Framebuffer overrides

.clippy.toml

@@ -7,5 +7,5 @@ check-private-items = true
 disallowed-macros = [
     # The `clippy::dbg_macro` lint only works with `std::dbg!`, thus we simulate
     # it here, see: https://github.com/rust-lang/rust-clippy/issues/11303.
-    { path = "kernel::dbg", reason = "the `dbg!` macro is intended as a debugging tool" },
+    { path = "kernel::dbg", reason = "the `dbg!` macro is intended as a debugging tool", allow-invalid = true },
 ]

.gitignore

@@ -82,7 +82,7 @@ modules.order
 #
 # Debian directory (make deb-pkg)
 #
-/debian/
+#/debian/
 
 #
 # Snap directory (make snap-pkg)

Documentation/ABI/testing/sysfs-devices-system-cpu

@@ -511,6 +511,7 @@ Description:	information about CPUs heterogeneity.
 
 What:		/sys/devices/system/cpu/vulnerabilities
 		/sys/devices/system/cpu/vulnerabilities/gather_data_sampling
+		/sys/devices/system/cpu/vulnerabilities/indirect_target_selection
 		/sys/devices/system/cpu/vulnerabilities/itlb_multihit
 		/sys/devices/system/cpu/vulnerabilities/l1tf
 		/sys/devices/system/cpu/vulnerabilities/mds

Documentation/admin-guide/gpio/gpio-aggregator.rst

@@ -69,6 +69,113 @@ write-only attribute files in sysfs.
 		    $ echo gpio-aggregator.0 > delete_device
 
 
+Aggregating GPIOs using Configfs
+--------------------------------
+
+**Group:** ``/config/gpio-aggregator``
+
+    This is the root directory of the gpio-aggregator configfs tree.
+
+**Group:** ``/config/gpio-aggregator/<example-name>``
+
+    This directory represents a GPIO aggregator device. You can assign any
+    name to ``<example-name>`` (e.g. ``agg0``), except names starting with
+    ``_sysfs`` prefix, which are reserved for auto-generated configfs
+    entries corresponding to devices created via Sysfs.
+
+**Attribute:** ``/config/gpio-aggregator/<example-name>/live``
+
+    The ``live`` attribute allows to trigger the actual creation of the device
+    once it's fully configured. Accepted values are:
+
+    * ``1``, ``yes``, ``true`` : enable the virtual device
+    * ``0``, ``no``, ``false`` : disable the virtual device
+
+**Attribute:** ``/config/gpio-aggregator/<example-name>/dev_name``
+
+    The read-only ``dev_name`` attribute exposes the name of the device as it
+    will appear in the system on the platform bus (e.g. ``gpio-aggregator.0``).
+    This is useful for identifying a character device for the newly created
+    aggregator. If it's ``gpio-aggregator.0``,
+    ``/sys/devices/platform/gpio-aggregator.0/gpiochipX`` path tells you that the
+    GPIO device id is ``X``.
+
+You must create subdirectories for each virtual line you want to
+instantiate, named exactly as ``line0``, ``line1``, ..., ``lineY``, when
+you want to instantiate ``Y+1`` (Y >= 0) lines.  Configure all lines before
+activating the device by setting ``live`` to 1.
+
+**Group:** ``/config/gpio-aggregator/<example-name>/<lineY>/``
+
+    This directory represents a GPIO line to include in the aggregator.
+
+**Attribute:** ``/config/gpio-aggregator/<example-name>/<lineY>/key``
+
+**Attribute:** ``/config/gpio-aggregator/<example-name>/<lineY>/offset``
+
+    The default values after creating the ``<lineY>`` directory are:
+
+    * ``key`` : <empty>
+    * ``offset`` : -1
+
+    ``key`` must always be explicitly configured, while ``offset`` depends.
+    Two configuration patterns exist for each ``<lineY>``:
+
+    (a). For lookup by GPIO line name:
+
+         * Set ``key`` to the line name.
+         * Ensure ``offset`` remains -1 (the default).
+
+    (b). For lookup by GPIO chip name and the line offset within the chip:
+
+         * Set ``key`` to the chip name.
+         * Set ``offset`` to the line offset (0 <= ``offset`` < 65535).
+
+**Attribute:** ``/config/gpio-aggregator/<example-name>/<lineY>/name``
+
+    The ``name`` attribute sets a custom name for lineY. If left unset, the
+    line will remain unnamed.
+
+Once the configuration is done, the ``'live'`` attribute must be set to 1
+in order to instantiate the aggregator device. It can be set back to 0 to
+destroy the virtual device. The module will synchronously wait for the new
+aggregator device to be successfully probed and if this doesn't happen, writing
+to ``'live'`` will result in an error. This is a different behaviour from the
+case when you create it using sysfs ``new_device`` interface.
+
+.. note::
+
+   For aggregators created via Sysfs, the configfs entries are
+   auto-generated and appear as ``/config/gpio-aggregator/_sysfs.<N>/``. You
+   cannot add or remove line directories with mkdir(2)/rmdir(2). To modify
+   lines, you must use the "delete_device" interface to tear down the
+   existing device and reconfigure it from scratch. However, you can still
+   toggle the aggregator with the ``live`` attribute and adjust the
+   ``key``, ``offset``, and ``name`` attributes for each line when ``live``
+   is set to 0 by hand (i.e. it's not waiting for deferred probe).
+
+Sample configuration commands
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+.. code-block:: sh
+
+    # Create a directory for an aggregator device
+    $ mkdir /sys/kernel/config/gpio-aggregator/agg0
+
+    # Configure each line
+    $ mkdir /sys/kernel/config/gpio-aggregator/agg0/line0
+    $ echo gpiochip0 > /sys/kernel/config/gpio-aggregator/agg0/line0/key
+    $ echo 6         > /sys/kernel/config/gpio-aggregator/agg0/line0/offset
+    $ echo test0     > /sys/kernel/config/gpio-aggregator/agg0/line0/name
+    $ mkdir /sys/kernel/config/gpio-aggregator/agg0/line1
+    $ echo gpiochip0 > /sys/kernel/config/gpio-aggregator/agg0/line1/key
+    $ echo 7         > /sys/kernel/config/gpio-aggregator/agg0/line1/offset
+    $ echo test1     > /sys/kernel/config/gpio-aggregator/agg0/line1/name
+
+    # Activate the aggregator device
+    $ echo 1         > /sys/kernel/config/gpio-aggregator/agg0/live
+
+
 Generic GPIO Driver
 -------------------
 

