From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 585B41F946 for ; Thu, 11 May 2023 12:59:09 +0000 (UTC) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6908C165C; Thu, 11 May 2023 05:59:53 -0700 (PDT) Received: from e125769.cambridge.arm.com (e125769.cambridge.arm.com [10.1.196.26]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id C26083F5A1; Thu, 11 May 2023 05:59:07 -0700 (PDT) From: Ryan Roberts To: Andrew Morton , "Matthew Wilcox (Oracle)" , "Kirill A. Shutemov" , SeongJae Park Cc: Ryan Roberts , linux-kernel@vger.kernel.org, linux-mm@kvack.org, damon@lists.linux.dev Subject: [PATCH v1 1/5] mm: vmalloc must set pte via arch code Date: Thu, 11 May 2023 13:58:44 +0100 Message-Id: <20230511125848.78621-2-ryan.roberts@arm.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20230511125848.78621-1-ryan.roberts@arm.com> References: <20230511125848.78621-1-ryan.roberts@arm.com> Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit It is bad practice to directly set pte entries within a pte table. Instead all modifications must go through arch-provided helpers such as set_pte_at() to give the arch code visibility and allow it to validate (and potentially modify) the operation. Fixes: 3e9a9e256b1e ("mm: add a vmap_pfn function") Signed-off-by: Ryan Roberts --- mm/vmalloc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 9683573f1225..d8d2fe797c55 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -2899,10 +2899,13 @@ struct vmap_pfn_data { static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private) { struct vmap_pfn_data *data = private; + pte_t ptent; if (WARN_ON_ONCE(pfn_valid(data->pfns[data->idx]))) return -EINVAL; - *pte = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot)); + + ptent = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot)); + set_pte_at(&init_mm, addr, pte, ptent); return 0; } -- 2.25.1