linux.git/arch/sparc/include, branch v6.5

locking: remove spin_lock_prefetch

2023-08-12T16:18:47+00:00

The only remaining consumer is new_inode, where it showed up in 2001 as
commit c37fa164f793 ("v2.4.9.9 -> v2.4.9.10") in a historical repo [1]
with a changelog which does not mention it.

Since then the line got only touched up to keep compiling.

While it may have been of benefit back in the day, it is guaranteed to
at best not get in the way in the multicore setting -- as the code
performs *a lot* of work between the prefetch and actual lock acquire,
any contention means the cacheline is already invalid by the time the
routine calls spin_lock().  It adds spurious traffic, for short.

On top of it prefetch is notoriously tricky to use for single-threaded
purposes, making it questionable from the get go.

As such, remove it.

I admit upfront I did not see value in benchmarking this change, but I
can do it if that is deemed appropriate.

Removal from new_inode and of the entire thing are in the same patch as
requested by Linus, so whatever weird looks can be directed at that guy.

Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/fs/inode.c?id=c37fa164f793735b32aa3f53154ff1a7659e6442 [1]
Signed-off-by: Mateusz Guzik 
Signed-off-by: Linus Torvalds

sparc: mark __arch_xchg() as __always_inline

2023-07-13T16:54:32+00:00

An otherwise correct change to the atomic operations uncovered an
existing bug in the sparc __arch_xchg() function, which is calls
__xchg_called_with_bad_pointer() when its arguments are unknown at
compile time:

ERROR: modpost: "__xchg_called_with_bad_pointer" [lib/atomic64_test.ko] undefined!

This now happens because gcc determines that it's better to not inline the
function. Avoid this by just marking the function as __always_inline
to force the compiler to do the right thing here.

Reported-by: Guenter Roeck 
Link: https://lore.kernel.org/all/c525adc9-6623-4660-8718-e0c9311563b8@roeck-us.net/
Fixes: d12157efc8e08 ("locking/atomic: make atomic*_{cmp,}xchg optional")
Signed-off-by: Arnd Bergmann 
Acked-by: Palmer Dabbelt 
Acked-by: Mark Rutland 
Reviewed-by: Sam Ravnborg 
Acked-by: Guenter Roeck 
Acked-by: Andi Shyti 
Link: https://lore.kernel.org/r/20230628094938.2318171-1-arnd@kernel.org
Signed-off-by: Kees Cook

Merge tag 'drm-next-2023-06-29' of git://anongit.freedesktop.org/drm/drm

2023-06-29T18:00:17+00:00

Pull drm updates from Dave Airlie:
 "There is one set of patches to misc for a i915 gsc/mei proxy driver.

  Otherwise it's mostly amdgpu/i915/msm, lots of hw enablement and lots
  of refactoring.

  core:
   - replace strlcpy with strscpy
   - EDID changes to support further conversion to struct drm_edid
   - Move i915 DSC parameter code to common DRM helpers
   - Add Colorspace functionality

  aperture:
   - ignore framebuffers with non-primary devices

  fbdev:
   - use fbdev i/o helpers
   - add Kconfig options for fb_ops helpers
   - use new fb io helpers directly in drivers

  sysfs:
   - export DRM connector ID

  scheduler:
   - Avoid an infinite loop

  ttm:
   - store function table in .rodata
   - Add query for TTM mem limit
   - Add NUMA awareness to pools
   - Export ttm_pool_fini()

  bridge:
   - fsl-ldb: support i.MX6SX
   - lt9211, lt9611: remove blanking packets
   - tc358768: implement input bus formats, devm cleanups
   - ti-snd65dsi86: implement wait_hpd_asserted
   - analogix: fix endless probe loop
   - samsung-dsim: support swapped clock, fix enabling, support var
     clock
   - display-connector: Add support for external power supply
   - imx: Fix module linking
   - tc358762: Support reset GPIO

  panel:
   - nt36523: Support Lenovo J606F
   - st7703: Support Anbernic RG353V-V2
   - InnoLux G070ACE-L01 support
   - boe-tv101wum-nl6: Improve initialization
   - sharp-ls043t1le001: Mode fixes
   - simple: BOE EV121WXM-N10-1850, S6D7AA0
   - Ampire AM-800480L1TMQW-T00H
   - Rocktech RK043FN48H
   - Starry himax83102-j02
   - Starry ili9882t

