Messages in this thread | | | Date | Fri, 6 Apr 2012 10:42:50 -0700 | Subject | Fwd: [PATCH -v3 40/47] PCI: Add pci bus removal through /sys/.../pci_bus/.../remove | From | Yinghai Lu <> |
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adding back the CC list
---------- Forwarded message ---------- From: Yinghai Lu <yhlu.kernel@gmail.com> Date: Fri, Apr 6, 2012 at 9:24 AM Subject: Re: [PATCH -v3 40/47] PCI: Add pci bus removal through /sys/.../pci_bus/.../remove To: Bjorn Helgaas <bhelgaas@google.com>
On Fri, Apr 6, 2012 at 9:07 AM, Bjorn Helgaas <bhelgaas@google.com> wrote: > On Fri, Apr 6, 2012 at 10:01 AM, Yinghai Lu <yhlu.kernel@gmail.com> wrote: >> On Fri, Apr 6, 2012 at 8:50 AM, Jiang Liu <liuj97@gmail.com> wrote: >>> Hi Yinghai, >>> I found many other drivers assume that a pci bus won't disappear if >>> the corresponding PCI bridge device still exists. The sysfs interface proposed >>> here breaks that assumption and may cause many access-after-free issues. >>> So what's the purpose of this interface? Should we remove this interface or >>> enhance other drivers to avoid invalid memory access issues? > > Can you point out some of the specifics about drivers making this > assumption? I'm not thrilled about the idea of removing a pci_bus > while the upstream bridge pci_dev still exists either.
I noticed that too. some hotplug driver link to those child bus instead of bridge... So have prepared some local patches to handle them.
> >> ok, will make it only show up on root bus. > > OK. I'm still interested in the specifics because I don't like the > way the pci_bus is exposed, even inside the kernel. The bus itself is > not an active entity, and we can't really do anything with it except > by touching a device connected to it.
I want to keep that to remove root bus that is not added acpi root.
Yinghai [unhandled content-type:application/octet-stream][unhandled content-type:application/octet-stream][unhandled content-type:application/octet-stream][unhandled content-type:application/octet-stream] | |