From 6ac72fa7f12a779ec9a142cbe6bbf6b58fc5d80a Mon Sep 17 00:00:00 2001
From: wangmingrong1 <wangmingrong1@xiaomi.com>
Date: Tue, 22 Apr 2025 12:01:59 +0800
Subject: [PATCH] kasan: Add configurable kasan initialization variable
 location

This can avoid crashes caused by uninitialized accesses to initialized variables in non-chip memory.

Signed-off-by: wangmingrong1 <wangmingrong1@xiaomi.com>
---
 mm/kasan/CMakeLists.txt | 6 ++++++
 mm/kasan/Kconfig        | 7 +++++++
 mm/kasan/Make.defs      | 4 ++++
 mm/kasan/hook.c         | 4 ++++
 4 files changed, 21 insertions(+)

diff --git a/mm/kasan/CMakeLists.txt b/mm/kasan/CMakeLists.txt
index ef3f50ae94..d33e1805fe 100644
--- a/mm/kasan/CMakeLists.txt
+++ b/mm/kasan/CMakeLists.txt
@@ -25,6 +25,12 @@ if(CONFIG_MM_KASAN)
   list(APPEND FLAGS ${NO_LTO})
   list(APPEND FLAGS -fno-builtin)
   list(APPEND FLAGS -fno-sanitize=kernel-address)
+
+  if(NOT "${CONFIG_MM_KASAN_MARK_LOCATION}" STREQUAL "")
+    target_compile_definitions(
+      mm PRIVATE -DMM_KASAN_MARK_LOCATION="${CONFIG_MM_KASAN_MARK_LOCATION}")
+  endif()
+
 endif()
 
 target_sources(mm PRIVATE ${SRCS})
diff --git a/mm/kasan/Kconfig b/mm/kasan/Kconfig
index 8520646a24..94934c6cf2 100644
--- a/mm/kasan/Kconfig
+++ b/mm/kasan/Kconfig
@@ -57,6 +57,13 @@ config MM_KASAN_INSTRUMENT_ALL
 		to check. Enabling this option will get image size increased
 		and performance decreased significantly.
 
+config MM_KASAN_MARK_LOCATION
+	string "Kasan's mark storage location"
+	---help---
+		The section where KASan mark is located. It can prevent
+		variables located in non-chip memory, and crashes
+		caused by instrumentation access
+
 if MM_KASAN_INSTRUMENT
 
 config MM_KASAN_REGIONS
diff --git a/mm/kasan/Make.defs b/mm/kasan/Make.defs
index 86ff1b6a45..911e77a792 100644
--- a/mm/kasan/Make.defs
+++ b/mm/kasan/Make.defs
@@ -28,6 +28,10 @@ ifeq ($(CONFIG_MM_KASAN),y)
   CFLAGS += -fno-sanitize=kernel-address
 endif
 
+ifneq ($(CONFIG_MM_KASAN_MARK_LOCATION),"")
+  CFLAGS += ${DEFINE_PREFIX}MM_KASAN_MARK_LOCATION=CONFIG_MM_KASAN_MARK_LOCATION
+endif
+
 # Add the core heap directory to the build
 
 DEPPATH += --dep-path kasan
diff --git a/mm/kasan/hook.c b/mm/kasan/hook.c
index e67b2cee1c..1127a37a08 100644
--- a/mm/kasan/hook.c
+++ b/mm/kasan/hook.c
@@ -120,7 +120,11 @@ static struct kasan_watchpoint_s g_watchpoint[MM_KASAN_WATCHPOINT];
 #endif
 
 #ifdef CONFIG_MM_KASAN
+#  ifdef MM_KASAN_MARK_LOCATION
+static uint32_t g_region_init locate_data(MM_KASAN_MARK_LOCATION);
+#  else
 static uint32_t g_region_init;
+#  endif
 #endif
 
 /****************************************************************************