From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69DF5C1B0D8 for ; Wed, 9 Dec 2020 01:14:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4212123B4B for ; Wed, 9 Dec 2020 01:14:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726222AbgLIBOS (ORCPT ); Tue, 8 Dec 2020 20:14:18 -0500 Received: from mail.kernel.org ([198.145.29.99]:37604 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726307AbgLIBNq (ORCPT ); Tue, 8 Dec 2020 20:13:46 -0500 From: paulmck@kernel.org Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: rcu@vger.kernel.org Cc: linux-kernel@vger.kernel.org, kernel-team@fb.com, mingo@kernel.org, jiangshanlai@gmail.com, akpm@linux-foundation.org, mathieu.desnoyers@efficios.com, josh@joshtriplett.org, tglx@linutronix.de, peterz@infradead.org, rostedt@goodmis.org, dhowells@redhat.com, edumazet@google.com, fweisbec@gmail.com, oleg@redhat.com, joel@joelfernandes.org, iamjoonsoo.kim@lge.com, andrii@kernel.org, "Paul E. McKenney" , linux-mm@kvack.org Subject: [PATCH v2 sl-b 3/5] mm: Make mem_dump_obj() handle vmalloc() memory Date: Tue, 8 Dec 2020 17:13:01 -0800 Message-Id: <20201209011303.32737-3-paulmck@kernel.org> X-Mailer: git-send-email 2.9.5 In-Reply-To: <20201209011124.GA31164@paulmck-ThinkPad-P72> References: <20201209011124.GA31164@paulmck-ThinkPad-P72> Precedence: bulk List-ID: X-Mailing-List: rcu@vger.kernel.org From: "Paul E. McKenney" This commit adds vmalloc() support to mem_dump_obj(). Note that the vmalloc_dump_obj() function combines the checking and dumping, in contrast with the split between kmem_valid_obj() and kmem_dump_obj(). The reason for the difference is that the checking in the vmalloc() case involves acquiring a global lock, and redundant acquisitions of global locks should be avoided, even on not-so-fast paths. Note that this change causes on-stack variables to be reported as vmalloc() storage from kernel_clone() or similar, depending on the degree of inlining that your compiler does. This is likely more helpful than the earlier "non-paged (local) memory". Cc: Andrew Morton Cc: Joonsoo Kim Cc: Reported-by: Andrii Nakryiko Signed-off-by: Paul E. McKenney --- include/linux/vmalloc.h | 6 ++++++ mm/util.c | 12 +++++++----- mm/vmalloc.c | 12 ++++++++++++ 3 files changed, 25 insertions(+), 5 deletions(-) diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 938eaf9..c89c2be 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -248,4 +248,10 @@ pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) int register_vmap_purge_notifier(struct notifier_block *nb); int unregister_vmap_purge_notifier(struct notifier_block *nb); +#ifdef CONFIG_MMU +bool vmalloc_dump_obj(void *object); +#else +static inline bool vmalloc_dump_obj(void *object) { return false; } +#endif + #endif /* _LINUX_VMALLOC_H */ diff --git a/mm/util.c b/mm/util.c index 8c2449f..ee99a0a 100644 --- a/mm/util.c +++ b/mm/util.c @@ -984,6 +984,12 @@ int __weak memcmp_pages(struct page *page1, struct page *page2) */ void mem_dump_obj(void *object) { + if (kmem_valid_obj(object)) { + kmem_dump_obj(object); + return; + } + if (vmalloc_dump_obj(object)) + return; if (!virt_addr_valid(object)) { if (object == NULL) pr_cont(" NULL pointer.\n"); @@ -993,10 +999,6 @@ void mem_dump_obj(void *object) pr_cont(" non-paged (local) memory.\n"); return; } - if (kmem_valid_obj(object)) { - kmem_dump_obj(object); - return; - } - pr_cont(" non-slab memory.\n"); + pr_cont(" non-slab/vmalloc memory.\n"); } EXPORT_SYMBOL_GPL(mem_dump_obj); diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 6ae491a..7421719 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -3431,6 +3431,18 @@ void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) } #endif /* CONFIG_SMP */ +bool vmalloc_dump_obj(void *object) +{ + struct vm_struct *vm; + void *objp = (void *)PAGE_ALIGN((unsigned long)object); + + vm = find_vm_area(objp); + if (!vm) + return false; + pr_cont(" vmalloc allocated at %pS\n", vm->caller); + return true; +} + #ifdef CONFIG_PROC_FS static void *s_start(struct seq_file *m, loff_t *pos) __acquires(&vmap_purge_lock) -- 2.9.5