[PATCH v2 13/21] mm/slab: move pre/post-alloc hooks from slab.h to slub.c

Vlastimil Babka
2023-11-20T18:34:45Z

We don't share the hooks between two slab implementations anymore so
they can be moved away from the header. As part of the move, also move
should_failslab() from slab_common.c as the pre_alloc hook uses it.
This means slab.h can stop including fault-inject.h and kmemleak.h.
Fix up some files that were depending on the includes transitively.

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
---
mm/kasan/report.c | 1 +
mm/memcontrol.c | 1 +
mm/slab.h | 72 -------------------------------------------------
mm/slab_common.c | 8 +-----
mm/slub.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
5 files changed, 84 insertions(+), 79 deletions(-)

diff --git a/mm/kasan/report.c b/mm/kasan/report.c
index e77facb62900..011f727bfaff 100644
--- a/mm/kasan/report.c
+++ b/mm/kasan/report.c
@@ -23,6 +23,7 @@
#include <linux/stacktrace.h>
#include <linux/string.h>
#include <linux/types.h>
+#include <linux/vmalloc.h>
#include <linux/kasan.h>
#include <linux/module.h>
#include <linux/sched/task_stack.h>
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 947fb50eba31..8a0603517065 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -64,6 +64,7 @@
#include <linux/psi.h>
#include <linux/seq_buf.h>
#include <linux/sched/isolation.h>
+#include <linux/kmemleak.h>
#include "internal.h"
#include <net/sock.h>
#include <net/ip.h>
diff --git a/mm/slab.h b/mm/slab.h
index 1ac3a2f8d4c0..65ebf86b3fe9 100644
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -9,8 +9,6 @@
#include <linux/kobject.h>
#include <linux/sched/mm.h>
#include <linux/memcontrol.h>
-#include <linux/fault-inject.h>
-#include <linux/kmemleak.h>
#include <linux/kfence.h>
#include <linux/kasan.h>

@@ -796,76 +794,6 @@ static inline size_t slab_ksize(const struct kmem_cache *s)
return s->size;
}

-static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
- struct list_lru *lru,
- struct obj_cgroup **objcgp,
- size_t size, gfp_t flags)
-{
- flags &= gfp_allowed_mask;
-
- might_alloc(flags);
-
- if (should_failslab(s, flags))
- return NULL;
-
- if (!memcg_slab_pre_alloc_hook(s, lru, objcgp, size, flags))
- return NULL;
-
- return s;
-}
-
-static inline void slab_post_alloc_hook(struct kmem_cache *s,
- struct obj_cgroup *objcg, gfp_t flags,
- size_t size, void **p, bool init,
- unsigned int orig_size)
-{
- unsigned int zero_size = s->object_size;
- bool kasan_init = init;
- size_t i;
-
- flags &= gfp_allowed_mask;
-
- /*
- * For kmalloc object, the allocated memory size(object_size) is likely
- * larger than the requested size(orig_size). If redzone check is
- * enabled for the extra space, don't zero it, as it will be redzoned
- * soon. The redzone operation for this extra space could be seen as a
- * replacement of current poisoning under certain debug option, and
- * won't break other sanity checks.
- */
- if (kmem_cache_debug_flags(s, SLAB_STORE_USER | SLAB_RED_ZONE) &&
- (s->flags & SLAB_KMALLOC))
- zero_size = orig_size;
-
- /*
- * When slub_debug is enabled, avoid memory initialization integrated
- * into KASAN and instead zero out the memory via the memset below with
- * the proper size. Otherwise, KASAN might overwrite SLUB redzones and
- * cause false-positive reports. This does not lead to a performance
- * penalty on production builds, as slub_debug is not intended to be
- * enabled there.
- */
- if (__slub_debug_enabled())
- kasan_init = false;
-
- /*
- * As memory initialization might be integrated into KASAN,
- * kasan_slab_alloc and initialization memset must be
- * kept together to avoid discrepancies in behavior.
- *
- * As p[i] might get tagged, memset and kmemleak hook come after KASAN.
- */
- for (i = 0; i < size; i++) {
- p[i] = kasan_slab_alloc(s, p[i], flags, kasan_init);
- if (p[i] && init && (!kasan_init || !kasan_has_integrated_init()))
- memset(p[i], 0, zero_size);
- kmemleak_alloc_recursive(p[i], s->object_size, 1,
- s->flags, flags);
- kmsan_slab_alloc(s, p[i], flags);
- }
-
- memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
-}

