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//===-- 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_common.h"
#include "sanitizer_common/sanitizer_stacktrace.h"
#include "gtest/gtest.h"
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;
};
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+2]; // 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 + 2];
// Bottom is one slot before the start because UnwindFast uses >.
fake_bottom = (uhwptr)mapping;
fake_bp = (uptr)&fake_stack[0];
start_pc = PC(0);
}
void FastUnwindTest::TearDown() {
size_t ps = GetPageSize();
UnmapOrDie(mapping, 2 * ps);
}
#if SANITIZER_CAN_FAST_UNWIND
void FastUnwindTest::UnwindFast() {
trace.UnwindFast(start_pc, fake_bp, fake_top, fake_bottom, kStackTraceMax);
}
TEST_F(FastUnwindTest, 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, 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, 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[0], 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, 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, 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]);
}
}
#endif // SANITIZER_CAN_FAST_UNWIND
TEST(SlowUnwindTest, ShortStackTrace) {
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);
}
} // namespace __sanitizer
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