kernel/linux.git/Documentation/ABI/testing, branch v5.10.257

PCI: Add sysfs attribute for device power state

2025-10-29T13:01:24+00:00

[ Upstream commit 80a129afb75cba8434fc5071bd6919172442315c ] While PCI power states D0-D3hot can be queried from user-space via lspci, D3cold cannot. lspci cannot provide an accurate value when the device is in D3cold as it has to restore the device to D0 before it can access its power state via the configuration space, leading to it reporting D0 or another on-state. Thus lspci cannot be used to diagnose power consumption issues for devices that can enter D3cold or to ensure that devices properly enter D3cold at all. Add a new sysfs device attribute for the PCI power state, showing the current power state as seen by the kernel. [bhelgaas: drop READ_ONCE(), see discussion at the link] Link: https://lore.kernel.org/r/20201102141520.831630-1-luzmaximilian@gmail.com Signed-off-by: Maximilian Luz Signed-off-by: Bjorn Helgaas Stable-dep-of: 48991e493507 ("PCI/sysfs: Ensure devices are powered for config reads") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

x86/vmscape: Enable the mitigation

2025-09-11T15:16:06+00:00

commit 556c1ad666ad90c50ec8fccb930dd5046cfbecfb upstream. Enable the previously added mitigation for VMscape. Add the cmdline vmscape={off|ibpb|force} and sysfs reporting. Signed-off-by: Pawan Gupta Signed-off-by: Dave Hansen Reviewed-by: Borislav Petkov (AMD) Reviewed-by: Dave Hansen Signed-off-by: Amit Shah Signed-off-by: Greg Kroah-Hartman

x86/bugs: Add a Transient Scheduler Attacks mitigation

2025-07-17T16:28:00+00:00

From: "Borislav Petkov (AMD)" Commit d8010d4ba43e9f790925375a7de100604a5e2dba upstream. Add the required features detection glue to bugs.c et all in order to support the TSA mitigation. Co-developed-by: Kim Phillips Signed-off-by: Kim Phillips Signed-off-by: Borislav Petkov (AMD) Reviewed-by: Pawan Gupta Signed-off-by: Greg Kroah-Hartman

x86/its: Enable Indirect Target Selection mitigation

2025-07-17T16:27:55+00:00

commit f4818881c47fd91fcb6d62373c57c7844e3de1c0 upstream. Indirect Target Selection (ITS) is a bug in some pre-ADL Intel CPUs with eIBRS. It affects prediction of indirect branch and RETs in the lower half of cacheline. Due to ITS such branches may get wrongly predicted to a target of (direct or indirect) branch that is located in the upper half of the cacheline. Scope of impact =============== Guest/host isolation -------------------- When eIBRS is used for guest/host isolation, the indirect branches in the VMM may still be predicted with targets corresponding to branches in the guest. Intra-mode ---------- cBPF or other native gadgets can be used for intra-mode training and disclosure using ITS. User/kernel isolation --------------------- When eIBRS is enabled user/kernel isolation is not impacted. Indirect Branch Prediction Barrier (IBPB) ----------------------------------------- After an IBPB, indirect branches may be predicted with targets corresponding to direct branches which were executed prior to IBPB. This is mitigated by a microcode update. Add cmdline parameter indirect_target_selection=off|on|force to control the mitigation to relocate the affected branches to an ITS-safe thunk i.e. located in the upper half of cacheline. Also add the sysfs reporting. When retpoline mitigation is deployed, ITS safe-thunks are not needed, because retpoline sequence is already ITS-safe. Similarly, when call depth tracking (CDT) mitigation is deployed (retbleed=stuff), ITS safe return thunk is not used, as CDT prevents RSB-underflow. To not overcomplicate things, ITS mitigation is not supported with spectre-v2 lfence;jmp mitigation. Moreover, it is less practical to deploy lfence;jmp mitigation on ITS affected parts anyways. Signed-off-by: Dave Hansen Reviewed-by: Josh Poimboeuf Reviewed-by: Alexandre Chartre Signed-off-by: Pawan Gupta Signed-off-by: Greg Kroah-Hartman

scsi: ufs: core: Fix spelling of a sysfs attribute name

2025-07-17T16:27:46+00:00

[ Upstream commit 021f243627ead17eb6500170256d3d9be787dad8 ] Change "resourse" into "resource" in the name of a sysfs attribute. Fixes: d829fc8a1058 ("scsi: ufs: sysfs: unit descriptor") Signed-off-by: Bart Van Assche Link: https://lore.kernel.org/r/20250624181658.336035-1-bvanassche@acm.org Reviewed-by: Avri Altman Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin

PCI: Add 'reset_subordinate' to reset hierarchy below bridge

2024-12-14T18:48:31+00:00

[ Upstream commit 2fa046449a82a7d0f6d9721dd83e348816038444 ] The "bus" and "cxl_bus" reset methods reset a device by asserting Secondary Bus Reset on the bridge leading to the device. These only work if the device is the only device below the bridge. Add a sysfs 'reset_subordinate' attribute on bridges that can assert Secondary Bus Reset regardless of how many devices are below the bridge. This resets all the devices below a bridge in a single command, including the locking and config space save/restore that reset methods normally do. This may be the only way to reset devices that don't support other reset methods (ACPI, FLR, PM reset, etc). Link: https://lore.kernel.org/r/20241025222755.3756162-1-kbusch@meta.com Signed-off-by: Keith Busch [bhelgaas: commit log, add capable(CAP_SYS_ADMIN) check] Signed-off-by: Bjorn Helgaas Reviewed-by: Alex Williamson Reviewed-by: Amey Narkhede Signed-off-by: Sasha Levin

PM / devfreq: Fix buffer overflow in trans_stat_show

2024-05-02T14:23:44+00:00

commit 08e23d05fa6dc4fc13da0ccf09defdd4bbc92ff4 upstream. Fix buffer overflow in trans_stat_show(). Convert simple snprintf to the more secure scnprintf with size of PAGE_SIZE. Add condition checking if we are exceeding PAGE_SIZE and exit early from loop. Also add at the end a warning that we exceeded PAGE_SIZE and that stats is disabled. Return -EFBIG in the case where we don't have enough space to write the full transition table. Also document in the ABI that this function can return -EFBIG error. Link: https://lore.kernel.org/all/20231024183016.14648-2-ansuelsmth@gmail.com/ Cc: stable@vger.kernel.org Closes: https://bugzilla.kernel.org/show_bug.cgi?id=218041 Fixes: e552bbaf5b98 ("PM / devfreq: Add sysfs node for representing frequency transition information.") Signed-off-by: Christian Marangi Signed-off-by: Chanwoo Choi Signed-off-by: Sasha Levin Signed-off-by: Jan Kiszka Signed-off-by: Greg Kroah-Hartman

x86/rfds: Mitigate Register File Data Sampling (RFDS)

2024-04-13T10:58:59+00:00

commit 8076fcde016c9c0e0660543e67bff86cb48a7c9c upstream. RFDS is a CPU vulnerability that may allow userspace to infer kernel stale data previously used in floating point registers, vector registers and integer registers. RFDS only affects certain Intel Atom processors. Intel released a microcode update that uses VERW instruction to clear the affected CPU buffers. Unlike MDS, none of the affected cores support SMT. Add RFDS bug infrastructure and enable the VERW based mitigation by default, that clears the affected buffers just before exiting to userspace. Also add sysfs reporting and cmdline parameter "reg_file_data_sampling" to control the mitigation. For details see: Documentation/admin-guide/hw-vuln/reg-file-data-sampling.rst [ pawan: - Resolved conflicts in sysfs reporting. - s/ATOM_GRACEMONT/ALDERLAKE_N/ATOM_GRACEMONT is called ALDERLAKE_N in 6.6. ] Signed-off-by: Pawan Gupta Signed-off-by: Dave Hansen Reviewed-by: Thomas Gleixner Acked-by: Josh Poimboeuf Signed-off-by: Greg Kroah-Hartman

net: sysfs: Fix /sys/class/net/ path for statistics

2024-02-23T07:42:23+00:00

[ Upstream commit 5b3fbd61b9d1f4ed2db95aaf03f9adae0373784d ] The Documentation/ABI/testing/sysfs-class-net-statistics documentation is pointing to the wrong path for the interface. Documentation is pointing to /sys/class/, instead of /sys/class/net/. Fix it by adding the `net/` directory before the interface. Fixes: 6044f9700645 ("net: sysfs: document /sys/class/net/statistics/*") Signed-off-by: Breno Leitao Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

net: sysfs: Fix /sys/class/net/ path

2024-02-23T07:42:17+00:00

[ Upstream commit ae3f4b44641dfff969604735a0dcbf931f383285 ] The documentation is pointing to the wrong path for the interface. Documentation is pointing to /sys/class/, instead of /sys/class/net/. Fix it by adding the `net/` directory before the interface. Fixes: 1a02ef76acfa ("net: sysfs: add documentation entries for /sys/class//queues") Signed-off-by: Breno Leitao Link: https://lore.kernel.org/r/20240131102150.728960-2-leitao@debian.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin