mm, slab: don't wrap internal functions with alloc_hooks()

The functions __kmalloc_noprof(), kmalloc_large_noprof(),
kmalloc_trace_noprof() and their _node variants are all internal to the
implementations of kmalloc_noprof() and kmalloc_node_noprof() and are
only declared in the "public" slab.h and exported so that those
implementations can be static inline and distinguish the build-time
constant size variants. The only other users for some of the internal
functions are slub_kunit and fortify_kunit tests which make very
short-lived allocations.

Therefore we can stop wrapping them with the alloc_hooks() macro.
Instead add a __ prefix to all of them and a comment documenting these
as internal. Also rename __kmalloc_trace() to __kmalloc_cache() which is
more descriptive - it is a variant of __kmalloc() where the exact
kmalloc cache has been already determined.

The usage in fortify_kunit can be removed completely, as the internal
functions should be tested already through kmalloc() tests in the
test variant that passes non-constant allocation size.

Reported-by: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Kent Overstreet <kent.overstreet@linux.dev>
Acked-by: David Rientjes <rientjes@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

diff --git a/include/linux/slab.h b/include/linux/slab.h
index 7247e217e21bd0faf6d8e4ab8770b48a14134c45..ed6bee5ec2b6ecf4b9bb1a4a09635e2c981dff19 100644 (file)
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -528,9 +528,6 @@ static_assert(PAGE_SHIFT <= 20);
 
 #include <linux/alloc_tag.h>
 
-void *__kmalloc_noprof(size_t size, gfp_t flags) __assume_kmalloc_alignment __alloc_size(1);
-#define __kmalloc(...)                         alloc_hooks(__kmalloc_noprof(__VA_ARGS__))
-
 /**
  * kmem_cache_alloc - Allocate an object
  * @cachep: The cache to allocate from.
@@ -568,31 +565,34 @@ static __always_inline void kfree_bulk(size_t size, void **p)
        kmem_cache_free_bulk(NULL, size, p);
 }
 
-void *__kmalloc_node_noprof(size_t size, gfp_t flags, int node) __assume_kmalloc_alignment
-                                                        __alloc_size(1);
-#define __kmalloc_node(...)                    alloc_hooks(__kmalloc_node_noprof(__VA_ARGS__))
-
 void *kmem_cache_alloc_node_noprof(struct kmem_cache *s, gfp_t flags,
                                   int node) __assume_slab_alignment __malloc;
 #define kmem_cache_alloc_node(...)     alloc_hooks(kmem_cache_alloc_node_noprof(__VA_ARGS__))
 
-void *kmalloc_trace_noprof(struct kmem_cache *s, gfp_t flags, size_t size)
-                   __assume_kmalloc_alignment __alloc_size(3);
+/*
+ * The following functions are not to be used directly and are intended only
+ * for internal use from kmalloc() and kmalloc_node()
+ * with the exception of kunit tests
+ */
+
+void *__kmalloc_noprof(size_t size, gfp_t flags)
+                               __assume_kmalloc_alignment __alloc_size(1);
+
+void *__kmalloc_node_noprof(size_t size, gfp_t flags, int node)
+                               __assume_kmalloc_alignment __alloc_size(1);
 
-void *kmalloc_node_trace_noprof(struct kmem_cache *s, gfp_t gfpflags,
-               int node, size_t size) __assume_kmalloc_alignment
-                                               __alloc_size(4);
-#define kmalloc_trace(...)                     alloc_hooks(kmalloc_trace_noprof(__VA_ARGS__))
+void *__kmalloc_cache_noprof(struct kmem_cache *s, gfp_t flags, size_t size)
+                               __assume_kmalloc_alignment __alloc_size(3);
 
-#define kmalloc_node_trace(...)                        alloc_hooks(kmalloc_node_trace_noprof(__VA_ARGS__))
+void *__kmalloc_cache_node_noprof(struct kmem_cache *s, gfp_t gfpflags,
+                                 int node, size_t size)
+                               __assume_kmalloc_alignment __alloc_size(4);
 
