mm: cma: fix corruption cma_sysfs_alloc_pages_count

Message ID	20210324192044.1505747-1-minchan@kernel.org (mailing list archive)
State	New, archived
Headers	show Return-Path: <SRS0=u5hr=IW=kvack.org=owner-linux-mm@kernel.org> DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1771961984 From: Minchan Kim <minchan@kernel.org> To: Andrew Morton <akpm@linux-foundation.org> Cc: linux-mm <linux-mm@kvack.org>, LKML <linux-kernel@vger.kernel.org>, gregkh@linuxfoundation.org, surenb@google.com, joaodias@google.com, jhubbard@nvidia.com, willy@infradead.org, digetx@gmail.com, Minchan Kim <minchan@kernel.org> Subject: [PATCH] mm: cma: fix corruption cma_sysfs_alloc_pages_count Date: Wed, 24 Mar 2021 12:20:44 -0700 Message-Id: <20210324192044.1505747-1-minchan@kernel.org> MIME-Version: 1.0 Received-SPF: none (gmail.com>: No applicable sender policy available) receiver=imf17; identity=mailfrom; envelope-from="<minchan.kim@gmail.com>"; helo=mail-pf1-f174.google.com; client-ip=209.85.210.174 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org Precedence: bulk
Series	mm: cma: fix corruption cma_sysfs_alloc_pages_count \| expand mm: cma: fix corruption cma_sysfs_alloc_pages_count

