[PATCH v3 03/39] kasan: group vmalloc code

Andrey Konovalov
2020-09-24T22:51:05Z

This is a preparatory commit for the upcoming addition of a new hardware
tag-based (MTE-based) KASAN mode.

Group all vmalloc-related function declarations in include/linux/kasan.h,
and their implementations in mm/kasan/common.c.

No functional changes.

Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
---
Change-Id: Ie20b6c689203cd6de4fd7f2c465ec081c00c5f15
---
include/linux/kasan.h | 41 +++++++++++++----------
mm/kasan/common.c | 78 ++++++++++++++++++++++---------------------
2 files changed, 63 insertions(+), 56 deletions(-)

diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 087fba34b209..bd5b4965a269 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -69,19 +69,6 @@ struct kasan_cache {
int free_meta_offset;
};

-/*
- * These functions provide a special case to support backing module
- * allocations with real shadow memory. With KASAN vmalloc, the special
- * case is unnecessary, as the work is handled in the generic case.
- */
-#ifndef CONFIG_KASAN_VMALLOC
-int kasan_module_alloc(void *addr, size_t size);
-void kasan_free_shadow(const struct vm_struct *vm);
-#else
-static inline int kasan_module_alloc(void *addr, size_t size) { return 0; }
-static inline void kasan_free_shadow(const struct vm_struct *vm) {}
-#endif
-
int kasan_add_zero_shadow(void *start, unsigned long size);
void kasan_remove_zero_shadow(void *start, unsigned long size);

@@ -150,9 +137,6 @@ static inline bool kasan_slab_free(struct kmem_cache *s, void *object,
return false;
}

-static inline int kasan_module_alloc(void *addr, size_t size) { return 0; }
-static inline void kasan_free_shadow(const struct vm_struct *vm) {}
-
static inline int kasan_add_zero_shadow(void *start, unsigned long size)
{
return 0;
@@ -205,13 +189,16 @@ static inline void *kasan_reset_tag(const void *addr)
#endif /* CONFIG_KASAN_SW_TAGS */

#ifdef CONFIG_KASAN_VMALLOC
+
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);
-#else
+
+#else /* CONFIG_KASAN_VMALLOC */
+
static inline int kasan_populate_vmalloc(unsigned long start,
unsigned long size)
{
@@ -226,7 +213,25 @@ static inline void kasan_release_vmalloc(unsigned long start,
unsigned long end,
unsigned long free_region_start,
unsigned long free_region_end) {}
-#endif
+
+#endif /* CONFIG_KASAN_VMALLOC */
+
+#if defined(CONFIG_KASAN) && !defined(CONFIG_KASAN_VMALLOC)
+
+/*
+ * These functions provide a special case to support backing module
+ * allocations with real shadow memory. With KASAN vmalloc, the special
+ * case is unnecessary, as the work is handled in the generic case.
+ */
+int kasan_module_alloc(void *addr, size_t size);
+void kasan_free_shadow(const struct vm_struct *vm);
+
+#else /* CONFIG_KASAN && !CONFIG_KASAN_VMALLOC */
+
+static inline int kasan_module_alloc(void *addr, size_t size) { return 0; }
+static inline void kasan_free_shadow(const struct vm_struct *vm) {}
+
+#endif /* CONFIG_KASAN && !CONFIG_KASAN_VMALLOC */

#ifdef CONFIG_KASAN_INLINE
void kasan_non_canonical_hook(unsigned long addr);
diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index 33d863f55db1..89e5ef9417a7 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -536,44 +536,6 @@ void kasan_kfree_large(void *ptr, unsigned long ip)
/* The object will be poisoned by page_alloc. */
}

-#ifndef CONFIG_KASAN_VMALLOC
-int kasan_module_alloc(void *addr, size_t size)
-{
- void *ret;
- size_t scaled_size;
- size_t shadow_size;
- unsigned long shadow_start;
-
- shadow_start = (unsigned long)kasan_mem_to_shadow(addr);
- scaled_size = (size + KASAN_SHADOW_MASK) >> KASAN_SHADOW_SCALE_SHIFT;
- shadow_size = round_up(scaled_size, PAGE_SIZE);
-
- if (WARN_ON(!PAGE_ALIGNED(shadow_start)))
- return -EINVAL;
-
- ret = __vmalloc_node_range(shadow_size, 1, shadow_start,
- shadow_start + shadow_size,
- GFP_KERNEL,
- PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE,
- __builtin_return_address(0));
-
- if (ret) {
- __memset(ret, KASAN_SHADOW_INIT, shadow_size);
- find_vm_area(addr)->flags |= VM_KASAN;
- kmemleak_ignore(ret);
- return 0;
- }
-
- return -ENOMEM;
-}
-
-void kasan_free_shadow(const struct vm_struct *vm)
-{
- if (vm->flags & VM_KASAN)
- vfree(kasan_mem_to_shadow(vm->addr));
-}
-#endif
-
#ifdef CONFIG_MEMORY_HOTPLUG
static bool shadow_mapped(unsigned long addr)
{
@@ -685,6 +647,7 @@ core_initcall(kasan_memhotplug_init);
#endif

#ifdef CONFIG_KASAN_VMALLOC
+
static int kasan_populate_vmalloc_pte(pte_t *ptep, unsigned long addr,
void *unused)
{
@@ -923,4 +886,43 @@ void kasan_release_vmalloc(unsigned long start, unsigned long end,
(unsigned long)shadow_end);
}
}
+
+#else /* CONFIG_KASAN_VMALLOC */
+
+int kasan_module_alloc(void *addr, size_t size)
+{
+ void *ret;
+ size_t scaled_size;
+ size_t shadow_size;
+ unsigned long shadow_start;
+
+ shadow_start = (unsigned long)kasan_mem_to_shadow(addr);
+ scaled_size = (size + KASAN_SHADOW_MASK) >> KASAN_SHADOW_SCALE_SHIFT;
+ shadow_size = round_up(scaled_size, PAGE_SIZE);
+
+ if (WARN_ON(!PAGE_ALIGNED(shadow_start)))
+ return -EINVAL;
+
+ ret = __vmalloc_node_range(shadow_size, 1, shadow_start,
+ shadow_start + shadow_size,
+ GFP_KERNEL,
+ PAGE_KERNEL, VM_NO_GUARD, NUMA_NO_NODE,
+ __builtin_return_address(0));
+
+ if (ret) {
+ __memset(ret, KASAN_SHADOW_INIT, shadow_size);
+ find_vm_area(addr)->flags |= VM_KASAN;
+ kmemleak_ignore(ret);
+ return 0;
+ }
+
+ return -ENOMEM;
+}
+
+void kasan_free_shadow(const struct vm_struct *vm)
+{
+ if (vm->flags & VM_KASAN)
+ vfree(kasan_mem_to_shadow(vm->addr));
+}
+
#endif
--
2.28.0.681.g6f77f65b4e-goog