-void *kmalloc_large_noprof(size_t size, gfp_t flags) __assume_page_alignment
-                                             __alloc_size(1);
-#define kmalloc_large(...)                     alloc_hooks(kmalloc_large_noprof(__VA_ARGS__))
+void *__kmalloc_large_noprof(size_t size, gfp_t flags)
+                               __assume_page_alignment __alloc_size(1);
 
-void *kmalloc_large_node_noprof(size_t size, gfp_t flags, int node) __assume_page_alignment
-                                                            __alloc_size(1);
-#define kmalloc_large_node(...)                        alloc_hooks(kmalloc_large_node_noprof(__VA_ARGS__))
+void *__kmalloc_large_node_noprof(size_t size, gfp_t flags, int node)
+                               __assume_page_alignment __alloc_size(1);
 
 /**
  * kmalloc - allocate kernel memory
@@ -654,10 +654,10 @@ static __always_inline __alloc_size(1) void *kmalloc_noprof(size_t size, gfp_t f
                unsigned int index;
 
                if (size > KMALLOC_MAX_CACHE_SIZE)
-                       return kmalloc_large_noprof(size, flags);
+                       return __kmalloc_large_noprof(size, flags);
 
                index = kmalloc_index(size);
-               return kmalloc_trace_noprof(
+               return __kmalloc_cache_noprof(
                                kmalloc_caches[kmalloc_type(flags, _RET_IP_)][index],
                                flags, size);
        }
@@ -671,10 +671,10 @@ static __always_inline __alloc_size(1) void *kmalloc_node_noprof(size_t size, gf
                unsigned int index;
 
                if (size > KMALLOC_MAX_CACHE_SIZE)
-                       return kmalloc_large_node_noprof(size, flags, node);
+                       return __kmalloc_large_node_noprof(size, flags, node);
 
                index = kmalloc_index(size);
-               return kmalloc_node_trace_noprof(
+               return __kmalloc_cache_node_noprof(
                                kmalloc_caches[kmalloc_type(flags, _RET_IP_)][index],
                                flags, node, size);
        }

diff --git a/lib/fortify_kunit.c b/lib/fortify_kunit.c
index 39da5b3bc649c28896e60d9dac974b98973da8d0..044f409ef85679799ecddf3406db2dbbc9af1b6a 100644 (file)
--- a/lib/fortify_kunit.c
+++ b/lib/fortify_kunit.c
@@ -233,11 +233,6 @@ static void fortify_test_alloc_size_##allocator##_dynamic(struct kunit *test) \
                kfree(p));                                              \
        checker(expected_size,                                          \
                kmalloc_array_node(alloc_size, 1, gfp, NUMA_NO_NODE),   \
-               kfree(p));                                              \
-       checker(expected_size, __kmalloc(alloc_size, gfp),              \
-               kfree(p));                                              \
-       checker(expected_size,                                          \
-               __kmalloc_node(alloc_size, gfp, NUMA_NO_NODE),          \
                kfree(p));                                              \
                                                                        \
        orig = kmalloc(alloc_size, gfp);                                \

diff --git a/lib/slub_kunit.c b/lib/slub_kunit.c
index 4ce9604388069dd927e367630e18cfce32010f41..e6667a28c0149141141c34f7ac4e03c1893727ea 100644 (file)
--- a/lib/slub_kunit.c
+++ b/lib/slub_kunit.c
@@ -140,7 +140,7 @@ static void test_kmalloc_redzone_access(struct kunit *test)
 {
        struct kmem_cache *s = test_kmem_cache_create("TestSlub_RZ_kmalloc", 32,
                                SLAB_KMALLOC|SLAB_STORE_USER|SLAB_RED_ZONE);
-       u8 *p = kmalloc_trace(s, GFP_KERNEL, 18);
+       u8 *p = __kmalloc_cache_noprof(s, GFP_KERNEL, 18);
 
        kasan_disable_current();
 

diff --git a/mm/slub.c b/mm/slub.c
index 0809760cf789d11ee385f1f31da71635a455dd71..95e0a3332c4498cb6e8cf0c8453c39bab08e9465 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4053,7 +4053,7 @@ EXPORT_SYMBOL(kmem_cache_alloc_node_noprof);
  * directly to the page allocator. We use __GFP_COMP, because we will need to
  * know the allocation order to free the pages properly in kfree.
  */
-static void *__kmalloc_large_node(size_t size, gfp_t flags, int node)
+static void *___kmalloc_large_node(size_t size, gfp_t flags, int node)
 {
        struct folio *folio;
        void *ptr = NULL;
@@ -4078,25 +4078,25 @@ static void *__kmalloc_large_node(size_t size, gfp_t flags, int node)
        return ptr;
 }
 
