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=-23.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_IN_DEF_DKIM_WL autolearn=ham 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 E9832C433E0 for ; Tue, 2 Feb 2021 18:01:24 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 6E6D264E3D for ; Tue, 2 Feb 2021 18:01:24 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6E6D264E3D Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id BEDB86B0071; Tue, 2 Feb 2021 13:01:23 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B9ECF6B0072; Tue, 2 Feb 2021 13:01:23 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A410C6B0073; Tue, 2 Feb 2021 13:01:23 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0074.hostedemail.com [216.40.44.74]) by kanga.kvack.org (Postfix) with ESMTP id 897536B0071 for ; Tue, 2 Feb 2021 13:01:23 -0500 (EST) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 14BDD3637 for ; Tue, 2 Feb 2021 18:01:23 +0000 (UTC) X-FDA: 77774094846.17.look35_27069d7275cc Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin17.hostedemail.com (Postfix) with ESMTP id D0C81180D0185 for ; Tue, 2 Feb 2021 18:01:22 +0000 (UTC) X-HE-Tag: look35_27069d7275cc X-Filterd-Recvd-Size: 8750 Received: from mail-pl1-f180.google.com (mail-pl1-f180.google.com [209.85.214.180]) by imf18.hostedemail.com (Postfix) with ESMTP for ; Tue, 2 Feb 2021 18:01:22 +0000 (UTC) Received: by mail-pl1-f180.google.com with SMTP id a16so1293958plh.8 for ; Tue, 02 Feb 2021 10:01:22 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=L1MZ9fF4ca6SaeZxY2832DoPpHMX3bUKUCoXNkXBzTg=; b=jNc6EBwzUkzTtMo8aKtmyGRuQeJI8FCv9ajgC1jsmbZugoDWUFBII58VnJu0uuN8t9 snMbSb8N7JVeJ/2WltI5QDNqqrOfw79I/JYj022yEqy4NYfkj1845rkFH8PjMwC8YJm1 hTFmkWBYfj9yY2j79PSKWV7XhF1iD0mzKfVeVkXyM6S5nNrq3y9rlzZTDtRnzuofKyjN kWNpd7yu3E5vPKhpKpd4HnvsxWVM/Fkpq6gq4BwX2jwPqafISPYJxHxUe0HixBpwwULc 3/WF8Ok/3LK+UNpI2Vwumkw95ili4WpTSMHWlv7Nd99tE5Sjwmk1c1V3DdNT/rvl6UEY prZg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=L1MZ9fF4ca6SaeZxY2832DoPpHMX3bUKUCoXNkXBzTg=; b=c9lUGpuxf6ZNWJtvFxEWIoynHmyHvB8YK5oKHXn16KnvqQZzp+yZHSAUb4sEots7ia oFpeqf5eIsHcks/VhZrFeRjEyhUZQSD4JUc0b8DjNZvnXyfauYaNFReIU9ZgsLkx2rNq fZi+ZKS86i3p7J1t2+DivI1w4iPvcQe4+oAjkuzSlFZuBCgfH1UTLt0yeNeAcHEI4pYy cxQrIiS8fg1PX1BJn9viVpiFFiKLeP+OOYgLBPyez51zgsd8tCbO1c50KIN4LPygMTG+ MkeAFimEQiT1g+3adz5EEUcP56MPNvEX+0twPNOCIJcYn2NpMyCguaAkl4Al+6xB6cy7 V3Cw== X-Gm-Message-State: AOAM53204fCRCZxP8iktDEtjkOlnrpP3AQ20Wd4H6y9sNNW0VImofTyR uA0fo2zL7/jX1ynwm4eCcVUnTKzB8/7NdAHHTgP3lA== X-Google-Smtp-Source: ABdhPJyD0h7LZ4QaTVYqzgxpWCXP9hJsjTvhDlivqpOVW/0uvtNZf6xwpn5YdGtZuubAcgENenHV4RtBk52X01pR3YE= X-Received: by 2002:a17:90b:350b:: with SMTP id ls11mr5531989pjb.166.1612288881120; Tue, 02 Feb 2021 10:01:21 -0800 (PST) MIME-Version: 1.0 References: In-Reply-To: From: Andrey Konovalov Date: Tue, 2 Feb 2021 19:01:09 +0100 Message-ID: Subject: Re: [PATCH 01/12] kasan, mm: don't save alloc stacks twice To: Marco Elver Cc: Catalin Marinas , Vincenzo Frascino , Dmitry Vyukov , Alexander Potapenko , Andrew Morton , Will Deacon , Andrey Ryabinin , Peter Collingbourne , Evgenii Stepanov , Branislav Rankov , Kevin Brodsky , kasan-dev , Linux ARM , Linux Memory Management List , LKML Content-Type: text/plain; charset="UTF-8" X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Tue, Feb 2, 2021 at 5:06 PM Marco Elver wrote: > > On Mon, Feb 01, 2021 at 08:43PM +0100, Andrey Konovalov wrote: > > Currently KASAN saves allocation stacks in both kasan_slab_alloc() and > > kasan_kmalloc() annotations. This patch changes KASAN to save allocation > > stacks for slab objects from kmalloc caches in kasan_kmalloc() only, > > and stacks for other slab objects in kasan_slab_alloc() only. > > > > This change requires ____kasan_kmalloc() knowing whether the object > > belongs to a kmalloc cache. This is implemented by adding a flag field > > to the kasan_info structure. That flag is only set for kmalloc caches > > via a new kasan_cache_create_kmalloc() annotation. > > > > Signed-off-by: Andrey Konovalov > > Reviewed-by: Marco Elver > > > --- > > include/linux/kasan.h | 9 +++++++++ > > mm/kasan/common.c | 18 ++++++++++++++---- > > mm/slab_common.c | 1 + > > 3 files changed, 24 insertions(+), 4 deletions(-) > > > > diff --git a/include/linux/kasan.h b/include/linux/kasan.h > > index 6d8f3227c264..2d5de4092185 100644 > > --- a/include/linux/kasan.h > > +++ b/include/linux/kasan.h > > @@ -83,6 +83,7 @@ static inline void kasan_disable_current(void) {} > > struct kasan_cache { > > int alloc_meta_offset; > > int free_meta_offset; > > + bool is_kmalloc; > > }; > > > > #ifdef CONFIG_KASAN_HW_TAGS > > @@ -143,6 +144,13 @@ static __always_inline void kasan_cache_create(struct kmem_cache *cache, > > __kasan_cache_create(cache, size, flags); > > } > > > > +void __kasan_cache_create_kmalloc(struct kmem_cache *cache); > > +static __always_inline void kasan_cache_create_kmalloc(struct kmem_cache *cache) > > +{ > > + if (kasan_enabled()) > > + __kasan_cache_create_kmalloc(cache); > > +} > > + > > size_t __kasan_metadata_size(struct kmem_cache *cache); > > static __always_inline size_t kasan_metadata_size(struct kmem_cache *cache) > > { > > @@ -278,6 +286,7 @@ static inline void kasan_free_pages(struct page *page, unsigned int order) {} > > static inline void kasan_cache_create(struct kmem_cache *cache, > > unsigned int *size, > > slab_flags_t *flags) {} > > +static inline void kasan_cache_create_kmalloc(struct kmem_cache *cache) {} > > static inline size_t kasan_metadata_size(struct kmem_cache *cache) { return 0; } > > static inline void kasan_poison_slab(struct page *page) {} > > static inline void kasan_unpoison_object_data(struct kmem_cache *cache, > > diff --git a/mm/kasan/common.c b/mm/kasan/common.c > > index fe852f3cfa42..374049564ea3 100644 > > --- a/mm/kasan/common.c > > +++ b/mm/kasan/common.c > > @@ -210,6 +210,11 @@ void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size, > > *size = optimal_size; > > } > > > > +void __kasan_cache_create_kmalloc(struct kmem_cache *cache) > > +{ > > + cache->kasan_info.is_kmalloc = true; > > +} > > + > > size_t __kasan_metadata_size(struct kmem_cache *cache) > > { > > if (!kasan_stack_collection_enabled()) > > @@ -394,17 +399,22 @@ void __kasan_slab_free_mempool(void *ptr, unsigned long ip) > > } > > } > > > > -static void set_alloc_info(struct kmem_cache *cache, void *object, gfp_t flags) > > +static void set_alloc_info(struct kmem_cache *cache, void *object, > > + gfp_t flags, bool kmalloc) > > { > > struct kasan_alloc_meta *alloc_meta; > > > > + /* Don't save alloc info for kmalloc caches in kasan_slab_alloc(). */ > > + if (cache->kasan_info.is_kmalloc && !kmalloc) > > + return; > > + > > alloc_meta = kasan_get_alloc_meta(cache, object); > > if (alloc_meta) > > kasan_set_track(&alloc_meta->alloc_track, flags); > > } > > > > static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object, > > - size_t size, gfp_t flags, bool keep_tag) > > + size_t size, gfp_t flags, bool kmalloc) > > { > > unsigned long redzone_start; > > unsigned long redzone_end; > > @@ -423,7 +433,7 @@ static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object, > > KASAN_GRANULE_SIZE); > > redzone_end = round_up((unsigned long)object + cache->object_size, > > KASAN_GRANULE_SIZE); > > - tag = assign_tag(cache, object, false, keep_tag); > > + tag = assign_tag(cache, object, false, kmalloc); > > > > /* Tag is ignored in set_tag without CONFIG_KASAN_SW/HW_TAGS */ > > kasan_unpoison(set_tag(object, tag), size); > > @@ -431,7 +441,7 @@ static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object, > > KASAN_KMALLOC_REDZONE); > > > > if (kasan_stack_collection_enabled()) > > - set_alloc_info(cache, (void *)object, flags); > > + set_alloc_info(cache, (void *)object, flags, kmalloc); > > It doesn't bother me too much, but: 'bool kmalloc' shadows function > 'kmalloc' so this is technically fine, but using 'kmalloc' as the > variable name here might be confusing and there is a small chance it > might cause problems in a future refactor. Good point. Does "is_kmalloc" sound good? Thanks!