Commit Graph

99225 Commits

Author SHA1 Message Date
Jiri Slaby (SUSE)
63f3cd5d80 tty: tty_driver: document both {,__}tty_alloc_driver() properly
__tty_alloc_driver()'s kernel-doc needed some care: describe the return
value using the standard "Returns:", and use the new enum tty_driver_flag
for @flags.

Then, the tty_alloc_driver() macro was undocumented, but referenced many
times in the docs. Copy the docs from the above (except the @owner
parameter, obviously).

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-15-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-20 08:00:51 -07:00
Jiri Slaby (SUSE)
109e06ae1d tty: tty_driver: convert "TTY Driver Flags" to an enum
Convert TTY_DRIVER_* macros (flags) to an enum. This allows for easier
kernel-doc (the comment needed fine tuning), grouping of these nicely,
and proper checking.

Given these are flags, define them using modern BIT() instead of hex
constants.

It turns out (thanks, kernel-doc checker) that internal
TTY_DRIVER_INSTALLED was undocumented. Fix that too.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-14-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-20 08:00:51 -07:00
Jiri Slaby (SUSE)
67acbcc324 tty: tty_driver: move TTY macros to the top
So that they can be referenced in structs once converted to enums (in
the next patches).

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-13-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-20 08:00:51 -07:00
Jiri Slaby (SUSE)
d2e38e713b tty: move N_TTY_BUF_SIZE to n_tty
"N_TTY_BUF_SIZE" is private to n_tty and shall not be exposed to the
world. Definitely not in tty.h somewhere in the middle of "struct
tty_struct".

This is a remnant of moving "read_flags" to "struct n_tty_data" in
commit 3fe780b379 ("TTY: move ldisc data from tty_struct: bitmaps").
But some cleanup was needed first (in previous patches).

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-5-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-20 08:00:50 -07:00
Jiri Slaby (SUSE)
a72f418703 tty: convert "TTY Struct Flags" to an enum
Convert TTY_* macros (flags) to an enum. This allows for easier
kernel-doc (the comment needed fine tuning), grouping of these nicely,
and proper checking.

Note that these are bit positions. So they are used such as
test_bit(TTY_THROTTLED, ...). Given these are not the user API (only
in-kernel API/ABI), the bit positions are NOT preserved in this patch.
All are renumbered naturally using the enum-auto-numbering.

Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250317070046.24386-2-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-20 08:00:50 -07:00
Greg Kroah-Hartman
e749820252 Merge 6.14-rc3 into tty-next
We need the tty changes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-17 07:25:34 +01:00
Linus Torvalds
ae5fa8ce7e Merge tag 'driver-core-6.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core api addition from Greg KH:
 "Here is a driver core new api for 6.14-rc3 that is being added to
  allow platform devices from stop being abused.

  It adds a new 'faux_device' structure and bus and api to allow almost
  a straight or simpler conversion from platform devices that were not
  really a platform device. It also comes with a binding for rust, with
  an example driver in rust showing how it's used.

  I'm adding this now so that the patches that convert the different
  drivers and subsystems can all start flowing into linux-next now
  through their different development trees, in time for 6.15-rc1.

  We have a number that are already reviewed and tested, but adding
  those conversions now doesn't seem right. For now, no one is using
  this, and it passes all build tests from 0-day and linux-next, so all
  should be good"

* tag 'driver-core-6.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
  rust/kernel: Add faux device bindings
  driver core: add a faux bus for use when a simple device/bus is needed
2025-02-16 12:54:42 -08:00
Linus Torvalds
82ff316456 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
 "ARM:

   - Large set of fixes for vector handling, especially in the
     interactions between host and guest state.

     This fixes a number of bugs affecting actual deployments, and
     greatly simplifies the FP/SIMD/SVE handling. Thanks to Mark Rutland
     for dealing with this thankless task.

   - Fix an ugly race between vcpu and vgic creation/init, resulting in
     unexpected behaviours

   - Fix use of kernel VAs at EL2 when emulating timers with nVHE

   - Small set of pKVM improvements and cleanups

  x86:

   - Fix broken SNP support with KVM module built-in, ensuring the PSP
     module is initialized before KVM even when the module
     infrastructure cannot be used to order initcalls

   - Reject Hyper-V SEND_IPI hypercalls if the local APIC isn't being
     emulated by KVM to fix a NULL pointer dereference

   - Enter guest mode (L2) from KVM's perspective before initializing
     the vCPU's nested NPT MMU so that the MMU is properly tagged for
     L2, not L1

   - Load the guest's DR6 outside of the innermost .vcpu_run() loop, as
     the guest's value may be stale if a VM-Exit is handled in the
     fastpath"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (25 commits)
  x86/sev: Fix broken SNP support with KVM module built-in
  KVM: SVM: Ensure PSP module is initialized if KVM module is built-in
  crypto: ccp: Add external API interface for PSP module initialization
  KVM: arm64: vgic: Hoist SGI/PPI alloc from vgic_init() to kvm_create_vgic()
  KVM: arm64: timer: Drop warning on failed interrupt signalling
  KVM: arm64: Fix alignment of kvm_hyp_memcache allocations
  KVM: arm64: Convert timer offset VA when accessed in HYP code
  KVM: arm64: Simplify warning in kvm_arch_vcpu_load_fp()
  KVM: arm64: Eagerly switch ZCR_EL{1,2}
  KVM: arm64: Mark some header functions as inline
  KVM: arm64: Refactor exit handlers
  KVM: arm64: Refactor CPTR trap deactivation
  KVM: arm64: Remove VHE host restore of CPACR_EL1.SMEN
  KVM: arm64: Remove VHE host restore of CPACR_EL1.ZEN
  KVM: arm64: Remove host FPSIMD saving for non-protected KVM
  KVM: arm64: Unconditionally save+flush host FPSIMD/SVE/SME state
  KVM: x86: Load DR6 with guest value only before entering .vcpu_run() loop
  KVM: nSVM: Enter guest mode before initializing nested NPT MMU
  KVM: selftests: Add CPUID tests for Hyper-V features that need in-kernel APIC
  KVM: selftests: Manage CPUID array in Hyper-V CPUID test's core helper
  ...
2025-02-16 10:25:12 -08:00
Paolo Bonzini
d3d0b8dfe0 Merge tag 'kvm-x86-fixes-6.14-rcN' of https://github.com/kvm-x86/linux into HEAD
KVM fixes for 6.14 part 1

 - Reject Hyper-V SEND_IPI hypercalls if the local APIC isn't being emulated
   by KVM to fix a NULL pointer dereference.

 - Enter guest mode (L2) from KVM's perspective before initializing the vCPU's
   nested NPT MMU so that the MMU is properly tagged for L2, not L1.

 - Load the guest's DR6 outside of the innermost .vcpu_run() loop, as the
   guest's value may be stale if a VM-Exit is handled in the fastpath.
2025-02-14 19:08:35 -05:00
Sean Christopherson
435b344a70 crypto: ccp: Add external API interface for PSP module initialization
KVM is dependent on the PSP SEV driver and PSP SEV driver needs to be
loaded before KVM module. In case of module loading any dependent
modules are automatically loaded but in case of built-in modules there
is no inherent mechanism available to specify dependencies between
modules and ensure that any dependent modules are loaded implicitly.

Add a new external API interface for PSP module initialization which
allows PSP SEV driver to be loaded explicitly if KVM is built-in.

Signed-off-by: Sean Christopherson <seanjc@google.com>
Co-developed-by: Ashish Kalra <ashish.kalra@amd.com>
Signed-off-by: Ashish Kalra <ashish.kalra@amd.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Message-ID: <15279ca0cad56a07cf12834ec544310f85ff5edc.1739226950.git.ashish.kalra@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-14 18:39:19 -05:00
Linus Torvalds
c7ab7b2a18 Merge tag 'efi-fixes-for-v6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi
Pull EFI fixes from Ard Biesheuvel:
 "Take the newly introduced EFI_MEMORY_HOT_PLUGGABLE memory attribute
  into account when placing the kernel image in memory at boot.

  Otherwise, the presence of the kernel image could prevent such a
  memory region from being unplugged at runtime if it was 'cold
  plugged', i.e., already plugged in at boot time (and exposed via the
  EFI memory map).

  This should ensure that the new EFI_MEMORY_HOT_PLUGGABLE memory
  attribute is used consistently by Linux before it ever turns up in
  production, ensuring that we can make meaningful use of it without
  running the risk of regressing existing users"

* tag 'efi-fixes-for-v6.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/efi/efi:
  efi: Use BIT_ULL() constants for memory attributes
  efi: Avoid cold plugged memory for placing the kernel
2025-02-14 13:56:04 -08:00
Linus Torvalds
1b8c8cdad1 Merge tag 'block-6.14-20250214' of git://git.kernel.dk/linux
Pull block fixes from Jens Axboe:

 - Fix for request rejection for batch addition

 - Fix a few issues for bogus mac partition tables

* tag 'block-6.14-20250214' of git://git.kernel.dk/linux:
  partitions: mac: fix handling of bogus partition table
  block: cleanup and fix batch completion adding conditions
2025-02-14 11:40:59 -08:00
Linus Torvalds
80868f5d3d Merge tag 'cgroup-for-6.14-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:

 - Fix a race window where a newly forked task could escape cgroup.kill

 - Remove incorrectly included steal time from cpu.stat::usage_usec

 - Minor update in selftest

* tag 'cgroup-for-6.14-rc2-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup: Remove steal time from usage_usec
  selftests/cgroup: use bash in test_cpuset_v1_hp.sh
  cgroup: fix race between fork and cgroup.kill
2025-02-14 11:00:42 -08:00
Douglas Anderson
a029a21938 Revert "kernel/debug: Mask KGDB NMI upon entry"
This reverts commit 5a14fead07.

No architectures ever implemented `enable_nmi` since the later patches
in the series adding it never landed. It's been a long time. Drop it.

NOTE: this is not a clean revert due to changes in the file in the
meantime.

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20250129082535.3.I2254953cd852f31f354456689d68b2d910de3fbe@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-14 10:05:43 +01:00
Douglas Anderson
c08b0f2c31 Revert "tty/serial: Add kgdb_nmi driver"
This reverts commit 0c57dfcc6c.

The functionality was supoosed to be used by a later patch in the
series that never landed [1]. Drop it.

NOTE: part of functionality was already reverted by commit
39d0be8743 ("serial: kgdb_nmi: Remove unused knock code"). Also note
that this revert is not a clean revert given code changes that have
happened in the meantime.

It's obvious that nobody is using this code since the two exposed
functions (kgdb_register_nmi_console() and
kgdb_unregister_nmi_console()) are both no-ops if
"arch_kgdb_ops.enable_nmi" is not defined. No architectures define it.

[1] https://lore.kernel.org/lkml/1348522080-32629-9-git-send-email-anton.vorontsov@linaro.org/

Signed-off-by: Douglas Anderson <dianders@chromium.org>
Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: URL [1]
Link: https://lore.kernel.org/r/20250129082535.1.Ia095eac1ae357f87d23e7af2206741f5d40788f1@changeid
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-14 10:05:43 +01:00
Linus Torvalds
348f968b89 Merge tag 'net-6.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
 "Including fixes from netfilter, wireless and bluetooth.

  Kalle Valo steps down after serving as the WiFi driver maintainer for
  over a decade.

  Current release - fix to a fix:

   - vsock: orphan socket after transport release, avoid null-deref

   - Bluetooth: L2CAP: fix corrupted list in hci_chan_del

  Current release - regressions:

   - eth:
      - stmmac: correct Rx buffer layout when SPH is enabled
      - iavf: fix a locking bug in an error path

   - rxrpc: fix alteration of headers whilst zerocopy pending

   - s390/qeth: move netif_napi_add_tx() and napi_enable() from under BH

   - Revert "netfilter: flowtable: teardown flow if cached mtu is stale"

  Current release - new code bugs:

   - rxrpc: fix ipv6 path MTU discovery, only ipv4 worked

   - pse-pd: fix deadlock in current limit functions

  Previous releases - regressions:

   - rtnetlink: fix netns refleak with rtnl_setlink()

   - wifi: brcmfmac: use random seed flag for BCM4355 and BCM4364
     firmware

  Previous releases - always broken:

   - add missing RCU protection of struct net throughout the stack

   - can: rockchip: bail out if skb cannot be allocated

   - eth: ti: am65-cpsw: base XDP support fixes

  Misc:

   - ethtool: tsconfig: update the format of hwtstamp flags, changes the
     uAPI but this uAPI was not in any release yet"

* tag 'net-6.14-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (72 commits)
  net: pse-pd: Fix deadlock in current limit functions
  rxrpc: Fix ipv6 path MTU discovery
  Reapply "net: skb: introduce and use a single page frag cache"
  s390/qeth: move netif_napi_add_tx() and napi_enable() from under BH
  mlxsw: Add return value check for mlxsw_sp_port_get_stats_raw()
  ipv6: mcast: add RCU protection to mld_newpack()
  team: better TEAM_OPTION_TYPE_STRING validation
  Bluetooth: L2CAP: Fix corrupted list in hci_chan_del
  Bluetooth: btintel_pcie: Fix a potential race condition
  Bluetooth: L2CAP: Fix slab-use-after-free Read in l2cap_send_cmd
  net: ethernet: ti: am65_cpsw: fix tx_cleanup for XDP case
  net: ethernet: ti: am65-cpsw: fix RX & TX statistics for XDP_TX case
  net: ethernet: ti: am65-cpsw: fix memleak in certain XDP cases
  vsock/test: Add test for SO_LINGER null ptr deref
  vsock: Orphan socket after transport release
  MAINTAINERS: Add sctp headers to the general netdev entry
  Revert "netfilter: flowtable: teardown flow if cached mtu is stale"
  iavf: Fix a locking bug in an error path
  rxrpc: Fix alteration of headers whilst zerocopy pending
  net: phylink: make configuring clock-stop dependent on MAC support
  ...
2025-02-13 12:17:04 -08:00
Jakub Kicinski
0892b84031 Reapply "net: skb: introduce and use a single page frag cache"
This reverts commit 011b033590.

