[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [PATCH 2/2] x86/time: add CF-clobber annotations


  • To: Jan Beulich <jbeulich@xxxxxxxx>
  • From: Andrew Cooper <Andrew.Cooper3@xxxxxxxxxx>
  • Date: Tue, 1 Mar 2022 14:35:14 +0000
  • Accept-language: en-GB, en-US
  • Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=citrix.com; dmarc=pass action=none header.from=citrix.com; dkim=pass header.d=citrix.com; arc=none
  • Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=RIry1fOwgDOAhhdNZBm4dA+nFybFDJJ02i51Nkot6Mw=; b=inQN0SYw0XGZ/EJ+uJwgnROxfWQNx5khB3N0e/wt/ClR335+lxZ+DFGYctOi8yFd8TLmo+LupS9QE0brkFiJhIT+HeUwvZF21VStFE/oSIrlZPyFyoCs7lnVWj3J8w0BJdsXw2Lhk8KVbR5oWkM5CwFhqQmX5tf5rSQsfk5ptNU8KHbY51NBAZPUI3hNATgDr7XXqdXBfAS2MyEj6t+Nf94YTdNQiLcZq3aOeuIqKPtqqyn5BdJr5sfyF8LAW2nm8y7a/MTW4Cd/O4L+FLREtsbS8+e0ZOTcIJozHtvkVibbfYhbyo+WW1+fW+c74flJvHSTq8kHE6HDUwjPd8iT8Q==
  • Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=Ud0D7KWKwR5HreP7O4N3VXBGd/tNEok3yj2fthRAwtl67+Fh9YMFcmVa1HSgy2wp+wPXrSy2IL3tgfAf/aifUCyLjCRZt97ghZHRPECqmzJVqdpNrSEsAd/bzfLEsrbxnFuWzAXT5otdJDFwBUHM7uvZIyK8WQoVISExkzoV3S1CwdYp+SX1fp5GAJ8DjKA8Ylf8wvEMRpC1qw6HlzXxjaEHOxj+ZY/hvfjqXInhOMpkl21Ly3LlwAxYirhGIgKF28qK3gFroWKFE/D3jKHGDieHv7jZJDlNtBu0rHhyAK0pwlYPcdWkQvjQPS2TlT6761/iGENKojlJi5JDtxCLSg==
  • Authentication-results: esa6.hc3370-68.iphmx.com; dkim=pass (signature verified) header.i=@citrix.onmicrosoft.com
  • Cc: Wei Liu <wl@xxxxxxx>, Roger Pau Monne <roger.pau@xxxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxxx>
  • Delivery-date: Tue, 01 Mar 2022 14:35:27 +0000
  • Ironport-data: A9a23:6ZJvbaJxeUIXCfTXFE+RzJUlxSXFcZb7ZxGr2PjKsXjdYENS1DVTz GAeC2zTa/fYZ2ejct9/adnn/U4DsJWGz4cxSFBlqX01Q3x08seUXt7xwmUcns+xwm8vaGo9s q3yv/GZdJhcokf0/0vrav67xZVF/fngqoDUUYYoAQgsA148IMsdoUg7wbRh2dYx2YLR7z6l4 rseneWOYDdJ5BYsWo4kw/rrRMRH5amaVJsw5zTSVNgT1LPsvyB94KE3fMldG0DQUIhMdtNWc s6YpF2PEsE1yD92Yj+tuu6TnkTn2dc+NyDW4pZdc/DKbhSvOkXee0v0XRYRQR4/ttmHozx+4 Mlxj5iCexVyAvHFveIZehcGIWZxBbITrdcrIVDn2SCS50jPcn+qyPRyFkAme4Yf/46bA0kXq 6ZecmpUKEne2aTmm9pXScE17ignBODtMJkSpTdLyjbBAOx9aZvCX7/L9ZlT2zJYasVmQ6uHP ZBHMWMHgBLoOSUWKlhHN60Hl9yMnGOjQmcfpn/OnP9ii4TU5FMoi+W8WDbPQfSaSMMQkkuGq 2bu+2XiHgpcJNGZ0SCC8H+nmqnIhyyTcJ0WPK218LhtmlL77m4ZBQASVFC7ieKkkUP4UNVaQ 3H44QJ38/J0rhbyCICgAVvo+xZooyLwRfJML9c+2jOfkZaI6iOfAkEKEAwGZ+Q54ZpeqSMR6 neFmNbgBDpKubKTSG6A+rr8kQ5eKRT5PkdZO3ZaEFJtD83L5dhq00mRFooL/Lud04WtcQwc1 Qxmu8TXa187qccQn5u28lnc695HjsiYF1Vljuk7s4/M0++YWGJHT9HwgbQ4xawZRGp8crVnl CJc8yR5xLpTZaxhbATXHI0w8EiBvp5pygH0j191BIUG/D+w4XOldo04yGggeBkxbZ1aJWawO R67VeZtCHl7ZiDCgUhfOd/ZNijX5fK4SYSNug78NLKinaSdhCfYpXozNCZ8LkjmkVQ2kLFXB HtoWZ3EMJruMow+lGDeb75EidcDn3lirUuOFcGT50n2itK2OS/KIYrpxXPTN4jVGovf+16Lm zueXuPXoyhivBrWOXGGodZOdglRdRDWx/ne8qRqSwJKGSI/cEkJAP7N27IxPYtjmqVejODT+ X+hHERfzTLCabfvc21mtlgLhGvTYKtC
  • Ironport-hdrordr: A9a23:lvUFNKwThFY8ND8YH9CJKrPxguskLtp133Aq2lEZdPULSKOlfp GV8MjziyWYtN9IYgBcpTiBUJPwJE81bfZOkMYs1MSZLXXbUQyTXc9fBOrZsnHd8kjFmNK1up 0QCpSWZOeAbmSSyPyKmjVQcOxQgeVvkprY/ds2pk0FJWoBCsFdBkVCe32m+yVNNVJ77PECZf 6hD7981lydkAMsH6OG7xc+Lor+juyOsKijTQ8NBhYh5gXLpyiv8qTGHx+R2Qpbey9TwJ85mF K10zDR1+GGibWW2xXc32jc49B9g9360OZOA8SKl4w8NijssAC1f45sMofy/wzd4dvfqmrCou O85yvIDP4DrE85uVvF5ycF7jOQlQrGLUWSkGNwz0GT+fARDwhKdPapzbgpDCcxrXBQ5u2UmZ g7r15w/fBsfGL9tTW46N7SWx5wkE2o5XIkjO4IlnRaFZATcblLsOUkjQho+bo7bWvHAbocYa FT5QDnlYJrWELfa2qcsnhkwdSqUHh2FhCaQlIassjQ1zRNhnh2w0YR2cRaxx47hd8AYogB4/ 6BPrVjlblIQMNTZaVhBP0ZSc/yDmDWWxrDPG+bPFyiHqAaPHDGrYLx/dwOlauXUY1NyIF3lI XKUVteu2J3c0XyCdeW1JkO6RzJSHXVZ0Wa9iif3ekPhlTRfsuYDcTYciFcryKJmYRrPvHm
  • List-id: Xen developer discussion <xen-devel.lists.xenproject.org>
  • Thread-index: AQHYLVxwam4XOlcoM0qksn/nZK0dPqyqgvIAgAAQwwCAAAGngIAAAwqA
  • Thread-topic: [PATCH 2/2] x86/time: add CF-clobber annotations

