From 4b8736964640fe160724e7135dc62883bddcdace Mon Sep 17 00:00:00 2001 From: Suren Baghdasaryan Date: Thu, 21 Mar 2024 09:36:45 -0700 Subject: [PATCH] mm/slab: add allocation accounting into slab allocation and free paths MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Account slab allocations using codetag reference embedded into slabobj_ext. Link: https://lkml.kernel.org/r/20240321163705.3067592-24-surenb@google.com Signed-off-by: Suren Baghdasaryan Co-developed-by: Kent Overstreet Signed-off-by: Kent Overstreet Reviewed-by: Kees Cook Reviewed-by: Vlastimil Babka Tested-by: Kees Cook Cc: Alexander Viro Cc: Alex Gaynor Cc: Alice Ryhl Cc: Andreas Hindborg Cc: Benno Lossin Cc: "Björn Roy Baron" Cc: Boqun Feng Cc: Christoph Lameter Cc: Dennis Zhou Cc: Gary Guo Cc: Miguel Ojeda Cc: Pasha Tatashin Cc: Peter Zijlstra Cc: Tejun Heo Cc: Wedson Almeida Filho Signed-off-by: Andrew Morton --- mm/slub.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 95 insertions(+), 1 deletion(-) diff --git a/mm/slub.c b/mm/slub.c index 666dcc3b8a2688..5840ab9633195b 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1932,7 +1932,68 @@ static inline void free_slab_obj_exts(struct slab *slab) kfree(obj_exts); slab->obj_exts = 0; } + +static inline bool need_slab_obj_ext(void) +{ + if (mem_alloc_profiling_enabled()) + return true; + + /* + * CONFIG_MEMCG_KMEM creates vector of obj_cgroup objects conditionally + * inside memcg_slab_post_alloc_hook. No other users for now. + */ + return false; +} + +static inline struct slabobj_ext * +prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p) +{ + struct slab *slab; + + if (!p) + return NULL; + + if (s->flags & SLAB_NO_OBJ_EXT) + return NULL; + + if (flags & __GFP_NO_OBJ_EXT) + return NULL; + + slab = virt_to_slab(p); + if (!slab_obj_exts(slab) && + WARN(alloc_slab_obj_exts(slab, s, flags, false), + "%s, %s: Failed to create slab extension vector!\n", + __func__, s->name)) + return NULL; + + return slab_obj_exts(slab) + obj_to_index(s, slab, p); +} + +static inline void +alloc_tagging_slab_free_hook(struct kmem_cache *s, struct slab *slab, void **p, + int objects) +{ +#ifdef CONFIG_MEM_ALLOC_PROFILING + struct slabobj_ext *obj_exts; + int i; + + if (!mem_alloc_profiling_enabled()) + return; + + obj_exts = slab_obj_exts(slab); + if (!obj_exts) + return; + + for (i = 0; i < objects; i++) { + unsigned int off = obj_to_index(s, slab, p[i]); + + alloc_tag_sub(&obj_exts[off].ref, s->size); + } +#endif +} + #else /* CONFIG_SLAB_OBJ_EXT */ + static int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, gfp_t gfp, bool new_slab) { @@ -1942,6 +2003,24 @@ static int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, static inline void free_slab_obj_exts(struct slab *slab) { } + +static inline bool need_slab_obj_ext(void) +{ + return false; +} + +static inline struct slabobj_ext * +prepare_slab_obj_exts_hook(struct kmem_cache *s, gfp_t flags, void *p) +{ + return NULL; +} + +static inline void +alloc_tagging_slab_free_hook(struct kmem_cache *s, struct slab *slab, void **p, + int objects) +{ +} + #endif /* CONFIG_SLAB_OBJ_EXT */ #ifdef CONFIG_MEMCG_KMEM @@ -2370,7 +2449,7 @@ static __always_inline void account_slab(struct slab *slab, int order, static __always_inline void unaccount_slab(struct slab *slab, int order, struct kmem_cache *s) { - if (memcg_kmem_online()) + if (memcg_kmem_online() || need_slab_obj_ext()) free_slab_obj_exts(slab); mod_node_page_state(slab_pgdat(slab), cache_vmstat_idx(s), @@ -3823,6 +3902,7 @@ void slab_post_alloc_hook(struct kmem_cache *s, struct obj_cgroup *objcg, unsigned int orig_size) { unsigned int zero_size = s->object_size; + struct slabobj_ext *obj_exts; bool kasan_init = init; size_t i; gfp_t init_flags = flags & gfp_allowed_mask; @@ -3865,6 +3945,18 @@ void slab_post_alloc_hook(struct kmem_cache *s, struct obj_cgroup *objcg, kmemleak_alloc_recursive(p[i], s->object_size, 1, s->flags, init_flags); kmsan_slab_alloc(s, p[i], init_flags); + if (need_slab_obj_ext()) { + obj_exts = prepare_slab_obj_exts_hook(s, flags, p[i]); +#ifdef CONFIG_MEM_ALLOC_PROFILING + /* + * Currently obj_exts is used only for allocation profiling. + * If other users appear then mem_alloc_profiling_enabled() + * check should be added before alloc_tag_add(). + */ + if (likely(obj_exts)) + alloc_tag_add(&obj_exts->ref, current->alloc_tag, s->size); +#endif + } } memcg_slab_post_alloc_hook(s, objcg, flags, size, p); @@ -4339,6 +4431,7 @@ void slab_free(struct kmem_cache *s, struct slab *slab, void *object, unsigned long addr) { memcg_slab_free_hook(s, slab, &object, 1); + alloc_tagging_slab_free_hook(s, slab, &object, 1); if (likely(slab_free_hook(s, object, slab_want_init_on_free(s)))) do_slab_free(s, slab, object, object, 1, addr); @@ -4349,6 +4442,7 @@ void slab_free_bulk(struct kmem_cache *s, struct slab *slab, void *head, void *tail, void **p, int cnt, unsigned long addr) { memcg_slab_free_hook(s, slab, p, cnt); + alloc_tagging_slab_free_hook(s, slab, p, cnt); /* * With KASAN enabled slab_free_freelist_hook modifies the freelist * to remove objects, whose reuse must be delayed.