From: Jiang Liu <liuj97@gmail.com>
To: Bjorn Helgaas <bhelgaas@google.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>,
Jesse Barnes <jbarnes@virtuousgeek.org>, x86 <x86@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org,
Randy Dunlap <rdunlap@xenotime.net>,
linux-doc@vger.kernel.org
Subject: Re: [PATCH -v3 40/47] PCI: Add pci bus removal through /sys/.../pci_bus/.../remove
Date: Sat, 07 Apr 2012 00:22:34 +0800 [thread overview]
Message-ID: <4F7F184A.3080001@gmail.com> (raw)
In-Reply-To: <CAErSpo6gitMTVXeMBOSJFRHvQT_iJ-RGmLduYsGEM+3YAPE2CQ@mail.gmail.com>
On 04/07/2012 12:07 AM, Bjorn Helgaas 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.
According to my understanding, following drivers may have such an assumption:
acpiphp, pciehp, shpcphp, acpi/pci_slot, acpi/pci_bind.
I suspect there are still other drivers have such issues.
>
>> 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.
>
> Bjorn
next prev parent reply other threads:[~2012-04-06 16:22 UTC|newest]
Thread overview: 58+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-19 5:45 [PATCH 00/47] PCI, x86: pci root bus hotplug support Yinghai Lu
2012-03-19 5:45 ` [PATCH -v3 01/47] IOMMU: Update dmar units devices list during hotplug Yinghai Lu
2012-03-19 5:45 ` [PATCH -v3 02/47] PNPACPI: Fix device ref leaking in acpi_pnp_match Yinghai Lu
2012-03-19 5:45 ` [PATCH -v3 03/47] IOMMU: Fix tboot force iommu logic Yinghai Lu
2012-03-19 5:45 ` [PATCH -v3 04/47] x86, PCI: Fix non acpi path pci_sysdata leaking with release_fn Yinghai Lu
2012-03-19 5:45 ` [PATCH -v3 05/47] PCI: Separate out pci_assign_unassigned_bus_resources() Yinghai Lu
2012-03-19 5:45 ` [PATCH -v3 06/47] PCI: Move back pci_rescan_bus() Yinghai Lu
2012-03-19 5:45 ` [PATCH -v3 07/47] PCI: pci_bus_size_bridges() should not size own bridge Yinghai Lu
2012-03-19 5:45 ` [PATCH -v3 08/47] PCI: Use __pci_bus_size_bridges() directly in pci_assign_unassigned_bus_resources() Yinghai Lu
2012-03-19 5:45 ` [PATCH -v3 09/47] PCI, sysfs: Use device_type and attr_groups with pci dev Yinghai Lu
2012-03-19 5:45 ` [PATCH -v3 10/47] PCI, sysfs: create rescan_bridge under /sys/.../pci/devices/... for pci bridges Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 11/47] PCI: Add pci_bus_add_single_device() Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 12/47] PCI: Make pci_rescan_bus_bridge_resize() use pci_scan_bridge instead Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 13/47] PCI: Clean up rescan_bus_bridge_resize() Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 14/47] PCI: Rescan bus or bridge using callback method too Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 15/47] PCI, sysfs: Clean up rescan/remove with scheule_callback Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 16/47] x86, PCI: Separate pcibios_allocate_bridge_resources() Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 17/47] x86, PCI: Separate pcibios_allocate_dev_resources() Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 18/47] x86, PCI: Let pcibios_allocate_bus_resources() take bus instead Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 19/47] PCI: Claim hw/fw allocated resources in hot add path Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 20/47] Correctly clean up pci root buses in function pci_remove_bus() Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 21/47] PCI: Move pci_stop_and_remove_behind_bridge() down Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 22/47] PCI: Add __pci_remove_bus_devices() Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 23/47] PCI: Use list_for_each_entry_safe instead of list_for_each_safe Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 24/47] PCI: Add pci_stop_and_remove_bus() Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 25/47] Fix an access-after-free issue in function pci_stop_and_remove_bus() Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 26/47] PCI, ACPI: Make acpi_pci_root_remove remove pci root bus too Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 27/47] PCI, acpiphp: Separate out hot-add support of pci host bridge Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 28/47] PCI, ACPI: Add pci_root_hp hot removal notification support Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 29/47] PCI, ACPI: Add alloc_acpi_hp_work() Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 30/47] PCI, acpiphp: Use acpi_hp_work Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 31/47] PCI, pci_root_hp: " Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 32/47] PCI, ACPI: Make kacpi_hotplug_wq static Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 33/47] PCI: Add debug print out for pci related dev release Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 34/47] PCI, pciehp: Separate pci_hp_add_bridge() Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 35/47] PCI, cphi_hotplug: Simplify configure_slot Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 36/47] PCI, shpchp: Simplify configure_device Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 37/47] PCI: Kill pci_is_reassignedev() Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 38/47] PCI, sysfs: Prepare to kill pci device rescan Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 39/47] ACPI: Enable SCI_EMULATE to manually simulate physical hotplug testing Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 40/47] PCI: Add pci bus removal through /sys/.../pci_bus/.../remove Yinghai Lu
2012-04-06 15:50 ` Jiang Liu
2012-04-06 16:01 ` Yinghai Lu
2012-04-06 16:07 ` Bjorn Helgaas
2012-04-06 16:22 ` Jiang Liu [this message]
[not found] ` <CAE9FiQUjsiEvGGZz4sPux5AM7ipDsqgqgh5bh2QA7GJVBTqDKw@mail.gmail.com>
2012-04-06 17:42 ` Fwd: " Yinghai Lu
2012-04-06 18:05 ` Bjorn Helgaas
2012-04-06 18:11 ` Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 41/47] PCI, ACPI: Add acpi_pci_root_rescan() Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 42/47] PCI: Add __pci_scan_root_bus() that can skip bus_add Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 43/47] x86, PCI: add __pci_scan_root_bus_on_node() " Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 44/47] x86, PCI: add __pcibios_scan_specific_bus " Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 45/47] x86, PCI: Add pcibios_root_rescan() Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 46/47] x86, PCI: Add arch version pci_root_rescan() Yinghai Lu
2012-03-19 5:46 ` [PATCH -v3 47/47] PCI: Add /sys/bus/pci/rescan_root Yinghai Lu
2012-03-19 21:37 ` [PATCH 00/47] PCI, x86: pci root bus hotplug support Bjorn Helgaas
2012-03-20 17:20 ` Yinghai Lu
2012-03-30 18:27 ` Yinghai Lu
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4F7F184A.3080001@gmail.com \
--to=liuj97@gmail.com \
--cc=akpm@linux-foundation.org \
--cc=bhelgaas@google.com \
--cc=gregkh@linuxfoundation.org \
--cc=jbarnes@virtuousgeek.org \
--cc=linux-doc@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pci@vger.kernel.org \
--cc=rdunlap@xenotime.net \
--cc=torvalds@linux-foundation.org \
--cc=x86@kernel.org \
--cc=yhlu.kernel@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).