// 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());
}