linux-kernel - Re: [PATCH v9 30/44] arm64: kasan: Allow enabling in-kernel MTE

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <6a72b3e3-1b35-5ead-bfff-f4e2f3d5296e@arm.com>
Date:   Thu, 12 Nov 2020 16:46:05 +0000
From:   Vincenzo Frascino <vincenzo.frascino@....com>
To:     Catalin Marinas <catalin.marinas@....com>,
        Andrey Konovalov <andreyknvl@...gle.com>
Cc:     Will Deacon <will.deacon@....com>,
        Dmitry Vyukov <dvyukov@...gle.com>,
        Andrey Ryabinin <aryabinin@...tuozzo.com>,
        Alexander Potapenko <glider@...gle.com>,
        Marco Elver <elver@...gle.com>,
        Evgenii Stepanov <eugenis@...gle.com>,
        Branislav Rankov <Branislav.Rankov@....com>,
        Kevin Brodsky <kevin.brodsky@....com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        kasan-dev@...glegroups.com, linux-arm-kernel@...ts.infradead.org,
        linux-mm@...ck.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v9 30/44] arm64: kasan: Allow enabling in-kernel MTE

Hi Catalin,

missed this one.

On 11/12/20 9:43 AM, Catalin Marinas wrote:
> On Tue, Nov 10, 2020 at 11:10:27PM +0100, Andrey Konovalov wrote:
>> From: Vincenzo Frascino <vincenzo.frascino@....com>
>>
>> Hardware tag-based KASAN relies on Memory Tagging Extension (MTE)
>> feature and requires it to be enabled. MTE supports
>>
>> This patch adds a new mte_init_tags() helper, that enables MTE in
>> Synchronous mode in EL1 and is intended to be called from KASAN runtime
>> during initialization.
> 
> There's no mte_init_tags() in this function.
> 
>> diff --git a/arch/arm64/kernel/mte.c b/arch/arm64/kernel/mte.c
>> index 600b26d65b41..7f477991a6cf 100644
>> --- a/arch/arm64/kernel/mte.c
>> +++ b/arch/arm64/kernel/mte.c
>> @@ -129,6 +129,13 @@ void *mte_set_mem_tag_range(void *addr, size_t size, u8 tag)
>>  	return ptr;
>>  }
>>  
>> +void mte_enable(void)
>> +{
>> +	/* Enable MTE Sync Mode for EL1. */
>> +	sysreg_clear_set(sctlr_el1, SCTLR_ELx_TCF_MASK, SCTLR_ELx_TCF_SYNC);
>> +	isb();
>> +}
> 
> Nitpick: maybe rename this to mte_enable_kernel() since MTE is already
> enabled for user apps.
> 

I will fix this in the next iteration.

-- 
Regards,
Vincenzo