//===-- sanitizer_stacktrace_test.cpp -------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of ThreadSanitizer/AddressSanitizer runtime.
//
//===----------------------------------------------------------------------===//
#include "sanitizer_common/sanitizer_stacktrace.h"
#include <string.h>
#include <algorithm>
#include <string>
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_internal_defs.h"
using testing::ContainsRegex;
using testing::MatchesRegex;
namespace __sanitizer {
class FastUnwindTest : public ::testing::Test {
protected:
virtual void SetUp();
virtual void TearDown();
void UnwindFast();
void *mapping;
uhwptr *fake_stack;
const uptr fake_stack_size = 10;
uhwptr start_pc;
uhwptr fake_bp;
uhwptr fake_top;
uhwptr fake_bottom;
BufferedStackTrace trace;
#if defined(__loongarch__) || defined(__riscv)
const uptr kFpOffset = 4;
const uptr kBpOffset = 2;
#else
const uptr kFpOffset = 2;
const uptr kBpOffset = 0;
#endif
private:
CommonFlags tmp_flags_;
};
static uptr PC(uptr idx) {
return (1<<20) + idx;
}
void FastUnwindTest::SetUp() {
size_t ps = GetPageSize();
mapping = MmapOrDie(2 * ps, "FastUnwindTest");
MprotectNoAccess((uptr)mapping, ps);
// Unwinder may peek 1 word down from the starting FP.
fake_stack = (uhwptr *)((uptr)mapping + ps + sizeof(uhwptr));
// Fill an array of pointers with fake fp+retaddr pairs. Frame pointers have
// even indices.
for (uptr i = 0; i + 1 < fake_stack_size; i += 2) {
fake_stack[i] = (uptr)&fake_stack[i + kFpOffset]; // fp
fake_stack[i+1] = PC(i + 1); // retaddr
}
// Mark the last fp point back up to terminate the stack trace.
fake_stack[RoundDownTo(fake_stack_size - 1, 2)] = (uhwptr)&fake_stack[0];
// Top is two slots past the end because UnwindFast subtracts two.
fake_top = (uhwptr)&fake_stack[fake_stack_size + kFpOffset];
// Bottom is one slot before the start because UnwindFast uses >.
fake_bottom = (uhwptr)mapping;
fake_bp = (uptr)&fake_stack[kBpOffset];
start_pc = PC(0);
tmp_flags_.CopyFrom(*common_flags());
}
void FastUnwindTest::TearDown() {
size_t ps = GetPageSize();
UnmapOrDie(mapping, 2 * ps);
// Restore default flags.
OverrideCommonFlags(tmp_flags_);
}
#if SANITIZER_CAN_FAST_UNWIND
#ifdef __sparc__
// Fake stacks don't meet SPARC UnwindFast requirements.
#define SKIP_ON_SPARC(x) DISABLED_##x
#else
#define SKIP_ON_SPARC(x) x
#endif
void FastUnwindTest::UnwindFast() {
trace.UnwindFast(start_pc, fake_bp, fake_top, fake_bottom, kStackTraceMax);
}
TEST_F(FastUnwindTest, SKIP_ON_SPARC(Basic)) {
UnwindFast();
// Should get all on-stack retaddrs and start_pc.
EXPECT_EQ(6U, trace.size);
EXPECT_EQ(start_pc, trace.trace[0]);
for (uptr i = 1; i <= 5; i++) {
EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);
}
}
// From: https://github.com/google/sanitizers/issues/162
TEST_F(FastUnwindTest, SKIP_ON_SPARC(FramePointerLoop)) {
// Make one fp point to itself.
fake_stack[4] = (uhwptr)&fake_stack[4];
UnwindFast();
// Should get all on-stack retaddrs up to the 4th slot and start_pc.
EXPECT_EQ(4U, trace.size);
EXPECT_EQ(start_pc, trace.trace[0]);
for (uptr i = 1; i <= 3; i++) {
EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);
}
}
TEST_F(FastUnwindTest, SKIP_ON_SPARC(MisalignedFramePointer)) {
// Make one fp misaligned.
fake_stack[4] += 3;
UnwindFast();
// Should get all on-stack retaddrs up to the 4th slot and start_pc.
EXPECT_EQ(4U, trace.size);
EXPECT_EQ(start_pc, trace.trace[0]);
for (uptr i = 1; i < 4U; i++) {
EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);
}
}
TEST_F(FastUnwindTest, OneFrameStackTrace) {
trace.Unwind(start_pc, fake_bp, nullptr, true, 1);
EXPECT_EQ(1U, trace.size);
EXPECT_EQ(start_pc, trace.trace[0]);
EXPECT_EQ((uhwptr)&fake_stack[kBpOffset], trace.top_frame_bp);
}
TEST_F(FastUnwindTest, ZeroFramesStackTrace) {
trace.Unwind(start_pc, fake_bp, nullptr, true, 0);
EXPECT_EQ(0U, trace.size);
EXPECT_EQ(0U, trace.top_frame_bp);
}
TEST_F(FastUnwindTest, SKIP_ON_SPARC(FPBelowPrevFP)) {
// The next FP points to unreadable memory inside the stack limits, but below
// current FP.
fake_stack[0] = (uhwptr)&fake_stack[-50];
fake_stack[1] = PC(1);
UnwindFast();
EXPECT_EQ(2U, trace.size);
EXPECT_EQ(PC(0), trace.trace[0]);
EXPECT_EQ(PC(1), trace.trace[1]);
}
TEST_F(FastUnwindTest, SKIP_ON_SPARC(CloseToZeroFrame)) {
// Make one pc a NULL pointer.
fake_stack[5] = 0x0;
UnwindFast();
// The stack should be truncated at the NULL pointer (and not include it).
EXPECT_EQ(3U, trace.size);
EXPECT_EQ(start_pc, trace.trace[0]);
for (uptr i = 1; i < 3U; i++) {
EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);
}
}
using StackPrintTest = FastUnwindTest;
TEST_F(StackPrintTest, SKIP_ON_SPARC(ContainsFullTrace)) {
// Override stack trace format to make testing code independent of default
// flag values.
CommonFlags flags;
flags.CopyFrom(*common_flags());
flags.stack_trace_format = "#%n %p";
OverrideCommonFlags(flags);
UnwindFast();
char buf[3000];
trace.PrintTo(buf, sizeof(buf));
EXPECT_THAT(std::string(buf),
MatchesRegex("(#[0-9]+ 0x[0-9a-f]+\n){" +
std::to_string(trace.size) + "}\n"));
}
TEST_F(StackPrintTest, SKIP_ON_SPARC(TruncatesContents)) {
UnwindFast();
char buf[3000];
uptr actual_len = trace.PrintTo(buf, sizeof(buf));
ASSERT_LT(actual_len, sizeof(buf));
char tinybuf[10];
trace.PrintTo(tinybuf, sizeof(tinybuf));
// This the truncation case.
ASSERT_GT(actual_len, sizeof(tinybuf));
// The truncated contents should be a prefix of the full contents.
size_t lastpos = sizeof(tinybuf) - 1;
EXPECT_EQ(strncmp(buf, tinybuf, lastpos), 0);
EXPECT_EQ(tinybuf[lastpos], '\0');
// Full bufffer has more contents...
EXPECT_NE(buf[lastpos], '\0');
}
TEST_F(StackPrintTest, SKIP_ON_SPARC(WorksWithEmptyStack)) {
char buf[3000];
trace.PrintTo(buf, sizeof(buf));
EXPECT_NE(strstr(buf, "<empty stack>"), nullptr);
}
TEST_F(StackPrintTest, SKIP_ON_SPARC(ReturnsCorrectLength)) {
UnwindFast();
char buf[3000];
uptr len = trace.PrintTo(buf, sizeof(buf));
size_t actual_len = strlen(buf);
ASSERT_LT(len, sizeof(buf));
EXPECT_EQ(len, actual_len);
char tinybuf[5];
len = trace.PrintTo(tinybuf, sizeof(tinybuf));
size_t truncated_len = strlen(tinybuf);
ASSERT_GE(len, sizeof(tinybuf));
EXPECT_EQ(len, actual_len);
EXPECT_EQ(truncated_len, sizeof(tinybuf) - 1);
}
TEST_F(StackPrintTest, SKIP_ON_SPARC(AcceptsZeroSize)) {
UnwindFast();
char buf[1];
EXPECT_GT(trace.PrintTo(buf, 0), 0u);
}
using StackPrintDeathTest = StackPrintTest;
TEST_F(StackPrintDeathTest, SKIP_ON_SPARC(RequiresNonNullBuffer)) {
UnwindFast();
EXPECT_DEATH(trace.PrintTo(NULL, 100), "");
}
#endif // SANITIZER_CAN_FAST_UNWIND
TEST(SlowUnwindTest, ShortStackTrace) {
UNINITIALIZED BufferedStackTrace stack;
uptr pc = StackTrace::GetCurrentPc();
uptr bp = GET_CURRENT_FRAME();
stack.Unwind(pc, bp, nullptr, false, /*max_depth=*/0);
EXPECT_EQ(0U, stack.size);
EXPECT_EQ(0U, stack.top_frame_bp);
stack.Unwind(pc, bp, nullptr, false, /*max_depth=*/1);
EXPECT_EQ(1U, stack.size);
EXPECT_EQ(pc, stack.trace[0]);
EXPECT_EQ(bp, stack.top_frame_bp);
}
TEST(GetCurrentPc, Basic) {
// Test that PCs obtained via GET_CURRENT_PC()
// and StackTrace::GetCurrentPc() are all different
// and are close to the function start.
struct Local {
static NOINLINE void Test() {
const uptr pcs[] = {
(uptr)&Local::Test,
GET_CURRENT_PC(),
StackTrace::GetCurrentPc(),
StackTrace::GetCurrentPc(),
};
for (uptr i = 0; i < ARRAY_SIZE(pcs); i++)
Printf("pc%zu: %p\n", i, (void *)(pcs[i]));
for (uptr i = 1; i < ARRAY_SIZE(pcs); i++) {
EXPECT_GT(pcs[i], pcs[0]);
EXPECT_LT(pcs[i], pcs[0] + 1000);
for (uptr j = 0; j < i; j++) EXPECT_NE(pcs[i], pcs[j]);
}
}
};
Local::Test();
}
// Dummy implementation. This should never be called, but is required to link
// non-optimized builds of this test.
void BufferedStackTrace::UnwindImpl(uptr pc, uptr bp, void *context,
bool request_fast, u32 max_depth) {
UNIMPLEMENTED();
}
} // namespace __sanitizer
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