Xen project Mailing List

Races in power IRP handling path.

To: "win-pv-devel@xxxxxxxxxxxxxxxxxxxx" <win-pv-devel@xxxxxxxxxxxxxxxxxxxx>

From: Martin Harvey <martin.harvey@xxxxxxxxxx>

Date: Tue, 11 Oct 2022 14:33:06 +0000

Accept-language: 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=2SRFancduubGmpk57L3p9I+Oeb511PpQerivMrBTpno=; b=KPhGC+CqibBrupvMonTWZ+tChcDyftIN83AaayoetchN9mE0pJ/lWTUpFd/XsbU/v+JxWFHHkiDDkE4xbDsh1c6puFFQYNxVXjF7DkIs2GFAuSjEDtOZbF6djEbWBdtNOPbkSBp3lHqhe6S1s4iXWu0YRPhQpyJZJ26y0x+/CuISx5NIrIDmiZes6I6GW6f2Tv0aVhVBtJA/yYkm1jtBI/qz1oyLLNXGmOZCDOS03foqT3p5LyC6fyZ/Og2DWogWHGH+XYcCDd1/90rr9/oCiVr8ta4JDWwmjl4LFO0msM1I/pCdPzSWqBdCxAeNW2BEe+JGJOuv3BgUJ0xD7NmXkw==

Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=A0cg2k9ISroLV9Yh/pw/lIdDG5PxEDvZ64bRBlBFcvH5d9MRuIRXASiu5kkexDITiq+ZVjwsvs9buwBYJIF9h+XbcH1J/xJUTQGFlYLJcr/aZYuwc/lrSrkCOOKNKTA+86X9HMNRMoVHc6+DteZivfI2vYjhCbMZWPYsKvpize0rEZKF8VFc3F9E3Dj9FSGNfYhQgdqL7uAUeq2kx351+PeRkHJopGXloS1n0WjD4SlfqygGUeqJzya0D+ATW5vm29vIRKpcM/XC8VDhoeeIhA4OXIKhLGJo85J5DGqM1pu8Bfs7F4yKZK9iBnSqIteQAXW13e6hmbfI0D8t6Fb6Gw==

Authentication-results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=citrix.com;

Delivery-date: Tue, 11 Oct 2022 14:33:20 +0000

Ironport-data: A9a23:5LrG3aBlkZ6E3hVW/yriw5YqxClBgxIJ4kV8jS/XYbTApDMlg2MHn zEXUDvXbveIZGumct4iO42z9EMH6seDyIBgQQY4rX1jcSlH+JHPbTi7wuUcHAvJd5GeExg3h yk6QoOdRCzhZiaE/n9BCpC48T8mk/ngqoPUUIbsIjp2SRJvVBAvgBdin/9RqoNziJ2yDhjlV ena+qUzA3f4nW8pWo4ow/jb8kk25K2r4GlwUmEWPpingnePzxH5M7pHTU2BByOQapVZGOe8W 9HCwNmRlo8O105wYj8Nuu+TnnwiGtY+DyDX4pZlc/HKbix5jj4zys4G2M80Mi+7vdkrc+dZk 72hvbToIesg0zaldO41C3G0GAkmVUFKFSOuzdFSfqV/wmWfG0YAzcmCA2kdPdE0yuJKDVoS1 uITBhMDPk3Al8CplefTpulE3qzPLeHNFaZG4jRM6G+cCvwrB5feX6/N+NlUmi8qgdxDFurfY MxfbidzaBPHYFtEPVJ/5JAWxb/0wCWgNWAI7gvN/sLb4ECKpOB1+L3kKsbUfJqKTN9Lk1ewr WPa5WXpRBodMbRzzBLVqCL92bSewUsXXqoeML6f9fNVoWSo/VY9CSVKT3Djg9S23xvWt9V3b hZ8FjAVhbcz8gmzUJzxUgO1pFaAvwUAQJxAHusi8gaPx6HIpQGDCQA5oiVpbdUnsIo6QGIs3 1rQx9fxX2U36/uSVG6X8aqSoXWqIy8JIGQeZCgCCwwY/93kp4J1hRXKJjp+LJOIYhTOMWmY6 1i3QOIW3N3/UeZjO32HwG36

Ironport-hdrordr: A9a23:GxDleKjEjaX4FM57UBHwMpuT+XBQX1Z13DAbv31ZSRFFG/FwyP rCoB1L73XJYWgqM03IwerwXpVoMkmsjKKdgLNhS4tKOTOLhILGFvAH0WKP+Vzd8k7Fh6dgPM VbAs9D4bTLZDAU4/oSizPIcOrIteP3lZxA8t2urUuFIzsLV4hQqyNCTiqLGEx/QwdLQbAjEo CH28ZBrz28PVwKc8WSHBA+LqP+juyOsKijTQ8NBhYh5gXLpyiv8qTGHx+R2Qpbey9TwI0l7X POn2XCl++eWrCAu1LhPl3onttrcejau5V+7Qu3+4kowwDX+0qVjUJaKv2/VX4O0aKSAR0R4a HxSl8bTr9OAjXqDymISFLWqnPd+Sdr5Hn4xVCCh3z/5cT/WTIhEsJEwZlUax3D9iMbzaRBOY 9wrhGkXqBsfGH9tTW448KNWwBhl0Kyr3ZnmekPj2ZHWY9bbLNKt4QQ8E5cDZ9FRUvBmfcaOf grCNuZ6OddcFucYXyctm5zwMa0VnB2GhudWEANtsGczjATlnFkyEkTwtAZgx47heYAYogB4/ 6BPrVjlblIQMNTZaVhBP0ZSc/yEWDJSQKkChPjHb0mLtB3B5vgke+J3Fxu3pDWRHUh9upPpL 3RFFVFqGU1Z0XiTcWTwZwjyGGyfFmA

List-id: Developer list for the Windows PV Drivers subproject <win-pv-devel.lists.xenproject.org>

Thread-index: AdjdfgIYsgA4b4/cQtWn6fzH2WpcQg==

Thread-topic: Races in power IRP handling path.

Hi,

Been debugging power IRP handling. I notice that we not only pend power IRPs on the dispatch path, but also use completion routines to try to force a synchronous completion (Forward irp synchronously). You might want to consider that setting a completion routine *outside* the dispatch handler on a pended IRP is likely to be a racey operation in and of itself.

MH.