Re: [Qemu-devel] [PATCH] migration: check length directly to make sure the range is aligned

From: Wei Yang <richardw.yang@linux.intel.com>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	rth@twiddle.net, Wei Yang <richardw.yang@linux.intel.com>,
	qemu-devel@nongnu.org, quintela@redhat.com
Subject: Re: [Qemu-devel] [PATCH] migration: check length directly to make sure the range is aligned
Date: Mon, 28 Oct 2019 09:10:15 +0800	[thread overview]
Message-ID: <20191028011015.GA3893@richard> (raw)
In-Reply-To: <20190719180651.GM3000@work-vm>

On Fri, Jul 19, 2019 at 07:06:51PM +0100, Dr. David Alan Gilbert wrote:
>* Paolo Bonzini (pbonzini@redhat.com) wrote:
>> On 19/07/19 19:54, Dr. David Alan Gilbert wrote:
>> >> -        if ((uintptr_t)host_endaddr & (rb->page_size - 1)) {
>> >> -            error_report("ram_block_discard_range: Unaligned end address: %p",
>> >> -                         host_endaddr);
>> >> +        if (length & (rb->page_size - 1)) {
>> >> +            error_report("ram_block_discard_range: Unaligned length: %lx",
>> >> +                         length);
>> > Yes, I *think* this is safe, we'll need to watch out for any warnings;
>> 
>> Do you mean compiler or QEMU warning?
>
>No, I mean lots of these error reports being printed out in some common
>case.
>

Hi, Dave

Haven't see you for a period of time :-)

>Dave
>
>  The patch is safe since there's an
>> 
>>     if ((uintptr_t)host_startaddr & (rb->page_size - 1)) {
>>         error_report("ram_block_discard_range: Unaligned start address: %p",
>>                      host_startaddr);
>>         goto err;
>>     }
>> 
>> just before this context.
>> 
>> Paolo
>--
>Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK

-- 
Wei Yang
Help you, Help me