From 5bb1bb353cfe343fc3c84faf06f72ba309fde541 Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Thu, 7 Jan 2021 13:46:11 -0800 Subject: mm: Don't build mm_dump_obj() on CONFIG_PRINTK=n kernels The mem_dump_obj() functionality adds a few hundred bytes, which is a small price to pay. Except on kernels built with CONFIG_PRINTK=n, in which mem_dump_obj() messages will be suppressed. This commit therefore makes mem_dump_obj() be a static inline empty function on kernels built with CONFIG_PRINTK=n and excludes all of its support functions as well. This avoids kernel bloat on systems that cannot use mem_dump_obj(). Cc: Christoph Lameter Cc: Pekka Enberg Cc: David Rientjes Cc: Joonsoo Kim Cc: Suggested-by: Andrew Morton Signed-off-by: Paul E. McKenney --- mm/slab.c | 2 ++ mm/slab.h | 2 ++ mm/slab_common.c | 2 ++ mm/slob.c | 2 ++ mm/slub.c | 2 ++ mm/util.c | 2 ++ mm/vmalloc.c | 2 ++ 7 files changed, 14 insertions(+) (limited to 'mm') diff --git a/mm/slab.c b/mm/slab.c index 51fd424e0d6d..2e64efeb99a1 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -3651,6 +3651,7 @@ void *__kmalloc_node_track_caller(size_t size, gfp_t flags, 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) { struct kmem_cache *cachep; @@ -3670,6 +3671,7 @@ void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page) if (DEBUG && cachep->flags & SLAB_STORE_USER) kpp->kp_ret = *dbg_userword(cachep, objp); } +#endif /** * __do_kmalloc - allocate memory diff --git a/mm/slab.h b/mm/slab.h index 076582f58f68..120b1d0dfb6d 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -619,6 +619,7 @@ static inline bool slab_want_init_on_free(struct kmem_cache *c) return false; } +#ifdef CONFIG_PRINTK #define KS_ADDRS_COUNT 16 struct kmem_obj_info { void *kp_ptr; @@ -630,5 +631,6 @@ struct kmem_obj_info { void *kp_stack[KS_ADDRS_COUNT]; }; void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page); +#endif #endif /* MM_SLAB_H */ diff --git a/mm/slab_common.c b/mm/slab_common.c index 88e833986332..cec95363e621 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -526,6 +526,7 @@ bool slab_is_available(void) return slab_state >= UP; } +#ifdef CONFIG_PRINTK /** * kmem_valid_obj - does the pointer reference a valid slab object? * @object: pointer to query. @@ -600,6 +601,7 @@ void kmem_dump_obj(void *object) pr_info(" %pS\n", kp.kp_stack[i]); } } +#endif #ifndef CONFIG_SLOB /* Create a cache during boot when no slab services are available yet */ diff --git a/mm/slob.c b/mm/slob.c index 0578429b991b..74d3f6e60666 100644 --- a/mm/slob.c +++ b/mm/slob.c @@ -461,11 +461,13 @@ out: spin_unlock_irqrestore(&slob_lock, flags); } +#ifdef CONFIG_PRINTK void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page) { kpp->kp_ptr = object; kpp->kp_page = page; } +#endif /* * End of slob allocator proper. Begin kmem_cache_alloc and kmalloc frontend. diff --git a/mm/slub.c b/mm/slub.c index e26c274b4657..077a019e4d7a 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3963,6 +3963,7 @@ int __kmem_cache_shutdown(struct kmem_cache *s) return 0; } +#ifdef CONFIG_PRINTK void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page) { void *base; @@ -4002,6 +4003,7 @@ void kmem_obj_info(struct kmem_obj_info *kpp, void *object, struct page *page) #endif #endif } +#endif /******************************************************************** * Kmalloc subsystem diff --git a/mm/util.c b/mm/util.c index 54870226cea6..2d497fe0f17d 100644 --- a/mm/util.c +++ b/mm/util.c @@ -983,6 +983,7 @@ int __weak memcmp_pages(struct page *page1, struct page *page2) return ret; } +#ifdef CONFIG_PRINTK /** * mem_dump_obj - Print available provenance information * @object: object for which to find provenance information. @@ -1013,3 +1014,4 @@ void mem_dump_obj(void *object) } pr_cont(" non-slab/vmalloc memory.