Sabrina reports that the revert may trigger warnings due to intervening
changes, especially the ability to rise MAX_SKB_FRAGS. Let's drop it
and revisit once that part is also ironed out.

Fixes: 011b033590 ("Revert "net: skb: introduce and use a single page frag cache"")
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://lore.kernel.org/6bf54579233038bc0e76056c5ea459872ce362ab.1739375933.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-13 08:49:44 -08:00
Greg Kroah-Hartman
35fa2d88ca driver core: add a faux bus for use when a simple device/bus is needed
Many drivers abuse the platform driver/bus system as it provides a
simple way to create and bind a device to a driver-specific set of
probe/release functions.  Instead of doing that, and wasting all of the
memory associated with a platform device, here is a "faux" bus that
can be used instead.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Reviewed-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Reviewed-by: Zijun Hu <quic_zijuhu@quicinc.com>
Link: https://lore.kernel.org/r/2025021026-atlantic-gibberish-3f0c@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-13 16:58:51 +01:00
Jens Axboe
1f47ed294a block: cleanup and fix batch completion adding conditions
The conditions for whether or not a request is allowed adding to a
completion batch are a bit hard to read, and they also have a few
issues. One is that ioerror may indeed be a random value on passthrough,
and it's being checked unconditionally of whether or not the given
request is a passthrough request or not.

Rewrite the conditions to be separate for easier reading, and only check
ioerror for non-passthrough requests. This fixes an issue with bio
unmapping on passthrough, where it fails getting added to a batch. This
both leads to suboptimal performance, and may trigger a potential
schedule-under-atomic condition for polled passthrough IO.

Fixes: f794f3351f ("block: add support for blk_mq_end_request_batch()")
Link: https://lore.kernel.org/r/20575f0a-656e-4bb3-9d82-dec6c7e3a35c@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2025-02-13 08:20:18 -07:00
Linus Torvalds
69b54314c9 Merge tag 'kbuild-fixes-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild fixes from Masahiro Yamada:

 - Suppress false-positive -Wformat-{overflow,truncation}-non-kprintf
   warnings regardless of the W= option

 - Avoid CONFIG_TRIM_UNUSED_KSYMS dropping symbols passed to symbol_get()

 - Fix a build regression of the Debian linux-headers package

* tag 'kbuild-fixes-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kbuild: install-extmod-build: add missing quotation marks for CC variable
  kbuild: fix misspelling in scripts/Makefile.lib
  kbuild: keep symbols for symbol_get() even with CONFIG_TRIM_UNUSED_KSYMS
  scripts/Makefile.extrawarn: Do not show clang's non-kprintf warnings at W=1
2025-02-09 10:05:32 -08:00
Linus Torvalds
954a209f43 Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
 "ARM:

   - Correctly clean the BSS to the PoC before allowing EL2 to access it
     on nVHE/hVHE/protected configurations

   - Propagate ownership of debug registers in protected mode after the
     rework that landed in 6.14-rc1

   - Stop pretending that we can run the protected mode without a GICv3
     being present on the host

   - Fix a use-after-free situation that can occur if a vcpu fails to
     initialise the NV shadow S2 MMU contexts

   - Always evaluate the need to arm a background timer for fully
     emulated guest timers

   - Fix the emulation of EL1 timers in the absence of FEAT_ECV

   - Correctly handle the EL2 virtual timer, specially when HCR_EL2.E2H==0

  s390:

   - move some of the guest page table (gmap) logic into KVM itself,
     inching towards the final goal of completely removing gmap from the
     non-kvm memory management code.

     As an initial set of cleanups, move some code from mm/gmap into kvm
     and start using __kvm_faultin_pfn() to fault-in pages as needed;
     but especially stop abusing page->index and page->lru to aid in the
     pgdesc conversion.

  x86:

   - Add missing check in the fix to defer starting the huge page
     recovery vhost_task

   - SRSO_USER_KERNEL_NO does not need SYNTHESIZED_F"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (31 commits)
  KVM: x86/mmu: Ensure NX huge page recovery thread is alive before waking
  KVM: remove kvm_arch_post_init_vm
  KVM: selftests: Fix spelling mistake "initally" -> "initially"
  kvm: x86: SRSO_USER_KERNEL_NO is not synthesized
  KVM: arm64: timer: Don't adjust the EL2 virtual timer offset
  KVM: arm64: timer: Correctly handle EL1 timer emulation when !FEAT_ECV
  KVM: arm64: timer: Always evaluate the need for a soft timer
  KVM: arm64: Fix nested S2 MMU structures reallocation
  KVM: arm64: Fail protected mode init if no vgic hardware is present
  KVM: arm64: Flush/sync debug state in protected mode
  KVM: s390: selftests: Streamline uc_skey test to issue iske after sske
  KVM: s390: remove the last user of page->index
  KVM: s390: move PGSTE softbits
  KVM: s390: remove useless page->index usage
  KVM: s390: move gmap_shadow_pgt_lookup() into kvm
  KVM: s390: stop using lists to keep track of used dat tables
  KVM: s390: stop using page->index for non-shadow gmaps
  KVM: s390: move some gmap shadowing functions away from mm/gmap.c
  KVM: s390: get rid of gmap_translate()
  KVM: s390: get rid of gmap_fault()
  ...
2025-02-09 09:41:38 -08:00
Linus Torvalds
9946eaf552 Merge tag 'hardening-v6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening fixes from Kees Cook:
 "Address a KUnit stack initialization regression that got tickled on
  m68k, and solve a Clang(v14 and earlier) bug found by 0day:

   - Fix stackinit KUnit regression on m68k

   - Use ARRAY_SIZE() for memtostr*()/strtomem*()"

* tag 'hardening-v6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  string.h: Use ARRAY_SIZE() for memtostr*()/strtomem*()
  compiler.h: Introduce __must_be_byte_array()
  compiler.h: Move C string helpers into C-only kernel section
  stackinit: Fix comment for test_small_end
  stackinit: Keep selftest union size small on m68k
2025-02-08 14:12:17 -08:00
Linus Torvalds
74b5161d57 Merge tag 'i2c-for-6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux
Pull i2c reverts from Wolfram Sang:
 "It turned out the new mechanism for handling created devices does not
  handle all muxing cases.

  Revert the changes to give a proper solution more time"

* tag 'i2c-for-6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  Revert "i2c: Replace list-based mechanism for handling auto-detected clients"
  Revert "i2c: Replace list-based mechanism for handling userspace-created clients"
2025-02-08 13:35:17 -08:00
Paolo Abeni
011b033590 Revert "net: skb: introduce and use a single page frag cache"
This reverts commit dbae2b0628 ("net: skb: introduce and use a single
page frag cache"). The intended goal of such change was to counter a
performance regression introduced by commit 3226b158e6 ("net: avoid
32 x truesize under-estimation for tiny skbs").

