--r-- | third_party/abseil_cpp/absl/debugging/symbolize_test.cc | 551 |
1 files changed, 551 insertions, 0 deletions
diff --git a/third_party/abseil_cpp/absl/debugging/symbolize_test.cc b/third_party/abseil_cpp/absl/debugging/symbolize_test.cc new file mode 100644 index 0000000000..a1d03aab53 --- /dev/null +++ b/third_party/abseil_cpp/absl/debugging/symbolize_test.cc @@ -0,0 +1,551 @@ +// Copyright 2018 The Abseil Authors. +// +// 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 +// +// https://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. + +#include "absl/debugging/symbolize.h" + +#ifndef _WIN32 +#include <fcntl.h> +#include <sys/mman.h> +#endif + +#include <cstring> +#include <iostream> +#include <memory> + +#include "gmock/gmock.h" +#include "gtest/gtest.h" +#include "absl/base/attributes.h" +#include "absl/base/casts.h" +#include "absl/base/internal/per_thread_tls.h" +#include "absl/base/internal/raw_logging.h" +#include "absl/base/optimization.h" +#include "absl/debugging/internal/stack_consumption.h" +#include "absl/memory/memory.h" + +using testing::Contains; + +#ifdef _WIN32 +#define ABSL_SYMBOLIZE_TEST_NOINLINE __declspec(noinline) +#else +#define ABSL_SYMBOLIZE_TEST_NOINLINE ABSL_ATTRIBUTE_NOINLINE +#endif + +// Functions to symbolize. Use C linkage to avoid mangled names. +extern "C" { +ABSL_SYMBOLIZE_TEST_NOINLINE void nonstatic_func() { + // The next line makes this a unique function to prevent the compiler from + // folding identical functions together. + volatile int x = __LINE__; + static_cast<void>(x); + ABSL_BLOCK_TAIL_CALL_OPTIMIZATION(); +} + +ABSL_SYMBOLIZE_TEST_NOINLINE static void static_func() { + // The next line makes this a unique function to prevent the compiler from + // folding identical functions together. + volatile int x = __LINE__; + static_cast<void>(x); + ABSL_BLOCK_TAIL_CALL_OPTIMIZATION(); +} +} // extern "C" + +struct Foo { + static void func(int x); +}; + +// A C++ method that should have a mangled name. +ABSL_SYMBOLIZE_TEST_NOINLINE void Foo::func(int) { + // The next line makes this a unique function to prevent the compiler from + // folding identical functions together. + volatile int x = __LINE__; + static_cast<void>(x); + ABSL_BLOCK_TAIL_CALL_OPTIMIZATION(); +} + +// Create functions that will remain in different text sections in the +// final binary when linker option "-z,keep-text-section-prefix" is used. +int ABSL_ATTRIBUTE_SECTION_VARIABLE(.text.unlikely) unlikely_func() { + return 0; +} + +int ABSL_ATTRIBUTE_SECTION_VARIABLE(.text.hot) hot_func() { + return 0; +} + +int ABSL_ATTRIBUTE_SECTION_VARIABLE(.text.startup) startup_func() { + return 0; +} + +int ABSL_ATTRIBUTE_SECTION_VARIABLE(.text.exit) exit_func() { + return 0; +} + +int /*ABSL_ATTRIBUTE_SECTION_VARIABLE(.text)*/ regular_func() { + return 0; +} + +// Thread-local data may confuse the symbolizer, ensure that it does not. +// Variable sizes and order are important. +#if ABSL_PER_THREAD_TLS +static ABSL_PER_THREAD_TLS_KEYWORD char symbolize_test_thread_small[1]; +static ABSL_PER_THREAD_TLS_KEYWORD char + symbolize_test_thread_big[2 * 1024 * 1024]; +#endif + +#if !defined(__EMSCRIPTEN__) +// Used