mm: Use struct slab in kmem_obj_info()

All three implementations of slab support kmem_obj_info() which reports
details of an object allocated from the slab allocator.  By using the
slab type instead of the page type, we make it obvious that this can
only be called for slabs.

[ vbabka@suse.cz: also convert the related kmem_valid_obj() to folios ]

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Roman Gushchin <guro@fb.com>

diff --git a/mm/slab.c b/mm/slab.c
index 7f147805d0abdbd5133976086cff318ca67ca9b1..44bc1fcd13936a59bbee8de8b015731c5c790415 100644 (file)
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -3646,21 +3646,21 @@ EXPORT_SYMBOL(__kmalloc_node_track_caller);
 #endif /* CONFIG_NUMA */
 
 #ifdef CONFIG_PRINTK
-void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page)
+void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
 {
        struct kmem_cache *cachep;
        unsigned int objnr;
        void *objp;
 
        kpp->kp_ptr = object;
-       kpp->kp_page = page;
-       cachep = page->slab_cache;
+       kpp->kp_slab = slab;
+       cachep = slab->slab_cache;
        kpp->kp_slab_cache = cachep;
        objp = object - obj_offset(cachep);
        kpp->kp_data_offset = obj_offset(cachep);
-       page = virt_to_head_page(objp);
-       objnr = obj_to_index(cachep, page, objp);
-       objp = index_to_obj(cachep, page, objnr);
+       slab = virt_to_slab(objp);
+       objnr = obj_to_index(cachep, slab_page(slab), objp);
+       objp = index_to_obj(cachep, slab_page(slab), objnr);
        kpp->kp_objp = objp;
        if (DEBUG && cachep->flags & SLAB_STORE_USER)
                kpp->kp_ret = *dbg_userword(cachep, objp);

diff --git a/mm/slab.h b/mm/slab.h
index 1408ada9ff7295aae17c2d8bb9fdfdfb9c23ec86..9ae9f6c3d1cb33f77130f1cc81315625813e52d1 100644 (file)
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -801,7 +801,7 @@ static inline void debugfs_slab_release(struct kmem_cache *s) { }
 #define KS_ADDRS_COUNT 16
 struct kmem_obj_info {
        void *kp_ptr;
-       struct page *kp_page;
+       struct slab *kp_slab;
        void *kp_objp;
        unsigned long kp_data_offset;
        struct kmem_cache *kp_slab_cache;
@@ -809,7 +809,7 @@ struct kmem_obj_info {
        void *kp_stack[KS_ADDRS_COUNT];
        void *kp_free_stack[KS_ADDRS_COUNT];
 };
-void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page);
+void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab);
 #endif
 
 #endif /* MM_SLAB_H */

diff --git a/mm/slab_common.c b/mm/slab_common.c
index e5d080a9300933cdde0eddb679ab34596825cd54..dc15566141d4447bda26128a9a0158c5128ee081 100644 (file)
--- a/mm/slab_common.c
+++ b/mm/slab_common.c
@@ -550,13 +550,13 @@ bool slab_is_available(void)
  */
 bool kmem_valid_obj(void *object)
 {
-       struct page *page;
+       struct folio *folio;
 
        /* Some arches consider ZERO_SIZE_PTR to be a valid address. */
        if (object < (void *)PAGE_SIZE || !virt_addr_valid(object))
                return false;
-       page = virt_to_head_page(object);
-       return PageSlab(page);
+       folio = virt_to_folio(object);
+       return folio_test_slab(folio);
 }
 EXPORT_SYMBOL_GPL(kmem_valid_obj);
 
@@ -579,18 +579,18 @@ void kmem_dump_obj(void *object)
 {
        char *cp = IS_ENABLED(CONFIG_MMU) ? "" : "/vmalloc";
        int i;
-       struct page *page;
+       struct slab *slab;
        unsigned long ptroffset;
        struct kmem_obj_info kp = { };
 
        if (WARN_ON_ONCE(!virt_addr_valid(object)))
                return;
-       page = virt_to_head_page(object);
-       if (WARN_ON_ONCE(!PageSlab(page))) {
+       slab = virt_to_slab(object);
+       if (WARN_ON_ONCE(!slab)) {
                pr_cont(" non-slab memory.\n");
                return;
        }
-       kmem_obj_info(&kp, object, page);
+       kmem_obj_info(&kp, object, slab);
        if (kp.kp_slab_cache)
                pr_cont(" slab%s %s", cp, kp.kp_slab_cache->name);
        else

diff --git a/mm/slob.c b/mm/slob.c
index c8a4290012a6dfd61c04e0671be7b02e21b32dba..d2d15e7f191c29c3410990750c5ee071899bdd86 100644 (file)
--- a/mm/slob.c
+++ b/mm/slob.c
@@ -462,10 +462,10 @@ out:
 }
 
 #ifdef CONFIG_PRINTK
-void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page)
+void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
 {
        kpp->kp_ptr = object;
-       kpp->kp_page = page;
+       kpp->kp_slab = slab;
 }
 #endif
 

diff --git a/mm/slub.c b/mm/slub.c
index 269e10d341a8ccfe49c4f4c017de871b85345841..8e9667815f8135844a9e10f07042031fc612ad86 100644 (file)
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4322,31 +4322,32 @@ int __kmem_cache_shutdown(struct kmem_cache *s)
 }
 
 #ifdef CONFIG_PRINTK
-void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page)
+void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct slab *slab)
 {
        void *base;
        int __maybe_unused i;
        unsigned int objnr;
        void *objp;
        void *objp0;
-       struct kmem_cache *s = page->slab_cache;
+       struct kmem_cache *s = slab->slab_cache;
        struct track __maybe_unused *trackp;
 
        kpp->kp_ptr = object;
-       kpp->kp_page = page;
+       kpp->kp_slab = slab;
        kpp->kp_slab_cache = s;
-       base = page_address(page);
+       base = slab_address(slab);
        objp0 = kasan_reset_tag(object);
 #ifdef CONFIG_SLUB_DEBUG
        objp = restore_red_left(s, objp0);
 #else
        objp = objp0;
 #endif
-       objnr = obj_to_index(s, page, objp);
+       objnr = obj_to_index(s, slab_page(slab), objp);
        kpp->kp_data_offset = (unsigned long)((char *)objp0 - (char *)objp);
        objp = base + s->size * objnr;
        kpp->kp_objp = objp;
-       if (WARN_ON_ONCE(objp < base || objp >= base + page->objects * s->size || (objp - base) % s->size) ||
+       if (WARN_ON_ONCE(objp < base || objp >= base + slab->objects * s->size
+                        || (objp - base) % s->size) ||
            !(s->flags & SLAB_STORE_USER))
                return;
 #ifdef CONFIG_SLUB_DEBUG