1 files changed, 80 insertions, 0 deletions
diff --git a/libsanitizer/sanitizer_common/sanitizer_linux.cc b/libsanitizer/sanitizer_common/sanitizer_linux.cc
index 75f2ee18a67..1d0bf02192c 100644
--- a/libsanitizer/sanitizer_common/sanitizer_linux.cc
+++ b/libsanitizer/sanitizer_common/sanitizer_linux.cc
@@ -17,6 +17,7 @@
 #include "sanitizer_mutex.h"
 #include "sanitizer_placement_new.h"
 #include "sanitizer_procmaps.h"
+#include "sanitizer_stacktrace.h"
 
 #include <fcntl.h>
 #include <pthread.h>
@@ -28,7 +29,9 @@
 #include <sys/time.h>
 #include <sys/types.h>
 #include <unistd.h>
+#include <unwind.h>
 #include <errno.h>
+#include <sys/prctl.h>
 
 // Are we using 32-bit or 64-bit syscalls?
 // x32 (which defines __x86_64__) has SANITIZER_WORDSIZE == 32
@@ -215,6 +218,14 @@ void ReExec() {
   execv(argv[0], argv.data());
 }
 
+void PrepareForSandboxing() {
+  // Some kinds of sandboxes may forbid filesystem access, so we won't be able
+  // to read the file mappings from /proc/self/maps. Luckily, neither the
+  // process will be able to load additional libraries, so it's fine to use the
+  // cached mappings.
+  MemoryMappingLayout::CacheMemoryMappings();
+}
+
 // ----------------- sanitizer_procmaps.h
 // Linker initialized.
 ProcSelfMapsBuff MemoryMappingLayout::cached_proc_self_maps_;
@@ -354,6 +365,75 @@ bool MemoryMappingLayout::GetObjectNameAndOffset(uptr addr, uptr *offset,
   return IterateForObjectNameAndOffset(addr, offset, filename, filename_size);
 }
 
+bool SanitizerSetThreadName(const char *name) {
+  return 0 == prctl(PR_SET_NAME, (unsigned long)name, 0, 0, 0);  // NOLINT
+}
+
+bool SanitizerGetThreadName(char *name, int max_len) {
+  char buff[17];
+  if (prctl(PR_GET_NAME, (unsigned long)buff, 0, 0, 0))  // NOLINT
+    return false;
+  internal_strncpy(name, buff, max_len);
+  name[max_len] = 0;
+  return true;
+}
+
+#ifndef SANITIZER_GO
+//------------------------- SlowUnwindStack -----------------------------------
+#ifdef __arm__
+#define UNWIND_STOP _URC_END_OF_STACK
+#define UNWIND_CONTINUE _URC_NO_REASON
+#else
+#define UNWIND_STOP _URC_NORMAL_STOP
+#define UNWIND_CONTINUE _URC_NO_REASON
+#endif
+
+uptr Unwind_GetIP(struct _Unwind_Context *ctx) {
+#ifdef __arm__
+  uptr val;
+  _Unwind_VRS_Result res = _Unwind_VRS_Get(ctx, _UVRSC_CORE,
+      15 /* r15 = PC */, _UVRSD_UINT32, &val);
+  CHECK(res == _UVRSR_OK && "_Unwind_VRS_Get failed");
+  // Clear the Thumb bit.
+  return val & ~(uptr)1;
+#else
+  return _Unwind_GetIP(ctx);
+#endif
+}
+
+_Unwind_Reason_Code Unwind_Trace(struct _Unwind_Context *ctx, void *param) {
+  StackTrace *b = (StackTrace*)param;
+  CHECK(b->size < b->max_size);
+  uptr pc = Unwind_GetIP(ctx);
+  b->trace[b->size++] = pc;
+  if (b->size == b->max_size) return UNWIND_STOP;
+  return UNWIND_CONTINUE;
+}
+
+static bool MatchPc(uptr cur_pc, uptr trace_pc) {
+  return cur_pc - trace_pc <= 64 || trace_pc - cur_pc <= 64;
+}
+
+void StackTrace::SlowUnwindStack(uptr pc, uptr max_depth) {
+  this->size = 0;
+  this->max_size = max_depth;
+  if (max_depth > 1) {
+    _Unwind_Backtrace(Unwind_Trace, this);
+    // We need to pop a few frames so that pc is on top.
+    // trace[0] belongs to the current function so we always pop it.
+    int to_pop = 1;
+    /**/ if (size > 1 && MatchPc(pc, trace[1])) to_pop = 1;
+    else if (size > 2 && MatchPc(pc, trace[2])) to_pop = 2;
+    else if (size > 3 && MatchPc(pc, trace[3])) to_pop = 3;
+    else if (size > 4 && MatchPc(pc, trace[4])) to_pop = 4;
+    else if (size > 5 && MatchPc(pc, trace[5])) to_pop = 5;
+    this->PopStackFrames(to_pop);
+  }
+  this->trace[0] = pc;
+}
+
+#endif  // #ifndef SANITIZER_GO
+
 }  // namespace __sanitizer
 
 #endif  // __linux__