diff --git a/mm/cma.c b/mm/cma.c index 90e27458ddb7..08c45157911a 100644 --- a/mm/cma.c +++ b/mm/cma.c @@ -509,11 +509,11 @@ struct page *cma_alloc(struct cma *cma, size_t count, unsigned int align, out: if (page) { count_vm_event(CMA_ALLOC_SUCCESS); - cma_sysfs_alloc_pages_count(cma, count); + cma_sysfs_account_success_pages(cma, count); } else { count_vm_event(CMA_ALLOC_FAIL); if (cma) - cma_sysfs_fail_pages_count(cma, count); + cma_sysfs_account_fail_pages(cma, count); } return page; diff --git a/mm/cma.h b/mm/cma.h index 95d1aa2d808a..37b9b7858c8e 100644 --- a/mm/cma.h +++ b/mm/cma.h @@ -5,12 +5,8 @@ #include <linux/debugfs.h> #include <linux/kobject.h> -struct cma_stat { - spinlock_t lock; - /* the number of CMA page successful allocations */ - unsigned long nr_pages_succeeded; - /* the number of CMA page allocation failures */ - unsigned long nr_pages_failed; +struct cma_kobject { + struct cma *cma; struct kobject kobj; }; @@ -27,7 +23,12 @@ struct cma { #endif char name[CMA_MAX_NAME]; #ifdef CONFIG_CMA_SYSFS - struct cma_stat *stat; + /* the number of CMA page successful allocations */ + atomic64_t nr_pages_succeeded; + /* the number of CMA page allocation failures */ + atomic64_t nr_pages_failed; + /* kobject requires dynamic object */ + struct cma_kobject *cma_kobj; #endif }; @@ -40,10 +41,12 @@ static inline unsigned long cma_bitmap_maxno(struct cma *cma) } #ifdef CONFIG_CMA_SYSFS -void cma_sysfs_alloc_pages_count(struct cma *cma, size_t count); -void cma_sysfs_fail_pages_count(struct cma *cma, size_t count); +void cma_sysfs_account_success_pages(struct cma *cma, unsigned long nr_pages); +void cma_sysfs_account_fail_pages(struct cma *cma, unsigned long nr_pages); #else -static inline void cma_sysfs_alloc_pages_count(struct cma *cma, size_t count) {}; -static inline void cma_sysfs_fail_pages_count(struct cma *cma, size_t count) {}; +static inline void cma_sysfs_account_success_pages(struct cma *cma, + unsigned long nr_pages) {}; +static inline void cma_sysfs_account_fail_pages(struct cma *cma, + unsigned long nr_pages) {}; #endif #endif diff --git a/mm/cma_sysfs.c b/mm/cma_sysfs.c index 3134b2b3a96d..a670a80aad6f 100644 --- a/mm/cma_sysfs.c +++ b/mm/cma_sysfs.c @@ -11,50 +11,54 @@ #include "cma.h" -static struct cma_stat *cma_stats; - -void cma_sysfs_alloc_pages_count(struct cma *cma, size_t count) +void cma_sysfs_account_success_pages(struct cma *cma, unsigned long nr_pages) { - spin_lock(&cma->stat->lock); - cma->stat->nr_pages_succeeded += count; - spin_unlock(&cma->stat->lock); + atomic64_add(nr_pages, &cma->nr_pages_succeeded); } -void cma_sysfs_fail_pages_count(struct cma *cma, size_t count) +void cma_sysfs_account_fail_pages(struct cma *cma, unsigned long nr_pages) { - spin_lock(&cma->stat->lock); - cma->stat->nr_pages_failed += count; - spin_unlock(&cma->stat->lock); + atomic64_add(nr_pages, &cma->nr_pages_failed); } #define CMA_ATTR_RO(_name) \ static struct kobj_attribute _name##_attr = __ATTR_RO(_name) -static struct kobject *cma_kobj; +static inline struct cma *cma_from_kobj(struct kobject *kobj) +{ + struct cma_kobject *cma_kobj = container_of(kobj, struct cma_kobject, + kobj); + struct cma *cma = cma_kobj->cma; + + return cma; +} static ssize_t alloc_pages_success_show(struct kobject *kobj, - struct kobj_attribute *attr, char *buf) + struct kobj_attribute *attr, char *buf) { - struct cma_stat *stat = container_of(kobj, struct cma_stat, kobj); + struct cma *cma = cma_from_kobj(kobj); - return sysfs_emit(buf, "%lu\n", stat->nr_pages_succeeded); + return sysfs_emit(buf, "%llu\n", + atomic64_read(&cma->nr_pages_succeeded)); } CMA_ATTR_RO(alloc_pages_success); static ssize_t alloc_pages_fail_show(struct kobject *kobj, - struct kobj_attribute *attr, char *buf) + struct kobj_attribute *attr, char *buf) { - struct cma_stat *stat = container_of(kobj, struct cma_stat, kobj); + struct cma *cma = cma_from_kobj(kobj); - return sysfs_emit(buf, "%lu\n", stat->nr_pages_failed); + return sysfs_emit(buf, "%llu\n", atomic64_read(&cma->nr_pages_failed)); } CMA_ATTR_RO(alloc_pages_fail); static void cma_kobj_release(struct kobject *kobj) { - struct cma_stat *stat = container_of(kobj, struct cma_stat, kobj); + struct cma *cma = cma_from_kobj(kobj); + struct cma_kobject *cma_kobj = cma->cma_kobj; - kfree(stat); + kfree(cma_kobj); + cma->cma_kobj = NULL; } static struct attribute *cma_attrs[] = { @@ -67,44 +71,50 @@ ATTRIBUTE_GROUPS(cma); static struct kobj_type cma_ktype = { .release = cma_kobj_release, .sysfs_ops = &kobj_sysfs_ops, - .default_groups = cma_groups + .default_groups = cma_groups, }; static int __init cma_sysfs_init(void) { - int i = 0; + struct kobject *cma_kobj_root; + struct cma_kobject *cma_kobj; struct cma *cma; + unsigned int i; + int err; - cma_kobj = kobject_create_and_add("cma", mm_kobj); - if (!cma_kobj) + cma_kobj_root = kobject_create_and_add("cma", mm_kobj); + if (!cma_kobj_root) return -ENOMEM; - cma_stats = kmalloc_array(cma_area_count, sizeof(struct cma_stat), - GFP_KERNEL|__GFP_ZERO); - if (ZERO_OR_NULL_PTR(cma_stats)) - goto out; + for (i = 0; i < cma_area_count; i++) { + cma_kobj = kzalloc(sizeof(*cma_kobj), GFP_KERNEL); + if (!cma_kobj) { + err = -ENOMEM; + goto out; + } - do { cma = &cma_areas[i]; - cma->stat = &cma_stats[i]; - spin_lock_init(&cma->stat->lock); - if (kobject_init_and_add(&cma->stat->kobj, &cma_ktype, - cma_kobj, "%s", cma->name)) { - kobject_put(&cma->stat->kobj); + cma->cma_kobj = cma_kobj; + cma_kobj->cma = cma; + err = kobject_init_and_add(&cma_kobj->kobj, &cma_ktype, + cma_kobj_root, "%s", cma->name); + if (err) { + kobject_put(&cma_kobj->kobj); goto out; } - } while (++i < cma_area_count); + } return 0; out: while (--i >= 0) { cma = &cma_areas[i]; - kobject_put(&cma->stat->kobj); - } - kfree(cma_stats); - kobject_put(cma_kobj); + kobject_put(&cma->cma_kobj->kobj); + kfree(cma->cma_kobj); + cma->cma_kobj = NULL; + } + kobject_put(cma_kobj_root); - return -ENOMEM; + return err; } subsys_initcall(cma_sysfs_init);

mm: cma: fix corruption cma_sysfs_alloc_pages_count

Commit Message

Comments

Patch