commit 05a2538f2b48500cf4e8a0a0ce76623cc5bafcf1 upstream.
With commit bcb5d6c76903 ("s390/pci: introduce lock to synchronize state
of zpci_dev's") the code to ignore power off of a PF that has child VFs
was changed from a direct return to a goto to the unlock and
pci_dev_put() section. The change however left the existing pci_dev_put()
untouched resulting in a doubple put. This can subsequently cause a use
after free if the struct pci_dev is released in an unexpected state.
Fix this by removing the extra pci_dev_put().
Cc: stable@vger.kernel.org
Fixes: bcb5d6c76903 ("s390/pci: introduce lock to synchronize state of zpci_dev's")
Signed-off-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Gerd Bayer <gbayer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit e3260237aaadc9799107ccb940c6688195c4518d upstream.
Hot-removal of nested PCI hotplug ports suffers from a long-standing race
condition which can lead to a deadlock: A parent hotplug port acquires
pci_lock_rescan_remove(), then waits for pciehp to unbind from a child
hotplug port. Meanwhile that child hotplug port tries to acquire
pci_lock_rescan_remove() as well in order to remove its own children.
The deadlock only occurs if the parent acquires pci_lock_rescan_remove()
first, not if the child happens to acquire it first.
Several workarounds to avoid the issue have been proposed and discarded
over the years, e.g.:
https://lore.kernel.org/r/4c882e25194ba8282b78fe963fec8faae7cf23eb.1529173804.git.lukas@wunner.de/
A proper fix is being worked on, but needs more time as it is nontrivial
and necessarily intrusive.
Recent commit 9d573d19547b ("PCI: pciehp: Detect device replacement during
system sleep") provokes more frequent occurrence of the deadlock when
removing more than one Thunderbolt device during system sleep. The commit
sought to detect device replacement, but also triggered on device removal.
Differentiating reliably between replacement and removal is impossible
because pci_get_dsn() returns 0 both if the device was removed, as well as
if it was replaced with one lacking a Device Serial Number.
Avoid the more frequent occurrence of the deadlock by checking whether the
hotplug port itself was hot-removed. If so, there's no sense in checking
whether its child device was replaced.
This works because the ->resume_noirq() callback is invoked in top-down
order for the entire hierarchy: A parent hotplug port detecting device
replacement (or removal) marks all children as removed using
pci_dev_set_disconnected() and a child hotplug port can then reliably
detect being removed.
Link: https://lore.kernel.org/r/02f166e24c87d6cde4085865cce9adfdfd969688.1741674172.git.lukas@wunner.de
Fixes: 9d573d19547b ("PCI: pciehp: Detect device replacement during system sleep")
Reported-by: Kenneth Crudup <kenny@panix.com>
Closes: https://lore.kernel.org/r/83d9302a-f743-43e4-9de2-2dd66d91ab5b@panix.com/
Reported-by: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
Closes: https://lore.kernel.org/r/20240926125909.2362244-1-acelan.kao@canonical.com/
Tested-by: Kenneth Crudup <kenny@panix.com>
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com>
Cc: stable@vger.kernel.org # v6.11+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 527664f738afb6f2c58022cd35e63801e5dc7aec ]
PCIe hotplug can operate in poll mode without interrupt handlers using a
polling kthread only. eb34da60edee ("PCI: pciehp: Disable hotplug
interrupt during suspend") failed to consider that and enables HPIE
(Hot-Plug Interrupt Enable) unconditionally when resuming the Port.
Only set HPIE if non-poll mode is in use. This makes
pcie_enable_interrupt() match how pcie_enable_notification() already
handles HPIE.
Link: https://lore.kernel.org/r/20250321162114.3939-1-ilpo.jarvinen@linux.intel.com
Fixes: eb34da60edee ("PCI: pciehp: Disable hotplug interrupt during suspend")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
The sysfs core now allows instances of 'struct bin_attribute' to be moved into read-only memory. Make use of that to protect them against accidental or malicious modifications. Link: https://lore.kernel.org/r/20241202-sysfs-const-bin_attr-pci-v1-4-c32360f495a7@weissschuh.net Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
- Reorganize kerneldoc parameter names to match order in function signature (Julia Lawall) - Remove kerneldoc return value descriptions from hotplug registration interfaces that don't return anything (Ilpo Järvinen) - Fix sysfs reset_method_store() memory leak (Todd Kjos) - Simplify pci_create_slot() (Ilpo Järvinen) - Fix incorrect printf format specifiers in pcitest (Luo Yifan) * pci/misc: tools: PCI: Fix incorrect printf format specifiers PCI: Simplify pci_create_slot() logic PCI: Fix reset_method_store() memory leak PCI: hotplug: Remove "Returns" kerneldoc from void functions PCI: hotplug: Reorganize kerneldoc parameter names
- Add hotplug controller driver for Marvell OCTEON multi-function device where function 0 has a management console interface to enable/disable and provision various personalities for the other functions (Shijith Thotton) * pci/hotplug-octeon: PCI: hotplug: Add OCTEON PCI hotplug controller driver
- Remove unused cpcihp struct cpci_hp_controller_ops.hardware_test (Guilherme Giacomo Simoes) - Remove unused cpqphp struct ctrl_dbg.ctrl (Christophe JAILLET) - Clean up cpqphp PCIBIOS_* return value confusion (Ilpo Järvinen) - Use pci_bus_read_dev_vendor_id() instead of hand-coded presence detection in cpqphp (Ilpo Järvinen) - Simplify cpqphp enumeration, which is already simple-minded and doesn't handle devices below hot-added bridges (Ilpo Järvinen) - Retain a reference to the pci_bus for the lifetime of a pci_slot to avoid a use-after-free when the thunderbolt driver resets USB4 host routers on boot, causing hotplug remove/add of downstream docks or other devices (Lukas Wunner) * pci/hotplug: PCI: Fix use-after-free of slot->bus on hot remove PCI: cpqphp: Simplify PCI_ScanBusForNonBridge() PCI: cpqphp: Use define to read class/revision dword PCI: cpqphp: Use pci_bus_read_dev_vendor_id() to detect presence PCI: cpqphp: Fix PCIBIOS_* return value confusion PCI: cpqphp: Remove unused struct ctrl_dbg.ctrl PCI: cpcihp: Remove unused struct cpci_hp_controller_ops.hardware_test
- Convert driver .remove_new() callbacks to .remove() again to finish the conversion from returning 'int' to being 'void' (Sergio Paracuellos) * pci/driver-remove: PCI: acpiphp_ampere_altra: Switch back to struct platform_driver::remove() PCI: controller: Switch back to struct platform_driver::remove()
This mostly reverts the commit b4c7d2076b4e ("PCI/LINK: Remove bandwidth
notification"). An upcoming commit extends this driver building PCIe
bandwidth controller on top of it.
