From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 DF4183E6DC3 for ; Fri, 26 Jun 2026 09:10:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782465006; cv=none; b=fnieOijNxv/n4AMsA67IuJEQtl82sRsEVk6g2Py+itaVqFC4v83cTDhSjE3rYux1sA4XUVGXZQ4bj+zfpljppptuHbD4aNiCmTmDvrkcfS07O0mBAS6+NYtdFlMBl8z+pL1pgW59AR0R1U2NchRf5p8Z5bYJSJPGfCM8fJh0wvE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782465006; c=relaxed/simple; bh=GT900ETDHKziu80zRoUerXJGnFDrRp/DlAKS4i9rpQA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=co1OedWJIOwuwQoa1XPHeKWFreEuyDiwXRSnN9rSusybohOwfqMhTsuN6xYtv7J3FMf45czV3eYbTR0WcyXwLC4woKbK/vDVuHlJFAQoORSInHGpdP4m0GRMuaO9NjAy17nmMSezOFqTeD1ERJy1jRs+Y+XuzoDTSf1WPUw5rhA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=NAPd9NEG; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="NAPd9NEG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D8AF91F000E9; Fri, 26 Jun 2026 09:09:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782465003; bh=Qgh7jq8hOPxIw6IuMTb/wxIsRLpeLI/zJPgah7TR+dk=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=NAPd9NEGGHGh3n6TeiTjy3pksVrolG9U+WluqwXZObPngFxHsNc7itjOCBAunxJpQ 4CopfFPzsC5G9dk8hwsVqD3hgponoSpbLiPZvB4ZEPH2SeRoumMnM06jDL4plhpW/Q PDuqr03gdxc7Y5ODOB87pWpTX70hwNj6Jsdg0j5mUHVIf1b3KvASHz6+Fy8TTF8Hyq Kh8RoAwSsfbuRCQoMRLK7R857Dgwf2oqjptFP9cfOAW7u3E8Ayrk+lETq5TX3poF/2 0C4mR7nlVZ9RLKJqcJq47Ch/9fxmNnywCoUSFkegEVBERBFnO+tOryfWxv2BgJwofh Tp8uIgOdYx6OQ== Message-ID: Date: Fri, 26 Jun 2026 11:09:48 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v7] mm: assert exclusive nid/zonenum bits at the page/folio access sites To: Leon Hwang , Hui Zhu , Andrew Morton , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kairui Song , Qi Zheng , Shakeel Butt , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: Hui Zhu References: <20260626032012.1049667-1-hui.zhu@linux.dev> <925c8686-9ff6-44c1-9780-63bd7cd8a1c3@linux.dev> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <925c8686-9ff6-44c1-9780-63bd7cd8a1c3@linux.dev> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit >> >> static inline enum zone_type folio_zonenum(const struct folio *folio) >> { >> +#if ZONES_WIDTH != 0 >> + ASSERT_EXCLUSIVE_BITS(folio->flags, ZONES_MASK << ZONES_PGSHIFT); >> +#endif >> return memdesc_zonenum(folio->flags); >> } >> > > Better to factor out a common macro alongside a comment for these two '#if'? Yes. And while looking at it, doesn't memdesc_section have similar problems? And there are other callers of memdesc_zonenum we wouldn't handle. So the macro approach is only partially helpful I thing. Maybe we should just pass by reference and fixup all callers? Ends up the cleanest. Untested: >From fb9b4e8c1d0419b960dc0cd4738d19d80d1fe14f Mon Sep 17 00:00:00 2001 From: "David Hildenbrand (Arm)" Date: Fri, 26 Jun 2026 11:06:39 +0200 Subject: [PATCH] mm: fix KASAN memdec_flags checks for zone/node/section Signed-off-by: David Hildenbrand (Arm) --- include/asm-generic/memory_model.h | 2 +- include/linux/mm.h | 23 +++++++++++++++-------- include/linux/mm_inline.h | 4 ++-- include/linux/mmzone.h | 24 ++++++++++++------------ mm/page_alloc.c | 6 +++--- mm/slab.h | 2 +- mm/sparse.c | 2 +- 7 files changed, 35 insertions(+), 28 deletions(-) diff --git a/include/asm-generic/memory_model.h b/include/asm-generic/memory_model.h index efa6610acbc79..f8404bc7773c2 100644 --- a/include/asm-generic/memory_model.h +++ b/include/asm-generic/memory_model.h @@ -53,7 +53,7 @@ static inline int pfn_valid(unsigned long pfn) */ #define __page_to_pfn(pg) \ ({ const struct page *__pg = (pg); \ - int __sec = memdesc_section(__pg->flags); \ + int __sec = memdesc_section(&__pg->flags); \ (unsigned long)(__pg - __section_mem_map_addr(__nr_to_section(__sec))); \ }) diff --git a/include/linux/mm.h b/include/linux/mm.h index 485df9c2dbddb..3111e4a6c9c4c 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2286,22 +2286,28 @@ static inline int page_zone_id(struct page *page) } #ifdef NODE_NOT_IN_PAGE_FLAGS -int memdesc_nid(memdesc_flags_t mdf); +int memdesc_nid(const memdesc_flags_t *mdf); +#elif defined(CONFIG_NUMA) +static inline int memdesc_nid(const memdesc_flags_t *mdf) +{ + ASSERT_EXCLUSIVE_BITS(mdf->f, NODES_MASK << NODES_PGSHIFT); + return (mdf->f >> NODES_PGSHIFT) & NODES_MASK; +} #else -static inline int memdesc_nid(memdesc_flags_t mdf) +static inline int memdesc_nid(const memdesc_flags_t *mdf) { - return (mdf.f >> NODES_PGSHIFT) & NODES_MASK; + return 0; } #endif static inline int page_to_nid(const struct page *page) { - return memdesc_nid(PF_POISONED_CHECK(page)->flags); + return memdesc_nid(&PF_POISONED_CHECK(page)->flags); } static inline int folio_nid(const struct folio *folio) { - return memdesc_nid(folio->flags); + return memdesc_nid(&folio->flags); } #ifdef CONFIG_NUMA_BALANCING @@ -2541,12 +2547,13 @@ static inline void set_page_section(struct page *page, unsigned long section) page->flags.f |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT; } -static inline unsigned long memdesc_section(memdesc_flags_t mdf) +static inline unsigned long memdesc_section(const memdesc_flags_t *mdf) { - return (mdf.f >> SECTIONS_PGSHIFT) & SECTIONS_MASK; + ASSERT_EXCLUSIVE_BITS(mdf->f, SECTIONS_MASK << SECTIONS_PGSHIFT); + return (mdf->f >> SECTIONS_PGSHIFT) & SECTIONS_MASK; } #else /* !SECTION_IN_PAGE_FLAGS */ -static inline unsigned long memdesc_section(memdesc_flags_t mdf) +static inline unsigned long memdesc_section(const memdesc_flags_t *mdf) { return 0; } diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h index a8430a7ae0544..efcddb9925add 100644 --- a/include/linux/mm_inline.h +++ b/include/linux/mm_inline.h @@ -650,7 +650,7 @@ static inline bool vma_has_recency(const struct vm_area_struct *vma) static inline size_t num_pages_contiguous(struct page **pages, size_t nr_pages) { struct page *cur_page = pages[0]; - unsigned long section = memdesc_section(cur_page->flags); + unsigned long section = memdesc_section(&cur_page->flags); size_t i; for (i = 1; i < nr_pages; i++) { @@ -660,7 +660,7 @@ static inline size_t num_pages_contiguous(struct page **pages, size_t nr_pages) * In unproblematic kernel configs, page_to_section() == 0 and * the whole check will get optimized out. */ - if (memdesc_section(cur_page->flags) != section) + if (memdesc_section(&cur_page->flags) != section) break; } diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index ca27121871475..19e709d7a13de 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -1272,31 +1272,31 @@ static inline bool zone_is_empty(const struct zone *zone) #define KASAN_TAG_MASK ((1UL << KASAN_TAG_WIDTH) - 1) #define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1) -static inline enum zone_type memdesc_zonenum(memdesc_flags_t flags) +static inline enum zone_type memdesc_zonenum(const memdesc_flags_t *flags) { - ASSERT_EXCLUSIVE_BITS(flags.f, ZONES_MASK << ZONES_PGSHIFT); - return (flags.f >> ZONES_PGSHIFT) & ZONES_MASK; + ASSERT_EXCLUSIVE_BITS(flags->f, ZONES_MASK << ZONES_PGSHIFT); + return (flags->f >> ZONES_PGSHIFT) & ZONES_MASK; } static inline enum zone_type page_zonenum(const struct page *page) { - return memdesc_zonenum(page->flags); + return memdesc_zonenum(&page->flags); } static inline enum zone_type folio_zonenum(const struct folio *folio) { - return memdesc_zonenum(folio->flags); + return memdesc_zonenum(&folio->flags); } #ifdef CONFIG_ZONE_DEVICE -static inline bool memdesc_is_zone_device(memdesc_flags_t mdf) +static inline bool memdesc_is_zone_device(const memdesc_flags_t *mdf) { return memdesc_zonenum(mdf) == ZONE_DEVICE; } static inline struct dev_pagemap *page_pgmap(const struct page *page) { - VM_WARN_ON_ONCE_PAGE(!memdesc_is_zone_device(page->flags), page); + VM_WARN_ON_ONCE_PAGE(!memdesc_is_zone_device(&page->flags), page); return page_folio(page)->pgmap; } @@ -1311,9 +1311,9 @@ static inline struct dev_pagemap *page_pgmap(const struct page *page) static inline bool zone_device_pages_have_same_pgmap(const struct page *a, const struct page *b) { - if (memdesc_is_zone_device(a->flags) != memdesc_is_zone_device(b->flags)) + if (memdesc_is_zone_device(&a->flags) != memdesc_is_zone_device(&b->flags)) return false; - if (!memdesc_is_zone_device(a->flags)) + if (!memdesc_is_zone_device(&a->flags)) return true; return page_pgmap(a) == page_pgmap(b); } @@ -1321,7 +1321,7 @@ static inline bool zone_device_pages_have_same_pgmap(const struct page *a, extern void memmap_init_zone_device(struct zone *, unsigned long, unsigned long, struct dev_pagemap *); #else -static inline bool memdesc_is_zone_device(memdesc_flags_t mdf) +static inline bool memdesc_is_zone_device(const memdesc_flags_t *mdf) { return false; } @@ -1338,12 +1338,12 @@ static inline struct dev_pagemap *page_pgmap(const struct page *page) static inline bool is_zone_device_page(const struct page *page) { - return memdesc_is_zone_device(page->flags); + return memdesc_is_zone_device(&page->flags); } static inline bool folio_is_zone_device(const struct folio *folio) { - return memdesc_is_zone_device(folio->flags); + return memdesc_is_zone_device(&folio->flags); } static inline bool is_zone_movable_page(const struct page *page) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index ee902a468c2f5..020a97ca018e9 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -6904,15 +6904,15 @@ static void __free_contig_range_common(unsigned long pfn, unsigned long nr_pages continue; } - if (start && memdesc_section(page->flags) != start_sec) { + if (start && memdesc_section(&page->flags) != start_sec) { free_prepared_contig_range(start, i - nr_start); start = page; nr_start = i; - start_sec = memdesc_section(page->flags); + start_sec = memdesc_section(&page->flags); } else if (!start) { start = page; nr_start = i; - start_sec = memdesc_section(page->flags); + start_sec = memdesc_section(&page->flags); } } diff --git a/mm/slab.h b/mm/slab.h index bf2f87acf5e3a..1ae8e6084ba32 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -155,7 +155,7 @@ static inline void *slab_address(const struct slab *slab) static inline int slab_nid(const struct slab *slab) { - return memdesc_nid(slab->flags); + return memdesc_nid(&slab->flags); } static inline pg_data_t *slab_pgdat(const struct slab *slab) diff --git a/mm/sparse.c b/mm/sparse.c index 16ac6df3c89fa..8e38477645131 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -43,7 +43,7 @@ static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned; static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned; #endif -int memdesc_nid(memdesc_flags_t mdf) +int memdesc_nid(const memdesc_flags_t *mdf) { return section_to_node_table[memdesc_section(mdf)]; } -- 2.43.0 -- Cheers, David