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Diffstat (limited to 'src/processor/stackwalker_mips_unittest.cc')
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diff --git a/src/processor/stackwalker_mips_unittest.cc b/src/processor/stackwalker_mips_unittest.cc new file mode 100644 index 00000000..ed4be4f5 --- /dev/null +++ b/src/processor/stackwalker_mips_unittest.cc @@ -0,0 +1,697 @@ +// Copyright (c) 2013, Google Inc. +// All rights reserved. +// +// Redistribution and use in source and binary forms, with or without +// modification, are permitted provided that the following conditions are +// met: +// +// * Redistributions of source code must retain the above copyright +// notice, this list of conditions and the following disclaimer. +// * Redistributions in binary form must reproduce the above +// copyright notice, this list of conditions and the following disclaimer +// in the documentation and/or other materials provided with the +// distribution. +// * Neither the name of Google Inc. nor the names of its +// contributors may be used to endorse or promote products derived from +// this software without specific prior written permission. +// +// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR +// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT +// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, +// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT +// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, +// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY +// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT +// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE +// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + +// Original author: Gordana Cmiljanovic <gordana.cmiljanovic@imgtec.com> + +// stackwalker_mips_unittest.cc: Unit tests for StackwalkerMIPS class. + +#include <string.h> +#include <string> +#include <vector> + +#include "breakpad_googletest_includes.h" +#include "common/test_assembler.h" +#include "common/using_std_string.h" +#include "google_breakpad/common/minidump_format.h" +#include "google_breakpad/processor/basic_source_line_resolver.h" +#include "google_breakpad/processor/call_stack.h" +#include "google_breakpad/processor/code_module.h" +#include "google_breakpad/processor/source_line_resolver_interface.h" +#include "google_breakpad/processor/stack_frame_cpu.h" +#include "processor/stackwalker_unittest_utils.h" +#include "processor/stackwalker_mips.h" +#include "processor/windows_frame_info.h" + +using google_breakpad::BasicSourceLineResolver; +using google_breakpad::CallStack; +using google_breakpad::CodeModule; +using google_breakpad::StackFrameSymbolizer; +using google_breakpad::StackFrame; +using google_breakpad::StackFrameMIPS; +using google_breakpad::Stackwalker; +using google_breakpad::StackwalkerMIPS; +using google_breakpad::SystemInfo; +using google_breakpad::WindowsFrameInfo; +using google_breakpad::test_assembler::kLittleEndian; +using google_breakpad::test_assembler::Label; +using google_breakpad::test_assembler::Section; +using std::vector; +using testing::_; +using testing::AnyNumber; +using testing::Return; +using testing::SetArgumentPointee; +using testing::Test; + +class StackwalkerMIPSFixture { + public: + StackwalkerMIPSFixture() + : stack_section(kLittleEndian), + // Give the two modules reasonable standard locations and names + // for tests to play with. + module1(0x00400000, 