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 BA6A81FCCE6 for ; Tue, 10 Dec 2024 07:27:11 +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=1733815634; cv=none; b=mk2CLXDabssceRrezNIMUFlnxk/jgHsaRboeTRoi/M3d4FcPSl95rrQFQU4GKUgfeRVRCNFWJmBACbxCTl6wHJy8u1YcMANUTRVhd36p9hj/PoJaZZGQ9yTHKl/ShADumYw5GjR9TLi/xoXUkFwQ5R0oEn2D1yAOitXnlgbg9zM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733815634; c=relaxed/simple; bh=cL1XLdx0ar7bGjJEheDDFTNMvNXlWQD5UGrEf/6Ikgo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Pn1Gs+I/h9w3MBv6H0umbI8lt7+gM9HFqhHe7/oUiOe4kyXxViWVFU9KRcukj8kIfBKGvavEzqDOSxYDrYoMyCvG9J7IeKgdfvWYFEYXlBWvUguZUqRq2i7bx78c3+mU5GZWJn5oH83MIXFtJgbxG9x2ty6v5VxEPuc4GS5mMrA= 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 E857EFEC; Mon, 9 Dec 2024 23:27:38 -0800 (PST) Received: from [10.163.48.173] (unknown [10.163.48.173]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id F04C83F720; Mon, 9 Dec 2024 23:27:06 -0800 (PST) Message-ID: <767de5f8-a650-4acf-966e-528fd08b09bb@arm.com> Date: Tue, 10 Dec 2024 12:57:04 +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 v3 2/2] arm64: remove CONFIG_RODATA_FULL_DEFAULT_ENABLED To: Huang Shijie , catalin.marinas@arm.com, will@kernel.org, corbet@lwn.net Cc: patches@amperecomputing.com, cl@linux.com, akpm@linux-foundation.org, thuth@redhat.com, rostedt@goodmis.org, xiongwei.song@windriver.com, ardb@kernel.org, inux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20241209072020.4743-1-shijie@os.amperecomputing.com> <20241209072020.4743-3-shijie@os.amperecomputing.com> Content-Language: en-US From: Anshuman Khandual In-Reply-To: <20241209072020.4743-3-shijie@os.amperecomputing.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit A small nit: arm64/Kconfig: Remove CONFIG_RODATA_FULL_DEFAULT_ENABLED On 12/9/24 12:50, Huang Shijie wrote: > After patch "arm64: refacotr the rodata=xxx", > the "rodata=on" becomes the default. > > ...................................... > if (!strcmp(arg, "on")) { > rodata_enabled = rodata_full = true; > return true; > } > ...................................... > > The rodata_full is always "true" via "rodata=on" and does not > depend on the config RODATA_FULL_DEFAULT_ENABLED anymore, > so it can be dropped. > > Signed-off-by: Huang Shijie > --- > arch/arm64/Kconfig | 14 -------------- > arch/arm64/mm/pageattr.c | 2 +- > 2 files changed, 1 insertion(+), 15 deletions(-) > > diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig > index cbfd357f94a6..1c69982302ed 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -1666,20 +1666,6 @@ config MITIGATE_SPECTRE_BRANCH_HISTORY > When taking an exception from user-space, a sequence of branches > or a firmware call overwrites the branch history. > > -config RODATA_FULL_DEFAULT_ENABLED > - bool "Apply r/o permissions of VM areas also to their linear aliases" > - default y > - help > - Apply read-only attributes of VM areas to the linear alias of > - the backing pages as well. This prevents code or read-only data > - from being modified (inadvertently or intentionally) via another > - mapping of the same memory page. This additional enhancement can > - be turned off at runtime by passing rodata=[off|on] (and turned on > - with rodata=full if this option is set to 'n') > - > - This requires the linear region to be mapped down to pages, > - which may adversely affect performance in some cases. > - > config ARM64_SW_TTBR0_PAN > bool "Emulate Privileged Access Never using TTBR0_EL1 switching" > depends on !KCSAN > diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c > index 39fd1f7ff02a..6eef08d8451e 100644 > --- a/arch/arm64/mm/pageattr.c > +++ b/arch/arm64/mm/pageattr.c > @@ -20,7 +20,7 @@ struct page_change_data { > pgprot_t clear_mask; > }; > > -bool rodata_full __ro_after_init = IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED); > +bool rodata_full __ro_after_init = true; > > bool can_set_direct_map(void) > { Otherwise LGTM Reviewed-by: Anshuman Khandual