From: Wei Yang <richardw.yang@linux.intel.com>
To: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: qemu-devel@nongnu.org, pbonzini@redhat.com, quintela@redhat.com,
Wei Yang <richardw.yang@linux.intel.com>,
rth@twiddle.net
Subject: Re: [Qemu-devel] [PATCH] migration: check length directly to make sure the range is aligned
Date: Mon, 19 Aug 2019 10:26:39 +0800 [thread overview]
Message-ID: <20190819022639.GA6368@richard> (raw)
In-Reply-To: <20190719175400.GJ3000@work-vm>
On Fri, Jul 19, 2019 at 06:54:00PM +0100, Dr. David Alan Gilbert wrote:
>* Wei Yang (richardw.yang@linux.intel.com) wrote:
>> Since the start addr is already checked, to make sure the range is
>> aligned, checking the length is enough.
>>
>> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
>> ---
>> exec.c | 7 +++----
>> 1 file changed, 3 insertions(+), 4 deletions(-)
>>
>> diff --git a/exec.c b/exec.c
>> index 50ea9c5aaa..8fa980baae 100644
>> --- a/exec.c
>> +++ b/exec.c
>> @@ -4067,10 +4067,9 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t start, size_t length)
>>
>> if ((start + length) <= rb->used_length) {
>> bool need_madvise, need_fallocate;
>> - uint8_t *host_endaddr = host_startaddr + length;
>> - 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;
>David Gibson's balloon fix from February means that the balloon code
>should now warn in it's case.
>
>rth: Want to pick this up?
>
>Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>
Hi, David
Do you like this one?
>> goto err;
>> }
>>
>> --
>> 2.17.1
>>
>--
>Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
--
Wei Yang
Help you, Help me
next prev parent reply other threads:[~2019-08-19 2:27 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-12 3:27 [Qemu-devel] [PATCH] migration: check length directly to make sure the range is aligned Wei Yang
2019-07-19 17:54 ` Dr. David Alan Gilbert
2019-07-19 18:03 ` Paolo Bonzini
2019-07-19 18:06 ` Dr. David Alan Gilbert
2019-10-01 7:54 ` Wei Yang
2019-10-28 1:10 ` Wei Yang
2019-10-29 7:04 ` Dr. David Alan Gilbert
2019-10-29 8:21 ` Wei Yang
2019-11-11 23:19 ` Paolo Bonzini
2019-08-19 2:26 ` Wei Yang [this message]
2019-09-13 23:58 ` Wei Yang
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