0x10000, "module1", "version1"), + module2(0x00500000, 0x10000, "module2", "version2") { + // Identify the system as a Linux system. + system_info.os = "Linux"; + system_info.os_short = "linux"; + system_info.os_version = "Observant Opossum"; // Jealous Jellyfish + system_info.cpu = "mips"; + system_info.cpu_info = ""; + + // Put distinctive values in the raw CPU context. + BrandContext(&raw_context); + + // Create some modules with some stock debugging information. + modules.Add(&module1); + modules.Add(&module2); + + // By default, none of the modules have symbol info; call + // SetModuleSymbols to override this. + EXPECT_CALL(supplier, GetCStringSymbolData(_, _, _, _, _)) + .WillRepeatedly(Return(MockSymbolSupplier::NOT_FOUND)); + + // Avoid GMOCK WARNING "Uninteresting mock function call - returning + // directly" for FreeSymbolData(). + EXPECT_CALL(supplier, FreeSymbolData(_)).Times(AnyNumber()); + + // Reset max_frames_scanned since it's static. + Stackwalker::set_max_frames_scanned(1024); + } + + // Set the Breakpad symbol information that supplier should return for + // MODULE to INFO. + void SetModuleSymbols(MockCodeModule* module, const string& info) { + size_t buffer_size; + char* buffer = supplier.CopySymbolDataAndOwnTheCopy(info, &buffer_size); + EXPECT_CALL(supplier, GetCStringSymbolData(module, &system_info, _, _, _)) + .WillRepeatedly(DoAll(SetArgumentPointee<3>(buffer), + SetArgumentPointee<4>(buffer_size), + Return(MockSymbolSupplier::FOUND))); + } + + // Populate stack_region with the contents of stack_section. Use + // stack_section.start() as the region's starting address. + void RegionFromSection() { + string contents; + ASSERT_TRUE(stack_section.GetContents(&contents)); + stack_region.Init(stack_section.start().Value(), contents); + } + + // Fill RAW_CONTEXT with pseudo-random data, for round-trip checking. + void BrandContext(MDRawContextMIPS* raw_context) { + uint8_t x = 173; + for (size_t i = 0; i < sizeof(*raw_context); ++i) + reinterpret_cast<uint8_t*>(raw_context)[i] = (x += 17); + } + + SystemInfo system_info; + MDRawContextMIPS raw_context; + Section stack_section; + MockMemoryRegion stack_region; + MockCodeModule module1; + MockCodeModule module2; + MockCodeModules modules; + MockSymbolSupplier supplier; + BasicSourceLineResolver resolver; + CallStack call_stack; + const vector<StackFrame*>* frames; +}; + +class SanityCheck: public StackwalkerMIPSFixture, public Test { }; + +TEST_F(SanityCheck, NoResolver) { + stack_section.start() = 0x80000000; + stack_section.D32(0).D32(0x0); + RegionFromSection(); + raw_context.epc = 0x00400020; + raw_context.iregs[MD_CONTEXT_MIPS_REG_SP] = 0x80000000; + + StackFrameSymbolizer frame_symbolizer(NULL, NULL); + StackwalkerMIPS walker(&system_info, &raw_context, &stack_region, &modules, + &frame_symbolizer); + // This should succeed, even without a resolver or supplier. + vector<const CodeModule*> modules_without_symbols; + vector<const CodeModule*> modules_with_corrupt_symbols; + ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols, + &modules_with_corrupt_symbols)); + ASSERT_EQ(1U, modules_without_symbols.size()); + ASSERT_EQ("module1", modules_without_symbols[0]->debug_file()); + ASSERT_EQ(0U, modules_with_corrupt_symbols.size()); + frames = call_stack.frames(); + ASSERT_EQ(1U, frames->size()); + StackFrameMIPS* frame = static_cast<StackFrameMIPS*>(frames->at(0)); + // Check that the values from the original raw context made it + // through