kernel/Documentation, branch linux-5.15.y

PCI: endpoint: Automatically create a function specific attributes group

2026-02-19T15:21:46Z

[ Upstream commit 70b3740f2c1941e2006d61539131b70d20cba9a6 ] A PCI endpoint function driver can define function specific attributes under its function configfs directory using the add_cfs() endpoint driver operation. This is done by tying up the mkdir operation for the function configfs directory to a call to the add_cfs() operation. However, there are no checks preventing the user from repeatedly creating function specific attribute directories with different names, resulting in the same endpoint specific attributes group being added multiple times, which also result in an invalid reference counting for the attribute groups. E.g., using the pci-epf-ntb function driver as an example, the user creates the function as follows: $ modprobe pci-epf-ntb $ cd /sys/kernel/config/pci_ep/functions/pci_epf_ntb $ mkdir func0 $ tree func0 func0/ |-- baseclass_code |-- cache_line_size |-- ... `-- vendorid $ mkdir func0/attrs $ tree func0 func0/ |-- attrs | |-- db_count | |-- mw1 | |-- mw2 | |-- mw3 | |-- mw4 | |-- num_mws | `-- spad_count |-- baseclass_code |-- cache_line_size |-- ... `-- vendorid At this point, the function can be started by linking the EP controller. However, if the user mistakenly creates again a directory: $ mkdir func0/attrs2 $ tree func0 func0/ |-- attrs | |-- db_count | |-- mw1 | |-- mw2 | |-- mw3 | |-- mw4 | |-- num_mws | `-- spad_count |-- attrs2 | |-- db_count | |-- mw1 | |-- mw2 | |-- mw3 | |-- mw4 | |-- num_mws | `-- spad_count |-- baseclass_code |-- cache_line_size |-- ... `-- vendorid The endpoint function specific attributes are duplicated and cause a crash when the endpoint function device is torn down: refcount_t: addition on 0; use-after-free. WARNING: CPU: 2 PID: 834 at lib/refcount.c:25 refcount_warn_saturate+0xc8/0x144 CPU: 2 PID: 834 Comm: rmdir Not tainted 6.3.0-rc1 #1 Hardware name: Pine64 RockPro64 v2.1 (DT) pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) ... Call trace: refcount_warn_saturate+0xc8/0x144 config_item_get+0x7c/0x80 configfs_rmdir+0x17c/0x30c vfs_rmdir+0x8c/0x204 do_rmdir+0x158/0x184 __arm64_sys_unlinkat+0x64/0x80 invoke_syscall+0x48/0x114 ... Fix this by modifying pci_epf_cfs_work() to execute the new function pci_ep_cfs_add_type_group() which itself calls pci_epf_type_add_cfs() to obtain the function specific attribute group and the group name (directory name) from the endpoint function driver. If the function driver defines an attribute group, pci_ep_cfs_add_type_group() then proceeds to register this group using configfs_register_group(), thus automatically exposing the function type specific configfs attributes to the user. E.g.: $ modprobe pci-epf-ntb $ cd /sys/kernel/config/pci_ep/functions/pci_epf_ntb $ mkdir func0 $ tree func0 func0/ |-- baseclass_code |-- cache_line_size |-- ... |-- pci_epf_ntb.0 | |-- db_count | |-- mw1 | |-- mw2 | |-- mw3 | |-- mw4 | |-- num_mws | `-- spad_count |-- primary |-- ... `-- vendorid With this change, there is no need for the user to create or delete directories in the endpoint function attributes directory. The pci_epf_type_group_ops group operations are thus removed. Also update the documentation for the pci-epf-ntb and pci-epf-vntb function drivers to reflect this change, removing the explanations showing the need to manually create the sub-directory for the function specific attributes. Link: https://lore.kernel.org/r/20230415023542.77601-2-dlemoal@kernel.org Signed-off-by: Damien Le Moal Signed-off-by: Lorenzo Pieralisi Signed-off-by: Bjorn Helgaas Reviewed-by: Manivannan Sadhasivam Stable-dep-of: 7c5c7d06bd1f ("PCI: endpoint: Avoid creating sub-groups asynchronously") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

timers: Update the documentation to reflect on the new timer_shutdown() API

2026-02-11T12:35:28Z

[ Upstream commit a31323bef2b66455920d054b160c17d4240f8fd4 ] In order to make sure that a timer is not re-armed after it is stopped before freeing, a new shutdown state is added to the timer code. The API timer_shutdown_sync() and timer_shutdown() must be called before the object that holds the timer can be freed. Update the documentation to reflect this new workflow. [ tglx: Updated to the new semantics and updated the zh_CN version ] Signed-off-by: Steven Rostedt (Google) Signed-off-by: Thomas Gleixner Tested-by: Guenter Roeck Reviewed-by: Jacob Keller Reviewed-by: Anna-Maria Behnsen Link: https://lore.kernel.org/r/20221110064147.712934793@goodmis.org Link: https://lore.kernel.org/r/20221123201625.375284489@linutronix.de Signed-off-by: Jeongjun Park Signed-off-by: Greg Kroah-Hartman

Documentation: Replace del_timer/del_timer_sync()

