linux-kernel - RE: [PATCH 2/2] pci-hyperv: properly handle device eject

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 14 Sep 2016 05:45:07 +0000
From:   Dexuan Cui <decui@...rosoft.com>
To:     Long Li <longli@...rosoft.com>, KY Srinivasan <kys@...rosoft.com>,
        "Haiyang Zhang" <haiyangz@...rosoft.com>,
        Bjorn Helgaas <bhelgaas@...gle.com>
CC:     "devel@...uxdriverproject.org" <devel@...uxdriverproject.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>
Subject: RE: [PATCH 2/2] pci-hyperv: properly handle device eject

> From: Long Li
> Sent: Wednesday, September 14, 2016 1:41
> 
> I think this code is safe here. If we reach the code
> pci_stop_and_remove_bus_device_locked, create_root_hv_pci_bus() is already
> called.

When hv_pci_probe() -> create_root_hv_pci_bus() -> pci_scan_child_bus() is running
on one cpu, I think nothing in the current code can prevent 
hv_eject_device_work() -> pci_stop_and_remove_bus_device_locked()
from running on another cpu?

The race window is pretty small however.

Thanks,
-- Dexuan