  amdgpu:
   - add new ctx query flag to handle reset better
   - add new query/set shadow buffer for rdna3
   - DCN 3.2/3.1.x/3.0.x updates
   - Enable DC_FP on loongarch
   - PCIe fix for RDNA2
   - improve DC FAMS/SubVP support for better power management
   - partition support for lots of engines
   - Take NUMA into account when allocating memory
   - Add new DRM_AMDGPU_WERROR config parameter to help with CI
   - Initial SMU13 overdrive support
   - Add support for new colorspace KMS API
   - W=1 fixes

  amdkfd:
   - Query TTM mem limit rather than hardcoding it
   - GC 9.4.3 partition support
   - Handle NUMA for partitions
   - Add debugger interface for enabling gdb
   - Add KFD event age tracking

  radeon:
   - Fix possible UAF

  i915:
   - new getparam for PXP support
   - GSC/MEI proxy driver
   - Meteorlake display enablement
   - avoid clearing preallocated framebuffers with TTM
   - implement framebuffer mmap support
   - Disable sampler indirect state in bindless heap
   - Enable fdinfo for GuC backends
   - GuC loading and firmware table handling fixes
   - Various refactors for multi-tile enablement
   - Define MOCS and PAT tables for MTL
   - GSC/MEI support for Meteorlake
   - PMU multi-tile support
   - Large driver kernel doc cleanup
   - Allow VRR toggling and arbitrary refresh rates
   - Support async flips on linear buffers on display ver 12+
   - Expose CRTC CTM property on ILK/SNB/VLV
   - New debugfs for display clock frequencies
   - Hotplug refactoring
   - Display refactoring
   - I915_GEM_CREATE_EXT_SET_PAT for Mesa on Meteorlake
   - Use large rings for compute contexts
   - HuC loading for MTL
   - Allow user to set cache at BO creation
   - MTL powermanagement enhancements
   - Switch to dedicated workqueues to stop using flush_scheduled_work()
   - Move display runtime init under display/
   - Remove 10bit gamma on desktop gen3 parts, they don't support it

  habanalabs:
   - uapi: return 0 for user queries if there was a h/w or f/w error
   - Add pci health check when we lose connection with the firmware.
     This can be used to distinguish between pci link down and firmware
     getting stuck.
   - Add more info to the error print when TPC interrupt occur.
   - Firmware fixes

  msm:
   - Adreno A660 bindings
   - SM8350 MDSS bindings fix
   - Added support for DPU on sm6350 and sm6375 platforms
   - Implemented tearcheck support to support vsync on SM150 and newer
     platforms
   - Enabled missing features (DSPP, DSC, split display) on sc8180x,
     sc8280xp, sm8450
   - Added support for DSI and 28nm DSI PHY on MSM8226 platform
   - Added support for DSI on sm6350 and sm6375 platforms
   - Added support for display controller on MSM8226 platform
   - A690 GPU support
   - Move cmdstream dumping out of fence signaling path
   - a610 support
   - Support for a6xx devices without GMU

  nouveau:
   - NULL ptr before deref fixes

  armada:
   - implement fbdev emulation as client

  sun4i:
   - fix mipi-dsi dotclock
   - release clocks

  vc4:
   - rgb range toggle property
   - BT601 / BT2020 HDMI support

  vkms:
   - convert to drmm helpers
   - add reflection and rotation support
   - fix rgb565 conversion

  gma500:
   - fix iomem access

  shmobile:
   - support renesas soc platform
   - enable fbdev

  mxsfb:
   - Add support for i.MX93 LCDIF

  stm:
   - dsi: Use devm_ helper
   - ltdc: Fix potential invalid pointer deref

  renesas:
   - Group drivers in renesas subdirectory to prepare for new platform
   - Drop deprecated R-Car H3 ES1.x support

  meson:
   - Add support for MIPI DSI displays

  virtio:
   - add sync object support

  mediatek:
   - Add display binding document for MT6795"

