[PATCH v6 20/39] kasan: add wrappers for vmalloc hooks

[andrey.konovalov@linux.dev]

From: Andrey Konovalov <andreyknvl@google.com>

Add wrappers around functions that [un]poison memory for vmalloc
allocations. These functions will be used by HW_TAGS KASAN and
therefore need to be disabled when kasan=off command line argument
is provided.

This patch does no functional changes for software KASAN modes.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
---
 include/linux/kasan.h | 17 +++++++++++++++--
 mm/kasan/shadow.c     |  5 ++---
 2 files changed, 17 insertions(+), 5 deletions(-)

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 46a63374c86f..da320069e7cf 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -424,8 +424,21 @@ void kasan_release_vmalloc(unsigned long start, unsigned long end,
 			   unsigned long free_region_start,
 			   unsigned long free_region_end);
 
-void kasan_unpoison_vmalloc(const void *start, unsigned long size);
-void kasan_poison_vmalloc(const void *start, unsigned long size);
+void __kasan_unpoison_vmalloc(const void *start, unsigned long size);
+static __always_inline void kasan_unpoison_vmalloc(const void *start,
+						   unsigned long size)
+{
+	if (kasan_enabled())
+		__kasan_unpoison_vmalloc(start, size);
+}
+
+void __kasan_poison_vmalloc(const void *start, unsigned long size);
+static __always_inline void kasan_poison_vmalloc(const void *start,
+						 unsigned long size)
+{
+	if (kasan_enabled())
+		__kasan_poison_vmalloc(start, size);
+}
 
 #else /* CONFIG_KASAN_VMALLOC */
 
diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
index bf7ab62fbfb9..39d0b32ebf70 100644
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -475,8 +475,7 @@ void kasan_release_vmalloc(unsigned long start, unsigned long end,
 	}
 }
 
-
-void kasan_unpoison_vmalloc(const void *start, unsigned long size)
+void __kasan_unpoison_vmalloc(const void *start, unsigned long size)
 {
 	if (!is_vmalloc_or_module_addr(start))
 		return;
@@ -488,7 +487,7 @@ void kasan_unpoison_vmalloc(const void *start, unsigned long size)
  * Poison the shadow for a vmalloc region. Called as part of the
  * freeing process at the time the region is freed.
  */
-void kasan_poison_vmalloc(const void *start, unsigned long size)
+void __kasan_poison_vmalloc(const void *start, unsigned long size)
 {
 	if (!is_vmalloc_or_module_addr(start))
 		return;
-- 
2.25.1