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=-8.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 A10DFC433E2 for ; Tue, 19 May 2020 15:48:23 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 76A3520809 for ; Tue, 19 May 2020 15:48:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="IU2z2khM"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="bn/NLnfD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 76A3520809 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:Reply-To:List-Subscribe:List-Help: List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version: References:Message-ID:Subject:To:From:Date:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=xLbhYqiCCwR4HqBjhP+LvworcwZZWa+kc7Ttaa5omD0=; b=IU2z2khMhwGUOv BqokJelyHSDs9D1iAtz+yLphrFdf4YkliPSIPGfpqRyXMfbvPxtczejJ7sdM0vA/eaoIbYbNrfVFw 8Rqtlt1ytA7oIoZEiLCHCGExxaGQPebmQ/mS84e9z4KSfYB1RooDb5GPivXcP9ehjBsdFgJdjh0Db XKTk9yVzdwvYKDGRv/95R5mp6HIAbfwLZk+IvDi9xESIfdEoEmQyYJzeDGiWeLu1UnK/6e32UZcHs LXv2y/w07c1yMV5gMaqQoZ0WIAtZycqHVLmTyu2JdrJionQOro+xJrCJkb5qOMIDFUeI5dW7PYlyo rflIYIDpJAFt4HJtW49Q==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jb4Te-000730-VD; Tue, 19 May 2020 15:48:22 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jb4Tc-00072P-1S; Tue, 19 May 2020 15:48:21 +0000 Received: from paulmck-ThinkPad-P72.home (50-39-105-78.bvtn.or.frontiernet.net [50.39.105.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7C5C920709; Tue, 19 May 2020 15:48:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589903299; bh=7sGpmOemTKou1SkDOKuXUD9OFaVHO0iNug1vnMIT5to=; h=Date:From:To:Cc:Subject:Reply-To:References:In-Reply-To:From; b=bn/NLnfD8LOiAz71tCS0RtryozPQl84Nu0NRP0BGsk1fO1GXShtAuOLDKIgFn1vdY tOeY+ce5lZc0xezqWV/1dnupSBYngrB+um0EVwD1wwEhotgZPeP2+GO8QagrhBzB3F ZkV591g7MAtER5EKyCFrBfL6VTpYNZXN58AfrNbM= Received: by paulmck-ThinkPad-P72.home (Postfix, from userid 1000) id 649EE3523462; Tue, 19 May 2020 08:48:19 -0700 (PDT) Date: Tue, 19 May 2020 08:48:19 -0700 From: "Paul E. McKenney" To: Walter Wu Subject: Re: [PATCH v4 1/4] rcu/kasan: record and print call_rcu() call stack Message-ID: <20200519154819.GJ2869@paulmck-ThinkPad-P72> References: <20200519022359.24115-1-walter-zh.wu@mediatek.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200519022359.24115-1-walter-zh.wu@mediatek.com> User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20200519_084820_126399_724F768B X-CRM114-Status: GOOD ( 22.89 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: paulmck@kernel.org Cc: wsd_upstream , linux-mm@kvack.org, Lai Jiangshan , Josh Triplett , kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org, Joel Fernandes , linux-mediatek@lists.infradead.org, Alexander Potapenko , linux-arm-kernel@lists.infradead.org, Matthias Brugger , Andrey Ryabinin , Andrew Morton , Dmitry Vyukov , Mathieu Desnoyers Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, May 19, 2020 at 10:23:59AM +0800, Walter Wu wrote: > This feature will record the last two call_rcu() call stacks and > prints up to 2 call_rcu() call stacks in KASAN report. > > When call_rcu() is called, we store the call_rcu() call stack into > slub alloc meta-data, so that the KASAN report can print rcu