* tag 'drm-next-2023-06-29' of git://anongit.freedesktop.org/drm/drm: (1791 commits)
  drm/i915: Fix a NULL vs IS_ERR() bug
  drm/i915: make i915_drm_client_fdinfo() reference conditional again
  drm/i915/huc: Fix missing error code in intel_huc_init()
  drm/i915/gsc: take a wakeref for the proxy-init-completion check
  drm/msm/a6xx: Add A610 speedbin support
  drm/msm/a6xx: Add A619_holi speedbin support
  drm/msm/a6xx: Use adreno_is_aXYZ macros in speedbin matching
  drm/msm/a6xx: Use "else if" in GPU speedbin rev matching
  drm/msm/a6xx: Fix some A619 tunables
  drm/msm/a6xx: Add A610 support
  drm/msm/a6xx: Add support for A619_holi
  drm/msm/adreno: Disable has_cached_coherent in GMU wrapper configurations
  drm/msm/a6xx: Introduce GMU wrapper support
  drm/msm/a6xx: Move CX GMU power counter enablement to hw_init
  drm/msm/a6xx: Extend and explain UBWC config
  drm/msm/a6xx: Remove both GBIF and RBBM GBIF halt on hw init
  drm/msm/a6xx: Add a helper for software-resetting the GPU
  drm/msm/a6xx: Improve a6xx_bus_clear_pending_transactions()
  drm/msm/a6xx: Move a6xx_bus_clear_pending_transactions to a6xx_gpu
  drm/msm/a6xx: Move force keepalive vote removal to a6xx_gmu_force_off()
  ...

Merge tag 'net-next-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

2023-06-28T23:43:10+00:00

Pull networking changes from Jakub Kicinski:
 "WiFi 7 and sendpage changes are the biggest pieces of work for this
  release. The latter will definitely require fixes but I think that we
  got it to a reasonable point.

  Core:

   - Rework the sendpage & splice implementations

     Instead of feeding data into sockets page by page extend sendmsg
     handlers to support taking a reference on the data, controlled by a
     new flag called MSG_SPLICE_PAGES

     Rework the handling of unexpected-end-of-file to invoke an
     additional callback instead of trying to predict what the right
     combination of MORE/NOTLAST flags is

     Remove the MSG_SENDPAGE_NOTLAST flag completely

   - Implement SCM_PIDFD, a new type of CMSG type analogous to
     SCM_CREDENTIALS, but it contains pidfd instead of plain pid

   - Enable socket busy polling with CONFIG_RT

   - Improve reliability and efficiency of reporting for ref_tracker

   - Auto-generate a user space C library for various Netlink families

  Protocols:

   - Allow TCP to shrink the advertised window when necessary, prevent
     sk_rcvbuf auto-tuning from growing the window all the way up to
     tcp_rmem[2]

   - Use per-VMA locking for "page-flipping" TCP receive zerocopy

   - Prepare TCP for device-to-device data transfers, by making sure
     that payloads are always attached to skbs as page frags

   - Make the backoff time for the first N TCP SYN retransmissions
     linear. Exponential backoff is unnecessarily conservative

   - Create a new MPTCP getsockopt to retrieve all info
     (MPTCP_FULL_INFO)

   - Avoid waking up applications using TLS sockets until we have a full
     record

   - Allow using kernel memory for protocol ioctl callbacks, paving the
     way to issuing ioctls over io_uring

   - Add nolocalbypass option to VxLAN, forcing packets to be fully
     encapsulated even if they are destined for a local IP address

   - Make TCPv4 use consistent hash in TIME_WAIT and SYN_RECV. Ensure
     in-kernel ECMP implementation (e.g. Open vSwitch) select the same
     link for all packets. Support L4 symmetric hashing in Open vSwitch

   - PPPoE: make number of hash bits configurable

   - Allow DNS to be overwritten by DHCPACK in the in-kernel DHCP client
     (ipconfig)

   - Add layer 2 miss indication and filtering, allowing higher layers
     (e.g. ACL filters) to make forwarding decisions based on whether
     packet matched forwarding state in lower devices (bridge)

   - Support matching on Connectivity Fault Management (CFM) packets

   - Hide the "link becomes ready" IPv6 messages by demoting their
     printk level to debug

