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 D1F091D7992; Fri, 6 Dec 2024 04:40:51 +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=1733460057; cv=none; b=kDECf5yT5DCzGTCjLCZbs9Lq+dTdOYC74znWEVnmjW52SeYEsOuBTZKmjMCwKHFWUE+SAv6aSmi57uS4UA0+L/kb4EtBjNjPA4oVbO/TvyASnoj+t3COOhXrNx9S+a7RJu5HBZPSzFkvQEaYhRM889QSpTnW1huXmGAmrgDJomg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733460057; c=relaxed/simple; bh=l6yU7EFV2DWH8QMiN44xfukKeyx8cYOUr0adyde+ZsY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=JercXY505oWSLIPHFMVDOz11KNuq8CozUXSEjIJyrqbZkzXEmhezi5JcKTBUGWg959PeU1IRwND87+9rmTU90C81sCTAEGCk9ouJcsGidi1cpF+3b+aGBeKcQmcON4F+rq4rxj6GfxFq1wvrDIcK2RoVg9tt54spEkb93Hh8GTE= 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 03BDC169E; Thu, 5 Dec 2024 20:41:19 -0800 (PST) Received: from [10.163.50.12] (unknown [10.163.50.12]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 99B7B3F58B; Thu, 5 Dec 2024 20:40:45 -0800 (PST) Message-ID: Date: Fri, 6 Dec 2024 10:10:43 +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 v2 2/4] arm64: remove CONFIG_RODATA_FULL_DEFAULT_ENABLED To: Huang Shijie , catalin.marinas@arm.com, will@kernel.org Cc: patches@amperecomputing.com, paulmck@kernel.org, akpm@linux-foundation.org, thuth@redhat.com, rostedt@goodmis.org, xiongwei.song@windriver.com, ardb@kernel.org, steven.price@arm.com, suzuki.poulose@arm.com, mark.rutland@arm.com, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, cl@os.amperecomputing.com References: <20241126085647.4993-1-shijie@os.amperecomputing.com> <20241126085647.4993-3-shijie@os.amperecomputing.com> Content-Language: en-US From: Anshuman Khandual In-Reply-To: <20241126085647.4993-3-shijie@os.amperecomputing.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/26/24 14:26, Huang Shijie wrote: > The default kernel is rodata=on which means Right but this is true only after the update in the series. if (!strcmp(arg, "on")) { rodata_enabled = rodata_full = true; return true; } 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. Please update this commit message with these context as well. > CONFIG_RODATA_FULL_DEFAULT_ENABLED is always enabled by default. > So we can remove CONFIG_RODATA_FULL_DEFAULT_ENABLED now. > > 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 4316b1fe8bf8..a9ca305a31d8 100644 > --- a/arch/arm64/Kconfig > +++ b/arch/arm64/Kconfig > @@ -1653,20 +1653,6 @@ 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) > { This patch can still follow the first one but after folding in the third patch.