-void *kmalloc_large_noprof(size_t size, gfp_t flags)
+void *__kmalloc_large_noprof(size_t size, gfp_t flags)
 {
-       void *ret = __kmalloc_large_node(size, flags, NUMA_NO_NODE);
+       void *ret = ___kmalloc_large_node(size, flags, NUMA_NO_NODE);
 
        trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << get_order(size),
                      flags, NUMA_NO_NODE);
        return ret;
 }
-EXPORT_SYMBOL(kmalloc_large_noprof);
+EXPORT_SYMBOL(__kmalloc_large_noprof);
 
-void *kmalloc_large_node_noprof(size_t size, gfp_t flags, int node)
+void *__kmalloc_large_node_noprof(size_t size, gfp_t flags, int node)
 {
-       void *ret = __kmalloc_large_node(size, flags, node);
+       void *ret = ___kmalloc_large_node(size, flags, node);
 
        trace_kmalloc(_RET_IP_, ret, size, PAGE_SIZE << get_order(size),
                      flags, node);
        return ret;
 }
-EXPORT_SYMBOL(kmalloc_large_node_noprof);
+EXPORT_SYMBOL(__kmalloc_large_node_noprof);
 
 static __always_inline
 void *__do_kmalloc_node(size_t size, gfp_t flags, int node,
@@ -4106,7 +4106,7 @@ void *__do_kmalloc_node(size_t size, gfp_t flags, int node,
        void *ret;
 
        if (unlikely(size > KMALLOC_MAX_CACHE_SIZE)) {
-               ret = __kmalloc_large_node(size, flags, node);
+               ret = __kmalloc_large_node_noprof(size, flags, node);
                trace_kmalloc(caller, ret, size,
                              PAGE_SIZE << get_order(size), flags, node);
                return ret;
@@ -4142,7 +4142,7 @@ void *kmalloc_node_track_caller_noprof(size_t size, gfp_t flags,
 }
 EXPORT_SYMBOL(kmalloc_node_track_caller_noprof);
 
-void *kmalloc_trace_noprof(struct kmem_cache *s, gfp_t gfpflags, size_t size)
+void *__kmalloc_cache_noprof(struct kmem_cache *s, gfp_t gfpflags, size_t size)
 {
        void *ret = slab_alloc_node(s, NULL, gfpflags, NUMA_NO_NODE,
                                            _RET_IP_, size);
@@ -4152,10 +4152,10 @@ void *kmalloc_trace_noprof(struct kmem_cache *s, gfp_t gfpflags, size_t size)
        ret = kasan_kmalloc(s, ret, size, gfpflags);
        return ret;
 }
-EXPORT_SYMBOL(kmalloc_trace_noprof);
+EXPORT_SYMBOL(__kmalloc_cache_noprof);
 
-void *kmalloc_node_trace_noprof(struct kmem_cache *s, gfp_t gfpflags,
-                        int node, size_t size)
+void *__kmalloc_cache_node_noprof(struct kmem_cache *s, gfp_t gfpflags,
+                                 int node, size_t size)
 {
        void *ret = slab_alloc_node(s, NULL, gfpflags, node, _RET_IP_, size);
 
@@ -4164,7 +4164,7 @@ void *kmalloc_node_trace_noprof(struct kmem_cache *s, gfp_t gfpflags,
        ret = kasan_kmalloc(s, ret, size, gfpflags);
        return ret;
 }
-EXPORT_SYMBOL(kmalloc_node_trace_noprof);
+EXPORT_SYMBOL(__kmalloc_cache_node_noprof);
 
 static noinline void free_to_partial_list(
        struct kmem_cache *s, struct slab *slab,