src/compiler-rt/lib/sanitizer_common/tests/sanitizer_stacktrace_test.cc

   1 //===-- sanitizer_stacktrace_test.cc --------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file is a part of ThreadSanitizer/AddressSanitizer runtime.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "sanitizer_common/sanitizer_common.h"
  15 #include "sanitizer_common/sanitizer_stacktrace.h"
  16 #include "gtest/gtest.h"
  17
  18 namespace __sanitizer {
  19
  20 class FastUnwindTest : public ::testing::Test {
  21  protected:
  22   virtual void SetUp();
  23   virtual void TearDown();
  24   bool TryFastUnwind(uptr max_depth) {
  25     if (!StackTrace::WillUseFastUnwind(true))
  26       return false;
  27     trace.Unwind(max_depth, start_pc, (uptr)&fake_stack[0], 0, fake_top,
  28                  fake_bottom, true);
  29     return true;
  30   }
  31
  32   void *mapping;
  33   uhwptr *fake_stack;
  34   const uptr fake_stack_size = 10;
  35   uhwptr start_pc;
  36   uhwptr fake_top;
  37   uhwptr fake_bottom;
  38   BufferedStackTrace trace;
  39 };
  40
  41 static uptr PC(uptr idx) {
  42   return (1<<20) + idx;
  43 }
  44
  45 void FastUnwindTest::SetUp() {
  46   size_t ps = GetPageSize();
  47   mapping = MmapOrDie(2 * ps, "FastUnwindTest");
  48   MprotectNoAccess((uptr)mapping, ps);
  49
  50   // Unwinder may peek 1 word down from the starting FP.
  51   fake_stack = (uhwptr *)((uptr)mapping + ps + sizeof(uhwptr));
  52
  53   // Fill an array of pointers with fake fp+retaddr pairs.  Frame pointers have
  54   // even indices.
  55   for (uptr i = 0; i + 1 < fake_stack_size; i += 2) {
  56     fake_stack[i] = (uptr)&fake_stack[i+2];  // fp
  57     fake_stack[i+1] = PC(i + 1); // retaddr
  58   }
  59   // Mark the last fp point back up to terminate the stack trace.
  60   fake_stack[RoundDownTo(fake_stack_size - 1, 2)] = (uhwptr)&fake_stack[0];
  61
  62   // Top is two slots past the end because FastUnwindStack subtracts two.
  63   fake_top = (uhwptr)&fake_stack[fake_stack_size + 2];
  64   // Bottom is one slot before the start because FastUnwindStack uses >.
  65   fake_bottom = (uhwptr)mapping;
  66   start_pc = PC(0);
  67 }
  68
  69 void FastUnwindTest::TearDown() {
  70   size_t ps = GetPageSize();
  71   UnmapOrDie(mapping, 2 * ps);
  72 }
  73
  74 TEST_F(FastUnwindTest, Basic) {
  75   if (!TryFastUnwind(kStackTraceMax))
  76     return;
  77   // Should get all on-stack retaddrs and start_pc.
  78   EXPECT_EQ(6U, trace.size);
  79   EXPECT_EQ(start_pc, trace.trace[0]);
  80   for (uptr i = 1; i <= 5; i++) {
  81     EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);
  82   }
  83 }
  84
  85 // From: https://github.com/google/sanitizers/issues/162
  86 TEST_F(FastUnwindTest, FramePointerLoop) {
  87   // Make one fp point to itself.
  88   fake_stack[4] = (uhwptr)&fake_stack[4];
  89   if (!TryFastUnwind(kStackTraceMax))
  90     return;
  91   // Should get all on-stack retaddrs up to the 4th slot and start_pc.
  92   EXPECT_EQ(4U, trace.size);
  93   EXPECT_EQ(start_pc, trace.trace[0]);
  94   for (uptr i = 1; i <= 3; i++) {
  95     EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);
  96   }
  97 }
  98
  99 TEST_F(FastUnwindTest, MisalignedFramePointer) {
 100   // Make one fp misaligned.
 101   fake_stack[4] += 3;
 102   if (!TryFastUnwind(kStackTraceMax))
 103     return;
 104   // Should get all on-stack retaddrs up to the 4th slot and start_pc.
 105   EXPECT_EQ(4U, trace.size);
 106   EXPECT_EQ(start_pc, trace.trace[0]);
 107   for (uptr i = 1; i < 4U; i++) {
 108     EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);
 109   }
 110 }
 111
 112 TEST_F(FastUnwindTest, OneFrameStackTrace) {
 113   if (!TryFastUnwind(1))
 114     return;
 115   EXPECT_EQ(1U, trace.size);
 116   EXPECT_EQ(start_pc, trace.trace[0]);
 117   EXPECT_EQ((uhwptr)&fake_stack[0], trace.top_frame_bp);
 118 }
 119
 120 TEST_F(FastUnwindTest, ZeroFramesStackTrace) {
 121   if (!TryFastUnwind(0))
 122     return;
 123   EXPECT_EQ(0U, trace.size);
 124   EXPECT_EQ(0U, trace.top_frame_bp);
 125 }
 126
 127 TEST_F(FastUnwindTest, FPBelowPrevFP) {
 128   // The next FP points to unreadable memory inside the stack limits, but below
 129   // current FP.
 130   fake_stack[0] = (uhwptr)&fake_stack[-50];
 131   fake_stack[1] = PC(1);
 132   if (!TryFastUnwind(3))
 133     return;
 134   EXPECT_EQ(2U, trace.size);
 135   EXPECT_EQ(PC(0), trace.trace[0]);
 136   EXPECT_EQ(PC(1), trace.trace[1]);
 137 }
 138
 139 TEST_F(FastUnwindTest, CloseToZeroFrame) {
 140   // Make one pc a NULL pointer.
 141   fake_stack[5] = 0x0;
 142   if (!TryFastUnwind(kStackTraceMax))
 143     return;
 144   // The stack should be truncated at the NULL pointer (and not include it).
 145   EXPECT_EQ(3U, trace.size);
 146   EXPECT_EQ(start_pc, trace.trace[0]);
 147   for (uptr i = 1; i < 3U; i++) {
 148     EXPECT_EQ(PC(i*2 - 1), trace.trace[i]);
 149   }
 150 }
 151
 152 TEST(SlowUnwindTest, ShortStackTrace) {
 153   if (StackTrace::WillUseFastUnwind(false))
 154     return;
 155   BufferedStackTrace stack;
 156   uptr pc = StackTrace::GetCurrentPc();
 157   uptr bp = GET_CURRENT_FRAME();
 158   stack.Unwind(0, pc, bp, 0, 0, 0, false);
 159   EXPECT_EQ(0U, stack.size);
 160   EXPECT_EQ(0U, stack.top_frame_bp);
 161   stack.Unwind(1, pc, bp, 0, 0, 0, false);
 162   EXPECT_EQ(1U, stack.size);
 163   EXPECT_EQ(pc, stack.trace[0]);
 164   EXPECT_EQ(bp, stack.top_frame_bp);
 165 }
 166
 167 }  // namespace __sanitizer