kernel/linux.git/drivers/pci/hotplug, branch v4.14.85

PCI: pciehp: Fix unprotected list iteration in IRQ handler

2018-08-24T11:09:23+00:00

commit 1204e35bedf4e5015cda559ed8c84789a6dae24e upstream. Commit b440bde74f04 ("PCI: Add pci_ignore_hotplug() to ignore hotplug events for a device") iterates over the devices on a hotplug port's subordinate bus in pciehp's IRQ handler without acquiring pci_bus_sem. It is thus possible for a user to cause a crash by concurrently manipulating the device list, e.g. by disabling slot power via sysfs on a different CPU or by initiating a remove/rescan via sysfs. This can't be fixed by acquiring pci_bus_sem because it may sleep. The simplest fix is to avoid the list iteration altogether and just check the ignore_hotplug flag on the port itself. This works because pci_ignore_hotplug() sets the flag both on the device as well as on its parent bridge. We do lose the ability to print the name of the device blocking hotplug in the debug message, but that's probably bearable. Fixes: b440bde74f04 ("PCI: Add pci_ignore_hotplug() to ignore hotplug events for a device") Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

PCI: pciehp: Fix use-after-free on unplug

2018-08-24T11:09:22+00:00

commit 281e878eab191cce4259abbbf1a0322e3adae02c upstream. When pciehp is unbound (e.g. on unplug of a Thunderbolt device), the hotplug_slot struct is deregistered and thus freed before freeing the IRQ. The IRQ handler and the work items it schedules print the slot name referenced from the freed structure in various informational and debug log messages, each time resulting in a quadruple dereference of freed pointers (hotplug_slot -> pci_slot -> kobject -> name). At best the slot name is logged as "(null)", at worst kernel memory is exposed in logs or the driver crashes: pciehp 0000:10:00.0:pcie204: Slot((null)): Card not present An attacker may provoke the bug by unplugging multiple devices on a Thunderbolt daisy chain at once. Unplugging can also be simulated by powering down slots via sysfs. The bug is particularly easy to trigger in poll mode. It has been present since the driver's introduction in 2004: https://git.kernel.org/tglx/history/c/c16b4b14d980 Fix by rearranging teardown such that the IRQ is freed first. Run the work items queued by the IRQ handler to completion before freeing the hotplug_slot struct by draining the work queue from the ->release_slot callback which is invoked by pci_hp_deregister(). Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Cc: stable@vger.kernel.org # v2.6.4 Signed-off-by: Greg Kroah-Hartman

PCI: hotplug: Don't leak pci_slot on registration failure

2018-08-24T11:09:22+00:00

commit 4ce6435820d1f1cc2c2788e232735eb244bcc8a3 upstream. If addition of sysfs files fails on registration of a hotplug slot, the struct pci_slot as well as the entry in the slot_list is leaked. The issue has been present since the hotplug core was introduced in 2002: https://git.kernel.org/tglx/history/c/a8a2069f432c Perhaps the idea was that even though sysfs addition fails, the slot should still be usable. But that's not how drivers use the interface, they abort probe if a non-zero value is returned. Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Cc: stable@vger.kernel.org # v2.4.15+ Cc: Greg Kroah-Hartman Signed-off-by: Greg Kroah-Hartman

PCI: pciehp: Assume NoCompl+ for Thunderbolt ports

2018-08-03T05:50:43+00:00

commit 493fb50e958c1c6deef7feff0b8c3855def78d75 upstream. Certain Thunderbolt 1 controllers claim to support Command Completed events (value of 0b in the No Command Completed Support field of the Slot Capabilities register) but in reality they neither set the Command Completed bit in the Slot Status register nor signal a Command Completed interrupt: 8086:1513 CV82524 [Light Ridge 4C 2010] 8086:151a DSL2310 [Eagle Ridge 2C 2011] 8086:151b CVL2510 [Light Peak 2C 2010] 8086:1547 DSL3510 [Cactus Ridge 4C 2012] 8086:1548 DSL3310 [Cactus Ridge 2C 2012] 8086:1549 DSL2210 [Port Ridge 1C 2011] All known newer chips (Redwood Ridge and onwards) set No Command Completed Support, indicating that they do not support Command Completed events. The user-visible impact is that after unplugging such a device, 2 seconds elapse until pciehp is unbound. That's because on ->remove, pcie_write_cmd() is called via pcie_disable_notification() and every call to pcie_write_cmd() takes 2 seconds (1 second for each invocation of pcie_wait_cmd()): [ 337.942727] pciehp 0000:0a:00.0:pcie204: Timeout on hotplug command 0x1038 (issued 21176 msec ago) [ 340.014735] pciehp 0000:0a:00.0:pcie204: Timeout on hotplug command 0x0000 (issued 2072 msec ago) That by itself has always been unpleasant, but the situation has become worse with commit cc27b735ad3a ("PCI/portdrv: Turn off PCIe services during shutdown"): Now pciehp is unbound on ->shutdown. Because Thunderbolt controllers typically have 4 hotplug ports, every reboot and shutdown is now delayed by 8 seconds, plus another 2 seconds for every attached Thunderbolt 1 device. Thunderbolt hotplug slots are not physical slots that one inserts cards into, but rather logical hotplug slots implemented in silicon. Devices appear beyond those logical slots once a PCI tunnel is established on top of the Thunderbolt Converged I/O switch. One would expect commands written to the Slot Control register to be executed immediately by the silicon, so for simplicity we always assume NoCompl+ for Thunderbolt ports. Fixes: cc27b735ad3a ("PCI/portdrv: Turn off PCIe services during shutdown") Tested-by: Mika Westerberg Signed-off-by: Lukas Wunner Signed-off-by: Bjorn Helgaas Reviewed-by: Mika Westerberg Cc: stable@vger.kernel.org # v4.12+ Cc: Sinan Kaya Cc: Yehezkel Bernat Cc: Michael Jamet Cc: Andreas Noever Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman

PCI: pciehp: Clear Presence Detect and Data Link Layer Status Changed on resume

2018-07-03T09:24:56+00:00

commit 13c65840feab8109194f9490c9870587173cb29d upstream. After a suspend/resume cycle the Presence Detect or Data Link Layer Status Changed bits might be set. If we don't clear them those events will not fire anymore and nothing happens for instance when a device is now hot-unplugged. Fix this by clearing those bits in a newly introduced function pcie_reenable_notification(). This should be fine because immediately after, we check if the adapter is still present by reading directly from the status register. Signed-off-by: Mika Westerberg Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki Reviewed-by: Andy Shevchenko Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

ACPI / hotplug / PCI: Check presence of slot itself in get_slot_status()

2018-04-24T07:36:25+00:00

commit 13d3047c81505cc0fb9bdae7810676e70523c8bf upstream. Mike Lothian reported that plugging in a USB-C device does not work properly in his Dell Alienware system. This system has an Intel Alpine Ridge Thunderbolt controller providing USB-C functionality. In these systems the USB controller (xHCI) is hotplugged whenever a device is connected to the port using ACPI-based hotplug. The ACPI description of the root port in question is as follows: Device (RP01) { Name (_ADR, 0x001C0000) Device (PXSX) { Name (_ADR, 0x02) Method (_RMV, 0, NotSerialized) { // ... } } Here _ADR 0x02 means device 0, function 2 on the bus under root port (RP01) but that seems to be incorrect because device 0 is the upstream port of the Alpine Ridge PCIe switch and it has no functions other than 0 (the bridge itself). When we get ACPI Notify() to the root port resulting from connecting a USB-C device, Linux tries to read PCI_VENDOR_ID from device 0, function 2 which of course always returns 0xffffffff because there is no such function and we never find the device. In Windows this works fine. Now, since we get ACPI Notify() to the root port and not to the PXSX device we should actually start our scan from there as well and not from the non-existent PXSX device. Fix this by checking presence of the slot itself (function 0) if we fail to do that otherwise. While there use pci_bus_read_dev_vendor_id() in get_slot_status(), which is the recommended way to read Device and Vendor IDs of devices on PCI buses. Link: https://bugzilla.kernel.org/show_bug.cgi?id=198557 Reported-by: Mike Lothian Signed-off-by: Mika Westerberg Signed-off-by: Bjorn Helgaas Reviewed-by: Rafael J. Wysocki Cc: Greg Kroah-Hartman Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

License cleanup: add SPDX GPL-2.0 license identifier to files with no license

2017-11-02T10:10:55+00:00

Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart Reviewed-by: Philippe Ombredanne Reviewed-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

Merge branch 'pci/misc' into next

2017-09-07T18:24:16+00:00

* pci/misc: PCI: Fix PCIe capability sizes PCI: Convert to using %pOF instead of full_name() PCI: Constify endpoint pci_epf_type device_type PCI: Constify bin_attribute structures PCI: Constify hotplug pci_device_id structures PCI: Constify hotplug attribute_group structures PCI: Constify label attribute_group structures PCI: Constify sysfs attribute_group structures

PCI: Convert to using %pOF instead of full_name()

2017-08-24T16:24:59+00:00

Now that we have a custom printf format specifier, convert users of full_name() to use %pOF instead. This is preparation for removing storing of the full path string for each node. Signed-off-by: Rob Herring Signed-off-by: Bjorn Helgaas Reviewed-by: Tyrel Datwyler Cc: Thomas Petazzoni Cc: Jason Cooper Cc: Thierry Reding Cc: Jonathan Hunter Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman

PCI: pciehp: Report power fault only once until we clear it

2017-08-15T18:46:31+00:00

When a power fault occurs, the power controller sets Power Fault Detected in the Slot Status register, and pciehp_isr() queues an INT_POWER_FAULT event to handle it. It also clears Power Fault Detected, but since nothing has yet changed to correct the power fault, the power controller will likely set it again immediately, which may cause an infinite loop when pcie_isr() rechecks Slot Status. Fix that by masking off Power Fault Detected from new events if the driver hasn't seen the power fault clear from the previous handling attempt. Fixes: fad214b0aa72 ("PCI: pciehp: Process all hotplug events before looking for new ones") Signed-off-by: Keith Busch [bhelgaas: changelog, pull test out and add comment] Signed-off-by: Bjorn Helgaas Cc: Mayurkumar Patel Cc: stable@vger.kernel.org # 4.9+