Documentation/admin-guide/hw-vuln/index.rst

@@ -22,3 +22,4 @@ are configurable at compile, boot or run time.
    srso
    gather_data_sampling
    reg-file-data-sampling
+   indirect-target-selection

Documentation/admin-guide/hw-vuln/indirect-target-selection.rst

@@ -0,0 +1,168 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+Indirect Target Selection (ITS)
+===============================
+
+ITS is a vulnerability in some Intel CPUs that support Enhanced IBRS and were
+released before Alder Lake. ITS may allow an attacker to control the prediction
+of indirect branches and RETs located in the lower half of a cacheline.
+
+ITS is assigned CVE-2024-28956 with a CVSS score of 4.7 (Medium).
+
+Scope of Impact
+---------------
+- **eIBRS Guest/Host Isolation**: Indirect branches in KVM/kernel may still be
+  predicted with unintended target corresponding to a branch in the guest.
+
+- **Intra-Mode BTI**: In-kernel training such as through cBPF or other native
+  gadgets.
+
+- **Indirect Branch Prediction Barrier (IBPB)**: After an IBPB, indirect
+  branches may still be predicted with targets corresponding to direct branches
+  executed prior to the IBPB. This is fixed by the IPU 2025.1 microcode, which
+  should be available via distro updates. Alternatively microcode can be
+  obtained from Intel's github repository [#f1]_.
+
+Affected CPUs
+-------------
+Below is the list of ITS affected CPUs [#f2]_ [#f3]_:
+
+   ========================  ============  ====================  ===============
+   Common name               Family_Model  eIBRS                 Intra-mode BTI
+                                           Guest/Host Isolation
+   ========================  ============  ====================  ===============
+   SKYLAKE_X (step >= 6)     06_55H        Affected              Affected
+   ICELAKE_X                 06_6AH        Not affected          Affected
+   ICELAKE_D                 06_6CH        Not affected          Affected
+   ICELAKE_L                 06_7EH        Not affected          Affected
+   TIGERLAKE_L               06_8CH        Not affected          Affected
+   TIGERLAKE                 06_8DH        Not affected          Affected
+   KABYLAKE_L (step >= 12)   06_8EH        Affected              Affected
+   KABYLAKE (step >= 13)     06_9EH        Affected              Affected
+   COMETLAKE                 06_A5H        Affected              Affected
+   COMETLAKE_L               06_A6H        Affected              Affected
+   ROCKETLAKE                06_A7H        Not affected          Affected
+   ========================  ============  ====================  ===============
+
+- All affected CPUs enumerate Enhanced IBRS feature.
+- IBPB isolation is affected on all ITS affected CPUs, and need a microcode
+  update for mitigation.
+- None of the affected CPUs enumerate BHI_CTRL which was introduced in Golden
+  Cove (Alder Lake and Sapphire Rapids). This can help guests to determine the
+  host's affected status.
+- Intel Atom CPUs are not affected by ITS.
+
+Mitigation
+----------
+As only the indirect branches and RETs that have their last byte of instruction
+in the lower half of the cacheline are vulnerable to ITS, the basic idea behind
+the mitigation is to not allow indirect branches in the lower half.
+
+This is achieved by relying on existing retpoline support in the kernel, and in
+compilers. ITS-vulnerable retpoline sites are runtime patched to point to newly
+added ITS-safe thunks. These safe thunks consists of indirect branch in the
+second half of the cacheline. Not all retpoline sites are patched to thunks, if
+a retpoline site is evaluated to be ITS-safe, it is replaced with an inline
+indirect branch.
+
+Dynamic thunks
+~~~~~~~~~~~~~~
+From a dynamically allocated pool of safe-thunks, each vulnerable site is
+replaced with a new thunk, such that they get a unique address. This could
+improve the branch prediction accuracy. Also, it is a defense-in-depth measure
+against aliasing.
+
+Note, for simplicity, indirect branches in eBPF programs are always replaced
