Account slab allocations using codetag reference embedded into slabobj_ext.
Signed-off-by: Suren Baghdasaryan <[email protected]> Co-developed-by: Kent Overstreet <[email protected]> Signed-off-by: Kent Overstreet <[email protected]> Reviewed-by: Kees Cook <[email protected]> --- mm/slub.c | 91 ++++++++++++++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 90 insertions(+), 1 deletion(-) diff --git a/mm/slub.c b/mm/slub.c index e94d3cc1b270..ea122aeb89fc 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1942,7 +1942,69 @@ 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 (!need_slab_obj_ext()) + return NULL; + + 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) +{ + 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); + } +} + #else /* CONFIG_SLAB_OBJ_EXT */ + static int alloc_slab_obj_exts(struct slab *slab, struct kmem_cache *s, gfp_t gfp, bool new_slab) { @@ -1952,6 +2014,24 @@ 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 @@ -2381,7 +2461,7 @@ 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), @@ -3833,6 +3913,7 @@ 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; @@ -3875,6 +3956,12 @@ 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); + obj_exts = prepare_slab_obj_exts_hook(s, flags, p[i]); +#ifdef CONFIG_MEM_ALLOC_PROFILING + /* obj_exts can be allocated for other reasons */ + if (likely(obj_exts) && mem_alloc_profiling_enabled()) + alloc_tag_add(&obj_exts->ref, current->alloc_tag, s->size); +#endif } memcg_slab_post_alloc_hook(s, objcg, flags, size, p); @@ -4353,6 +4440,7 @@ 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); @@ -4363,6 +4451,7 @@ 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. -- 2.44.0.278.ge034bb2e1d-goog
