From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 78E0D12B169 for ; Thu, 19 Dec 2024 03:05:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734577528; cv=none; b=MuPz02nD53V5Xn9n/yLn6QA6ZzXBS1ot64DBBqoUqAgNcGJ/YoB97fzEpZcy0Vek8/o2WZgHyf6rpahJdHKgA1MkkZQfWSE+8DEjcAoBDajO+mbYHr0/SAt6UfmmiO72B4PswnunFgvCt+0lYsN1GstwrG7EeXLT5NC2NvhI6Ek= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734577528; c=relaxed/simple; bh=vIpw+WY8LWpXQaj2nt4kpLVr9Vj65D4qvdo03bcVo6Y=; h=Date:To:From:Subject:Message-Id; b=U9yABZWT3NLchx0KcUfE0CP55s2yMU9yZahSipllPXi0z9ALtzHuXEkFjkRehFrBUw61FHUDCoE5bd1/XuHsPpWs30AuDAmCt0bxotI8gYDolMU+GPWC31i9thR12ZkFaEXhjRpopX0xWWaHhUbeU5k1pWoV67vt3TRxrwgL/fg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=iyYZ7+5i; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="iyYZ7+5i" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 05F1AC4CECD; Thu, 19 Dec 2024 03:05:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1734577528; bh=vIpw+WY8LWpXQaj2nt4kpLVr9Vj65D4qvdo03bcVo6Y=; h=Date:To:From:Subject:From; b=iyYZ7+5iwhGSi6mFn6PZpTfRFBLl85geqOnttAkbkXAmoFMZuN3AzbDjruTnfr4Ir 72pl4zGPgecHqnpK61GxmJ/NFSMIRsSk3FvIWgJ+TXup4t6k0XLHdgNQf/n7+NNdKG CbNy0SiC2/a6UyYr/mlM+TbMCCWabZC/WDiIYYbU= Date: Wed, 18 Dec 2024 19:05:27 -0800 To: mm-commits@vger.kernel.org,willy@infradead.org,wangkefeng.wang@huawei.com,vgupta@kernel.org,vbabka@suse.cz,ryan.roberts@arm.com,mathieu.desnoyers@efficios.com,linmiaohe@huawei.com,keescook@chromium.org,jhubbard@nvidia.com,glider@google.com,geert+renesas@glider.be,david@redhat.com,ziy@nvidia.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] mm-use-clear_user_highpage-for-arch-with-special-user-folio-handling.patch removed from -mm tree Message-Id: <20241219030528.05F1AC4CECD@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm: use clear_user_(high)page() for arch with special user folio handling has been removed from the -mm tree. Its filename was mm-use-clear_user_highpage-for-arch-with-special-user-folio-handling.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Zi Yan Subject: mm: use clear_user_(high)page() for arch with special user folio handling Date: Mon, 9 Dec 2024 13:23:26 -0500 Some architectures have special handling after clearing user folios: architectures, which set cpu_dcache_is_aliasing() to true, require flushing dcache; arc, which sets cpu_icache_is_aliasing() to true, changes folio->flags to make icache coherent to dcache. So __GFP_ZERO using only clear_page() is not enough to zero user folios and clear_user_(high)page() must be used. Otherwise, user data will be corrupted. Fix it by always clearing user folios with clear_user_(high)page() when cpu_dcache_is_aliasing() is true or cpu_icache_is_aliasing() is true. Rename alloc_zeroed() to user_alloc_needs_zeroing() and invert the logic to clarify its intend. Link: https://lkml.kernel.org/r/20241209182326.2955963-2-ziy@nvidia.com Fixes: 5708d96da20b ("mm: avoid zeroing user movable page twice with init_on_alloc=1") Signed-off-by: Zi Yan Reported-by: Geert Uytterhoeven Closes: https://lore.kernel.org/linux-mm/CAMuHMdV1hRp_NtR5YnJo=HsfgKQeH91J537Gh4gKk3PFZhSkbA@mail.gmail.com/ Tested-by: Geert Uytterhoeven Acked-by: Vlastimil Babka Cc: Alexander Potapenko Cc: David Hildenbrand Cc: John Hubbard Cc: Kees Cook Cc: Kefeng Wang Cc: Mathieu Desnoyers Cc: Matthew Wilcox Cc: Miaohe Lin Cc: Ryan Roberts Cc: Vineet Gupta Signed-off-by: Andrew Morton --- include/linux/highmem.h | 8 +++++++- include/linux/mm.h | 18 ++++++++++++++++++ mm/huge_memory.c | 9 +++++---- mm/internal.h | 6 ------ mm/memory.c | 10 +++++----- 5 files changed, 35 insertions(+), 16 deletions(-) --- a/include/linux/highmem.h~mm-use-clear_user_highpage-for-arch-with-special-user-folio-handling +++ a/include/linux/highmem.h @@ -224,7 +224,13 @@ static inline struct folio *vma_alloc_zeroed_movable_folio(struct vm_area_struct *vma, unsigned long vaddr) { - return vma_alloc_folio(GFP_HIGHUSER_MOVABLE | __GFP_ZERO, 0, vma, vaddr); + struct folio *folio; + + folio = vma_alloc_folio(GFP_HIGHUSER_MOVABLE, 0, vma, vaddr); + if (folio && user_alloc_needs_zeroing()) + clear_user_highpage(&folio->page, vaddr); + + return folio; } #endif --- a/include/linux/mm.h~mm-use-clear_user_highpage-for-arch-with-special-user-folio-handling +++ a/include/linux/mm.h @@ -31,6 +31,7 @@ #include #include #include +#include struct mempolicy; struct anon_vma; @@ -4184,6 +4185,23 @@ static inline int do_mseal(unsigned long } #endif +/* + * user_alloc_needs_zeroing checks if a user folio from page allocator needs to + * be zeroed or not. + */ +static inline bool user_alloc_needs_zeroing(void) +{ + /* + * for user folios, arch with cache aliasing requires cache flush and + * arc changes folio->flags to make icache coherent with dcache, so + * always return false to make caller use + * clear_user_page()/clear_user_highpage(). + */ + return cpu_dcache_is_aliasing() || cpu_icache_is_aliasing() || + !static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, + &init_on_alloc); +} + int arch_get_shadow_stack_status(struct task_struct *t, unsigned long __user *status); int arch_set_shadow_stack_status(struct task_struct *t, unsigned long status); int arch_lock_shadow_stack_status(struct task_struct *t, unsigned long status); --- a/mm/huge_memory.c~mm-use-clear_user_highpage-for-arch-with-special-user-folio-handling +++ a/mm/huge_memory.c @@ -1176,11 +1176,12 @@ static struct folio *vma_alloc_anon_foli folio_throttle_swaprate(folio, gfp); /* - * When a folio is not zeroed during allocation (__GFP_ZERO not used), - * folio_zero_user() is used to make sure that the page corresponding - * to the faulting address will be hot in the cache after zeroing. + * When a folio is not zeroed during allocation (__GFP_ZERO not used) + * or user folios require special handling, folio_zero_user() is used to + * make sure that the page corresponding to the faulting address will be + * hot in the cache after zeroing. */ - if (!alloc_zeroed()) + if (user_alloc_needs_zeroing()) folio_zero_user(folio, addr); /* * The memory barrier inside __folio_mark_uptodate makes sure that --- a/mm/internal.h~mm-use-clear_user_highpage-for-arch-with-special-user-folio-handling +++ a/mm/internal.h @@ -1285,12 +1285,6 @@ void touch_pud(struct vm_area_struct *vm void touch_pmd(struct vm_area_struct *vma, unsigned long addr, pmd_t *pmd, bool write); -static inline bool alloc_zeroed(void) -{ - return static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, - &init_on_alloc); -} - /* * Parses a string with mem suffixes into its order. Useful to parse kernel * parameters. --- a/mm/memory.c~mm-use-clear_user_highpage-for-arch-with-special-user-folio-handling +++ a/mm/memory.c @@ -4733,12 +4733,12 @@ static struct folio *alloc_anon_folio(st folio_throttle_swaprate(folio, gfp); /* * When a folio is not zeroed during allocation - * (__GFP_ZERO not used), folio_zero_user() is used - * to make sure that the page corresponding to the - * faulting address will be hot in the cache after - * zeroing. + * (__GFP_ZERO not used) or user folios require special + * handling, folio_zero_user() is used to make sure + * that the page corresponding to the faulting address + * will be hot in the cache after zeroing. */ - if (!alloc_zeroed()) + if (user_alloc_needs_zeroing()) folio_zero_user(folio, vmf->address); return folio; } _ Patches currently in -mm which might be from ziy@nvidia.com are