1 files changed, 280 insertions, 0 deletions
diff --git a/lib/asan/asan_stack.cc b/lib/asan/asan_stack.cc
new file mode 100644
index 000000000000..8163983bce7d
--- /dev/null
+++ b/lib/asan/asan_stack.cc
@@ -0,0 +1,280 @@
+//===-- asan_stack.cc -------------------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file is a part of AddressSanitizer, an address sanity checker.
+//
+// Code for ASan stack trace.
+//===----------------------------------------------------------------------===//
+#include "asan_interceptors.h"
+#include "asan_lock.h"
+#include "asan_stack.h"
+#include "asan_thread.h"
+#include "asan_thread_registry.h"
+
+#include <string.h>
+
+#if ASAN_USE_SYSINFO == 1
+#include "sysinfo/sysinfo.h"
+#endif
+
+#ifdef ASAN_USE_EXTERNAL_SYMBOLIZER
+extern bool
+ASAN_USE_EXTERNAL_SYMBOLIZER(const void *pc, char *out, int out_size);
+#endif
+
+namespace __asan {
+
+// ----------------------- ProcSelfMaps ----------------------------- {{{1
+#if ASAN_USE_SYSINFO == 1
+class ProcSelfMaps {
+ public:
+  void Init() {
+    ScopedLock lock(&mu_);
+    if (map_size_ != 0) return;  // already inited
+    if (FLAG_v >= 2) {
+      Printf("ProcSelfMaps::Init()\n");
+    }
+    ProcMapsIterator it(0, &proc_self_maps_);   // 0 means "current pid"
+
+    uint64 start, end, offset;
+    int64 inode;
+    char *flags, *filename;
+    CHECK(map_size_ == 0);
+    while (it.Next(&start, &end, &flags, &offset, &inode, &filename)) {
+      CHECK(map_size_ < kMaxProcSelfMapsSize);
+      Mapping &mapping = memory_map[map_size_];
+      mapping.beg = start;
+      mapping.end = end;
+      mapping.offset = offset;
+      real_strncpy(mapping.name,
+                   filename, ASAN_ARRAY_SIZE(mapping.name));
+      mapping.name[ASAN_ARRAY_SIZE(mapping.name) - 1] = 0;
+      if (FLAG_v >= 2) {
+        Printf("[%ld] [%p,%p] off %p %s\n", map_size_,
+               mapping.beg, mapping.end, mapping.offset, mapping.name);
+      }
+      map_size_++;
+    }
+  }
+
+  void Print() {
+    Printf("%s\n", proc_self_maps_);
+  }
+
+  void PrintPc(uintptr_t pc, int idx) {
+    for (size_t i = 0; i < map_size_; i++) {
+      Mapping &m = memory_map[i];
+      if (pc >= m.beg && pc < m.end) {
+        uintptr_t offset = pc - m.beg;
+        if (i == 0) offset = pc;
+        Printf("    #%d 0x%lx (%s+0x%lx)\n", idx, pc, m.name, offset);
+        return;
+      }
+    }
+    Printf("  #%d 0x%lx\n", idx, pc);
+  }
+
+ private:
+  void copy_until_new_line(const char *str, char *dest, size_t max_size) {
+    size_t i = 0;
+    for (; str[i] && str[i] != '\n' && i < max_size - 1; i++) {
+      dest[i] = str[i];
+    }
+    dest[i] = 0;
+  }
+
+
+  struct Mapping {
+    uintptr_t beg, end, offset;
+    char name[1000];
+  };
+  static const size_t kMaxNumMapEntries = 4096;
+  static const size_t kMaxProcSelfMapsSize = 1 << 20;
+  ProcMapsIterator::Buffer proc_self_maps_;
+  size_t map_size_;
+  Mapping memory_map[kMaxNumMapEntries];
+
+  static AsanLock mu_;
+};
+
+static ProcSelfMaps proc_self_maps;
+AsanLock ProcSelfMaps::mu_(LINKER_INITIALIZED);
+
+
+void AsanStackTrace::PrintStack(uintptr_t *addr, size_t size) {
+  proc_self_maps.Init();
+  for (size_t i = 0; i < size && addr[i]; i++) {
+    uintptr_t pc = addr[i];
+    // int line;
+    proc_self_maps.PrintPc(pc, i);
+    // Printf("  #%ld 0x%lx %s\n", i, pc, rtn.c_str());
+  }
+}
+#elif defined(ASAN_USE_EXTERNAL_SYMBOLIZER)
+void AsanStackTrace::PrintStack(uintptr_t *addr, size_t size) {
+  for (size_t i = 0; i < size && addr[i]; i++) {
+    uintptr_t pc = addr[i];
+    char buff[4096];
+    ASAN_USE_EXTERNAL_SYMBOLIZER((void*)pc, buff, sizeof(buff));
+    Printf("  #%ld 0x%lx %s\n", i, pc, buff);
+  }
+}
+
+#else  // ASAN_USE_SYSINFO
+void AsanStackTrace::PrintStack(uintptr_t *addr, size_t size) {
+  for (size_t i = 0; i < size && addr[i]; i++) {
+    uintptr_t pc = addr[i];
+    Printf("  #%ld 0x%lx\n", i, pc);
+  }
+}
+#endif  // ASAN_USE_SYSINFO
+
+#ifdef __arm__
+#define UNWIND_STOP _URC_END_OF_STACK
+#define UNWIND_CONTINUE _URC_OK
+#else
+#define UNWIND_STOP _URC_NORMAL_STOP
+#define UNWIND_CONTINUE _URC_NO_REASON
+#endif
+
+// ----------------------- AsanStackTrace ----------------------------- {{{1
+uintptr_t AsanStackTrace::GetCurrentPc() {
+  return GET_CALLER_PC();
+}
+
+void AsanStackTrace::FastUnwindStack(uintptr_t pc, uintptr_t bp) {
+  CHECK(size == 0 && trace[0] == pc);
+  size = 1;
+  if (!asan_inited) return;
+  AsanThread *t = asanThreadRegistry().GetCurrent();
+  if (!t) return;
+  uintptr_t *frame = (uintptr_t*)bp;
+  uintptr_t *prev_frame = frame;
+  uintptr_t *top = (uintptr_t*)t->stack_top();
+  uintptr_t *bottom = (uintptr_t*)t->stack_bottom();
+  while (frame >= prev_frame &&
+         frame < top &&
+         frame > bottom &&
+         size < max_size) {
+    uintptr_t pc1 = frame[1];
+    if (pc1 != pc) {
+      trace[size++] = pc1;
+    }
+    prev_frame = frame;
+    frame = (uintptr_t*)frame[0];
+  }
+}
+
+// On 32-bits we don't compress stack traces.