below to hopefully inhibit some compiler/linker optimizations +// that may remove kHpageTextPadding, kPadding0, and kPadding1 from +// the binary. +static volatile bool volatile_bool = false; + +// Force the binary to be large enough that a THP .text remap will succeed. +static constexpr size_t kHpageSize = 1 << 21; +const char kHpageTextPadding[kHpageSize * 4] ABSL_ATTRIBUTE_SECTION_VARIABLE( + .text) = ""; +#endif // !defined(__EMSCRIPTEN__) + +static char try_symbolize_buffer[4096]; + +// A wrapper function for absl::Symbolize() to make the unit test simple. The +// limit must be < sizeof(try_symbolize_buffer). Returns null if +// absl::Symbolize() returns false, otherwise returns try_symbolize_buffer with +// the result of absl::Symbolize(). +static const char *TrySymbolizeWithLimit(void *pc, int limit) { + ABSL_RAW_CHECK(limit <= sizeof(try_symbolize_buffer), + "try_symbolize_buffer is too small"); + + // Use the heap to facilitate heap and buffer sanitizer tools. + auto heap_buffer = absl::make_unique<char[]>(sizeof(try_symbolize_buffer)); + bool found = absl::Symbolize(pc, heap_buffer.get(), limit); + if (found) { + ABSL_RAW_CHECK(strnlen(heap_buffer.get(), limit) < limit, + "absl::Symbolize() did not properly terminate the string"); + strncpy(try_symbolize_buffer, heap_buffer.get(), + sizeof(try_symbolize_buffer) - 1); + try_symbolize_buffer[sizeof(try_symbolize_buffer) - 1] = '\0'; + } + + return found ? try_symbolize_buffer : nullptr; +} + +// A wrapper for TrySymbolizeWithLimit(), with a large limit. +static const char *TrySymbolize(void *pc) { + return TrySymbolizeWithLimit(pc, sizeof(try_symbolize_buffer)); +} + +#ifdef ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE + +TEST(Symbolize, Cached) { + // Compilers should give us pointers to them. + EXPECT_STREQ("nonstatic_func", TrySymbolize((void *)(&nonstatic_func))); + + // The name of an internal linkage symbol is not specified; allow either a + // mangled or an unmangled name here. + const char *static_func_symbol = TrySymbolize((void *)(&static_func)); + EXPECT_TRUE(strcmp("static_func", static_func_symbol) == 0 || + strcmp("static_func()", static_func_symbol) == 0); + + EXPECT_TRUE(nullptr == TrySymbolize(nullptr)); +} + +TEST(Symbolize, Truncation) { + constexpr char kNonStaticFunc[] = "nonstatic_func"; + EXPECT_STREQ("nonstatic_func", + TrySymbolizeWithLimit((void *)(&nonstatic_func), + strlen(kNonStaticFunc) + 1)); + EXPECT_STREQ("nonstatic_...", + TrySymbolizeWithLimit((void *)(&nonstatic_func), + strlen(kNonStaticFunc) + 0)); + EXPECT_STREQ("nonstatic...", + TrySymbolizeWithLimit((void *)(&nonstatic_func), + strlen(kNonStaticFunc) - 1)); + EXPECT_STREQ("n...", TrySymbolizeWithLimit((void *)(&nonstatic_func), 5)); + EXPECT_STREQ("...", TrySymbolizeWithLimit((void *)(&nonstatic_func), 4)); + EXPECT_STREQ("..", TrySymbolizeWithLimit((void *)(&nonstatic_func), 3)); + EXPECT_STREQ(".", TrySymbolizeWithLimit((void *)(&nonstatic_func), 2)); + EXPECT_STREQ("", TrySymbolizeWithLimit((void *)(&nonstatic_func), 1)); + EXPECT_EQ(nullptr, TrySymbolizeWithLimit((void *)(&nonstatic_func), 0)); +} + +TEST(Symbolize, SymbolizeWithDemangling) { + Foo::func(100); + EXPECT_STREQ("Foo::func()", TrySymbolize((void *)(&Foo::func))); +} + +TEST(Symbolize, SymbolizeSplitTextSections) { + EXPECT_STREQ("unlikely_func()", TrySymbolize((void *)(&unlikely_func))); + EXPECT_STREQ("hot_func()", TrySymbolize((void *)(&hot_func))); + EXPECT_STREQ("startup_func()", TrySymbolize((void *)(&startup_func))); + EXPECT_STREQ("exit_func()", TrySymbolize((void *)(&exit_func))); + EXPECT_STREQ("regular_func()", TrySymbolize((void *)(®ular_func))); +} + +// Tests that verify that Symbolize stack footprint is within some limit. +#ifdef ABSL_INTERNAL_HAVE_DEBUGGING_STACK_CONSUMPTION + +static void *g_pc_to_symbolize; +static char g_symbolize_buffer[4096]; +static char *g_symbolize_result; + +static void SymbolizeSignalHandler(int signo) { + if (absl::Symbolize(g_pc_to_symbolize, g_symbolize_buffer, + sizeof(g_symbolize_buffer))) { + g_symbolize_result = g_symbolize_buffer; + } else { + g_symbolize_result = nullptr; + } +} + +// Call Symbolize and figure out the stack footprint of this call. +static const char *SymbolizeStackConsumption(void *pc, int *stack_consumed) { + g_pc_to_symbolize = pc; + *stack_consumed = absl::debugging_internal::GetSignalHandlerStackConsumption( + SymbolizeSignalHandler); + return g_symbolize_result; +} + +static int GetStackConsumptionUpperLimit() { + // Symbolize stack consumption should be within 2kB. + int stack_consumption_upper_limit = 2048; +#if defined(ADDRESS_SANITIZER) || defined(MEMORY_SANITIZER) || \ + defined(THREAD_SANITIZER) + // Account for sanitizer instrumentation requiring additional stack space. + stack_consumption_upper_limit *= 5; +#endif + return stack_consumption_upper_limit; +} + +TEST(Symbolize, SymbolizeStackConsumption) { + int stack_consumed = 0; + + const char *symbol = + SymbolizeStackConsumption((void *)(&nonstatic_func), &stack_consumed); + EXPECT_STREQ("nonstatic_func", symbol); + EXPECT_GT(stack_consumed, 0); + EXPECT_LT(stack_consumed, GetStackConsumptionUpperLimit()); + + // The name of an internal linkage symbol is not specified; allow either a + // mangled or an unmangled name here. + symbol = SymbolizeStackConsumption((void *)(&static_func), &stack_consumed); + EXPECT_TRUE(strcmp("static_func", symbol) == 0 || + strcmp("static_func()", symbol) == 0); + EXPECT_GT(stack_consumed, 0); + EXPECT_LT(stack_consumed, GetStackConsumptionUpperLimit()); +} + +TEST(Symbolize, SymbolizeWithDemanglingStackConsumption) { + Foo::func(100); + int stack_consumed = 0; + + const char *symbol = + SymbolizeStackConsumption((void *)(&Foo::func), &stack_consumed); + + EXPECT_STREQ("Foo::func()", symbol); + EXPECT_GT(stack_consumed, 0); + EXPECT_LT(stack_consumed, GetStackConsumptionUpperLimit()); +} + +#endif // ABSL_INTERNAL_HAVE_DEBUGGING_STACK_CONSUMPTION + +// Use a 64K page size for PPC. +const size_t kPageSize = 64 << 10; +// We place a read-only symbols into the .text section and verify that we can +// symbolize them and other symbols after remapping them. +const char kPadding0[kPageSize * 4] ABSL_ATTRIBUTE_SECTION_VARIABLE(.text) = + ""; +const char kPadding1[kPageSize * 4] ABSL_ATTRIBUTE_SECTION_VARIABLE(.text) = + ""; + +static int