From: George Dunlap <george.dunlap@citrix.com>
To: Jan Beulich <JBeulich@suse.com>,
Andrew Cooper <andrew.cooper3@citrix.com>
Cc: George Dunlap <George.Dunlap@eu.citrix.com>,
Stefano Stabellini <sstabellini@kernel.org>,
Tim Deegan <tim@xen.org>, Xen-devel <xen-devel@lists.xen.org>
Subject: Re: [PATCH 1/3] xen/common: Avoid undefined behaviour by shifting into a sign bit
Date: Fri, 5 Aug 2016 15:07:01 +0100 [thread overview]
Message-ID: <66230005-b8dc-8a47-0795-95bedd373425@citrix.com> (raw)
In-Reply-To: <57A4B8FE02000078001033DA@prv-mh.provo.novell.com>
On 05/08/16 15:04, Jan Beulich wrote:
>>>> On 05.08.16 at 15:50, <andrew.cooper3@citrix.com> wrote:
>> --- a/xen/common/domctl.c
>> +++ b/xen/common/domctl.c
>> @@ -188,7 +188,7 @@ void getdomaininfo(struct domain *d, struct xen_domctl_getdomaininfo *info)
>> (d->controller_pause_count > 0 ? XEN_DOMINF_paused : 0) |
>> (d->debugger_attached ? XEN_DOMINF_debugged : 0) |
>> (d->is_xenstore ? XEN_DOMINF_xs_domain : 0) |
>> - d->shutdown_code << XEN_DOMINF_shutdownshift;
>> + (unsigned int)d->shutdown_code << XEN_DOMINF_shutdownshift;
>
> Is adding a cast here really the most suitable fix? The only two places
> shutdown_code gets set (besides the -1 initialization) have their right
> side a u8. Nothing ever checks for the value being negative (there are
> just two -1 checks), so converting the field to u8 or unsigned int (and
> using a sentinel different from -1) should both work, avoiding the need
> for a cast.
This seems sensible if possible.
The other bits:
Reviewed-by: George Dunlap <george.dunlap@citrix.com>
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next prev parent reply other threads:[~2016-08-05 14:07 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-08-05 13:50 [PATCH 1/3] xen/common: Avoid undefined behaviour by shifting into a sign bit Andrew Cooper
2016-08-05 13:50 ` [PATCH 2/3] xen/x86: " Andrew Cooper
2016-08-05 14:06 ` Jan Beulich
2016-08-05 13:50 ` [PATCH 3/3] x86/microcode: Avoid undefined behaviour from signed integer overflow Andrew Cooper
2016-08-05 14:09 ` Jan Beulich
2016-08-11 8:42 ` Tian, Kevin
2016-08-05 14:04 ` [PATCH 1/3] xen/common: Avoid undefined behaviour by shifting into a sign bit Jan Beulich
2016-08-05 14:07 ` George Dunlap [this message]
2016-08-09 12:48 ` [PATCH] " Andrew Cooper
2016-08-09 12:48 ` [PATCH] xen/x86: " Andrew Cooper
2016-08-09 12:48 ` [PATCH] x86/microcode: Avoid undefined behaviour from signed integer overflow Andrew Cooper
2016-08-09 14:00 ` [PATCH] xen/common: Avoid undefined behaviour by shifting into a sign bit Jan Beulich
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