/*
* The slab lists for all objects.
diff --git a/mm/slab_common.c b/mm/slab_common.c
index 63b8411db7ce..bbc2e3f061f1 100644
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -21,6 +21,7 @@
#include <linux/swiotlb.h>
#include <linux/proc_fs.h>
#include <linux/debugfs.h>
+#include <linux/kmemleak.h>
#include <linux/kasan.h>
#include <asm/cacheflush.h>
#include <asm/tlbflush.h>
@@ -1470,10 +1471,3 @@ EXPORT_TRACEPOINT_SYMBOL(kmem_cache_alloc);
EXPORT_TRACEPOINT_SYMBOL(kfree);
EXPORT_TRACEPOINT_SYMBOL(kmem_cache_free);

-int should_failslab(struct kmem_cache *s, gfp_t gfpflags)
-{
- if (__should_failslab(s, gfpflags))
- return -ENOMEM;
- return 0;
-}
-ALLOW_ERROR_INJECTION(should_failslab, ERRNO);
diff --git a/mm/slub.c b/mm/slub.c
index 979932d046fd..9eb6508152c2 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -34,6 +34,7 @@
#include <linux/memory.h>
#include <linux/math64.h>
#include <linux/fault-inject.h>
+#include <linux/kmemleak.h>
#include <linux/stacktrace.h>
#include <linux/prefetch.h>
#include <linux/memcontrol.h>
@@ -3494,6 +3495,86 @@ static __always_inline void maybe_wipe_obj_freeptr(struct kmem_cache *s,
0, sizeof(void *));
}

+noinline int should_failslab(struct kmem_cache *s, gfp_t gfpflags)
+{
+ if (__should_failslab(s, gfpflags))
+ return -ENOMEM;
+ return 0;
+}
+ALLOW_ERROR_INJECTION(should_failslab, ERRNO);
+
+static inline struct kmem_cache *slab_pre_alloc_hook(struct kmem_cache *s,
+ struct list_lru *lru,
+ struct obj_cgroup **objcgp,
+ size_t size, gfp_t flags)
+{
+ flags &= gfp_allowed_mask;
+
+ might_alloc(flags);
+
+ if (should_failslab(s, flags))
+ return NULL;
+
+ if (!memcg_slab_pre_alloc_hook(s, lru, objcgp, size, flags))
+ return NULL;
+
+ return s;
+}
+
+static inline void slab_post_alloc_hook(struct kmem_cache *s,
+ struct obj_cgroup *objcg, gfp_t flags,
+ size_t size, void **p, bool init,
+ unsigned int orig_size)
+{
+ unsigned int zero_size = s->object_size;
+ bool kasan_init = init;
+ size_t i;
+
+ flags &= gfp_allowed_mask;
+
+ /*
+ * For kmalloc object, the allocated memory size(object_size) is likely
+ * larger than the requested size(orig_size). If redzone check is
+ * enabled for the extra space, don't zero it, as it will be redzoned
+ * soon. The redzone operation for this extra space could be seen as a
+ * replacement of current poisoning under certain debug option, and
+ * won't break other sanity checks.
+ */
+ if (kmem_cache_debug_flags(s, SLAB_STORE_USER | SLAB_RED_ZONE) &&
+ (s->flags & SLAB_KMALLOC))
+ zero_size = orig_size;
+
+ /*
+ * When slub_debug is enabled, avoid memory initialization integrated
+ * into KASAN and instead zero out the memory via the memset below with
+ * the proper size. Otherwise, KASAN might overwrite SLUB redzones and
+ * cause false-positive reports. This does not lead to a performance
+ * penalty on production builds, as slub_debug is not intended to be
+ * enabled there.
+ */
+ if (__slub_debug_enabled())
+ kasan_init = false;
+
+ /*
+ * As memory initialization might be integrated into KASAN,
+ * kasan_slab_alloc and initialization memset must be
+ * kept together to avoid discrepancies in behavior.
+ *
+ * As p[i] might get tagged, memset and kmemleak hook come after KASAN.
+ */
+ for (i = 0; i < size; i++) {
+ p[i] = kasan_slab_alloc(s, p[i], flags, kasan_init);
+ if (p[i] && init && (!kasan_init ||
+ !kasan_has_integrated_init()))
+ memset(p[i], 0, zero_size);
+ kmemleak_alloc_recursive(p[i], s->object_size, 1,
+ s->flags, flags);
+ kmsan_slab_alloc(s, p[i], flags);
+ }
+
+ memcg_slab_post_alloc_hook(s, objcg, flags, size, p);
+}
+
/*
* Inlined fastpath so that allocation functions (kmalloc, kmem_cache_alloc)
* have the fastpath folded into their functions. So no function call

--
2.42.1