FilterElfHeader(struct dl_phdr_info *info, size_t size, void *data) { + for (int i = 0; i < info->dlpi_phnum; i++) { + if (info->dlpi_phdr[i].p_type == PT_LOAD && + info->dlpi_phdr[i].p_flags == (PF_R | PF_X)) { + const void *const vaddr = + absl::bit_cast<void *>(info->dlpi_addr + info->dlpi_phdr[i].p_vaddr); + const auto segsize = info->dlpi_phdr[i].p_memsz; + + const char *self_exe; + if (info->dlpi_name != nullptr && info->dlpi_name[0] != '\0') { + self_exe = info->dlpi_name; + } else { + self_exe = "/proc/self/exe"; + } + + absl::debugging_internal::RegisterFileMappingHint( + vaddr, reinterpret_cast<const char *>(vaddr) + segsize, + info->dlpi_phdr[i].p_offset, self_exe); + + return 1; + } + } + + return 1; +} + +TEST(Symbolize, SymbolizeWithMultipleMaps) { + // Force kPadding0 and kPadding1 to be linked in. + if (volatile_bool) { + ABSL_RAW_LOG(INFO, "%s", kPadding0); + ABSL_RAW_LOG(INFO, "%s", kPadding1); + } + + // Verify we can symbolize everything. + char buf[512]; + memset(buf, 0, sizeof(buf)); + absl::Symbolize(kPadding0, buf, sizeof(buf)); + EXPECT_STREQ("kPadding0", buf); + + memset(buf, 0, sizeof(buf)); + absl::Symbolize(kPadding1, buf, sizeof(buf)); + EXPECT_STREQ("kPadding1", buf); + + // Specify a hint for the executable segment. + dl_iterate_phdr(FilterElfHeader, nullptr); + + // Reload at least one page out of kPadding0, kPadding1 + const char *ptrs[] = {kPadding0, kPadding1}; + + for (const char *ptr : ptrs) { + const int kMapFlags = MAP_ANONYMOUS | MAP_PRIVATE; + void *addr = mmap(nullptr, kPageSize, PROT_READ, kMapFlags, 0, 0); + ASSERT_NE(addr, MAP_FAILED); + + // kPadding[0-1] is full of zeroes, so we can remap anywhere within it, but + // we ensure there is at least a full page of padding. + void *remapped = reinterpret_cast<void *>( + reinterpret_cast<uintptr_t>(ptr + kPageSize) & ~(kPageSize - 1ULL)); + + const int kMremapFlags = (MREMAP_MAYMOVE | MREMAP_FIXED); + void *ret = mremap(addr, kPageSize, kPageSize, kMremapFlags, remapped); + ASSERT_NE(ret, MAP_FAILED); + } + + // Invalidate the symbolization cache so we are forced to rely on the hint. + absl::Symbolize(nullptr, buf, sizeof(buf)); + + // Verify we can still symbolize. + const char *expected[] = {"kPadding0", "kPadding1"}; + const size_t offsets[] = {0, kPageSize, 2 * kPageSize, 3 * kPageSize}; + + for (int i = 0; i < 2; i++) { + for (size_t offset : offsets) { + memset(buf, 0, sizeof(buf)); + absl::Symbolize(ptrs[i] + offset, buf, sizeof(buf)); + EXPECT_STREQ(expected[i], buf); + } + } +} + +// Appends string(*args->arg) to args->symbol_buf. +static void DummySymbolDecorator( + const absl::debugging_internal::SymbolDecoratorArgs *args) { + std::string *message = static_cast<std::string *>(args->arg); + strncat(args->symbol_buf, message->c_str(), + args->symbol_buf_size - strlen(args->symbol_buf) - 1); +} + +TEST(Symbolize, InstallAndRemoveSymbolDecorators) { + int ticket_a; + std::string a_message("a"); + EXPECT_GE(ticket_a = absl::debugging_internal::InstallSymbolDecorator( + DummySymbolDecorator, &a_message), + 0); + + int ticket_b; + std::string b_message("b"); + EXPECT_GE(ticket_b = absl::debugging_internal::InstallSymbolDecorator( + DummySymbolDecorator, &b_message), + 0); + + int ticket_c; + std::string c_message("c"); + EXPECT_GE(ticket_c = absl::debugging_internal::InstallSymbolDecorator( + DummySymbolDecorator, &c_message), + 0); + + char *address = reinterpret_cast<char *>(1); + EXPECT_STREQ("abc", TrySymbolize(address++)); + + EXPECT_TRUE(absl::debugging_internal::RemoveSymbolDecorator(ticket_b)); + + EXPECT_STREQ("ac", TrySymbolize(address++)); + + // Cleanup: remove all remaining decorators so other stack traces don't + // get mystery "ac" decoration. + EXPECT_TRUE(absl::debugging_internal::RemoveSymbolDecorator(ticket_a)); + EXPECT_TRUE(absl::debugging_internal::RemoveSymbolDecorator(ticket_c)); +} + +// Some versions of Clang with optimizations enabled seem to be able +// to optimize away the .data section if no variables live in the +// section. This variable should get placed in the .data section, and +// the test below checks for the existence of a .data section. +static int in_data_section = 1; + +TEST(Symbolize, ForEachSection) { + int fd = TEMP_FAILURE_RETRY(open("/proc/self/exe", O_RDONLY)); + ASSERT_NE(fd, -1); + + std::vector<std::string> sections; + ASSERT_TRUE(absl::debugging_internal::ForEachSection( + fd, [§ions](const std::string &name, const ElfW(Shdr) &) { + sections.push_back(name); + return true; + })); + + // Check for the presence of common section names. + EXPECT_THAT(sections, Contains(".text")); + EXPECT_THAT(sections, Contains(".rodata")); + EXPECT_THAT(sections, Contains(".bss")); + ++in_data_section; + EXPECT_THAT(sections, Contains(".data")); + + close(fd); +} + +// x86 specific tests. Uses some inline assembler. +extern "C" { +inline void *ABSL_ATTRIBUTE_ALWAYS_INLINE inline_func() { + void *pc = nullptr; +#if defined(__i386__) + __asm__ __volatile__("call 1f;\n 1: pop %[PC]" : [ PC ] "=r"(pc)); +#elif defined(__x86_64__) + __asm__ __volatile__("leaq 0(%%rip),%[PC];\n" : [ PC ] "=r"(pc)); +#endif + return pc; +} + +void *ABSL_ATTRIBUTE_NOINLINE non_inline_func() { + void *pc = nullptr; +#if defined(__i386__) + __asm__ __volatile__("call 1f;\n 1: pop %[PC]" : [ PC ] "=r"(pc)); +#elif defined(__x86_64__) + __asm__ __volatile__("leaq 0(%%rip),%[PC];\n" : [ PC ] "=r"(pc)); +#endif + return pc; +} + +void ABSL_ATTRIBUTE_NOINLINE TestWithPCInsideNonInlineFunction() { +#if defined(ABSL_HAVE_ATTRIBUTE_NOINLINE) && \ + (defined(__i386__) || defined(__x86_64__)) + void *pc = non_inline_func(); + const char *symbol = TrySymbolize(pc); + ABSL_RAW_CHECK(symbol != nullptr, "TestWithPCInsideNonInlineFunction failed"); + ABSL_RAW_CHECK(strcmp(symbol, "non_inline_func") == 0, + "TestWithPCInsideNonInlineFunction failed"); + std::cout << "TestWithPCInsideNonInlineFunction passed" << std::endl; +#endif +} + +void ABSL_ATTRIBUTE_NOINLINE TestWithPCInsideInlineFunction() { +#if defined(ABSL_HAVE_ATTRIBUTE_ALWAYS_INLINE) && \ + (defined(__i386__) || defined(__x86_64__)) + void *pc = inline_func(); // Must be inlined. + const char *symbol = TrySymbolize(pc); + ABSL_RAW_CHECK(symbol != nullptr, "TestWithPCInsideInlineFunction failed"); + ABSL_RAW_CHECK(strcmp(symbol, __FUNCTION__) == 0, + "TestWithPCInsideInlineFunction