[hwasan,asan] Intercept vfork.

Summary: AArch64 only for now.

Reviewers: vitalybuka, pcc

Subscribers: srhines, kubamracek, mgorny, javed.absar, krytarowski, kristof.beyls, jdoerfert, #sanitizers, llvm-commits, kcc

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D58313

llvm-svn: 354625

1 files changed, 24 insertions, 0 deletions

diff --git a/compiler-rt/lib/hwasan/hwasan.cc b/compiler-rt/lib/hwasan/hwasan.cc
index 9c83f73bd98..3a87dea26d3 100644
--- a/compiler-rt/lib/hwasan/hwasan.cc
+++ b/compiler-rt/lib/hwasan/hwasan.cc
@@ -477,6 +477,30 @@ void __hwasan_handle_longjmp(const void *sp_dst) {
   TagMemory(sp, dst - sp, 0);
 }
 
+void __hwasan_handle_vfork(const void *sp_dst) {
+  uptr sp = (uptr)sp_dst;
+  Thread *t = GetCurrentThread();
+  CHECK(t);
+  uptr top = t->stack_top();
+  uptr bottom = t->stack_bottom();
+  static const uptr kMaxExpectedCleanupSize = 64 << 20;  // 64M
+  if (top == 0 || bottom == 0 || sp < bottom || sp >= top ||
+      sp - bottom > kMaxExpectedCleanupSize) {
+    Report(
+        "WARNING: HWASan is ignoring requested __hwasan_handle_vfork: "
+        "stack top: %zx; current %zx; bottom: %zx \n"
+        "False positive error reports may follow\n",
+        top, sp, bottom);
+    return;
+  }
+  TagMemory(bottom, sp - bottom, 0);
+}
+
+void *__hwasan_extra_spill_area() {
+  Thread *t = GetCurrentThread();
+  return &t->vfork_spill();
+}
+
 void __hwasan_print_memory_usage() {
   InternalScopedString s(kMemoryUsageBufferSize);
   HwasanFormatMemoryUsage(s);