+with a jump to a static thunk in __x86_indirect_its_thunk_array. If required,
+in future this can be changed to use dynamic thunks.
+
+All vulnerable RETs are replaced with a static thunk, they do not use dynamic
+thunks. This is because RETs get their prediction from RSB mostly that does not
+depend on source address. RETs that underflow RSB may benefit from dynamic
+thunks. But, RETs significantly outnumber indirect branches, and any benefit
+from a unique source address could be outweighed by the increased icache
+footprint and iTLB pressure.
+
+Retpoline
+~~~~~~~~~
+Retpoline sequence also mitigates ITS-unsafe indirect branches. For this
+reason, when retpoline is enabled, ITS mitigation only relocates the RETs to
+safe thunks. Unless user requested the RSB-stuffing mitigation.
+
+RSB Stuffing
+~~~~~~~~~~~~
+RSB-stuffing via Call Depth Tracking is a mitigation for Retbleed RSB-underflow
+attacks. And it also mitigates RETs that are vulnerable to ITS.
+
+Mitigation in guests
+^^^^^^^^^^^^^^^^^^^^
+All guests deploy ITS mitigation by default, irrespective of eIBRS enumeration
+and Family/Model of the guest. This is because eIBRS feature could be hidden
+from a guest. One exception to this is when a guest enumerates BHI_DIS_S, which
+indicates that the guest is running on an unaffected host.
+
+To prevent guests from unnecessarily deploying the mitigation on unaffected
+platforms, Intel has defined ITS_NO bit(62) in MSR IA32_ARCH_CAPABILITIES. When
+a guest sees this bit set, it should not enumerate the ITS bug. Note, this bit
+is not set by any hardware, but is **intended for VMMs to synthesize** it for
+guests as per the host's affected status.
+
+Mitigation options
+^^^^^^^^^^^^^^^^^^
+The ITS mitigation can be controlled using the "indirect_target_selection"
+kernel parameter. The available options are:
+
+   ======== ===================================================================
+   on       (default)  Deploy the "Aligned branch/return thunks" mitigation.
+	    If spectre_v2 mitigation enables retpoline, aligned-thunks are only
+	    deployed for the affected RET instructions. Retpoline mitigates
+	    indirect branches.
+
+   off      Disable ITS mitigation.
+
+   vmexit   Equivalent to "=on" if the CPU is affected by guest/host isolation
+	    part of ITS. Otherwise, mitigation is not deployed. This option is
+	    useful when host userspace is not in the threat model, and only
+	    attacks from guest to host are considered.
+
+   stuff    Deploy RSB-fill mitigation when retpoline is also deployed.
+	    Otherwise, deploy the default mitigation. When retpoline mitigation
+	    is enabled, RSB-stuffing via Call-Depth-Tracking also mitigates
+	    ITS.
+
+   force    Force the ITS bug and deploy the default mitigation.
+   ======== ===================================================================
+
+Sysfs reporting
+---------------
+
+The sysfs file showing ITS mitigation status is:
+
+  /sys/devices/system/cpu/vulnerabilities/indirect_target_selection
+
+Note, microcode mitigation status is not reported in this file.
+
+The possible values in this file are:
+
+.. list-table::
+
+   * - Not affected
+     - The processor is not vulnerable.
+   * - Vulnerable
+     - System is vulnerable and no mitigation has been applied.
+   * - Vulnerable, KVM: Not affected
+     - System is vulnerable to intra-mode BTI, but not affected by eIBRS
+       guest/host isolation.
+   * - Mitigation: Aligned branch/return thunks
+     - The mitigation is enabled, affected indirect branches and RETs are
+       relocated to safe thunks.
+   * - Mitigation: Retpolines, Stuffing RSB
+     - The mitigation is enabled using retpoline and RSB stuffing.
+
+References
+----------
+.. [#f1] Microcode repository - https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files
+
+.. [#f2] Affected Processors list - https://www.intel.com/content/www/us/en/developer/topic-technology/software-security-guidance/processors-affected-consolidated-product-cpu-model.html
+
+.. [#f3] Affected Processors list (machine readable) - https://github.com/intel/Intel-affected-processor-list