   - HSR: don't enable promiscuous mode if device offloads the proto

   - Support active scanning in IEEE 802.15.4

   - Continue work on Multi-Link Operation for WiFi 7

  BPF:

   - Add precision propagation for subprogs and callbacks. This allows
     maintaining verification efficiency when subprograms are used, or
     in fact passing the verifier at all for complex programs,
     especially those using open-coded iterators

   - Improve BPF's {g,s}setsockopt() length handling. Previously BPF
     assumed the length is always equal to the amount of written data.
     But some protos allow passing a NULL buffer to discover what the
     output buffer *should* be, without writing anything

   - Accept dynptr memory as memory arguments passed to helpers

   - Add routing table ID to bpf_fib_lookup BPF helper

   - Support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands

   - Drop bpf_capable() check in BPF_MAP_FREEZE command (used to mark
     maps as read-only)

   - Show target_{obj,btf}_id in tracing link fdinfo

   - Addition of several new kfuncs (most of the names are
     self-explanatory):
      - Add a set of new dynptr kfuncs: bpf_dynptr_adjust(),
        bpf_dynptr_is_null(), bpf_dynptr_is_rdonly(), bpf_dynptr_size()
        and bpf_dynptr_clone().
      - bpf_task_under_cgroup()
      - bpf_sock_destroy() - force closing sockets
      - bpf_cpumask_first_and(), rework bpf_cpumask_any*() kfuncs

  Netfilter:

   - Relax set/map validation checks in nf_tables. Allow checking
     presence of an entry in a map without using the value

   - Increase ip_vs_conn_tab_bits range for 64BIT builds

   - Allow updating size of a set

   - Improve NAT tuple selection when connection is closing

  Driver API:

   - Integrate netdev with LED subsystem, to allow configuring HW
     "offloaded" blinking of LEDs based on link state and activity
     (i.e. packets coming in and out)

   - Support configuring rate selection pins of SFP modules

   - Factor Clause 73 auto-negotiation code out of the drivers, provide
     common helper routines

   - Add more fool-proof helpers for managing lifetime of MDIO devices
     associated with the PCS layer

   - Allow drivers to report advanced statistics related to Time Aware
     scheduler offload (taprio)

   - Allow opting out of VF statistics in link dump, to allow more VFs
     to fit into the message

   - Split devlink instance and devlink port operations

  New hardware / drivers:

   - Ethernet:
      - Synopsys EMAC4 IP support (stmmac)
      - Marvell 88E6361 8 port (5x1GE + 3x2.5GE) switches
      - Marvell 88E6250 7 port switches
      - Microchip LAN8650/1 Rev.B0 PHYs
      - MediaTek MT7981/MT7988 built-in 1GE PHY driver

   - WiFi:
      - Realtek RTL8192FU, 2.4 GHz, b/g/n mode, 2T2R, 300 Mbps
      - Realtek RTL8723DS (SDIO variant)
      - Realtek RTL8851BE

   - CAN:
      - Fintek F81604

  Drivers:

   - Ethernet NICs:
      - Intel (100G, ice):
         - support dynamic interrupt allocation
         - use meta data match instead of VF MAC addr on slow-path
      - nVidia/Mellanox:
         - extend link aggregation to handle 4, rather than just 2 ports
         - spawn sub-functions without any features by default
      - OcteonTX2:
         - support HTB (Tx scheduling/QoS) offload
         - make RSS hash generation configurable
         - support selecting Rx queue using TC filters
      - Wangxun (ngbe/txgbe):
         - add basic Tx/Rx packet offloads
         - add phylink support (SFP/PCS control)
      - Freescale/NXP (enetc):
         - report TAPRIO packet statistics
      - Solarflare/AMD:
         - support matching on IP ToS and UDP source port of outer
           header
         - VxLAN and GENEVE tunnel encapsulation over IPv4 or IPv6
         - add devlink dev info support for EF10

   - Virtual NICs:
      - Microsoft vNIC:
         - size the Rx indirection table based on requested
           configuration
         - support VLAN tagging
      - Amazon vNIC:
         - try to reuse Rx buffers if not fully consumed, useful for ARM
           servers running with 16kB pages
      - Google vNIC:
         - support TCP segmentation of >64kB frames