to the context in the stack frame. + EXPECT_EQ(0, memcmp(&raw_context, &frame->context, sizeof(raw_context))); +} + +class GetContextFrame: public StackwalkerMIPSFixture, public Test { }; + +TEST_F(GetContextFrame, Simple) { + stack_section.start() = 0x80000000; + stack_section.D32(0).D32(0x0); + RegionFromSection(); + raw_context.epc = 0x00400020; + raw_context.iregs[MD_CONTEXT_MIPS_REG_SP] = 0x80000000; + + StackFrameSymbolizer frame_symbolizer(&supplier, &resolver); + StackwalkerMIPS walker(&system_info, &raw_context, &stack_region, &modules, + &frame_symbolizer); + vector<const CodeModule*> modules_without_symbols; + vector<const CodeModule*> modules_with_corrupt_symbols; + ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols, + &modules_with_corrupt_symbols)); + ASSERT_EQ(1U, modules_without_symbols.size()); + ASSERT_EQ("module1", modules_without_symbols[0]->debug_file()); + ASSERT_EQ(0U, modules_with_corrupt_symbols.size()); + frames = call_stack.frames(); + StackFrameMIPS* frame = static_cast<StackFrameMIPS*>(frames->at(0)); + // Check that the values from the original raw context made it + // through to the context in the stack frame. + EXPECT_EQ(0, memcmp(&raw_context, &frame->context, sizeof(raw_context))); +} + +// The stackwalker should be able to produce the context frame even +// without stack memory present. +TEST_F(GetContextFrame, NoStackMemory) { + raw_context.epc = 0x00400020; + raw_context.iregs[MD_CONTEXT_MIPS_REG_SP] = 0x80000000; + + StackFrameSymbolizer frame_symbolizer(&supplier, &resolver); + StackwalkerMIPS walker(&system_info, &raw_context, NULL, &modules, + &frame_symbolizer); + vector<const CodeModule*> modules_without_symbols; + vector<const CodeModule*> modules_with_corrupt_symbols; + ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols, + &modules_with_corrupt_symbols)); + ASSERT_EQ(1U, modules_without_symbols.size()); + ASSERT_EQ("module1", modules_without_symbols[0]->debug_file()); + ASSERT_EQ(0U, modules_with_corrupt_symbols.size()); + frames = call_stack.frames(); + StackFrameMIPS* frame = static_cast<StackFrameMIPS*>(frames->at(0)); + // Check that the values from the original raw context made it + // through to the context in the stack frame. + EXPECT_EQ(0, memcmp(&raw_context, &frame->context, sizeof(raw_context))); +} + +class GetCallerFrame: public StackwalkerMIPSFixture, public Test { }; + +TEST_F(GetCallerFrame, ScanWithoutSymbols) { + // When the stack walker resorts to scanning the stack, + // only addresses located within loaded modules are + // considered valid return addresses. + // Force scanning through three frames to ensure that the + // stack pointer is set properly in scan-recovered frames. + stack_section.start() = 0x80000000; + uint32_t return_address1 = 0x00400100; + uint32_t return_address2 = 0x00400900; + Label frame1_sp, frame2_sp; + stack_section + // frame 0 + .Append(16, 0) // space + + .D32(0x00490000) // junk that's not + .D32(0x00600000) // a return address + + .D32(frame1_sp) // stack pointer + .D32(return_address1) // actual return address + // frame 1 + .Mark(&frame1_sp) + .Append(16, 0) // space + + .D32(0xF0000000) // more junk + .D32(0x0000000D) + + .D32(frame2_sp) // stack pointer + .D32(return_address2) // actual return address + // frame 2 + .Mark(&frame2_sp) + .Append(32, 0); // end of stack + RegionFromSection(); + + raw_context.epc = 