2026-02-11T12:35:28Z

[ Upstream commit 87bdd932e85881895d4720255b40ac28749c4e32 ] Adjust to the new preferred function names. Suggested-by: Steven Rostedt Signed-off-by: Thomas Gleixner Reviewed-by: Jacob Keller Reviewed-by: Anna-Maria Behnsen Link: https://lore.kernel.org/r/20221123201625.075320635@linutronix.de Signed-off-by: Jeongjun Park Signed-off-by: Greg Kroah-Hartman

Documentation: Remove bogus claim about del_timer_sync()

2026-02-11T12:35:27Z

[ Upstream commit b0b0aa5d858d4d2fe39a5e4486e0550e858108f6 ] del_timer_sync() does not return the number of times it tried to delete the timer which rearms itself. It's clearly documented: The function returns whether it has deactivated a pending timer or not. This part of the documentation is from 2003 where del_timer_sync() really returned the number of deletion attempts for unknown reasons. The code was rewritten in 2005, but the documentation was not updated. Signed-off-by: Thomas Gleixner Reviewed-by: Jacob Keller Reviewed-by: Anna-Maria Behnsen Link: https://lore.kernel.org/r/20221123201624.452282769@linutronix.de Signed-off-by: Jeongjun Park Signed-off-by: Greg Kroah-Hartman

fou: Don't allow 0 for FOU_ATTR_IPPROTO.

2026-02-06T15:41:52Z

[ Upstream commit 7a9bc9e3f42391e4c187e099263cf7a1c4b69ff5 ] fou_udp_recv() has the same problem mentioned in the previous patch. If FOU_ATTR_IPPROTO is set to 0, skb is not freed by fou_udp_recv() nor "resubmit"-ted in ip_protocol_deliver_rcu(). Let's forbid 0 for FOU_ATTR_IPPROTO. Fixes: 23461551c0062 ("fou: Support for foo-over-udp RX path") Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260115172533.693652-4-kuniyu@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netlink: add a proto specification for FOU

2026-02-06T15:41:52Z

[ Upstream commit 4eb77b4ecd3c5eaab83adf76e67e0a7ed2a24418 ] FOU has a reasonably modern Genetlink family. Add a spec. Acked-by: Stanislav Fomichev Signed-off-by: Jakub Kicinski Signed-off-by: Paolo Abeni Stable-dep-of: 7a9bc9e3f423 ("fou: Don't allow 0 for FOU_ATTR_IPPROTO.") Signed-off-by: Sasha Levin

fs_context: drop the unused lsm_flags member

2026-01-19T12:09:38Z

[ Upstream commit 4e04143c869c5b6d499fbd5083caa860d5c942c3 ] This isn't ever used by VFS now, and it couldn't even work. Any FS that uses the SECURITY_LSM_NATIVE_LABELS flag needs to also process the value returned back from the LSM, so it needs to do its security_sb_set_mnt_opts() call on its own anyway. Signed-off-by: Ondrej Mosnacek Signed-off-by: Christian Brauner (Microsoft) Stable-dep-of: 8675c69816e4 ("NFS: Automounted filesystems should inherit ro,noexec,nodev,sync flags") Signed-off-by: Sasha Levin

dt-bindings: PCI: amlogic: Fix the register name of the DBI region

2026-01-19T12:09:27Z

[ Upstream commit 4813dea9e272ba0a57c50b8d51d440dd8e3ccdd7 ] Binding incorrectly specifies the 'DBI' region as 'ELBI'. DBI is a must have region for DWC controllers as it has the Root Port and controller specific registers, while ELBI has optional registers. Hence, fix the binding. Though this is an ABI break, this change is needed to accurately describe the PCI memory map. Fixes: 7cd210391101 ("dt-bindings: PCI: meson: add DT bindings for Amlogic Meson PCIe controller") Signed-off-by: Manivannan Sadhasivam Signed-off-by: Manivannan Sadhasivam Link: https://patch.msgid.link/20251101-pci-meson-fix-v1-1-c50dcc56ed6a@oss.qualcomm.com Signed-off-by: Sasha Levin

dt-bindings: PCI: convert amlogic,meson-pcie.txt to dt-schema

2026-01-19T12:09:27Z

[ Upstream commit b80b848bdf56bd402b7a91aea5b77cec93dfe4c2 ] Convert the Amlogic Meson AXG DWC PCIe SoC controller bindings to dt-schema. Link: https://lore.kernel.org/r/20221117-b4-amlogic-bindings-convert-v4-5-34e623dbf789@linaro.org Signed-off-by: Neil Armstrong Signed-off-by: Lorenzo Pieralisi Reviewed-by: Krzysztof Kozlowski Stable-dep-of: 4813dea9e272 ("dt-bindings: PCI: amlogic: Fix the register name of the DBI region") Signed-off-by: Sasha Levin

Documentation: process: Also mention Sasha Levin as stable tree maintainer

2026-01-19T12:09:19Z

commit ba2457109d5b47a90fe565b39524f7225fc23e60 upstream. Sasha has also maintaining stable branch in conjunction with Greg since cb5d21946d2a2f ("MAINTAINERS: Add Sasha as a stable branch maintainer"). Mention him in 2.Process.rst. Cc: stable@vger.kernel.org Signed-off-by: Bagas Sanjaya Reviewed-by: Randy Dunlap Acked-by: Greg Kroah-Hartman Signed-off-by: Jonathan Corbet Message-ID: <20251022034336.22839-1-bagasdotme@gmail.com> Signed-off-by: Greg Kroah-Hartman