From patchwork Fri Sep 8 13:39:22 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Tao X-Patchwork-Id: 13377483 X-Patchwork-Delegate: bpf@iogearbox.net Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 76DAE63C9 for ; Fri, 8 Sep 2023 13:39:40 +0000 (UTC) Received: from dggsgout12.his.huawei.com (dggsgout12.his.huawei.com [45.249.212.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CDE3B1BEA for ; Fri, 8 Sep 2023 06:39:37 -0700 (PDT) Received: from mail02.huawei.com (unknown [172.30.67.143]) by dggsgout12.his.huawei.com (SkyGuard) with ESMTP id 4Rhxzl1P2Nz4f3l7b for ; Fri, 8 Sep 2023 21:39:31 +0800 (CST) Received: from huaweicloud.com (unknown [10.175.124.27]) by APP4 (Coremail) with SMTP id gCh0CgDHVqkPJPtkRmSwCg--.44307S7; Fri, 08 Sep 2023 21:39:34 +0800 (CST) From: Hou Tao To: bpf@vger.kernel.org Cc: Martin KaFai Lau , Alexei Starovoitov , Andrii Nakryiko , Song Liu , Hao Luo , Yonghong Song , Daniel Borkmann , KP Singh , Stanislav Fomichev , Jiri Olsa , John Fastabend , =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= , houtao1@huawei.com Subject: [PATCH bpf 3/4] bpf: Ensure unit_size is matched with slab cache object size Date: Fri, 8 Sep 2023 21:39:22 +0800 Message-Id: <20230908133923.2675053-4-houtao@huaweicloud.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20230908133923.2675053-1-houtao@huaweicloud.com> References: <20230908133923.2675053-1-houtao@huaweicloud.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: gCh0CgDHVqkPJPtkRmSwCg--.44307S7 X-Coremail-Antispam: 1UD129KBjvJXoWxCF48ur4fAFyUury3tFyxKrg_yoW5XFyfpF y7CF1rKrsYyFW7Wa1aqrs7Ca4ft340qF17J3yaq3409r4rXr1DGF4DJry2gF98urWrJa13 Jr1kKr40krWUArJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUB0b4IE77IF4wAFF20E14v26rWj6s0DM7CY07I20VC2zVCF04k2 6cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI8067AKxVWUWw A2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28CjxkF64kEwVA0rcxS w2x7M28EF7xvwVC0I7IYx2IY67AKxVW5JVW7JwA2z4x0Y4vE2Ix0cI8IcVCY1x0267AKxV WxJVW8Jr1l84ACjcxK6I8E87Iv67AKxVW0oVCq3wA2z4x0Y4vEx4A2jsIEc7CjxVAFwI0_ GcCE3s1le2I262IYc4CY6c8Ij28IcVAaY2xG8wAqx4xG64xvF2IEw4CE5I8CrVC2j2WlYx 0E2Ix0cI8IcVAFwI0_Jr0_Jr4lYx0Ex4A2jsIE14v26r1j6r4UMcvjeVCFs4IE7xkEbVWU JVW8JwACjcxG0xvY0x0EwIxGrwACI402YVCY1x02628vn2kIc2xKxwCF04k20xvY0x0EwI xGrwCFx2IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480 Y4vE14v26r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7 IYx2IY67AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Cr0_Gr1UMIIF0xvE42xK 8VAvwI8IcIk0rVWUJVWUCwCI42IY6I8E87Iv67AKxVWUJVW8JwCI42IY6I8E87Iv6xkF7I 0E14v26r4j6r4UJbIYCTnIWIevJa73UjIFyTuYvjxUFYFCUUUUU X-CM-SenderInfo: xkrx3t3r6k3tpzhluzxrxghudrp/ X-CFilter-Loop: Reflected X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,RCVD_IN_MSPIKE_H2, SPF_HELO_NONE,SPF_NONE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: bpf@iogearbox.net From: Hou Tao Add extra check in bpf_mem_alloc_init() to ensure the unit_size of bpf_mem_cache is matched with the object_size of underlying slab cache. If these two sizes are unmatched, print a warning once and return -EINVAL in bpf_mem_alloc_init(), so the mismatch can be found early and the potential issue can be prevented. Suggested-by: Alexei Starovoitov Signed-off-by: Hou Tao Signed-off-by: Hou Tao --- kernel/bpf/memalloc.c | 33 +++++++++++++++++++++++++++++++-- 1 file changed, 31 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/memalloc.c b/kernel/bpf/memalloc.c index 90c1ed8210a2..1c22b90e754a 100644 --- a/kernel/bpf/memalloc.c +++ b/kernel/bpf/memalloc.c @@ -486,6 +486,24 @@ static void prefill_mem_cache(struct bpf_mem_cache *c, int cpu) alloc_bulk(c, c->unit_size <= 256 ? 4 : 1, cpu_to_node(cpu), false); } +static int check_obj_size(struct bpf_mem_cache *c, unsigned int idx) +{ + struct llist_node *first; + unsigned int obj_size; + + first = c->free_llist.first; + if (!first) + return 0; + + obj_size = ksize(first); + if (obj_size != c->unit_size) { + WARN_ONCE(1, "bpf_mem_cache[%u]: unexpected object size %u, expect %u\n", + idx, obj_size, c->unit_size); + return -EINVAL; + } + return 0; +} + /* When size != 0 bpf_mem_cache for each cpu. * This is typical bpf hash map use case when all elements have equal size. * @@ -496,10 +514,10 @@ static void prefill_mem_cache(struct bpf_mem_cache *c, int cpu) int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu) { static u16 sizes[NUM_CACHES] = {96, 192, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096}; + int cpu, i, err, unit_size, percpu_size = 0; struct bpf_mem_caches *cc, __percpu *pcc; struct bpf_mem_cache *c, __percpu *pc; struct obj_cgroup *objcg = NULL; - int cpu, i, unit_size, percpu_size = 0; if (size) { pc = __alloc_percpu_gfp(sizeof(*pc), 8, GFP_KERNEL); @@ -537,6 +555,7 @@ int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu) pcc = __alloc_percpu_gfp(sizeof(*cc), 8, GFP_KERNEL); if (!pcc) return -ENOMEM; + err = 0; #ifdef CONFIG_MEMCG_KMEM objcg = get_obj_cgroup_from_current(); #endif @@ -557,10 +576,20 @@ int bpf_mem_alloc_init(struct bpf_mem_alloc *ma, int size, bool percpu) if (i != bpf_mem_cache_idx(c->unit_size)) continue; prefill_mem_cache(c, cpu); + err = check_obj_size(c, i); + if (err) + goto out; } } + +out: ma->caches = pcc; - return 0; + /* refill_work is either zeroed or initialized, so it is safe to + * call irq_work_sync(). + */ + if (err) + bpf_mem_alloc_destroy(ma); + return err; } static void drain_mem_cache(struct bpf_mem_cache *c)