Merge patch series "ns: support file handles"

Christian Brauner <brauner@kernel.org> says:

For a while now we have supported file handles for pidfds. This has
proven to be very useful.

Extend the concept to cover namespaces as well. After this patchset it
is possible to encode and decode namespace file handles using the
commong name_to_handle_at() and open_by_handle_at() apis.

Namespaces file descriptors can already be derived from pidfds which
means they aren't subject to overmount protection bugs. IOW, it's
irrelevant if the caller would not have access to an appropriate
/proc/<pid>/ns/ directory as they could always just derive the namespace
based on a pidfd already.

It has the same advantage as pidfds. It's possible to reliably and for
the lifetime of the system refer to a namespace without pinning any
resources and to compare them.

Permission checking is kept simple. If the caller is located in the
namespace the file handle refers to they are able to open it otherwise
they must hold privilege over the owning namespace of the relevant
namespace.

Both the network namespace and the mount namespace already have an
associated cookie that isn't recycled and is fully exposed to userspace.
Move this into ns_common and use the same id space for all namespaces so
they can trivially and reliably be compared.

There's more coming based on the iterator infrastructure but the series
is large enough and focuses on file handles.

Extensive selftests included.

* patches from https://lore.kernel.org/20250912-work-namespace-v2-0-1a247645cef5@kernel.org: (33 commits)
  selftests/namespaces: add file handle selftests
  selftests/namespaces: add identifier selftests
  tools: update nsfs.h uapi header
  nsfs: add missing id retrieval support
  nsfs: support exhaustive file handles
  nsfs: support file handles
  nsfs: add current_in_namespace()
  ns: add to_<type>_ns() to respective headers
  uts: support ns lookup
  user: support ns lookup
  time: support ns lookup
  pid: support ns lookup
  net: support ns lookup
  ipc: support ns lookup
  cgroup: support ns lookup
  mnt: support ns lookup
  nstree: make iterator generic
  ns: remove ns_alloc_inum()
  uts: use ns_common_init()
  user: use ns_common_init()
  ...

Signed-off-by: Christian Brauner <brauner@kernel.org>

Author: brauner

.mailmap

@@ -226,6 +226,8 @@ Domen Puncer <domen@coderock.org>
 Douglas Gilbert <dougg@torque.net>
 Drew Fustini <fustini@kernel.org> <drew@pdp7.com>
 <duje@dujemihanovic.xyz> <duje.mihanovic@skole.hr>
+Easwar Hariharan <easwar.hariharan@linux.microsoft.com> <easwar.hariharan@intel.com>
+Easwar Hariharan <easwar.hariharan@linux.microsoft.com> <eahariha@linux.microsoft.com>
 Ed L. Cashin <ecashin@coraid.com>
 Elliot Berman <quic_eberman@quicinc.com> <eberman@codeaurora.org>
 Enric Balletbo i Serra <eballetbo@kernel.org> <enric.balletbo@collabora.com>

CREDITS

@@ -3222,6 +3222,10 @@ D: AIC5800 IEEE 1394, RAW I/O on 1394
 D: Starter of Linux1394 effort
 S: ask per mail for current address
 
+N: Boris Pismenny
+E: borisp@mellanox.com
+D: Kernel TLS implementation and offload support.
+
 N: Nicolas Pitre
 E: nico@fluxnic.net
 D: StrongARM SA1100 support integrator & hacker
@@ -4168,6 +4172,9 @@ S: 1513 Brewster Dr.
 S: Carrollton, TX 75010
 S: USA
 
+N: Dave Watson
+D: Kernel TLS implementation.
+
 N: Tim Waugh
 E: tim@cyberelk.net
 D: Co-architect of the parallel-port sharing system

Documentation/ABI/stable/sysfs-block

@@ -731,7 +731,7 @@ Contact:	linux-block@vger.kernel.org
 Description:
 		[RW] If the device is registered for writeback throttling, then
 		this file shows the target minimum read latency. If this latency
-		is exceeded in a given window of time (see wb_window_usec), then
+		is exceeded in a given window of time (see curr_win_nsec), then
 		the writeback throttling will start scaling back writes. Writing
 		a value of '0' to this file disables the feature. Writing a
 		value of '-1' to this file resets the value to the default

Documentation/admin-guide/blockdev/zoned_loop.rst

@@ -79,7 +79,7 @@ zone_capacity_mb   Device zone capacity (must always be equal to or lower than
                    the zone size. Default: zone size.
 conv_zones         Total number of conventioanl zones starting from sector 0.
                    Default: 8.
-base_dir           Path to the base directoy where to create the directory
+base_dir           Path to the base directory where to create the directory
                    containing the zone files of the device.
                    Default=/var/local/zloop.
                    The device directory containing the zone files is always

