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 7DBFF4E4C4B; Wed, 14 Oct 2026 09:38:34 +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=1791970715; cv=none; b=A6JxeiPsz0X9JUby/x4I2WBhHkUqKs5wAfySyGv9DB9FZGTqxCeahPUnwwEt5DVjs8HYq5NLXCS0RUXGQUB8tydOAzj4KKiv1/8DoKyb183xTknR3aaLJsj7UJthIosMtYXK4EwGzhI4PgcamrW1ZhclnM9NITlS8UtakWPZY7s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791970715; c=relaxed/simple; bh=AxKdmJrP0IH3YpfUlw2dNutWImngnRPxoK/25soqHT8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=OS4d5KNNySyw76rkShDOD1hi+7bzRwXfNHjYZdYpid9YbcYWpXSxdVU3xpBXny3y9iFiyuvYYevfV8BLvn+6WnmG0AWK68e+JLKhUPUVQjgu9Lk6IvVuuo/gMkngIsLeGMLJEUe1d4UTaYk0xuPFrBTlYNuTQXXeWlopho6NWFQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=eG0jUYG+; 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="eG0jUYG+" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 92FDB1F00A08; Wed, 14 Oct 2026 09:38:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791970714; bh=KpXJrzBDyvJvMZGQ7sWNVin16ZGNhFmi7scpeRJwY88=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=eG0jUYG+FHPC1mIGBXF1XswYvWqsvCRJ5g1WeWMqfBOTk7qeccaNz1bXKpRGDLiWt cl814MgIVDFjDkY4hxw9NYvt+1ChdY6Kn8HS9OwlJkdOiiXm1ldSZ0oSBYupNcL4Kb VMdOWNcagKOW3CvJ5kbtm5qf1Int1kDfIV+OSf1vhkEoWBalH/u2c+tsnjSPqKr3ei zggVoHfRQ2+BPJMcXv5+UwWqjabHz/WNlmQHjgaTe5OnDEDOpCGSWZmh0PbVsiG52t 0w8/QCPoUnwTtiB/3rNIJKxqhnGkAnXbnQvNkO3Gdj5lCMMTd0Itd04ZifoMYQMA8v bt7T7IiHlzFOQ== Message-ID: Date: Wed, 14 Oct 2026 11:37:48 +0200 Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 11/21] riscv: mm: use proper set_pXd() for generic compile-time folded patable in vmalloc_fault() To: Yeoreum Yun , Russell King , Huacai Chen , WANG Xuerui , Thomas Bogendoerfer , Catalin Marinas , Will Deacon , Arnd Bergmann , Andrew Morton , Kairui Song , Qi Zheng , Shakeel Butt , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Johannes Weiner , Michal Hocko , Lorenzo Stoakes , Tianrui Zhao , Bibo Mao , Anup Patel , Atish Patra , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonas Bonn , Stefan Kristiansson , Stafford Horne Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-openrisc@vger.kernel.org References: <20260921-dummy_ptxp3-v1-0-cd40cf68242e@arm.com> <20260921-dummy_ptxp3-v1-11-cd40cf68242e@arm.com> 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: <20260921-dummy_ptxp3-v1-11-cd40cf68242e@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/21/26 12:55, Yeoreum Yun wrote: > The behaviour of pXdp_get() will change with generic compile-time folded > page tables, making it invalid to use set_pXd() with the result of > pXdp_get(). Instead, the appropriate first-level set_pXd() must be paired > with the corresponding pXdp_get(). > > Therefore, call the appropriate set_pXd() for generic compile-time folded > page tables so that vmalloc_fault() continues to handle folded entries > correctly when checking pXd_present(). > > There should be no functional change. > > Since most architectures use a similar pattern to handle vmalloc fault > by syncing the faulted entry, it would be worth cleaning this up by > introducing a common helper