\n"); } +#endif diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 4f5f8c907897..d5f2a84e488a 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3450,6 +3450,7 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) } #endif /* CONFIG_SMP */ +#ifdef CONFIG_PRINTK bool vmalloc_dump_obj(void *object) { struct vm_struct *vm; @@ -3462,6 +3463,7 @@ bool vmalloc_dump_obj(void *object) vm->nr_pages, (unsigned long)vm->addr, vm->caller); return true; } +#endif #ifdef CONFIG_PROC_FS static void *s_start(struct seq_file *m, loff_t *pos) -- cgit v1.2.3 From 0d3dd2c8eadb7d4404b8788f552fb2b824fe2c7e Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Mon, 7 Dec 2020 21:23:36 -0800 Subject: rcutorture: Add crude tests for mem_dump_obj() This commit adds a few crude tests for mem_dump_obj() to rcutorture runs. Just to prevent bitrot, you understand! Signed-off-by: Paul E. McKenney --- kernel/rcu/rcutorture.c | 39 +++++++++++++++++++++++++++++++++++++++ mm/slab_common.c | 2 ++ mm/util.c | 1 + 3 files changed, 42 insertions(+) (limited to 'mm') diff --git a/kernel/rcu/rcutorture.c b/kernel/rcu/rcutorture.c index 99657ffa6688..8e93f2e5da79 100644 --- a/kernel/rcu/rcutorture.c +++ b/kernel/rcu/rcutorture.c @@ -1861,6 +1861,45 @@ rcu_torture_stats(void *arg) torture_shutdown_absorb("rcu_torture_stats"); } while (!torture_must_stop()); torture_kthread_stopping("rcu_torture_stats"); + + { + struct rcu_head *rhp; + struct kmem_cache *kcp; + static int z; + + kcp = kmem_cache_create("rcuscale", 136, 8, SLAB_STORE_USER, NULL); + rhp = kmem_cache_alloc(kcp, GFP_KERNEL); + pr_alert("mem_dump_obj() slab test: rcu_torture_stats = %px, &rhp = %px, rhp = %px, &z = %px\n", stats_task, &rhp, rhp, &z); + pr_alert("mem_dump_obj(ZERO_SIZE_PTR):"); + mem_dump_obj(ZERO_SIZE_PTR); + pr_alert("mem_dump_obj(NULL):"); + mem_dump_obj(NULL); + pr_alert("mem_dump_obj(%px):", &rhp); + mem_dump_obj(&rhp); + pr_alert("mem_dump_obj(%px):", rhp); + mem_dump_obj(rhp); + pr_alert("mem_dump_obj(%px):", &rhp->func); + mem_dump_obj(&rhp->func); + pr_alert("mem_dump_obj(%px):", &z); + mem_dump_obj(&z); + kmem_cache_free(kcp, rhp); + kmem_cache_destroy(kcp); + rhp = kmalloc(sizeof(*rhp), GFP_KERNEL); + pr_alert("mem_dump_obj() kmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp); + pr_alert("mem_dump_obj(kmalloc %px):", rhp); + mem_dump_obj(rhp); + pr_alert("mem_dump_obj(kmalloc %px):", &rhp->func); + mem_dump_obj(&rhp->func); + kfree(rhp); + rhp = vmalloc(4096); + pr_alert("mem_dump_obj() vmalloc test: rcu_torture_stats = %px, &rhp = %px, rhp = %px\n", stats_task, &rhp, rhp); + pr_alert("mem_dump_obj(vmalloc %px):", rhp); + mem_dump_obj(rhp); + pr_alert("mem_dump_obj(vmalloc %px):", &rhp->func); + mem_dump_obj(&rhp->func); + vfree(rhp); + } + return 0; } diff --git a/mm/slab_common.c b/mm/slab_common.c index cec95363e621..4c6107e39f9a 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -545,6 +545,7 @@ bool kmem_valid_obj(void *object) page = virt_to_head_page(object); return PageSlab(page); } +EXPORT_SYMBOL_GPL(kmem_valid_obj); /** * kmem_dump_obj - Print available slab provenance information @@ -601,6 +602,7 @@ void kmem_dump_obj(void *object) pr_info(" %pS\n", kp.kp_stack[i]); } } +EXPORT_SYMBOL_GPL(kmem_dump_obj); #endif #ifndef CONFIG_SLOB diff --git a/mm/util.c b/mm/util.c index 2d497fe0f17d..c37e24d5fa43 100644 --- a/mm/util.c +++ b/mm/util.c @@ -1014,4 +1014,5 @@ void mem_dump_obj(void *object) } pr_cont(" non-slab/vmalloc memory.\n"); } +EXPORT_SYMBOL_GPL(mem_dump_obj); #endif -- cgit v1.2.3