0x00405510; + raw_context.iregs[MD_CONTEXT_MIPS_REG_SP] = stack_section.start().Value(); + raw_context.iregs[MD_CONTEXT_MIPS_REG_RA] = return_address1; + + StackFrameSymbolizer frame_symbolizer(&supplier, &resolver); + StackwalkerMIPS walker(&system_info, &raw_context, &stack_region, &modules, + &frame_symbolizer); + vector<const CodeModule*> modules_without_symbols; + vector<const CodeModule*> modules_with_corrupt_symbols; + ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols, + &modules_with_corrupt_symbols)); + ASSERT_EQ(1U, modules_without_symbols.size()); + ASSERT_EQ("module1", modules_without_symbols[0]->debug_file()); + ASSERT_EQ(0U, modules_with_corrupt_symbols.size()); + frames = call_stack.frames(); + ASSERT_EQ(3U, frames->size()); + + StackFrameMIPS* frame0 = static_cast<StackFrameMIPS*>(frames->at(0)); + EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust); + ASSERT_EQ(StackFrameMIPS::CONTEXT_VALID_ALL, frame0->context_validity); + EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context))); + + StackFrameMIPS* frame1 = static_cast<StackFrameMIPS*>(frames->at(1)); + EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame1->trust); + ASSERT_EQ((StackFrameMIPS::CONTEXT_VALID_PC | + StackFrameMIPS::CONTEXT_VALID_SP | + StackFrameMIPS::CONTEXT_VALID_FP | + StackFrameMIPS::CONTEXT_VALID_RA), + frame1->context_validity); + EXPECT_EQ(return_address1 - 2 * sizeof(return_address1), frame1->context.epc); + EXPECT_EQ(frame1_sp.Value(), frame1->context.iregs[MD_CONTEXT_MIPS_REG_SP]); + + StackFrameMIPS* frame2 = static_cast<StackFrameMIPS*>(frames->at(2)); + EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame2->trust); + ASSERT_EQ((StackFrameMIPS::CONTEXT_VALID_PC | + StackFrameMIPS::CONTEXT_VALID_SP | + StackFrameMIPS::CONTEXT_VALID_FP | + StackFrameMIPS::CONTEXT_VALID_RA), + frame2->context_validity); + EXPECT_EQ(return_address2 - 2 * sizeof(return_address2), frame2->context.epc); + EXPECT_EQ(frame2_sp.Value(), frame2->context.iregs[MD_CONTEXT_MIPS_REG_SP]); +} + +TEST_F(GetCallerFrame, ScanWithFunctionSymbols) { + // During stack scanning, if a potential return address + // is located within a loaded module that has symbols, + // it is only considered a valid return address if it + // lies within a function's bounds. + stack_section.start() = 0x80000000; + uint32_t return_address = 0x00500200; + Label frame1_sp; + stack_section + // frame 0 + .Append(16, 0) // space + + .D32(0x00490000) // junk that's not + .D32(0x00600000) // a return address + + .D32(0x00401000) // a couple of plausible addresses + .D32(0x0050F000) // that are not within functions + + .D32(frame1_sp) // stack pointer + .D32(return_address) // actual return address + // frame 1 + .Mark(&frame1_sp) + .Append(32, 0); // end of stack + RegionFromSection(); + + raw_context.epc = 0x00400200; + raw_context.iregs[MD_CONTEXT_MIPS_REG_SP] = stack_section.start().Value(); + raw_context.iregs[MD_CONTEXT_MIPS_REG_RA] = return_address; + + SetModuleSymbols(&module1, + // The youngest frame's function. + "FUNC 100 400 10 monotreme\n"); + SetModuleSymbols(&module2, + // The calling frame's function. + "FUNC 100 400 10 marsupial\n"); + + StackFrameSymbolizer frame_symbolizer(&supplier, &resolver); + StackwalkerMIPS walker(&system_info, &raw_context, &stack_region, &modules, + &frame_symbolizer); + vector<const CodeModule*> modules_without_symbols; + vector<const CodeModule*> modules_with_corrupt_symbols; + ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols, + &modules_with_corrupt_symbols)); + ASSERT_EQ(0U, modules_without_symbols.size()); + ASSERT_EQ(0U, modules_with_corrupt_symbols.size()); + frames = call_stack.frames(); + ASSERT_EQ(2U, frames->size()); + + StackFrameMIPS* frame0 = static_cast<StackFrameMIPS*>(frames->at(0)); + EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust); + ASSERT_EQ(StackFrameMIPS::CONTEXT_VALID_ALL, frame0->context_validity); + EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context))); + EXPECT_EQ("monotreme", frame0->function_name); + EXPECT_EQ(0x00400100U, frame0->function_base); + + StackFrameMIPS* frame1 = static_cast<StackFrameMIPS*>(frames->at(1)); + EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame1->trust); + ASSERT_EQ((StackFrameMIPS::CONTEXT_VALID_PC | + StackFrameMIPS::CONTEXT_VALID_SP | + StackFrameMIPS::CONTEXT_VALID_FP | + StackFrameMIPS::CONTEXT_VALID_RA), + frame1->context_validity); + EXPECT_EQ(return_address - 2 * sizeof(return_address), frame1->context.epc); + EXPECT_EQ(frame1_sp.Value(), frame1->context.iregs[MD_CONTEXT_MIPS_REG_SP]); + EXPECT_EQ("marsupial", frame1->function_name); + EXPECT_EQ(0x00500100U, frame1->function_base); +} + +TEST_F(GetCallerFrame, CheckStackFrameSizeLimit) { + // If the stackwalker resorts to stack scanning, it will scan only + // 1024 bytes of stack which correspondes to maximum size of stack frame. + stack_section.start() = 0x80000000; + uint32_t return_address1 = 0x00500100; + uint32_t return_address2 = 0x00500900; + Label frame1_sp, frame2_sp; + stack_section + // frame 0 + .Append(32, 0) // space + + .D32(0x00490000) // junk that's not + .D32(0x00600000) // a return address + + .Append(96, 0) // more space + + .D32(frame1_sp) // stack pointer + .D32(return_address1) // actual return address + // frame 1 + .Mark(&frame1_sp) + .Append(128 * 4, 0) // space + + .D32(0x00F00000) // more junk + .D32(0x0000000D) + + .Append(128 * 4, 0) // more space + + .D32(frame2_sp) // stack pointer + .D32(return_address2) // actual return address + // (won't be found) + // frame 2 + .Mark(&frame2_sp) + .Append(32, 0); // end of stack + RegionFromSection(); + + raw_context.epc = 0x00405510; + raw_context.iregs[MD_CONTEXT_MIPS_REG_SP] = stack_section.start().Value(); + raw_context.iregs[MD_CONTEXT_MIPS_REG_RA] = return_address1; + + StackFrameSymbolizer frame_symbolizer(&supplier, &resolver); + StackwalkerMIPS walker(&system_info, &raw_context, &stack_region, &modules, + &frame_symbolizer); + vector<const CodeModule*> modules_without_symbols; + vector<const CodeModule*> modules_with_corrupt_symbols; + ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols, + &modules_with_corrupt_symbols)); + ASSERT_EQ(2U, modules_without_symbols.size()); + ASSERT_EQ("module1", modules_without_symbols[0]->debug_file()); + ASSERT_EQ("module2", modules_without_symbols[1]->debug_file()); + ASSERT_EQ(0U, modules_with_corrupt_symbols.size()); + frames = call_stack.frames(); + ASSERT_EQ(2U, frames->size()); + + StackFrameMIPS* frame0 = static_cast<StackFrameMIPS*>(frames->at(0)); + EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust); + ASSERT_EQ(StackFrameMIPS::CONTEXT_VALID_ALL, frame0->context_validity); + EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context))); + + StackFrameMIPS* frame1 = static_cast<StackFrameMIPS*>(frames->at(1)); + EXPECT_EQ(StackFrame::FRAME_TRUST_SCAN, frame1->trust); + ASSERT_EQ((StackFrameMIPS::CONTEXT_VALID_PC | + StackFrameMIPS::CONTEXT_VALID_SP | + StackFrameMIPS::CONTEXT_VALID_FP | + StackFrameMIPS::CONTEXT_VALID_RA), + frame1->context_validity); + EXPECT_EQ(return_address1 - 2 * sizeof(return_address1), frame1->context.epc); + EXPECT_EQ(frame1_sp.Value(), frame1->context.iregs[MD_CONTEXT_MIPS_REG_SP]); +} + +// Test that set_max_frames_scanned prevents using stack scanning +// to find caller frames. +TEST_F(GetCallerFrame, ScanningNotAllowed) { + // When the stack walker resorts to scanning the stack, + // only fixed number of frames are allowed to be scanned out from stack + stack_section.start() = 0x80000000; + uint32_t return_address1 = 0x00500100; + uint32_t return_address2 = 0x00500900; + Label frame1_sp, frame2_sp; + stack_section + // frame 0 + .Append(32, 0) // space + + .D32(0x00490000) // junk that's not + .D32(0x00600000) // a return address + + .Append(96, 0) // more space + + .D32(frame1_sp) // stack pointer + .D32(return_address1) // actual return address + // frame 1 + .Mark(&frame1_sp) + .Append(128 * 4, 0) // space + + .D32(0x00F00000) // more junk + .D32(0x0000000D) + + .Append(128 * 4, 0) // more space + + .D32(frame2_sp) // stack pointer + .D32(return_address2) // actual return address + // (won't be found) + // frame 2 + .Mark(&frame2_sp) + .Append(32, 0); // end of stack + RegionFromSection(); + + raw_context.epc = 0x00405510; + raw_context.iregs[MD_CONTEXT_MIPS_REG_SP] = stack_section.start().Value(); + raw_context.iregs[MD_CONTEXT_MIPS_REG_RA] = return_address1; + + StackFrameSymbolizer frame_symbolizer(&supplier, &resolver); + StackwalkerMIPS walker(&system_info, &raw_context, &stack_region, &modules, + &frame_symbolizer); + Stackwalker::set_max_frames_scanned(0); + + vector<const CodeModule*> modules_without_symbols; + vector<const CodeModule*> modules_with_corrupt_symbols; + ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols, + &modules_with_corrupt_symbols)); + ASSERT_EQ(1U, modules_without_symbols.size()); + ASSERT_EQ("module1", modules_without_symbols[0]->debug_file()); + ASSERT_EQ(0U, modules_with_corrupt_symbols.size()); + frames = call_stack.frames(); + ASSERT_EQ(1U, frames->size()); + + StackFrameMIPS* frame0 = static_cast<StackFrameMIPS*>(frames->at(0)); + EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust); + ASSERT_EQ(StackFrameMIPS::CONTEXT_VALID_ALL, frame0->context_validity); + EXPECT_EQ(0, memcmp(&raw_context, &frame0->context, sizeof(raw_context))); +} + +struct CFIFixture: public StackwalkerMIPSFixture { + CFIFixture() { + // Provide some STACK CFI records; + SetModuleSymbols(&module1, + // The youngest frame's function. + "FUNC 4000 1000 0 enchiridion\n" + // Initially, nothing has been pushed on the stack, + // and the return address is still in the $ra register. + "STACK CFI INIT 4000 1000 .cfa: $sp 0 + .ra: $ra\n" + // Move stack pointer. + "STACK CFI 4004 .cfa: $sp 32 +\n" + // store $fp and ra + "STACK CFI 4008 $fp: .cfa -8 + ^ .ra: .cfa -4 + ^\n" + // restore $fp + "STACK CFI 400c .cfa: $fp 32 +\n" + // restore $sp + "STACK CFI 4018 .cfa: $sp 32 +\n" + + "STACK CFI 4020 $fp: $fp .cfa: $sp 0 + .ra: .ra\n" + + // The calling function. + "FUNC 5000 1000 0 epictetus\n" + // Initially, nothing has been pushed on the stack, + // and the return address is still in the $ra register. + "STACK CFI INIT 5000 1000 .cfa: $sp .ra: $ra\n" + // Mark it as end of stack. + "STACK CFI INIT 5000 8 .cfa: $sp 0 + .ra: $ra\n" + + // A function whose CFI makes the stack pointer + // go backwards. + "FUNC 