Documentation/admin-guide/kernel-parameters.txt

@@ -2178,6 +2178,23 @@
 			different crypto accelerators. This option can be used
 			to achieve best performance for particular HW.
 
+	indirect_target_selection= [X86,Intel] Mitigation control for Indirect
+			Target Selection(ITS) bug in Intel CPUs. Updated
+			microcode is also required for a fix in IBPB.
+
+			on:     Enable mitigation (default).
+			off:    Disable mitigation.
+			force:	Force the ITS bug and deploy default
+				mitigation.
+			vmexit: Only deploy mitigation if CPU is affected by
+				guest/host isolation part of ITS.
+			stuff:	Deploy RSB-fill mitigation when retpoline is
+				also deployed. Otherwise, deploy the default
+				mitigation.
+
+			For details see:
+			Documentation/admin-guide/hw-vuln/indirect-target-selection.rst
+
 	init=		[KNL]
 			Format: <full_path>
 			Run specified binary instead of /sbin/init as init
@@ -3116,6 +3133,8 @@
 			* max_sec_lba48: Set or clear transfer size limit to
 			  65535 sectors.
 
+			* external: Mark port as external (hotplug-capable).
+
 			* [no]lpm: Enable or disable link power management.
 
 			* [no]setxfer: Indicate if transfer speed mode setting
@@ -3664,6 +3683,7 @@
 				expose users to several CPU vulnerabilities.
 				Equivalent to: if nokaslr then kpti=0 [ARM64]
 					       gather_data_sampling=off [X86]
+					       indirect_target_selection=off [X86]
 					       kvm.nx_huge_pages=off [X86]
 					       l1tf=off [X86]
 					       mds=off [X86]
@@ -4642,6 +4662,12 @@
 		nomsi		[MSI] If the PCI_MSI kernel config parameter is
 				enabled, this kernel boot option can be used to
 				disable the use of MSI interrupts system-wide.
+		clearmsi	[X86] Clears MSI/MSI-X enable bits early in boot
+				time in order to avoid issues like adapters
+				screaming irqs and preventing boot progress.
+				Also, it enforces the PCI Local Bus spec
+				rule that those bits should be 0 in system reset
+				events (useful for kexec/kdump cases).
 		noioapicquirk	[APIC] Disable all boot interrupt quirks.
 				Safety option to keep boot IRQs enabled. This
 				should never be necessary.
@@ -7241,6 +7267,8 @@
 			This is just one of many ways that can clear memory. Make sure your system
 			keeps the content of memory across reboots before relying on this option.
 
+			NB: Both the mapped address and size must be page aligned for the architecture.
+
 			See also Documentation/trace/debugging.rst