[hwasan] add stack frame descriptions.

Summary:
At compile-time, create an array of {PC,HumanReadableStackFrameDescription}
for every function that has an instrumented frame, and pass this array
to the run-time at the module-init time.
Similar to how we handle pc-table in SanitizerCoverage.
The run-time is dummy, will add the actual logic in later commits.

Reviewers: morehouse, eugenis

Reviewed By: eugenis

Subscribers: srhines, llvm-commits, kubamracek

Differential Revision: https://reviews.llvm.org/D53227

llvm-svn: 344985

2 files changed, 23 insertions, 0 deletions

diff --git a/compiler-rt/lib/hwasan/hwasan.cc b/compiler-rt/lib/hwasan/hwasan.cc
index 02aee4d61c6..518cd11ff30 100644
--- a/compiler-rt/lib/hwasan/hwasan.cc
+++ b/compiler-rt/lib/hwasan/hwasan.cc
@@ -220,6 +220,22 @@ void UpdateMemoryUsage() {
 void UpdateMemoryUsage() {}
 #endif
 
+struct FrameDescription {
+  uptr PC;
+  const char *Descr;
+};
+
+void InitFrameDescriptors(uptr b, uptr e) {
+  FrameDescription *beg = reinterpret_cast<FrameDescription *>(b);
+  FrameDescription *end = reinterpret_cast<FrameDescription *>(e);
+  // Must have at least one entry, which we can use for a linked list.
+  CHECK_GE(end - beg, 1U);
+  if (Verbosity()) {
+    for (FrameDescription *frame_descr = beg; frame_descr < end; frame_descr++)
+      Printf("Frame: %p %s\n", frame_descr->PC, frame_descr->Descr);
+  }
+}
+
 } // namespace __hwasan
 
 // Interface.
@@ -238,6 +254,10 @@ void __hwasan_shadow_init() {
   hwasan_shadow_inited = 1;
 }
 
+void __hwasan_init_frames(uptr beg, uptr end) {
+  InitFrameDescriptors(beg, end);
+}
+
 void __hwasan_init() {
   CHECK(!hwasan_init_is_running);
   if (hwasan_inited) return;
diff --git a/compiler-rt/lib/hwasan/hwasan_interface_internal.h b/compiler-rt/lib/hwasan/hwasan_interface_internal.h
index 448997e5e88..0e49a3fc267 100644
--- a/compiler-rt/lib/hwasan/hwasan_interface_internal.h
+++ b/compiler-rt/lib/hwasan/hwasan_interface_internal.h
@@ -37,6 +37,9 @@ using __sanitizer::u16;
 using __sanitizer::u8;
 
 SANITIZER_INTERFACE_ATTRIBUTE
+void __hwasan_init_frames(uptr, uptr);
+
+SANITIZER_INTERFACE_ATTRIBUTE
 extern uptr __hwasan_shadow_memory_dynamic_address;
 
 SANITIZER_INTERFACE_ATTRIBUTE