   - Ethernet embedded switches:
      - Marvell (mv88e6xxx):
         - enable USXGMII (88E6191X)
      - Microchip:
         - lan966x: add support for Egress Stage 0 ACL engine
         - lan966x: support mapping packet priority to internal switch
           priority (based on PCP or DSCP)

   - Ethernet PHYs:
      - Broadcom PHYs:
         - support for Wake-on-LAN for BCM54210E/B50212E
         - report LPI counter
      - Microsemi PHYs: support RGMII delay configuration (VSC85xx)
      - Micrel PHYs: receive timestamp in the frame (LAN8841)
      - Realtek PHYs: support optional external PHY clock
      - Altera TSE PCS: merge the driver into Lynx PCS which it is a
        variant of

   - CAN: Kvaser PCIEcan:
      - support packet timestamping

   - WiFi:
      - Intel (iwlwifi):
         - major update for new firmware and Multi-Link Operation (MLO)
         - configuration rework to drop test devices and split the
           different families
         - support for segmented PNVM images and power tables
         - new vendor entries for PPAG (platform antenna gain) feature
      - Qualcomm 802.11ax (ath11k):
         - Multiple Basic Service Set Identifier (MBSSID) and Enhanced
           MBSSID Advertisement (EMA) support in AP mode
         - support factory test mode
      - RealTek (rtw89):
         - add RSSI based antenna diversity
         - support U-NII-4 channels on 5 GHz band
      - RealTek (rtl8xxxu):
         - AP mode support for 8188f
         - support USB RX aggregation for the newer chips"

* tag 'net-next-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1602 commits)
  net: scm: introduce and use scm_recv_unix helper
  af_unix: Skip SCM_PIDFD if scm->pid is NULL.
  net: lan743x: Simplify comparison
  netlink: Add __sock_i_ino() for __netlink_diag_dump().
  net: dsa: avoid suspicious RCU usage for synced VLAN-aware MAC addresses
  Revert "af_unix: Call scm_recv() only after scm_set_cred()."
  phylink: ReST-ify the phylink_pcs_neg_mode() kdoc
  libceph: Partially revert changes to support MSG_SPLICE_PAGES
  net: phy: mscc: fix packet loss due to RGMII delays
  net: mana: use vmalloc_array and vcalloc
  net: enetc: use vmalloc_array and vcalloc
  ionic: use vmalloc_array and vcalloc
  pds_core: use vmalloc_array and vcalloc
  gve: use vmalloc_array and vcalloc
  octeon_ep: use vmalloc_array and vcalloc
  net: usb: qmi_wwan: add u-blox 0x1312 composition
  perf trace: fix MSG_SPLICE_PAGES build error
  ipvlan: Fix return value of ipvlan_queue_xmit()
  netfilter: nf_tables: fix underflow in chain reference counter
  netfilter: nf_tables: unbind non-anonymous set if rule construction fails
  ...

Merge tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-06-28T17:59:38+00:00

Pull non-mm updates from Andrew Morton:

 - Arnd Bergmann has fixed a bunch of -Wmissing-prototypes in top-level
   directories

 - Douglas Anderson has added a new "buddy" mode to the hardlockup
   detector. It permits the detector to work on architectures which
   cannot provide the required interrupts, by having CPUs periodically
   perform checks on other CPUs

 - Zhen Lei has enhanced kexec's ability to support two crash regions

 - Petr Mladek has done a lot of cleanup on the hard lockup detector's
   Kconfig entries