stack. > > [1]https://bugzilla.kernel.org/show_bug.cgi?id=198437 > [2]https://groups.google.com/forum/#!searchin/kasan-dev/better$20stack$20traces$20for$20rcu%7Csort:date/kasan-dev/KQsjT_88hDE/7rNUZprRBgAJ > > Signed-off-by: Walter Wu > Suggested-by: Dmitry Vyukov > Cc: Andrey Ryabinin > Cc: Dmitry Vyukov > Cc: Alexander Potapenko > Cc: Andrew Morton > Cc: Paul E. McKenney > Cc: Josh Triplett > Cc: Mathieu Desnoyers > Cc: Lai Jiangshan > Cc: Joel Fernandes >From an RCU perspective: Acked-by: Paul E. McKenney > --- > include/linux/kasan.h | 2 ++ > kernel/rcu/tree.c | 2 ++ > lib/Kconfig.kasan | 2 ++ > mm/kasan/common.c | 4 ++-- > mm/kasan/generic.c | 19 +++++++++++++++++++ > mm/kasan/kasan.h | 10 ++++++++++ > mm/kasan/report.c | 24 ++++++++++++++++++++++++ > 7 files changed, 61 insertions(+), 2 deletions(-) > > diff --git a/include/linux/kasan.h b/include/linux/kasan.h > index 31314ca7c635..23b7ee00572d 100644 > --- a/include/linux/kasan.h > +++ b/include/linux/kasan.h > @@ -174,11 +174,13 @@ static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; } > > void kasan_cache_shrink(struct kmem_cache *cache); > void kasan_cache_shutdown(struct kmem_cache *cache); > +void kasan_record_aux_stack(void *ptr); > > #else /* CONFIG_KASAN_GENERIC */ > > static inline void kasan_cache_shrink(struct kmem_cache *cache) {} > static inline void kasan_cache_shutdown(struct kmem_cache *cache) {} > +static inline void kasan_record_aux_stack(void *ptr) {} > > #endif /* CONFIG_KASAN_GENERIC */ > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index 06548e2ebb72..36a4ff7f320b 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -57,6 +57,7 @@ > #include > #include > #include > +#include > #include "../time/tick-internal.h" > > #include "tree.h" > @@ -2668,6 +2669,7 @@ __call_rcu(struct rcu_head *head, rcu_callback_t func) > head->func = func; > head->next = NULL; > local_irq_save(flags); > + kasan_record_aux_stack(head); > rdp = this_cpu_ptr(&rcu_data); > > /* Add the callback to our list. */ > diff --git a/lib/Kconfig.kasan b/lib/Kconfig.kasan > index 81f5464ea9e1..4e83cf6e3caa 100644 > --- a/lib/Kconfig.kasan > +++ b/lib/Kconfig.kasan > @@ -58,6 +58,8 @@ config KASAN_GENERIC > For better error detection enable CONFIG_STACKTRACE. > Currently CONFIG_KASAN_GENERIC doesn't work with CONFIG_DEBUG_SLAB > (the resulting kernel does not boot). > + In generic mode KASAN prints the last two call_rcu() call stacks in > + reports. > > config KASAN_SW_TAGS > bool "Software tag-based mode" > diff --git a/mm/kasan/common.c b/mm/kasan/common.c > index 2906358e42f0..8bc618289bb1 100644 > --- a/mm/kasan/common.c > +++ b/mm/kasan/common.c > @@ -41,7 +41,7 @@ > #include "kasan.h" > #include "../slab.h" > > -static inline depot_stack_handle_t save_stack(gfp_t flags) > +depot_stack_handle_t kasan_save_stack(gfp_t flags) > { > unsigned long entries[KASAN_STACK_DEPTH]; > unsigned int nr_entries; > @@ -54,7 +54,7 @@ static inline depot_stack_handle_t save_stack(gfp_t flags) > static inline void set_track(struct kasan_track *track, gfp_t flags) > { > track->pid = current->pid; > - track->stack = save_stack(flags); > + track->stack = kasan_save_stack(flags); > } > > void kasan_enable_current(void) > diff --git a/mm/kasan/generic.c b/mm/kasan/generic.c > index 56ff8885fe2e..3372bdcaf92a 100644 > --- a/mm/kasan/generic.c > +++ b/mm/kasan/generic.c > @@ -325,3 +325,22 @@ DEFINE_ASAN_SET_SHADOW(f2); > DEFINE_ASAN_SET_SHADOW(f3); > DEFINE_ASAN_SET_SHADOW(f5); > DEFINE_ASAN_SET_SHADOW(f8); > + > +void kasan_record_aux_stack(void *addr) > +{ > + struct page *page = kasan_addr_to_page(addr); > + struct kmem_cache *cache; > + struct kasan_alloc_meta *alloc_info; > + void *object; > + > + if (!(page && PageSlab(page))) > + return; > + > + cache = page->slab_cache; > + object = nearest_obj(cache, page, addr); > + alloc_info = get_alloc_info(cache, object); > + > + /* record the last two call_rcu() call stacks */ > + alloc_info->aux_stack[1] = alloc_info->aux_stack[0]; > + alloc_info->aux_stack[0] = kasan_save_stack(GFP_NOWAIT); > +} > diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h > index e8f37199d885..a7391bc83070 100644 > --- a/mm/kasan/kasan.h > +++ b/mm/kasan/kasan.h > @@ -104,7 +104,15 @@ struct kasan_track { > > struct kasan_alloc_meta { > struct kasan_track alloc_track; > +#ifdef CONFIG_KASAN_GENERIC > + /* > + * call_rcu() call stack is stored into struct kasan_alloc_meta. > + * The free stack is stored into struct kasan_free_meta. > + */ > + depot_stack_handle_t aux_stack[2]; > +#else > struct kasan_track free_track[KASAN_NR_FREE_STACKS]; > +#endif > #ifdef CONFIG_KASAN_SW_TAGS_IDENTIFY > u8 free_pointer_tag[KASAN_NR_FREE_STACKS]; > u8 free_track_idx; > @@ -159,6 +167,8 @@ void kasan_report_invalid_free(void *object, unsigned long ip); > > struct page *kasan_addr_to_page(const void *addr); > > +depot_stack_handle_t kasan_save_stack(gfp_t flags); > + > #if defined(CONFIG_KASAN_GENERIC) && \ > (defined(CONFIG_SLAB) || defined(CONFIG_SLUB)) > void quarantine_put(struct kasan_free_meta *info, struct kmem_cache *cache); > diff --git a/mm/kasan/report.c b/mm/kasan/report.c > index 80f23c9da6b0..6f8f2bf8f53b 100644 > --- a/mm/kasan/report.c > +++ b/mm/kasan/report.c > @@ -179,6 +179,17 @@ static struct kasan_track *kasan_get_free_track(struct kmem_cache *cache, > return &alloc_meta->free_track[i]; > } > > +#ifdef CONFIG_KASAN_GENERIC > +static void print_stack(depot_stack_handle_t stack) > +{ > + unsigned long *entries; > + unsigned int nr_entries; > + > + nr_entries = stack_depot_fetch(stack, &entries); > + stack_trace_print(entries, nr_entries, 0); > +} > +#endif > + > static void describe_object(struct kmem_cache *cache, void *object, > const void *addr, u8 tag) > { > @@ -192,6 +203,19 @@ static void describe_object(struct kmem_cache *cache, void *object, > free_track = kasan_get_free_track(cache, object, tag); > print_track(free_track, "Freed"); > pr_err("\n"); > + > +#ifdef CONFIG_KASAN_GENERIC > + if (alloc_info->aux_stack[0]) { > + pr_err("Last one call_rcu() call stack:\n"); > + print_stack(alloc_info->aux_stack[0]); > + pr_err("\n"); > + } > + if (alloc_info->aux_stack[1]) { > + pr_err("Second to last call_rcu() call stack:\n"); > + print_stack(alloc_info->aux_stack[1]); > + pr_err("\n"); > + } > +#endif > } > > describe_object_addr(cache, object, addr); > -- > 2.18.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel