From 78c33f3f5e9770623b357f1d7d1ba0952d7461ee Mon Sep 17 00:00:00 2001
From: Elliott Hughes <enh@google.com>
Date: Thu, 11 Aug 2022 23:43:36 +0000
Subject: [PATCH] Switch to C23's memset_explicit().

Test: treehugger
Change-Id: Ib6ef45cedaf95fa251d0b03de0f14701f910d063
---
 KeyBuffer.h  | 18 ++----------------
 Keystore.cpp |  2 +-
 2 files changed, 3 insertions(+), 17 deletions(-)

diff --git a/KeyBuffer.h b/KeyBuffer.h
index a68311f..4468220 100644
--- a/KeyBuffer.h
+++ b/KeyBuffer.h
@@ -17,32 +17,18 @@
 #ifndef ANDROID_VOLD_KEYBUFFER_H
 #define ANDROID_VOLD_KEYBUFFER_H
 
-#include <cstring>
+#include <string.h>
 #include <memory>
 #include <vector>
 
 namespace android {
 namespace vold {
 
-/**
- * Variant of memset() that should never be optimized away. Borrowed from keymaster code.
- */
-#ifdef __clang__
-#define OPTNONE __attribute__((optnone))
-#else  // not __clang__
-#define OPTNONE __attribute__((optimize("O0")))
-#endif  // not __clang__
-inline OPTNONE void* memset_s(void* s, int c, size_t n) {
-    if (!s) return s;
-    return memset(s, c, n);
-}
-#undef OPTNONE
-
 // Allocator that delegates useful work to standard one but zeroes data before deallocating.
 class ZeroingAllocator : public std::allocator<char> {
   public:
     void deallocate(pointer p, size_type n) {
-        memset_s(p, 0, n);
+        memset_explicit(p, 0, n);
         std::allocator<char>::deallocate(p, n);
     }
 };
diff --git a/Keystore.cpp b/Keystore.cpp
index d993b0d..6040f2d 100644
--- a/Keystore.cpp
+++ b/Keystore.cpp
@@ -48,7 +48,7 @@ KeystoreOperation::~KeystoreOperation() {
 }
 
 static void zeroize_vector(std::vector<uint8_t>& vec) {
-    memset_s(vec.data(), 0, vec.size());
+    memset_explicit(vec.data(), 0, vec.size());
 }
 
 static bool logKeystore2ExceptionIfPresent(::ndk::ScopedAStatus& rc, const std::string& func_name) {