 - And the usual bunch of singleton patches in various places

* tag 'mm-nonmm-stable-2023-06-24-19-23' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (72 commits)
  kernel/time/posix-stubs.c: remove duplicated include
  ocfs2: remove redundant assignment to variable bit_off
  watchdog/hardlockup: fix typo in config HARDLOCKUP_DETECTOR_PREFER_BUDDY
  powerpc: move arch_trigger_cpumask_backtrace from nmi.h to irq.h
  devres: show which resource was invalid in __devm_ioremap_resource()
  watchdog/hardlockup: define HARDLOCKUP_DETECTOR_ARCH
  watchdog/sparc64: define HARDLOCKUP_DETECTOR_SPARC64
  watchdog/hardlockup: make HAVE_NMI_WATCHDOG sparc64-specific
  watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h
  watchdog/hardlockup: make the config checks more straightforward
  watchdog/hardlockup: sort hardlockup detector related config values a logical way
  watchdog/hardlockup: move SMP barriers from common code to buddy code
  watchdog/buddy: simplify the dependency for HARDLOCKUP_DETECTOR_PREFER_BUDDY
  watchdog/buddy: don't copy the cpumask in watchdog_next_cpu()
  watchdog/buddy: cleanup how watchdog_buddy_check_hardlockup() is called
  watchdog/hardlockup: remove softlockup comment in touch_nmi_watchdog()
  watchdog/hardlockup: in watchdog_hardlockup_check() use cpumask_copy()
  watchdog/hardlockup: don't use raw_cpu_ptr() in watchdog_hardlockup_kick()
  watchdog/hardlockup: HAVE_NMI_WATCHDOG must implement watchdog_hardlockup_probe()
  watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe fails
  ...

Merge tag 'locking-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-06-27T21:14:30+00:00

Pull locking updates from Ingo Molnar:

 - Introduce cmpxchg128() -- aka. the demise of cmpxchg_double()

   The cmpxchg128() family of functions is basically & functionally the
   same as cmpxchg_double(), but with a saner interface.

   Instead of a 6-parameter horror that forced u128 - u64/u64-halves
   layout details on the interface and exposed users to complexity,
   fragility & bugs, use a natural 3-parameter interface with u128
   types.

 - Restructure the generated atomic headers, and add kerneldoc comments
   for all of the generic atomic{,64,_long}_t operations.

   The generated definitions are much cleaner now, and come with
   documentation.

 - Implement lock_set_cmp_fn() on lockdep, for defining an ordering when
   taking multiple locks of the same type.

   This gets rid of one use of lockdep_set_novalidate_class() in the
   bcache code.

 - Fix raw_cpu_generic_try_cmpxchg() bug due to an unintended variable
   shadowing generating garbage code on Clang on certain ARM builds.

* tag 'locking-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
  locking/atomic: scripts: fix ${atomic}_dec_if_positive() kerneldoc
  percpu: Fix self-assignment of __old in raw_cpu_generic_try_cmpxchg()
  locking/atomic: treewide: delete arch_atomic_*() kerneldoc
  locking/atomic: docs: Add atomic operations to the driver basic API documentation
  locking/atomic: scripts: generate kerneldoc comments
  docs: scripts: kernel-doc: accept bitwise negation like ~@var
  locking/atomic: scripts: simplify raw_atomic*() definitions
  locking/atomic: scripts: simplify raw_atomic_long*() definitions
  locking/atomic: scripts: split pfx/name/sfx/order
  locking/atomic: scripts: restructure fallback ifdeffery
  locking/atomic: scripts: build raw_atomic_long*() directly
  locking/atomic: treewide: use raw_atomic*_()
  locking/atomic: scripts: add trivial raw_atomic*_()
  locking/atomic: scripts: factor out order template generation
  locking/atomic: scripts: remove leftover "${mult}"
  locking/atomic: scripts: remove bogus order parameter
  locking/atomic: xtensa: add preprocessor symbols
  locking/atomic: x86: add preprocessor symbols
  locking/atomic: sparc: add preprocessor symbols
  locking/atomic: sh: add preprocessor symbols
  ...

watchdog/hardlockup: declare arch_touch_nmi_watchdog() only in linux/nmi.h

2023-06-19T23:25:29+00:00

arch_touch_nmi_watchdog() needs a different implementation for various
hardlockup detector implementations. And it does nothing when
any hardlockup detector is not built at all.

arch_touch_nmi_watchdog() is declared via linux/nmi.h. And it must be
defined as an empty function when there is no hardlockup detector.
It is done directly in this header file for the perf and buddy detectors.
And it is done in the included asm/linux.h for arch specific detectors.

The reason probably is that the arch specific variants build the code
using another conditions. For example, powerpc64/sparc64 builds the code
when CONFIG_PPC_WATCHDOG is enabled.