On 01/03/2022 14:24, Andrew Cooper wrote:
> On 01/03/2022 14:18, Jan Beulich wrote:
>> On 01.03.2022 14:18, Andrew Cooper wrote:
>>> On 01/03/2022 11:06, Jan Beulich wrote:
>>>> With bed9ae54df44 ("x86/time: switch platform timer hooks to altcall")
>>>> in place we can further arrange for ENDBR removal from the functions no
>>>> longer subject to indirect calls. Note that plt_tsc is left untouched,
>>>> for not holding any pointer eligible for ENDBR removal.
>>> I'd be tempted to include it, for consistency sake alone.
>>>
>>> It is less likely to go wrong in the future if another hook is introduced.
>> Can do, sure.
>>
>>>> Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
>>> With the commit message, I'm not not certain if this is linked to the
>>> previous patch.
>>>
>>> Overall it looks fine, but I'd like to get clarity on this point.
>> Converting read_tsc() was discussed (with Roger) earlier on, so I'd
>> view this as a separate change. As said in reply to your comments on
>> the 1st patch, how exactly read_tsc() looks like is orthogonal to
>> the changes here at least as long as it doesn't live in .text.
> Ok.  Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

Actually, you probably want to move plt_src into __ro_after_init along
with this change.

~Andrew

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.