[asan] Add __asan_set_shadow_*

Summary:
We are poisoning small allocas using store instruction from instrumented code.
For larger allocas we'd like to insert function calls instead of multiple stores.

PR27453

Reviewers: kcc, eugenis

Subscribers: llvm-commits, kubabrecka

Differential Revision: https://reviews.llvm.org/D23616

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@279019 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 24 insertions, 0 deletions

diff --git a/lib/asan/asan_poisoning.cc b/lib/asan/asan_poisoning.cc
index 65c44019d..e1a3f2d6d 100644
--- a/lib/asan/asan_poisoning.cc
+++ b/lib/asan/asan_poisoning.cc
@@ -314,6 +314,30 @@ static void PoisonAlignedStackMemory(uptr addr, uptr size, bool do_poison) {
   }
 }
 
+void __asan_set_shadow_00(uptr addr, uptr size) {
+  REAL(memset)((void *)addr, 0, size);
+}
+
+void __asan_set_shadow_f1(uptr addr, uptr size) {
+  REAL(memset)((void *)addr, 0xf1, size);
+}
+
+void __asan_set_shadow_f2(uptr addr, uptr size) {
+  REAL(memset)((void *)addr, 0xf2, size);
+}
+
+void __asan_set_shadow_f3(uptr addr, uptr size) {
+  REAL(memset)((void *)addr, 0xf3, size);
+}
+
+void __asan_set_shadow_f5(uptr addr, uptr size) {
+  REAL(memset)((void *)addr, 0xf5, size);
+}
+
+void __asan_set_shadow_f8(uptr addr, uptr size) {
+  REAL(memset)((void *)addr, 0xf8, size);
+}
+
 void __asan_poison_stack_memory(uptr addr, uptr size) {
   if (!__asan_option_detect_stack_use_after_scope) return;
   VReport(1, "poisoning: %p %zx\n", (void *)addr, size);