failed"); + std::cout << "TestWithPCInsideInlineFunction passed" << std::endl; +#endif +} +} + +// Test with a return address. +void ABSL_ATTRIBUTE_NOINLINE TestWithReturnAddress() { +#if defined(ABSL_HAVE_ATTRIBUTE_NOINLINE) + void *return_address = __builtin_return_address(0); + const char *symbol = TrySymbolize(return_address); + ABSL_RAW_CHECK(symbol != nullptr, "TestWithReturnAddress failed"); + ABSL_RAW_CHECK(strcmp(symbol, "main") == 0, "TestWithReturnAddress failed"); + std::cout << "TestWithReturnAddress passed" << std::endl; +#endif +} + +#elif defined(_WIN32) +#if !defined(ABSL_CONSUME_DLL) + +TEST(Symbolize, Basics) { + EXPECT_STREQ("nonstatic_func", TrySymbolize((void *)(&nonstatic_func))); + + // The name of an internal linkage symbol is not specified; allow either a + // mangled or an unmangled name here. + const char *static_func_symbol = TrySymbolize((void *)(&static_func)); + ASSERT_TRUE(static_func_symbol != nullptr); + EXPECT_TRUE(strstr(static_func_symbol, "static_func") != nullptr); + + EXPECT_TRUE(nullptr == TrySymbolize(nullptr)); +} + +TEST(Symbolize, Truncation) { + constexpr char kNonStaticFunc[] = "nonstatic_func"; + EXPECT_STREQ("nonstatic_func", + TrySymbolizeWithLimit((void *)(&nonstatic_func), + strlen(kNonStaticFunc) + 1)); + EXPECT_STREQ("nonstatic_...", + TrySymbolizeWithLimit((void *)(&nonstatic_func), + strlen(kNonStaticFunc) + 0)); + EXPECT_STREQ("nonstatic...", + TrySymbolizeWithLimit((void *)(&nonstatic_func), + strlen(kNonStaticFunc) - 1)); + EXPECT_STREQ("n...", TrySymbolizeWithLimit((void *)(&nonstatic_func), 5)); + EXPECT_STREQ("...", TrySymbolizeWithLimit((void *)(&nonstatic_func), 4)); + EXPECT_STREQ("..", TrySymbolizeWithLimit((void *)(&nonstatic_func), 3)); + EXPECT_STREQ(".", TrySymbolizeWithLimit((void *)(&nonstatic_func), 2)); + EXPECT_STREQ("", TrySymbolizeWithLimit((void *)(&nonstatic_func), 1)); + EXPECT_EQ(nullptr, TrySymbolizeWithLimit((void *)(&nonstatic_func), 0)); +} + +TEST(Symbolize, SymbolizeWithDemangling) { + const char *result = TrySymbolize((void *)(&Foo::func)); + ASSERT_TRUE(result != nullptr); + EXPECT_TRUE(strstr(result, "Foo::func") != nullptr) << result; +} + +#endif // !defined(ABSL_CONSUME_DLL) +#else // Symbolizer unimplemented + +TEST(Symbolize, Unimplemented) { + char buf[64]; + EXPECT_FALSE(absl::Symbolize((void *)(&nonstatic_func), buf, sizeof(buf))); + EXPECT_FALSE(absl::Symbolize((void *)(&static_func), buf, sizeof(buf))); + EXPECT_FALSE(absl::Symbolize((void *)(&Foo::func), buf, sizeof(buf))); +} + +#endif + +int main(int argc, char **argv) { +#if !defined(__EMSCRIPTEN__) + // Make sure kHpageTextPadding is linked into the binary. + if (volatile_bool) { + ABSL_RAW_LOG(INFO, "%s", kHpageTextPadding); + } +#endif // !defined(__EMSCRIPTEN__) + +#if ABSL_PER_THREAD_TLS + // Touch the per-thread variables. + symbolize_test_thread_small[0] = 0; + symbolize_test_thread_big[0] = 0; +#endif + + absl::InitializeSymbolizer(argv[0]); + testing::InitGoogleTest(&argc, argv); + +#ifdef ABSL_INTERNAL_HAVE_ELF_SYMBOLIZE + TestWithPCInsideInlineFunction(); + TestWithPCInsideNonInlineFunction(); + TestWithReturnAddress(); +#endif + + return RUN_ALL_TESTS(); +} |