Add dfsan_weak_hook_memcmp

Summary:
Add a weak hook to be called from dfsan's custom memcmp.
The primary user will be lib/Fuzzer.
If this works well we'll add more hooks (strcmp, etc).

Test Plan: Will be covered by lib/Fuzzer tests.

Reviewers: pcc

Reviewed By: pcc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D9541

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@236679 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 0 deletions

diff --git a/include/sanitizer/dfsan_interface.h b/include/sanitizer/dfsan_interface.h
index 79dbf2f36..84ffd49f8 100644
--- a/include/sanitizer/dfsan_interface.h
+++ b/include/sanitizer/dfsan_interface.h
@@ -91,6 +91,16 @@ void dfsan_set_write_callback(dfsan_write_callback_t labeled_write_callback);
 /// <label> <parent label 1> <parent label 2> <label description if any>
 void dfsan_dump_labels(int fd);
 
+/// Whenever a dfsan's custom function is called the corresponding
+/// hook is called it non-zero. The hooks should be defined by the user.
+/// The primary use case is taint-guided fuzzing, where the fuzzer
+/// needs to see the parameters of the function and the labels.
+/// FIXME: implement more hooks.
+
+/// memcmp hook.
+void dfsan_weak_hook_memcmp(void *caller_pc, const void *s1, const void *s2,
+                            size_t n, dfsan_label s1_label,
+                            dfsan_label s2_label, dfsan_label n_label);
 #ifdef __cplusplus
 }  // extern "C"