6000 1000 20 palinal\n" + "STACK CFI INIT 6000 1000 .cfa: $sp 4 - .ra: $ra\n" + + // A function with CFI expressions that can't be + // evaluated. + "FUNC 7000 1000 20 rhetorical\n" + "STACK CFI INIT 7000 1000 .cfa: moot .ra: ambiguous\n" + ); + + // Provide some distinctive values for the caller's registers. + expected.epc = 0x00405508; + expected.iregs[MD_CONTEXT_MIPS_REG_S0] = 0x0; + expected.iregs[MD_CONTEXT_MIPS_REG_S1] = 0x1; + expected.iregs[MD_CONTEXT_MIPS_REG_S2] = 0x2; + expected.iregs[MD_CONTEXT_MIPS_REG_S3] = 0x3; + expected.iregs[MD_CONTEXT_MIPS_REG_S4] = 0x4; + expected.iregs[MD_CONTEXT_MIPS_REG_S5] = 0x5; + expected.iregs[MD_CONTEXT_MIPS_REG_S6] = 0x6; + expected.iregs[MD_CONTEXT_MIPS_REG_S7] = 0x7; + expected.iregs[MD_CONTEXT_MIPS_REG_SP] = 0x80000000; + expected.iregs[MD_CONTEXT_MIPS_REG_FP] = 0x80000000; + expected.iregs[MD_CONTEXT_MIPS_REG_RA] = 0x00405510; + + // Expect CFI to recover all callee-save registers. Since CFI is the + // only stack frame construction technique we have, aside from the + // context frame itself, there's no way for us to have a set of valid + // registers smaller than this. + expected_validity = (StackFrameMIPS::CONTEXT_VALID_PC | + StackFrameMIPS::CONTEXT_VALID_S0 | + StackFrameMIPS::CONTEXT_VALID_S1 | + StackFrameMIPS::CONTEXT_VALID_S2 | + StackFrameMIPS::CONTEXT_VALID_S3 | + StackFrameMIPS::CONTEXT_VALID_S4 | + StackFrameMIPS::CONTEXT_VALID_S5 | + StackFrameMIPS::CONTEXT_VALID_S6 | + StackFrameMIPS::CONTEXT_VALID_S7 | + StackFrameMIPS::CONTEXT_VALID_SP | + StackFrameMIPS::CONTEXT_VALID_FP | + StackFrameMIPS::CONTEXT_VALID_RA); + + // By default, context frames provide all registers, as normal. + context_frame_validity = StackFrameMIPS::CONTEXT_VALID_ALL; + + // By default, registers are unchanged. + raw_context = expected; + } + + // Walk the stack, using stack_section as the contents of the stack + // and raw_context as the current register values. (Set the stack + // pointer to the stack's starting address.) Expect two stack + // frames; in the older frame, expect the callee-saves registers to + // have values matching those in 'expected'. + void CheckWalk() { + RegionFromSection(); + raw_context.iregs[MD_CONTEXT_MIPS_REG_SP] = stack_section.start().Value(); + + StackFrameSymbolizer frame_symbolizer(&supplier, &resolver); + StackwalkerMIPS walker(&system_info, &raw_context, &stack_region, + &modules, &frame_symbolizer); + vector<const CodeModule*> modules_without_symbols; + vector<const CodeModule*> modules_with_corrupt_symbols; + ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols, + &modules_with_corrupt_symbols)); + ASSERT_EQ(0U, modules_without_symbols.size()); + ASSERT_EQ(0U, modules_with_corrupt_symbols.size()); + frames = call_stack.frames(); + ASSERT_EQ(2U, frames->size()); + + StackFrameMIPS* frame0 = static_cast<StackFrameMIPS*>(frames->at(0)); + EXPECT_EQ(StackFrame::FRAME_TRUST_CONTEXT, frame0->trust); + ASSERT_EQ(StackFrameMIPS::CONTEXT_VALID_ALL, frame0->context_validity); + EXPECT_EQ("enchiridion", frame0->function_name); + EXPECT_EQ(0x00404000U, frame0->function_base); + + StackFrameMIPS* frame1 = static_cast<StackFrameMIPS*>(frames->at(1)); + EXPECT_EQ(StackFrame::FRAME_TRUST_CFI, frame1->trust); + ASSERT_EQ(expected_validity, frame1->context_validity); + EXPECT_EQ(expected.iregs[MD_CONTEXT_MIPS_REG_S0], + frame1->context.iregs[MD_CONTEXT_MIPS_REG_S0]); + EXPECT_EQ(expected.iregs[MD_CONTEXT_MIPS_REG_S1], + frame1->context.iregs[MD_CONTEXT_MIPS_REG_S1]); + EXPECT_EQ(expected.iregs[MD_CONTEXT_MIPS_REG_S2], + frame1->context.iregs[MD_CONTEXT_MIPS_REG_S2]); + EXPECT_EQ(expected.iregs[MD_CONTEXT_MIPS_REG_S3], + frame1->context.iregs[MD_CONTEXT_MIPS_REG_S3]); + EXPECT_EQ(expected.iregs[MD_CONTEXT_MIPS_REG_S4], + frame1->context.iregs[MD_CONTEXT_MIPS_REG_S4]); + EXPECT_EQ(expected.iregs[MD_CONTEXT_MIPS_REG_S5], + frame1->context.iregs[MD_CONTEXT_MIPS_REG_S5]); + EXPECT_EQ(expected.iregs[MD_CONTEXT_MIPS_REG_S6], + frame1->context.iregs[MD_CONTEXT_MIPS_REG_S6]); + EXPECT_EQ(expected.iregs[MD_CONTEXT_MIPS_REG_S7], + frame1->context.iregs[MD_CONTEXT_MIPS_REG_S7]); + EXPECT_EQ(expected.iregs[MD_CONTEXT_MIPS_REG_FP], + frame1->context.iregs[MD_CONTEXT_MIPS_REG_FP]); + EXPECT_EQ(expected.iregs[MD_CONTEXT_MIPS_REG_RA], + frame1->context.iregs[MD_CONTEXT_MIPS_REG_RA]); + EXPECT_EQ(expected.iregs[MD_CONTEXT_MIPS_REG_SP], + frame1->context.iregs[MD_CONTEXT_MIPS_REG_SP]); + EXPECT_EQ(expected.epc, frame1->context.epc); + EXPECT_EQ(expected.epc, frame1->instruction); + EXPECT_EQ("epictetus", frame1->function_name); + EXPECT_EQ(0x00405000U, frame1->function_base); + } + + // The values we expect to find for the caller's registers. + MDRawContextMIPS expected; + + // The validity mask for expected. + int expected_validity; + + // The validity mask to impose on the context frame. + int context_frame_validity; +}; + +class CFI: public CFIFixture, public Test { }; + +// TODO(gordanac): add CFI tests + +TEST_F(CFI, At4004) { + Label frame1_sp = expected.iregs[MD_CONTEXT_MIPS_REG_SP]; + stack_section + // frame0 + .Append(24, 0) // space + .D32(frame1_sp) // stack pointer + .D32(0x00405510) // return address + .Mark(&frame1_sp); // This effectively sets stack_section.start(). + raw_context.epc = 0x00404004; + CheckWalk(); +} + +// Check that we reject rules that would cause the stack pointer to +// move in the wrong direction. +TEST_F(CFI, RejectBackwards) { + raw_context.epc = 0x40005000; + raw_context.iregs[MD_CONTEXT_MIPS_REG_SP] = 0x80000000; + raw_context.iregs[MD_CONTEXT_MIPS_REG_RA] = 0x00405510; + + StackFrameSymbolizer frame_symbolizer(&supplier, &resolver); + StackwalkerMIPS walker(&system_info, &raw_context, &stack_region, &modules, + &frame_symbolizer); + vector<const CodeModule*> modules_without_symbols; + vector<const CodeModule*> modules_with_corrupt_symbols; + ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols, + &modules_with_corrupt_symbols)); + ASSERT_EQ(0U, modules_without_symbols.size()); + ASSERT_EQ(0U, modules_with_corrupt_symbols.size()); + frames = call_stack.frames(); + ASSERT_EQ(1U, frames->size()); +} + +// Check that we reject rules whose expressions' evaluation fails. +TEST_F(CFI, RejectBadExpressions) { + raw_context.epc = 0x00407000; + raw_context.iregs[MD_CONTEXT_MIPS_REG_SP] = 0x80000000; + raw_context.iregs[MD_CONTEXT_MIPS_REG_RA] = 0x00405510; + + StackFrameSymbolizer frame_symbolizer(&supplier, &resolver); + StackwalkerMIPS walker(&system_info, &raw_context, &stack_region, &modules, + &frame_symbolizer); + vector<const CodeModule*> modules_without_symbols; + vector<const CodeModule*> modules_with_corrupt_symbols; + ASSERT_TRUE(walker.Walk(&call_stack, &modules_without_symbols, + &modules_with_corrupt_symbols)); + ASSERT_EQ(0U, modules_without_symbols.size()); + ASSERT_EQ(0U, modules_with_corrupt_symbols.size()); + frames = call_stack.frames(); + ASSERT_EQ(1U, frames->size()); +} |