Unfortunately, the blamed commit introduces another regression for the
virtio_net driver. Such a driver calls napi_alloc_skb() with a tiny
size, so that the whole head frag could fit a 512-byte block.

The single page frag cache uses a 1K fragment for such allocation, and
the additional overhead, under small UDP packets flood, makes the page
allocator a bottleneck.

Thanks to commit bf9f1baa27 ("net: add dedicated kmem_cache for
typical/small skb->head"), this revert does not re-introduce the
original regression. Actually, in the relevant test on top of this
revert, I measure a small but noticeable positive delta, just above
noise level.

The revert itself required some additional mangling due to the
introduction of the SKB_HEAD_ALIGN() helper and local lock infra in the
affected code.

Suggested-by: Eric Dumazet <edumazet@google.com>
Fixes: dbae2b0628 ("net: skb: introduce and use a single page frag cache")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/e649212fde9f0fdee23909ca0d14158d32bb7425.1738877290.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-07 17:20:22 -08:00
Linus Torvalds
8c67da5bc1 Merge tag 'vfs-6.14-rc2.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs fixes from Christian Brauner:

 - Fix fsnotify FMODE_NONOTIFY* handling.

   This also disables fsnotify on all pseudo files by default apart from
   very select exceptions. This carries a regression risk so we need to
   watch out and adapt accordingly. However, it is overall a significant
   improvement over the current status quo where every rando file can
   get fsnotify enabled.

 - Cleanup and simplify lockref_init() after recent lockref changes.

 - Fix vboxfs build with gcc-15.

 - Add an assert into inode_set_cached_link() to catch corrupt links.

 - Allow users to also use an empty string check to detect whether a
   given mount option string was empty or not.

 - Fix how security options were appended to statmount()'s ->mnt_opt
   field.

 - Fix statmount() selftests to always check the returned mask.

 - Fix uninitialized value in vfs_statx_path().

 - Fix pidfs_ioctl() sanity checks to guard against ioctl() overloading
   and preserve extensibility.

* tag 'vfs-6.14-rc2.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  vfs: sanity check the length passed to inode_set_cached_link()
  pidfs: improve ioctl handling
  fsnotify: disable pre-content and permission events by default
  selftests: always check mask returned by statmount(2)
  fsnotify: disable notification by default for all pseudo files
  fs: fix adding security options to statmount.mnt_opt
  fsnotify: use accessor to set FMODE_NONOTIFY_*
  lockref: remove count argument of lockref_init
  gfs2: switch to lockref_init(..., 1)
  gfs2: use lockref_init for gl_lockref
  statmount: let unset strings be empty
  vboxsf: fix building with GCC 15
  fs/stat.c: avoid harmless garbage value problem in vfs_statx_path()
2025-02-07 09:22:31 -08:00
Mateusz Guzik
37d11cfc63 vfs: sanity check the length passed to inode_set_cached_link()
This costs a strlen() call when instatianating a symlink.

Preferably it would be hidden behind VFS_WARN_ON (or compatible), but
there is no such facility at the moment. With the facility in place the
call can be patched out in production kernels.

In the meantime, since the cost is being paid unconditionally, use the
result to a fixup the bad caller.

This is not expected to persist in the long run (tm).

Sample splat:
bad length passed for symlink [/tmp/syz-imagegen43743633/file0/file0] (got 131109, expected 37)
[rest of WARN blurp goes here]

Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Link: https://lore.kernel.org/r/20250204213207.337980-1-mjguzik@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-07 10:29:59 +01:00
Amir Goldstein
95101401bb fsnotify: use accessor to set FMODE_NONOTIFY_*
The FMODE_NONOTIFY_* bits are a 2-bits mode.  Open coding manipulation
of those bits is risky.  Use an accessor file_set_fsnotify_mode() to
set the mode.

Rename file_set_fsnotify_mode() => file_set_fsnotify_mode_from_watchers()
to make way for the simple accessor name.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20250203223205.861346-2-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-07 10:27:26 +01:00
Andreas Gruenbacher
bb504b4d64 lockref: remove count argument of lockref_init
All users of lockref_init() now initialize the count to 1, so hardcode
that and remove the count argument.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Link: https://lore.kernel.org/r/20250130135624.1899988-4-agruenba@redhat.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-07 10:27:25 +01:00
Kees Cook
6270f4deba string.h: Use ARRAY_SIZE() for memtostr*()/strtomem*()
The destination argument of memtostr*() and strtomem*() must be a
fixed-size char array at compile time, so there is no need to use
__builtin_object_size() (which is useful for when an argument is
either a pointer or unknown). Instead use ARRAY_SIZE(), which has the
benefit of working around a bug in Clang (fixed[1] in 15+) that got
__builtin_object_size() wrong sometimes.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501310832.kiAeOt2z-lkp@intel.com/
Suggested-by: Kent Overstreet <kent.overstreet@linux.dev>
Link: d8e0a6d5e9 [1]
Tested-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Kees Cook <kees@kernel.org>
2025-02-06 18:48:04 -08:00
Kees Cook
20e5cc26e5 compiler.h: Introduce __must_be_byte_array()
In preparation for adding stricter type checking to the str/mem*()
helpers, provide a way to check that a variable is a byte array
via __must_be_byte_array().

Suggested-by: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Kees Cook <kees@kernel.org>
2025-02-06 18:48:02 -08:00
Kees Cook
cb7380de9e compiler.h: Move C string helpers into C-only kernel section
The C kernel helpers for evaluating C Strings were positioned where they
were visible to assembly inclusion, which was not intended. Move them
into the kernel and C-only area of the header so future changes won't
confuse the assembler.

Fixes: d7a516c6ee ("compiler.h: Fix undefined BUILD_BUG_ON_ZERO()")
Fixes: 559048d156 ("string: Check for "nonstring" attribute on strscpy() arguments")
Reviewed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Kees Cook <kees@kernel.org>
2025-02-06 18:48:00 -08:00
Eric Dumazet
482ad2a4ac net: add dev_net_rcu() helper
dev->nd_net can change, readers should either
use rcu_read_lock() or RTNL.

We currently use a generic helper, dev_net() with
no debugging support. We probably have many hidden bugs.

Add dev_net_rcu() helper for callers using rcu_read_lock()
protection.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250205155120.1676781-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-06 16:14:14 -08:00
Linus Torvalds
3cf0a98fea Merge tag 'net-6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
 "Interestingly the recent kmemleak improvements allowed our CI to catch
  a couple of percpu leaks addressed here.

  We (mostly Jakub, to be accurate) are working to increase review
  coverage over the net code-base tweaking the MAINTAINER entries.