PCIe bandwidth notifications were first added in the commit e8303bb7a75c
("PCI/LINK: Report degraded links via link bandwidth notification") but
later had to be removed. The significant changes compared with the old
bandwidth notification driver include:
1) Don't print the notifications into kernel log, just keep the Link
Speed cached in struct pci_bus updated. While somewhat unfortunate,
the log spam was the source of complaints that eventually lead to
the removal of the bandwidth notifications driver (see the links
below for further information).
2) Besides the Link Bandwidth Management Interrupt, also enable Link
Autonomous Bandwidth Interrupt to cover the other source of bandwidth
changes.
3) Handle Link Speed updates robustly. Refresh the cached Link Speed
when enabling Bandwidth Notification Interrupts, and solve the race
between Link Speed read and LBMS/LABS update in
pcie_bwnotif_irq_thread().
4) Use concurrency safe LNKCTL RMW operations.
5) The driver is now called PCIe bwctrl (bandwidth controller) instead
of just bandwidth notifications because of increased scope and
functionality within the driver.
6) Coexist with the Target Link Speed quirk in pcie_failed_link_retrain().
Provide LBMS counting API for it.
7) Tweaks to variable/functions names for consistency and length reasons.
Bandwidth Notifications enable the cur_bus_speed in the struct pci_bus to
keep track PCIe Link Speed changes.
[bhelgaas: This is based on previous work by Alexandru Gagniuc
<mr.nuke.me@gmail.com>; see e8303bb7a75c ("PCI/LINK: Report degraded links
via link bandwidth notification")]
Link: https://lore.kernel.org/r/20241018144755.7875-7-ilpo.jarvinen@linux.intel.com
Link: https://lore.kernel.org/all/20190429185611.121751-1-helgaas@kernel.org/
Link: https://lore.kernel.org/linux-pci/20190501142942.26972-1-keith.busch@intel.com/
Link: https://lore.kernel.org/linux-pci/20200115221008.GA191037@google.com/
Suggested-by: Lukas Wunner <lukas@wunner.de> # Building bwctrl on top of bwnotif
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
[bhelgaas: squash fix to drop IRQF_ONESHOT and convert to hardirq handler:
https://lore.kernel.org/r/20241115165717.15233-1-ilpo.jarvinen@linux.intel.com]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Tested-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Add a PCI hotplug controller driver for the OCTEON PCIe device. The OCTEON
PCIe device is a multi-function device where function 0 serves as the PCI
hotplug controller.
There is an out-of-band management console interface to firmware running on
function 0 whereby an administrator can disable functions to save power or
enable them with one of several personalities (virtio-net, virtio-crypto,
NVMe, etc) for the other functions. Function 0 initiates hotplug events
handled by this driver when the other functions are enabled or disabled.
+--------------------------------+
| Root Port |
+--------------------------------+
|
PCIe
|
+---------------------------------------------------------------+
| OCTEON PCIe Multifunction Device |
+---------------------------------------------------------------+
| | | |
| | | |
+---------------------+ +----------------+ +-----+ +----------------+
| Function 0 | | Function 1 | | ... | | Function 7 |
| (Hotplug controller)| | (Hotplug slot) | | | | (Hotplug slot) |
+---------------------+ +----------------+ +-----+ +----------------+
|
|
+-------------------------+
| Controller Firmware |
+-------------------------+
The hotplug controller driver enables hotplugging of non-controller
functions within the same device. During probing, the driver removes
the non-controller functions and registers them as PCI hotplug slots.
These slots are added back by the driver, only upon request from the
device firmware.
The controller uses MSI-X interrupts to notify the host of hotplug
events initiated by the OCTEON firmware. Additionally, the driver
allows users to enable or disable individual functions via sysfs slot
entries, as provided by the PCI hotplug framework.
Link: https://lore.kernel.org/r/20241111134523.2796699-1-sthotton@marvell.com
Co-developed-by: Vamsi Attunuru <vattunuru@marvell.com>
Signed-off-by: Vamsi Attunuru <vattunuru@marvell.com>
Signed-off-by: Shijith Thotton <sthotton@marvell.com>
[bhelgaas: use pci_info() when possible]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>