in the near future. > > Signed-off-by: Yeoreum Yun > --- @ Riscv maintainers, is this good enough until we get some more generic cleanups in this area? > arch/riscv/mm/fault.c | 52 ++++++++++++++++++++++++++++++++------------------- > 1 file changed, 33 insertions(+), 19 deletions(-) > > diff --git a/arch/riscv/mm/fault.c b/arch/riscv/mm/fault.c > index 04ed6f8acae4f..b2bcaf10d13f1 100644 > --- a/arch/riscv/mm/fault.c > +++ b/arch/riscv/mm/fault.c > @@ -167,14 +167,16 @@ bad_area(struct pt_regs *regs, struct mm_struct *mm, int code, > > static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long addr) > { > - pgd_t *pgd, *pgd_k; > - pud_t *pud_k; > - p4d_t *p4d_k; > - pmd_t *pmd_k; > - pte_t *pte_k; > + pgd_t *pgdp_k, *pgdp, pgd_k; > + p4d_t *p4dp_k, *p4dp; > + pud_t *pudp_k, *pudp, pud_k; > + pmd_t *pmdp_k, *pmdp, pmd_k; > + pte_t *ptep_k; > int index; > unsigned long pfn; > > + BUILD_BUG_ON(CONFIG_PGTABLE_LEVELS != 5 && CONFIG_PGTABLE_LEVELS != 2); > + > /* User mode accesses just cause a SIGSEGV */ > if (user_mode(regs)) > return do_trap(regs, SIGSEGV, code, addr); > @@ -189,39 +191,51 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a > */ > index = pgd_index(addr); > pfn = csr_read(CSR_SATP) & SATP_PPN; > - pgd = (pgd_t *)pfn_to_virt(pfn) + index; > - pgd_k = init_mm.pgd + index; > > - if (!pgd_present(pgdp_get(pgd_k))) { > + pgdp = (pgd_t *)pfn_to_virt(pfn) + index; > + pgdp_k = init_mm.pgd + index; > + > + pgd_k = pgdp_get(pgdp_k); > + if (!pgd_present(pgd_k)) { > no_context(regs, addr); > return; > } > - set_pgd(pgd, pgdp_get(pgd_k)); > + if (CONFIG_PGTABLE_LEVELS == 5) > + set_pgd(pgdp, pgd_k); > > - p4d_k = p4d_offset(pgd_k, addr); > - if (!p4d_present(p4dp_get(p4d_k))) { > + p4dp = p4d_offset(pgdp, addr); > + p4dp_k = p4d_offset(pgdp_k, addr); > + if (!p4d_present(p4dp_get(p4dp_k))) { > no_context(regs, addr); > return; > } > > - pud_k = pud_offset(p4d_k, addr); > - if (!pud_present(pudp_get(pud_k))) { > + pudp = pud_offset(p4dp, addr); > + pudp_k = pud_offset(p4dp_k, addr); > + > + pud_k = pudp_get(pudp_k); > + if (!pud_present(pud_k)) { > no_context(regs, addr); > return; > } > - if (pud_leaf(pudp_get(pud_k))) > + if (pud_leaf(pud_k)) > goto flush_tlb; > > /* > * Since the vmalloc area is global, it is unnecessary > * to copy individual PTEs > */ > - pmd_k = pmd_offset(pud_k, addr); > - if (!pmd_present(pmdp_get(pmd_k))) { > + pmdp = pmd_offset(pudp, addr); > + pmdp_k = pmd_offset(pudp_k, addr); > + > + pmd_k = pmdp_get(pmdp_k); > + if (!pmd_present(pmd_k)) { > no_context(regs, addr); > return; > } > - if (pmd_leaf(pmdp_get(pmd_k))) > + if (CONFIG_PGTABLE_LEVELS == 2) > + set_pmd(pmdp, pmd_k); > + if (pmd_leaf(pmd_k)) > goto flush_tlb; > > /* > @@ -230,8 +244,8 @@ static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long a > * addresses. If we don't do this, this will just > * silently loop forever. > */ > - pte_k = pte_offset_kernel(pmd_k, addr); > - if (!pte_present(ptep_get(pte_k))) { > + ptep_k = pte_offset_kernel(pmdp_k, addr); > + if (!pte_present(ptep_get(ptep_k))) { > no_context(regs, addr); > return; > } > -- Cheers, David