Another reason might be that these architectures define more functions
in asm/nmi.h anyway.

However the generic code actually knows when the function will be
implemented. It happens when some full featured or the sparc64-specific
hardlockup detector is built.

In particular, CONFIG_HARDLOCKUP_DETECTOR can be enabled only when
a generic or arch-specific full featured hardlockup detector is available.
The only exception is sparc64 which can be built even when the global
HARDLOCKUP_DETECTOR switch is disabled.

The information about sparc64 is a bit complicated. The hardlockup
detector is built there when CONFIG_HAVE_NMI_WATCHDOG is set and
CONFIG_HAVE_HARDLOCKUP_DETECTOR_ARCH is not set.

People might wonder whether this change really makes things easier.
The motivation is:

  + The current logic in linux/nmi.h is far from obvious.
    For example, arch_touch_nmi_watchdog() is defined as {} when
    neither CONFIG_HARDLOCKUP_DETECTOR_COUNTS_HRTIMER nor
    CONFIG_HAVE_NMI_WATCHDOG is defined.

  + The change synchronizes the checks in lib/Kconfig.debug and
    in the generic code.

  + It is a step that will help cleaning HAVE_NMI_WATCHDOG related
    checks.

The change should not change the existing behavior.

Link: https://lkml.kernel.org/r/20230616150618.6073-4-pmladek@suse.com
Signed-off-by: Petr Mladek 
Reviewed-by: Douglas Anderson 
Cc: Christophe Leroy 
Cc: "David S. Miller" 
Cc: Michael Ellerman 
Cc: Nicholas Piggin 
Signed-off-by: Andrew Morton

sparc/cpu: Switch to arch_cpu_finalize_init()

2023-06-16T08:16:00+00:00

check_bugs() is about to be phased out. Switch over to the new
arch_cpu_finalize_init() implementation.

No functional change.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Sam Ravnborg 
Link: https://lore.kernel.org/r/20230613224545.431995857@linutronix.de

net: core: add getsockopt SO_PEERPIDFD

2023-06-12T09:45:50+00:00

Add SO_PEERPIDFD which allows to get pidfd of peer socket holder pidfd.
This thing is direct analog of SO_PEERCRED which allows to get plain PID.

Cc: "David S. Miller" 
Cc: Eric Dumazet 
Cc: Jakub Kicinski 
Cc: Paolo Abeni 
Cc: Leon Romanovsky 
Cc: David Ahern 
Cc: Arnd Bergmann 
Cc: Kees Cook 
Cc: Christian Brauner 
Cc: Kuniyuki Iwashima 
Cc: Lennart Poettering 
Cc: Luca Boccassi 
Cc: Daniel Borkmann 
Cc: Stanislav Fomichev 
Cc: bpf@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Reviewed-by: Christian Brauner 
Acked-by: Stanislav Fomichev 
Tested-by: Luca Boccassi 
Signed-off-by: Alexander Mikhalitsyn 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

scm: add SO_PASSPIDFD and SCM_PIDFD

2023-06-12T09:45:49+00:00

Implement SCM_PIDFD, a new type of CMSG type analogical to SCM_CREDENTIALS,
but it contains pidfd instead of plain pid, which allows programmers not
to care about PID reuse problem.

We mask SO_PASSPIDFD feature if CONFIG_UNIX is not builtin because
it depends on a pidfd_prepare() API which is not exported to the kernel
modules.

Idea comes from UAPI kernel group:
https://uapi-group.org/kernel-features/

Big thanks to Christian Brauner and Lennart Poettering for productive
discussions about this.

Cc: "David S. Miller" 
Cc: Eric Dumazet 
Cc: Jakub Kicinski 
Cc: Paolo Abeni 
Cc: Leon Romanovsky 
Cc: David Ahern 
Cc: Arnd Bergmann 
Cc: Kees Cook 
Cc: Christian Brauner 
Cc: Kuniyuki Iwashima 
Cc: Lennart Poettering 
Cc: Luca Boccassi 
Cc: linux-kernel@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Tested-by: Luca Boccassi 
Reviewed-by: Kuniyuki Iwashima 
Reviewed-by: Christian Brauner 
Signed-off-by: Alexander Mikhalitsyn 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller