Re: [PATCH v2 4/6] xen: add SAF deviation for safe cast removal

From: Nicola Vetrini <nicola.vetrini@bugseng.com>
To: Jan Beulich <jbeulich@suse.com>
Cc: "Simone Ballarin" <simone.ballarin@bugseng.com>,
	consulting@bugseng.com,
	"Maria Celeste Cesario" <maria.celeste.cesario@bugseng.com>,
	"Andrew Cooper" <andrew.cooper3@citrix.com>,
	"George Dunlap" <george.dunlap@citrix.com>,
	"Julien Grall" <julien@xen.org>,
	"Stefano Stabellini" <sstabellini@kernel.org>,
	"Wei Liu" <wl@xen.org>,
	"Bertrand Marquis" <bertrand.marquis@arm.com>,
	"Michal Orzel" <michal.orzel@amd.com>,
	"Volodymyr Babchuk" <Volodymyr_Babchuk@epam.com>,
	"Roger Pau Monné" <roger.pau@citrix.com>,
	xen-devel@lists.xenproject.org
Subject: Re: [PATCH v2 4/6] xen: add SAF deviation for safe cast removal
Date: Tue, 19 Dec 2023 16:03:27 +0100	[thread overview]
Message-ID: <8251c32b9af3da9e69538285d0e1c25c@bugseng.com> (raw)
In-Reply-To: <7dfb364e-e144-4a92-825a-71394610b931@suse.com>

On 2023-12-19 12:28, Jan Beulich wrote:
> On 19.12.2023 12:05, Simone Ballarin wrote:
>> --- a/xen/arch/arm/guestcopy.c
>> +++ b/xen/arch/arm/guestcopy.c
>> @@ -109,6 +109,7 @@ static unsigned long copy_guest(void *buf, 
>> uint64_t addr, unsigned int len,
>> 
>>  unsigned long raw_copy_to_guest(void *to, const void *from, unsigned 
>> int len)
>>  {
>> +    /* SAF-3-safe COPY_to_guest doesn't modify from */
>>      return copy_guest((void *)from, (vaddr_t)to, len,
>>                        GVA_INFO(current), COPY_to_guest | 
>> COPY_linear);
>>  }
>> @@ -116,6 +117,7 @@ unsigned long raw_copy_to_guest(void *to, const 
>> void *from, unsigned int len)
>>  unsigned long raw_copy_to_guest_flush_dcache(void *to, const void 
>> *from,
>>                                               unsigned int len)
>>  {
>> +    /* SAF-3-safe COPY_to_guest doesn't modify from */
>>      return copy_guest((void *)from, (vaddr_t)to, len, 
>> GVA_INFO(current),
>>                        COPY_to_guest | COPY_flush_dcache | 
>> COPY_linear);
>>  }
> 
> Unlike below for x86, here in both cases the comment cover more than
> just the one function argument they are intended to cover. I think we
> want to limit the scope of such comments as much as possible (and
> hence have as little as possible on the immediately following line).
> 
> Jan

Ok, noted for v3.

-- 
Nicola Vetrini, BSc
Software Engineer, BUGSENG srl (https://bugseng.com)