From 3ebcc4c8f593821a64c265af19f4786889d94dc0 Mon Sep 17 00:00:00 2001
From: Dmitry Muhomor <muhomor.dmitry@gmail.com>
Date: Thu, 26 Oct 2023 10:22:55 +0300
Subject: [PATCH] android: add function for disabling MTE at runtime

On Android, MTE is always enabled in Zygote, and is disabled after fork for apps that didn't opt-in
to MTE.

Depends on the slab canary adjustments in the previous commit.
---
 h_malloc.c         | 8 ++++++++
 include/h_malloc.h | 1 +
 2 files changed, 9 insertions(+)

diff --git a/h_malloc.c b/h_malloc.c
index 9a3a732..c3ce7e2 100644
--- a/h_malloc.c
+++ b/h_malloc.c
@@ -2148,3 +2148,11 @@ COLD EXPORT int h_malloc_set_state(UNUSED void *state) {
     return -2;
 }
 #endif
+
+#ifdef __ANDROID__
+COLD EXPORT void h_malloc_disable_memory_tagging(void) {
+#ifdef HAS_ARM_MTE
+    __is_memtag_enabled = false;
+#endif
+}
+#endif
diff --git a/include/h_malloc.h b/include/h_malloc.h
index 5824abb..0eee395 100644
--- a/include/h_malloc.h
+++ b/include/h_malloc.h
@@ -99,6 +99,7 @@ int h_malloc_iterate(uintptr_t base, size_t size, void (*callback)(uintptr_t ptr
               void *arg);
 void h_malloc_disable(void);
 void h_malloc_enable(void);
+void h_malloc_disable_memory_tagging(void);
 #endif
 
 // hardened_malloc extensions