Documentation/admin-guide/cgroup-v2.rst

@@ -435,8 +435,8 @@ both cgroups.
 Controlling Controllers
 -----------------------
 
-Availablity
-~~~~~~~~~~~
+Availability
+~~~~~~~~~~~~
 
 A controller is available in a cgroup when it is supported by the kernel (i.e.,
 compiled in, not disabled and not attached to a v1 hierarchy) and listed in the

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

@@ -214,8 +214,8 @@ Spectre_v1            X
 Spectre_v2            X                           X
 Spectre_v2_user                      X                           X            *       (Note 1)
 SRBDS                 X              X            X              X
-SRSO                  X                           X
-SSB                                                                                   (Note 4)
+SRSO                  X              X            X              X
+SSB                                  X
 TAA                   X              X            X              X            *       (Note 2)
 TSA                   X              X            X              X
 =============== ============== ============ ============= ============== ============ ========
@@ -229,9 +229,6 @@ Notes:
    3 --  Disables SMT if cross-thread mitigations are fully enabled, the CPU is
    vulnerable, and STIBP is not supported
 
-   4 --  Speculative store bypass is always enabled by default (no kernel
-   mitigation applied) unless overridden with spec_store_bypass_disable option
-
 When an attack-vector is disabled, all mitigations for the vulnerabilities
 listed in the above table are disabled, unless mitigation is required for a
 different enabled attack-vector or a mitigation is explicitly selected via a

Documentation/core-api/symbol-namespaces.rst

@@ -76,20 +76,21 @@ unit as preprocessor statement. The above example would then read::
 within the corresponding compilation unit before the #include for
 <linux/export.h>. Typically it's placed before the first #include statement.
 
-Using the EXPORT_SYMBOL_GPL_FOR_MODULES() macro
------------------------------------------------
+Using the EXPORT_SYMBOL_FOR_MODULES() macro
+-------------------------------------------
 
 Symbols exported using this macro are put into a module namespace. This
-namespace cannot be imported.
+namespace cannot be imported. These exports are GPL-only as they are only
+intended for in-tree modules.
 
 The macro takes a comma separated list of module names, allowing only those
 modules to access this symbol. Simple tail-globs are supported.
 
 For example::
 
-  EXPORT_SYMBOL_GPL_FOR_MODULES(preempt_notifier_inc, "kvm,kvm-*")
+  EXPORT_SYMBOL_FOR_MODULES(preempt_notifier_inc, "kvm,kvm-*")
 
-will limit usage of this symbol to modules whoes name matches the given
+will limit usage of this symbol to modules whose name matches the given
 patterns.
 
 How to use Symbols exported in Namespaces

Documentation/devicetree/bindings/display/msm/qcom,mdp5.yaml

@@ -60,7 +60,6 @@ properties:
           - const: bus
           - const: core
           - const: vsync
-          - const: lut
           - const: tbu
           - const: tbu_rt
         # MSM8996 has additional iommu clock

Documentation/devicetree/bindings/net/thead,th1520-gmac.yaml

@@ -62,11 +62,13 @@ properties:
     items:
       - description: GMAC main clock
       - description: Peripheral registers interface clock
+      - description: APB glue registers interface clock
 
   clock-names:
     items:
       - const: stmmaceth
       - const: pclk
+      - const: apb
 
   interrupts:
     items:
@@ -88,8 +90,8 @@ examples:
         compatible = "thead,th1520-gmac", "snps,dwmac-3.70a";
         reg = <0xe7070000 0x2000>, <0xec003000 0x1000>;
         reg-names = "dwmac", "apb";
-        clocks = <&clk 1>, <&clk 2>;
-        clock-names = "stmmaceth", "pclk";
+        clocks = <&clk 1>, <&clk 2>, <&clk 3>;
+        clock-names = "stmmaceth", "pclk", "apb";
         interrupts = <66>;
         interrupt-names = "macirq";
         phy-mode = "rgmii-id";

Documentation/devicetree/bindings/regulator/infineon,ir38060.yaml

@@ -7,7 +7,7 @@ $schema: http://devicetree.org/meta-schemas/core.yaml#
 title: Infineon Buck Regulators with PMBUS interfaces
 
 maintainers:
-  - Not Me.
+  - Guenter Roeck <linux@roeck-us.net>
 
 allOf:
   - $ref: regulator.yaml#