  Current release - regressions:

   - core: harmonize tstats and dstats

   - ipv6: fix dst refleaks in rpl, seg6 and ioam6 lwtunnels

   - eth: tun: revert fix group permission check

   - eth: stmmac: revert "specify hardware capability value when FIFO
     size isn't specified"

  Previous releases - regressions:

   - udp: gso: do not drop small packets when PMTU reduces

   - rxrpc: fix race in call state changing vs recvmsg()

   - eth: ice: fix Rx data path for heavy 9k MTU traffic

   - eth: vmxnet3: fix tx queue race condition with XDP

  Previous releases - always broken:

   - sched: pfifo_tail_enqueue: drop new packet when sch->limit == 0

   - ethtool: ntuple: fix rss + ring_cookie check

   - rxrpc: fix the rxrpc_connection attend queue handling

  Misc:

   - recognize Kuniyuki Iwashima as a maintainer"

* tag 'net-6.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (34 commits)
  Revert "net: stmmac: Specify hardware capability value when FIFO size isn't specified"
  MAINTAINERS: add a sample ethtool section entry
  MAINTAINERS: add entry for ethtool
  rxrpc: Fix race in call state changing vs recvmsg()
  rxrpc: Fix call state set to not include the SERVER_SECURING state
  net: sched: Fix truncation of offloaded action statistics
  tun: revert fix group permission check
  selftests/tc-testing: Add a test case for qdisc_tree_reduce_backlog()
  netem: Update sch->q.qlen before qdisc_tree_reduce_backlog()
  selftests/tc-testing: Add a test case for pfifo_head_drop qdisc when limit==0
  pfifo_tail_enqueue: Drop new packet when sch->limit == 0
  selftests: mptcp: connect: -f: no reconnect
  net: rose: lock the socket in rose_bind()
  net: atlantic: fix warning during hot unplug
  rxrpc: Fix the rxrpc_connection attend queue handling
  net: harmonize tstats and dstats
  selftests: drv-net: rss_ctx: don't fail reconfigure test if queue offset not supported
  selftests: drv-net: rss_ctx: add missing cleanup in queue reconfigure
  ethtool: ntuple: fix rss + ring_cookie check
  ethtool: rss: fix hiding unsupported fields in dumps
  ...
2025-02-06 09:14:54 -08:00
Masahiro Yamada
4c56eb33e6 kbuild: keep symbols for symbol_get() even with CONFIG_TRIM_UNUSED_KSYMS
Linus observed that the symbol_request(utf8_data_table) call fails when
CONFIG_UNICODE=y and CONFIG_TRIM_UNUSED_KSYMS=y.

symbol_get() relies on the symbol data being present in the ksymtab for
symbol lookups. However, EXPORT_SYMBOL_GPL(utf8_data_table) is dropped
due to CONFIG_TRIM_UNUSED_KSYMS, as no module references it in this case.

Probably, this has been broken since commit dbacb0ef67 ("kconfig option
for TRIM_UNUSED_KSYMS").

This commit addresses the issue by leveraging modpost. Symbol names
passed to symbol_get() are recorded in the special .no_trim_symbol
section, which is then parsed by modpost to forcibly keep such symbols.
The .no_trim_symbol section is discarded by the linker scripts, so there
is no impact on the size of the final vmlinux or modules.

This commit cannot resolve the issue for direct calls to __symbol_get()
because the symbol name is not known at compile-time.

Although symbol_get() may eventually be deprecated, this workaround
should be good enough meanwhile.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2025-02-06 01:08:58 +09:00
Wolfram Sang
3bfa08fe9e Revert "i2c: Replace list-based mechanism for handling auto-detected clients"
This reverts commit 56a50667cb. Mux
handling is not sufficiently implemented. It needs more time.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
2025-02-05 14:22:12 +01:00
Wolfram Sang
c4d3dfd8cc Revert "i2c: Replace list-based mechanism for handling userspace-created clients"
This reverts commit 3cfe39b3a8. Mux
handling is not sufficiently implemented. It needs more time.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
2025-02-05 14:21:36 +01:00
Paolo Bonzini
6f61269495 KVM: remove kvm_arch_post_init_vm
The only statement in a kvm_arch_post_init_vm implementation
can be moved into the x86 kvm_arch_init_vm.  Do so and remove all
traces from architecture-independent code.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-04 11:27:45 -05:00
Dr. David Alan Gilbert
42e128c9d5 tty/ldsem: Remove unused ldsem_down_write_trylock
ldsem_down_write_trylock() was added in 2013 by
commit 4898e640ca ("tty: Add timed, writer-prioritized rw semaphore")
but hasn't been used.

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Jiri Slaby <jirislaby@kernel.org>
Link: https://lore.kernel.org/r/20250122012559.441006-1-linux@treblig.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-02-04 14:38:42 +01:00
Ard Biesheuvel
bbc4578537 efi: Use BIT_ULL() constants for memory attributes
For legibility, use the existing BIT_ULL() to generate the u64 type EFI
memory attribute macros.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2025-02-04 14:08:22 +01:00
Ard Biesheuvel
ba69e0750b efi: Avoid cold plugged memory for placing the kernel
UEFI 2.11 introduced EFI_MEMORY_HOT_PLUGGABLE to annotate system memory
regions that are 'cold plugged' at boot, i.e., hot pluggable memory that
is available from early boot, and described as system RAM by the
firmware.

Existing loaders and EFI applications running in the boot context will
happily use this memory for allocating data structures that cannot be
freed or moved at runtime, and this prevents the memory from being
unplugged. Going forward, the new EFI_MEMORY_HOT_PLUGGABLE attribute
should be tested, and memory annotated as such should be avoided for
such allocations.

In the EFI stub, there are a couple of occurrences where, instead of the
high-level AllocatePages() UEFI boot service, a low-level code sequence
is used that traverses the EFI memory map and carves out the requested
number of pages from a free region. This is needed, e.g., for allocating
as low as possible, or for allocating pages at random.

While AllocatePages() should presumably avoid special purpose memory and
cold plugged regions, this manual approach needs to incorporate this
logic itself, in order to prevent the kernel itself from ending up in a
hot unpluggable region, preventing it from being unplugged.

So add the EFI_MEMORY_HOTPLUGGABLE macro definition, and check for it
where appropriate.

Cc: stable@vger.kernel.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2025-02-04 14:08:22 +01:00
Paolo Abeni
d3ed6dee73 net: harmonize tstats and dstats
After the blamed commits below, some UDP tunnel use dstats for
accounting. On the xmit path, all the UDP-base tunnels ends up
using iptunnel_xmit_stats() for stats accounting, and the latter
assumes the relevant (tunnel) network device uses tstats.

The end result is some 'funny' stat report for the mentioned UDP
tunnel, e.g. when no packet is actually dropped and a bunch of
packets are transmitted:

gnv2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue \
		state UNKNOWN mode DEFAULT group default qlen 1000
    link/ether ee:7d:09:87:90:ea brd ff:ff:ff:ff:ff:ff
    RX:  bytes packets errors dropped  missed   mcast
         14916      23      0      15       0       0
    TX:  bytes packets errors dropped carrier collsns
             0    1566      0       0       0       0

Address the issue ensuring the same binary layout for the overlapping
fields of dstats and tstats. While this solution is a bit hackish, is
smaller and with no performance pitfall compared to other alternatives
i.e. supporting both dstat and tstat in iptunnel_xmit_stats() or
reverting the blamed commit.