+// On 64-bits we compress stack traces: if a given pc differes slightly from
+// the previous one, we record a 31-bit offset instead of the full pc.
+size_t AsanStackTrace::CompressStack(AsanStackTrace *stack,
+                                   uint32_t *compressed, size_t size) {
+#if __WORDSIZE == 32
+  // Don't compress, just copy.
+  size_t res = 0;
+  for (size_t i = 0; i < stack->size && i < size; i++) {
+    compressed[i] = stack->trace[i];
+    res++;
+  }
+  if (stack->size < size)
+    compressed[stack->size] = 0;
+#else  // 64 bits, compress.
+  uintptr_t prev_pc = 0;
+  const uintptr_t kMaxOffset = (1ULL << 30) - 1;
+  uintptr_t c_index = 0;
+  size_t res = 0;
+  for (size_t i = 0, n = stack->size; i < n; i++) {
+    uintptr_t pc = stack->trace[i];
+    if (!pc) break;
+    if ((int64_t)pc < 0) break;
+    // Printf("C pc[%ld] %lx\n", i, pc);
+    if (prev_pc - pc < kMaxOffset || pc - prev_pc < kMaxOffset) {
+      uintptr_t offset = (int64_t)(pc - prev_pc);
+      offset |= (1U << 31);
+      if (c_index >= size) break;
+      // Printf("C co[%ld] offset %lx\n", i, offset);
+      compressed[c_index++] = offset;
+    } else {
+      uintptr_t hi = pc >> 32;
+      uintptr_t lo = (pc << 32) >> 32;
+      CHECK((hi & (1 << 31)) == 0);
+      if (c_index + 1 >= size) break;
+      // Printf("C co[%ld] hi/lo: %lx %lx\n", c_index, hi, lo);
+      compressed[c_index++] = hi;
+      compressed[c_index++] = lo;
+    }
+    res++;
+    prev_pc = pc;
+  }
+  if (c_index < size)
+    compressed[c_index] = 0;
+  if (c_index + 1 < size)
+    compressed[c_index + 1] = 0;
+#endif  // __WORDSIZE
+
+  // debug-only code
+#if 0
+  AsanStackTrace check_stack;
+  UncompressStack(&check_stack, compressed, size);
+  if (res < check_stack.size) {
+    Printf("res %ld check_stack.size %ld; c_size %ld\n", res,
+           check_stack.size, size);
+  }
+  // |res| may be greater than check_stack.size, because
+  // UncompressStack(CompressStack(stack)) eliminates the 0x0 frames.
+  CHECK(res >= check_stack.size);
+  CHECK(0 == real_memcmp(check_stack.trace, stack->trace,
+                         check_stack.size * sizeof(uintptr_t)));
+#endif
+
+  return res;
+}
+
+void AsanStackTrace::UncompressStack(AsanStackTrace *stack,
+                                     uint32_t *compressed, size_t size) {
+#if __WORDSIZE == 32
+  // Don't uncompress, just copy.
+  stack->size = 0;
+  for (size_t i = 0; i < size && i < kStackTraceMax; i++) {
+    if (!compressed[i]) break;
+    stack->size++;
+    stack->trace[i] = compressed[i];
+  }
+#else  // 64 bits, uncompress
+  uintptr_t prev_pc = 0;
+  stack->size = 0;
+  for (size_t i = 0; i < size && stack->size < kStackTraceMax; i++) {
+    uint32_t x = compressed[i];
+    uintptr_t pc = 0;
+    if (x & (1U << 31)) {
+      // Printf("U co[%ld] offset: %x\n", i, x);
+      // this is an offset
+      int32_t offset = x;
+      offset = (offset << 1) >> 1;  // remove the 31-byte and sign-extend.
+      pc = prev_pc + offset;
+      CHECK(pc);
+    } else {
+      // CHECK(i + 1 < size);
+      if (i + 1 >= size) break;
+      uintptr_t hi = x;
+      uintptr_t lo = compressed[i+1];
+      // Printf("U co[%ld] hi/lo: %lx %lx\n", i, hi, lo);
+      i++;
+      pc = (hi << 32) | lo;
+      if (!pc) break;
+    }
+    // Printf("U pc[%ld] %lx\n", stack->size, pc);
+    stack->trace[stack->size++] = pc;
+    prev_pc = pc;
+  }
+#endif  // __WORDSIZE
+}
+
+}  // namespace __asan