[PATCH v6 19/39] kasan: reorder vmalloc hooks

andrey.konovalov
2022-01-24T18:49:52Z

Group functions that [de]populate shadow memory for vmalloc.
Group functions that [un]poison memory for vmalloc.

This patch does no functional changes but prepares KASAN code for
adding vmalloc support to HW_TAGS KASAN.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Alexander Potapenko <glider@google.com>
---
include/linux/kasan.h | 20 +++++++++-----------
mm/kasan/shadow.c | 43 ++++++++++++++++++++++---------------------
2 files changed, 31 insertions(+), 32 deletions(-)

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 55f1d4edf6b5..46a63374c86f 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -418,34 +418,32 @@ static inline void kasan_init_hw_tags(void) { }

#ifdef CONFIG_KASAN_VMALLOC

+void kasan_populate_early_vm_area_shadow(void *start, unsigned long size);
int kasan_populate_vmalloc(unsigned long addr, unsigned long size);
-void kasan_poison_vmalloc(const void *start, unsigned long size);
-void kasan_unpoison_vmalloc(const void *start, unsigned long size);
void kasan_release_vmalloc(unsigned long start, unsigned long end,
unsigned long free_region_start,
unsigned long free_region_end);

-void kasan_populate_early_vm_area_shadow(void *start, unsigned long size);
+void kasan_unpoison_vmalloc(const void *start, unsigned long size);
+void kasan_poison_vmalloc(const void *start, unsigned long size);

#else /* CONFIG_KASAN_VMALLOC */

+static inline void kasan_populate_early_vm_area_shadow(void *start,
+ unsigned long size) { }
static inline int kasan_populate_vmalloc(unsigned long start,
unsigned long size)
{
return 0;
}
-
-static inline void kasan_poison_vmalloc(const void *start, unsigned long size)
-{ }
-static inline void kasan_unpoison_vmalloc(const void *start, unsigned long size)
-{ }
static inline void kasan_release_vmalloc(unsigned long start,
unsigned long end,
unsigned long free_region_start,
- unsigned long free_region_end) {}
+ unsigned long free_region_end) { }

-static inline void kasan_populate_early_vm_area_shadow(void *start,
- unsigned long size)
+static inline void kasan_unpoison_vmalloc(const void *start, unsigned long size)
+{ }
+static inline void kasan_poison_vmalloc(const void *start, unsigned long size)
{ }

#endif /* CONFIG_KASAN_VMALLOC */
diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c
index e5c4393eb861..bf7ab62fbfb9 100644
--- a/mm/kasan/shadow.c
+++ b/mm/kasan/shadow.c
@@ -345,27 +345,6 @@ int kasan_populate_vmalloc(unsigned long addr, unsigned long size)
return 0;
}

-/*
- * 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)
-{
- if (!is_vmalloc_or_module_addr(start))
- return;
-
- size = round_up(size, KASAN_GRANULE_SIZE);
- kasan_poison(start, size, KASAN_VMALLOC_INVALID, false);
-}
-
-void kasan_unpoison_vmalloc(const void *start, unsigned long size)
-{
- if (!is_vmalloc_or_module_addr(start))
- return;
-
- kasan_unpoison(start, size, false);
-}
-
static int kasan_depopulate_vmalloc_pte(pte_t *ptep, unsigned long addr,
void *unused)
{
@@ -496,6 +475,28 @@ void kasan_release_vmalloc(unsigned long start, unsigned long end,
}
}

+
+void kasan_unpoison_vmalloc(const void *start, unsigned long size)
+{
+ if (!is_vmalloc_or_module_addr(start))
+ return;
+
+ kasan_unpoison(start, size, false);
+}
+
+/*
+ * 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)
+{
+ if (!is_vmalloc_or_module_addr(start))
+ return;
+
+ size = round_up(size, KASAN_GRANULE_SIZE);
+ kasan_poison(start, size, KASAN_VMALLOC_INVALID, false);
+}
+
#else /* CONFIG_KASAN_VMALLOC */

int kasan_alloc_module_shadow(void *addr, size_t size, gfp_t gfp_mask)