With time we should possibly move all the IP-based tunnel (and virtual
devices) to dstats.

Fixes: c77200c074 ("bareudp: Handle stats using NETDEV_PCPU_STAT_DSTATS.")
Fixes: 6fa6de3022 ("geneve: Handle stats using NETDEV_PCPU_STAT_DSTATS.")
Fixes: be226352e8 ("vxlan: Handle stats using NETDEV_PCPU_STAT_DSTATS.")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Link: https://patch.msgid.link/2e1c444cf0f63ae472baff29862c4c869be17031.1738432804.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-03 18:39:59 -08:00
Linus Torvalds
f286757b64 Merge tag 'timers-urgent-2025-02-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fixes from Thomas Gleixner:

 - Properly cast the input to secs_to_jiffies() to unsigned long as
   otherwise the result uses the data type of the input variable, which
   causes result range checks to fail if the input data type is signed
   and smaller than unsigned long.

 - Handle late armed hrtimers gracefully on CPU hotplug

   There are legitimate cases where a hrtimer is (re)armed on an
   outgoing CPU after the timers have been migrated away. This triggers
   warnings and caused people to implement horrible workarounds in RCU.
   But those workarounds are incomplete and do not cover e.g. the
   scheduler hrtimers.

   Stop this by force moving timer which are enqueued on the current CPU
   after timer migration to be queued on a remote online CPU.

   This allows to undo the workarounds in a seperate step.

 - Demote a warning level printk() to info level in the clocksource
   watchdog code as there is no point to emit a warning level message
   for a purely informational message.

 - Mark a helper function __always_inline and move it into the existing
   #ifdef block to avoid 'unused function' warnings from CLANG

* tag 'timers-urgent-2025-02-03' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  jiffies: Cast to unsigned long in secs_to_jiffies() conversion
  clocksource: Use pr_info() for "Checking clocksource synchronization" message
  hrtimers: Force migrate away hrtimers queued after CPUHP_AP_HRTIMERS_DYING
  hrtimers: Mark is_migration_base() with __always_inline
2025-02-03 09:10:56 -08:00
Shakeel Butt
b69bb476de cgroup: fix race between fork and cgroup.kill
Tejun reported the following race between fork() and cgroup.kill at [1].

Tejun:
  I was looking at cgroup.kill implementation and wondering whether there
  could be a race window. So, __cgroup_kill() does the following:

   k1. Set CGRP_KILL.
   k2. Iterate tasks and deliver SIGKILL.
   k3. Clear CGRP_KILL.

  The copy_process() does the following:

   c1. Copy a bunch of stuff.
   c2. Grab siglock.
   c3. Check fatal_signal_pending().
   c4. Commit to forking.
   c5. Release siglock.
   c6. Call cgroup_post_fork() which puts the task on the css_set and tests
       CGRP_KILL.

  The intention seems to be that either a forking task gets SIGKILL and
  terminates on c3 or it sees CGRP_KILL on c6 and kills the child. However, I
  don't see what guarantees that k3 can't happen before c6. ie. After a
  forking task passes c5, k2 can take place and then before the forking task
  reaches c6, k3 can happen. Then, nobody would send SIGKILL to the child.
  What am I missing?

This is indeed a race. One way to fix this race is by taking
cgroup_threadgroup_rwsem in write mode in __cgroup_kill() as the fork()
side takes cgroup_threadgroup_rwsem in read mode from cgroup_can_fork()
to cgroup_post_fork(). However that would be heavy handed as this adds
one more potential stall scenario for cgroup.kill which is usually
called under extreme situation like memory pressure.

To fix this race, let's maintain a sequence number per cgroup which gets
incremented on __cgroup_kill() call. On the fork() side, the
cgroup_can_fork() will cache the sequence number locally and recheck it
against the cgroup's sequence number at cgroup_post_fork() site. If the
sequence numbers mismatch, it means __cgroup_kill() can been called and
we should send SIGKILL to the newly created task.

Reported-by: Tejun Heo <tj@kernel.org>
Closes: https://lore.kernel.org/all/Z5QHE2Qn-QZ6M-KW@slm.duckdns.org/ [1]
Fixes: 661ee62809 ("cgroup: introduce cgroup.kill")
Cc: stable@vger.kernel.org # v5.14+
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2025-02-02 06:54:51 -10:00
Linus Torvalds
a86bf2283d Merge tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc vfs cleanups from Al Viro:
 "Two unrelated patches - one is a removal of long-obsolete include in
  overlayfs (it used to need fs/internal.h, but the extern it wanted has
  been moved back to include/linux/namei.h) and another introduces
  convenience helper constructing struct qstr by a NUL-terminated
  string"

* tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  add a string-to-qstr constructor
  fs/overlayfs/namei.c: get rid of include ../internal.h
2025-02-01 15:07:56 -08:00
Linus Torvalds
03cc3579bc Merge tag 'mm-hotfixes-stable-2025-02-01-03-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
 "21 hotfixes. 8 are cc:stable and the remainder address post-6.13
  issues. 13 are for MM and 8 are for non-MM.

  All are singletons, please see the changelogs for details"

* tag 'mm-hotfixes-stable-2025-02-01-03-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (21 commits)
  MAINTAINERS: include linux-mm for xarray maintenance
  revert "xarray: port tests to kunit"
  MAINTAINERS: add lib/test_xarray.c
  mailmap, MAINTAINERS, docs: update Carlos's email address
  mm/hugetlb: fix hugepage allocation for interleaved memory nodes
  mm: gup: fix infinite loop within __get_longterm_locked
  mm, swap: fix reclaim offset calculation error during allocation
  .mailmap: update email address for Christopher Obbard
  kfence: skip __GFP_THISNODE allocations on NUMA systems
  nilfs2: fix possible int overflows in nilfs_fiemap()
  mm: compaction: use the proper flag to determine watermarks
  kernel: be more careful about dup_mmap() failures and uprobe registering
  mm/fake-numa: handle cases with no SRAT info
  mm: kmemleak: fix upper boundary check for physical address objects
  mailmap: add an entry for Hamza Mahfooz
  MAINTAINERS: mailmap: update Yosry Ahmed's email address
  scripts/gdb: fix aarch64 userspace detection in get_current_task
  mm/vmscan: accumulate nr_demoted for accurate demotion statistics
  ocfs2: fix incorrect CPU endianness conversion causing mount failure
  mm/zsmalloc: add __maybe_unused attribute for is_first_zpdesc()
  ...
2025-02-01 09:49:20 -08:00
liuye
1c7b17cf05 mm/vmscan: fix hard LOCKUP in function isolate_lru_folios
This fixes the following hard lockup in isolate_lru_folios() during memory
reclaim.  If the LRU mostly contains ineligible folios this may trigger
watchdog.

