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 E6885313E26 for ; Wed, 15 Oct 2025 06:46:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760510789; cv=none; b=cw1UY3fG6OFe2zg9wU/wx4D2D/8o8KdukB06CwhCIEYQ4vYDX0i54u22DE6jnLanyfb+gFaM1NmNW9NmVeegfEuJcCojDcF/PzN8VuZv6ue4ngtc4SkSFCYowmnEf7SbOjT0YiLSl3KmVZoH4uuz78NHuP3mvpdxkxd9Yh2GFvc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760510789; c=relaxed/simple; bh=jdO6iUffukrVUTW8YZ+T3nrokT9QURV2O59Xbm4Chgg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ia28jKqJlz0mjMJPJ1G5vowiaJ6N08kSl2OyBSGwVfbAI5YIINZNLfqHezhkXqguXVFItMGURpujXSJ0QrH+Z/kRGeA+1EN6L2JnKVJfLqO7cmh2va2Dxhcf31p5thzzuDmhEFLfqMSHhVPDxc3O5riBha2qV4uTlUSkauj8Y/E= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com 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 21BAA1A32; Tue, 14 Oct 2025 23:46:17 -0700 (PDT) Received: from [10.163.67.182] (unknown [10.163.67.182]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 334E83F6A8; Tue, 14 Oct 2025 23:46:21 -0700 (PDT) Message-ID: <00bf0498-8f11-466e-9f2a-f7e656ecddf9@arm.com> Date: Wed, 15 Oct 2025 12:16:18 +0530 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 1/2] arm64: mm: make linear mapping permission update more robust for patial range To: Yang Shi , ryan.roberts@arm.com, cl@gentwo.org, catalin.marinas@arm.com, will@kernel.org Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org References: <20251013232803.3065100-1-yang@os.amperecomputing.com> <20251013232803.3065100-2-yang@os.amperecomputing.com> Content-Language: en-US From: Dev Jain In-Reply-To: <20251013232803.3065100-2-yang@os.amperecomputing.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 14/10/25 4:57 am, Yang Shi wrote: > The commit fcf8dda8cc48 ("arm64: pageattr: Explicitly bail out when changing > permissions for vmalloc_huge mappings") made permission update for > partial range more robust. But the linear mapping permission update > still assumes update the whole range by iterating from the first page > all the way to the last page of the area. > > Make it more robust by updating the linear mapping permission from the > page mapped by start address, and update the number of numpages. > > Fixes: fcf8dda8cc48 ("arm64: pageattr: Explicitly bail out when changing permissions for vmalloc_huge mappings") > Signed-off-by: Yang Shi > --- > arch/arm64/mm/pageattr.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c > index 5135f2d66958..c21a2c319028 100644 > --- a/arch/arm64/mm/pageattr.c > +++ b/arch/arm64/mm/pageattr.c > @@ -148,7 +148,6 @@ static int change_memory_common(unsigned long addr, int numpages, > unsigned long size = PAGE_SIZE * numpages; > unsigned long end = start + size; > struct vm_struct *area; > - int i; > > if (!PAGE_ALIGNED(addr)) { > start &= PAGE_MASK; > @@ -184,8 +183,9 @@ static int change_memory_common(unsigned long addr, int numpages, > */ > if (rodata_full && (pgprot_val(set_mask) == PTE_RDONLY || > pgprot_val(clear_mask) == PTE_RDONLY)) { > - for (i = 0; i < area->nr_pages; i++) { > - __change_memory_common((u64)page_address(area->pages[i]), > + unsigned long idx = (start - (unsigned long)area->addr) >> PAGE_SHIFT; > + for (int i = 0; i < numpages; i++) { > + __change_memory_common((u64)page_address(area->pages[idx++]), > PAGE_SIZE, set_mask, clear_mask); Why not just use idx as the iterator in the for loop? Using i and then incrementing idx is confusing. As noted by Ryan, the fixes commit is wrong. The issues persists from commit c55191e. After fixing these: Reviewed-by: Dev Jain > } > }