watchdog: Watchdog detected hard LOCKUP on cpu 173
RIP: 0010:native_queued_spin_lock_slowpath+0x255/0x2a0
Call Trace:
	_raw_spin_lock_irqsave+0x31/0x40
	folio_lruvec_lock_irqsave+0x5f/0x90
	folio_batch_move_lru+0x91/0x150
	lru_add_drain_per_cpu+0x1c/0x40
	process_one_work+0x17d/0x350
	worker_thread+0x27b/0x3a0
	kthread+0xe8/0x120
	ret_from_fork+0x34/0x50
	ret_from_fork_asm+0x1b/0x30

lruvec->lru_lock owner:

PID: 2865     TASK: ffff888139214d40  CPU: 40   COMMAND: "kswapd0"
 #0 [fffffe0000945e60] crash_nmi_callback at ffffffffa567a555
 #1 [fffffe0000945e68] nmi_handle at ffffffffa563b171
 #2 [fffffe0000945eb0] default_do_nmi at ffffffffa6575920
 #3 [fffffe0000945ed0] exc_nmi at ffffffffa6575af4
 #4 [fffffe0000945ef0] end_repeat_nmi at ffffffffa6601dde
    [exception RIP: isolate_lru_folios+403]
    RIP: ffffffffa597df53  RSP: ffffc90006fb7c28  RFLAGS: 00000002
    RAX: 0000000000000001  RBX: ffffc90006fb7c60  RCX: ffffea04a2196f88
    RDX: ffffc90006fb7c60  RSI: ffffc90006fb7c60  RDI: ffffea04a2197048
    RBP: ffff88812cbd3010   R8: ffffea04a2197008   R9: 0000000000000001
    R10: 0000000000000000  R11: 0000000000000001  R12: ffffea04a2197008
    R13: ffffea04a2197048  R14: ffffc90006fb7de8  R15: 0000000003e3e937
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018
    <NMI exception stack>
 #5 [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53
 #6 [ffffc90006fb7cf8] shrink_active_list at ffffffffa597f788
 #7 [ffffc90006fb7da8] balance_pgdat at ffffffffa5986db0
 #8 [ffffc90006fb7ec0] kswapd at ffffffffa5987354
 #9 [ffffc90006fb7ef8] kthread at ffffffffa5748238
crash>

Scenario:
User processe are requesting a large amount of memory and keep page active.
Then a module continuously requests memory from ZONE_DMA32 area.
Memory reclaim will be triggered due to ZONE_DMA32 watermark alarm reached.
However pages in the LRU(active_anon) list are mostly from
the ZONE_NORMAL area.

Reproduce:
Terminal 1: Construct to continuously increase pages active(anon).
mkdir /tmp/memory
mount -t tmpfs -o size=1024000M tmpfs /tmp/memory
dd if=/dev/zero of=/tmp/memory/block bs=4M
tail /tmp/memory/block

Terminal 2:
vmstat -a 1
active will increase.
procs ---memory--- ---swap-- ---io---- -system-- ---cpu--- ...
 r  b   swpd   free  inact active   si   so    bi    bo
 1  0   0 1445623076 45898836 83646008    0    0     0
 1  0   0 1445623076 43450228 86094616    0    0     0
 1  0   0 1445623076 41003480 88541364    0    0     0
 1  0   0 1445623076 38557088 90987756    0    0     0
 1  0   0 1445623076 36109688 93435156    0    0     0
 1  0   0 1445619552 33663256 95881632    0    0     0
 1  0   0 1445619804 31217140 98327792    0    0     0
 1  0   0 1445619804 28769988 100774944    0    0     0
 1  0   0 1445619804 26322348 103222584    0    0     0
 1  0   0 1445619804 23875592 105669340    0    0     0

cat /proc/meminfo | head
Active(anon) increase.
MemTotal:       1579941036 kB
MemFree:        1445618500 kB
MemAvailable:   1453013224 kB
Buffers:            6516 kB
Cached:         128653956 kB
SwapCached:            0 kB
Active:         118110812 kB
Inactive:       11436620 kB
Active(anon):   115345744 kB
Inactive(anon):   945292 kB

When the Active(anon) is 115345744 kB, insmod module triggers
the ZONE_DMA32 watermark.

perf record -e vmscan:mm_vmscan_lru_isolate -aR
perf script
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=2
nr_skipped=2 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=0
nr_skipped=0 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=28835844
nr_skipped=28835844 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=1 nr_requested=32 nr_scanned=28835844
nr_skipped=28835844 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=29
nr_skipped=29 nr_taken=0 lru=active_anon
isolate_mode=0 classzone=1 order=0 nr_requested=32 nr_scanned=0
nr_skipped=0 nr_taken=0 lru=active_anon

See nr_scanned=28835844.
28835844 * 4k = 115343376KB approximately equal to 115345744 kB.

If increase Active(anon) to 1000G then insmod module triggers
the ZONE_DMA32 watermark. hard lockup will occur.

In my device nr_scanned = 0000000003e3e937 when hard lockup.
Convert to memory size 0x0000000003e3e937 * 4KB = 261072092 KB.

   [ffffc90006fb7c28] isolate_lru_folios at ffffffffa597df53
    ffffc90006fb7c30: 0000000000000020 0000000000000000
    ffffc90006fb7c40: ffffc90006fb7d40 ffff88812cbd3000
    ffffc90006fb7c50: ffffc90006fb7d30 0000000106fb7de8
    ffffc90006fb7c60: ffffea04a2197008 ffffea0006ed4a48
    ffffc90006fb7c70: 0000000000000000 0000000000000000
    ffffc90006fb7c80: 0000000000000000 0000000000000000
    ffffc90006fb7c90: 0000000000000000 0000000000000000
    ffffc90006fb7ca0: 0000000000000000 0000000003e3e937
    ffffc90006fb7cb0: 0000000000000000 0000000000000000
    ffffc90006fb7cc0: 8d7c0b56b7874b00 ffff88812cbd3000

About the Fixes:
Why did it take eight years to be discovered?

The problem requires the following conditions to occur:
1. The device memory should be large enough.
2. Pages in the LRU(active_anon) list are mostly from the ZONE_NORMAL area.
3. The memory in ZONE_DMA32 needs to reach the watermark.

If the memory is not large enough, or if the usage design of ZONE_DMA32
area memory is reasonable, this problem is difficult to detect.

notes:
The problem is most likely to occur in ZONE_DMA32 and ZONE_NORMAL,
but other suitable scenarios may also trigger the problem.

Link: https://lkml.kernel.org/r/20241119060842.274072-1-liuye@kylinos.cn
Fixes: b2e18757f2 ("mm, vmscan: begin reclaiming pages on a per-node basis")
Signed-off-by: liuye <liuye@kylinos.cn>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Yang Shi <yang@os.amperecomputing.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-02-01 03:53:23 -08:00
Linus Torvalds
1b5f3c51fb Merge tag 'riscv-for-linus-6.14-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V updates from Palmer Dabbelt:

 - The PH1520 pinctrl and dwmac drivers are enabeled in defconfig

 - A redundant AQRL barrier has been removed from the futex cmpxchg
   implementation

 - Support for the T-Head vector extensions, which includes exposing
   these extensions to userspace on systems that implement them

 - Some more page table information is now printed on die() and systems
   that cause PA overflows

* tag 'riscv-for-linus-6.14-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  riscv: add a warning when physical memory address overflows
  riscv/mm/fault: add show_pte() before die()
  riscv: Add ghostwrite vulnerability
  selftests: riscv: Support xtheadvector in vector tests
  selftests: riscv: Fix vector tests
  riscv: hwprobe: Document thead vendor extensions and xtheadvector extension
  riscv: hwprobe: Add thead vendor extension probing
  riscv: vector: Support xtheadvector save/restore
  riscv: Add xtheadvector instruction definitions
  riscv: csr: Add CSR encodings for CSR_VXRM/CSR_VXSAT
  RISC-V: define the elements of the VCSR vector CSR
  riscv: vector: Use vlenb from DT for thead
  riscv: Add thead and xtheadvector as a vendor extension
  riscv: dts: allwinner: Add xtheadvector to the D1/D1s devicetree
  dt-bindings: cpus: add a thead vlen register length property
  dt-bindings: riscv: Add xtheadvector ISA extension description
  RISC-V: Mark riscv_v_init() as __init
  riscv: defconfig: drop RT_GROUP_SCHED=y
  riscv/futex: Optimize atomic cmpxchg
  riscv: defconfig: enable pinctrl and dwmac support for TH1520
2025-01-31 15:13:25 -08:00
Linus Torvalds
fd8c09ad0d Merge tag 'kbuild-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild
Pull Kbuild updates from Masahiro Yamada:

 - Support multiple hook locations for maint scripts of Debian package

 - Remove 'cpio' from the build tool requirement

 - Introduce gendwarfksyms tool, which computes CRCs for export symbols
   based on the DWARF information

 - Support CONFIG_MODVERSIONS for Rust

 - Resolve all conflicts in the genksyms parser

 - Fix several syntax errors in genksyms

* tag 'kbuild-v6.14' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (64 commits)
  kbuild: fix Clang LTO with CONFIG_OBJTOOL=n
  kbuild: Strip runtime const RELA sections correctly
  kconfig: fix memory leak in sym_warn_unmet_dep()
  kconfig: fix file name in warnings when loading KCONFIG_DEFCONFIG_LIST
  genksyms: fix syntax error for attribute before init-declarator
  genksyms: fix syntax error for builtin (u)int*x*_t types
  genksyms: fix syntax error for attribute after 'union'
  genksyms: fix syntax error for attribute after 'struct'
  genksyms: fix syntax error for attribute after abstact_declarator
  genksyms: fix syntax error for attribute before nested_declarator
  genksyms: fix syntax error for attribute before abstract_declarator
  genksyms: decouple ATTRIBUTE_PHRASE from type-qualifier
  genksyms: record attributes consistently for init-declarator
  genksyms: restrict direct-declarator to take one parameter-type-list
  genksyms: restrict direct-abstract-declarator to take one parameter-type-list
  genksyms: remove Makefile hack
  genksyms: fix last 3 shift/reduce conflicts
  genksyms: fix 6 shift/reduce conflicts and 5 reduce/reduce conflicts
  genksyms: reduce type_qualifier directly to decl_specifier
  genksyms: rename cvar_qualifier to type_qualifier
  ...
2025-01-31 12:07:07 -08:00
Linus Torvalds
9755ffd989 Merge tag 'block-6.14-20250131' of git://git.kernel.dk/linux
Pull more block updates from Jens Axboe:

 - MD pull request via Song:
      - Fix a md-cluster regression introduced

 - More sysfs race fixes

 - Mark anything inside queue freezing as not being able to do IO for
   memory allocations

 - Fix for a regression introduced in loop in this merge window

 - Fix for a regression in queue mapping setups introduced in this merge
   window

 - Fix for the block dio fops attempting an iov_iter revert upton
   getting -EIOCBQUEUED on the read side. This one is going to stable as
   well

* tag 'block-6.14-20250131' of git://git.kernel.dk/linux:
  block: force noio scope in blk_mq_freeze_queue
  block: fix nr_hw_queue update racing with disk addition/removal
  block: get rid of request queue ->sysfs_dir_lock
  loop: don't clear LO_FLAGS_PARTSCAN on LOOP_SET_STATUS{,64}
  md/md-bitmap: Synchronize bitmap_get_stats() with bitmap lifetime
  blk-mq: create correct map for fallback case
  block: don't revert iter for -EIOCBQUEUED
2025-01-31 11:49:30 -08:00
Linus Torvalds
c82da38b28 Merge tag 'io_uring-6.14-20250131' of git://git.kernel.dk/linux
Pull more io_uring updates from Jens Axboe:

 - Series cleaning up the alloc cache changes from this merge window,
   and then another series on top making it better yet.

   This also solves an issue with KASAN_EXTRA_INFO, by making io_uring
   resilient to KASAN using parts of the freed struct for storage

 - Cleanups and simplications to buffer cloning and io resource node
   management

 - Fix an issue introduced in this merge window where READ/WRITE_ONCE
   was used on an atomic_t, which made some archs complain

 - Fix for an errant connect retry when the socket has been shut down

 - Fix for multishot and provided buffers

* tag 'io_uring-6.14-20250131' of git://git.kernel.dk/linux:
  io_uring/net: don't retry connect operation on EPOLLERR
  io_uring/rw: simplify io_rw_recycle()
  io_uring: remove !KASAN guards from cache free
  io_uring/net: extract io_send_select_buffer()
  io_uring/net: clean io_msg_copy_hdr()
  io_uring/net: make io_net_vec_assign() return void
  io_uring: add alloc_cache.c
  io_uring: dont ifdef io_alloc_cache_kasan()
  io_uring: include all deps for alloc_cache.h
  io_uring: fix multishots with selected buffers
  io_uring/register: use atomic_read/write for sq_flags migration
  io_uring/alloc_cache: get rid of _nocache() helper
  io_uring: get rid of alloc cache init_once handling
  io_uring/uring_cmd: cleanup struct io_uring_cmd_data layout
  io_uring/uring_cmd: use cached cmd_op in io_uring_cmd_sock()
  io_uring/msg_ring: don't leave potentially dangling ->tctx pointer
  io_uring/rsrc: Move lockdep assert from io_free_rsrc_node() to caller
  io_uring/rsrc: remove unused parameter ctx for io_rsrc_node_alloc()
  io_uring: clean up io_uring_register_get_file()
  io_uring/rsrc: Simplify buffer cloning by locking both rings
2025-01-31 11:29:23 -08:00