Commit Graph
50900 Commits
Author SHA1 Message Date
Linus Torvalds 68010e7b3d Merge tag 'trace-v7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing fixes from Steven Rostedt:

 - Fix possible dereference of uninitialized pointer

   When validating the persistent ring buffer on boot up, if the first
   validation fails, a reference to "head_page" is performed in the
   error path, but it skips over the initialization of that variable.
   Move the initialization before the first validation check.

 - Fix use of event length in validation of persistent ring buffer

   On boot up, the persistent ring buffer is checked to see if it is
   valid by several methods. One being to walk all the events in the
   memory location to make sure they are all valid. The length of the
   event is used to move to the next event. This length is determined by
   the data in the buffer. If that length is corrupted, it could
   possibly make the next event to check located at a bad memory
   location.

   Validate the length field of the event when doing the event walk.

 - Fix function graph on archs that do not support use of ftrace_ops

   When an architecture defines HAVE_DYNAMIC_FTRACE_WITH_ARGS, it means
   that its function graph tracer uses the ftrace_ops of the function
   tracer to call its callbacks. This allows a single registered
   callback to be called directly instead of checking the callback's
   meta data's hash entries against the function being traced.

   For architectures that do not support this feature, it must always
   call the loop function that tests each registered callback (even if
   there's only one). The loop function tests each callback's meta data
   against its hash of functions and will call its callback if the
   function being traced is in its hash map.

   The issue was that there was no check against this and the direct
   function was being called even if the architecture didn't support it.
   This meant that if function tracing was enabled at the same time as a
   callback was registered with the function graph tracer, its callback
   would be called for every function that the function tracer also
   traced, even if the callback's meta data only wanted to be called
   back for a small subset of functions.

   Prevent the direct calling for those architectures that do not
   support it.

 - Fix references to trace_event_file for hist files

   The hist files used event_file_data() to get a reference to the
   associated trace_event_file the histogram was attached to. This would
   return a pointer even if the trace_event_file is about to be freed
   (via RCU). Instead it should use the event_file_file() helper that
   returns NULL if the trace_event_file is marked to be freed so that no
   new references are added to it.

 - Wake up hist poll readers when an event is being freed

   When polling on a hist file, the task is only awoken when a hist
   trigger is triggered. This means that if an event is being freed
   while there's a task waiting on its hist file, it will need to wait
   until the hist trigger occurs to wake it up and allow the freeing to
   happen. Note, the event will not be completely freed until all
   references are removed, and a hist poller keeps a reference. But it
   should still be woken when the event is being freed.

* tag 'trace-v7.0-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  tracing: Wake up poll waiters for hist files when removing an event
  tracing: Fix checking of freed trace_event_file for hist files
  fgraph: Do not call handlers direct when not using ftrace_ops
  tracing: ring-buffer: Fix to check event length before using
  ring-buffer: Fix possible dereference of uninitialized pointer
2026-02-20 15:05:26 -08:00
Petr Pavlu 9678e53179 tracing: Wake up poll waiters for hist files when removing an event
The event_hist_poll() function attempts to verify whether an event file is
being removed, but this check may not occur or could be unnecessarily
delayed. This happens because hist_poll_wakeup() is currently invoked only
from event_hist_trigger() when a hist command is triggered. If the event
file is being removed, no associated hist command will be triggered and a
waiter will be woken up only after an unrelated hist command is triggered.

Fix the issue by adding a call to hist_poll_wakeup() in
remove_event_file_dir() after setting the EVENT_FILE_FL_FREED flag. This
ensures that a task polling on a hist file is woken up and receives
EPOLLERR.

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://patch.msgid.link/20260219162737.314231-3-petr.pavlu@suse.com
Fixes: 1bd13edbbe ("tracing/hist: Add poll(POLLIN) support on hist file")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-19 15:25:11 -05:00
Petr Pavlu f0a0da1f90 tracing: Fix checking of freed trace_event_file for hist files
The event_hist_open() and event_hist_poll() functions currently retrieve
a trace_event_file pointer from a file struct by invoking
event_file_data(), which simply returns file->f_inode->i_private. The
functions then check if the pointer is NULL to determine whether the event
is still valid. This approach is flawed because i_private is assigned when
an eventfs inode is allocated and remains set throughout its lifetime.
Instead, the code should call event_file_file(), which checks for
EVENT_FILE_FL_FREED. Using the incorrect access function may result in the
code potentially opening a hist file for an event that is being removed or
becoming stuck while polling on this file.

Correct the access method to event_file_file() in both functions.

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Link: https://patch.msgid.link/20260219162737.314231-2-petr.pavlu@suse.com
Fixes: 1bd13edbbe ("tracing/hist: Add poll(POLLIN) support on hist file")
Signed-off-by: Petr Pavlu <petr.pavlu@suse.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-19 15:23:49 -05:00
Steven Rostedt f4ff9f646a fgraph: Do not call handlers direct when not using ftrace_ops
The function graph tracer was modified to us the ftrace_ops of the
function tracer. This simplified the code as well as allowed more features
of the function graph tracer.

Not all architectures were converted over as it required the
implementation of HAVE_DYNAMIC_FTRACE_WITH_ARGS to implement. For those
architectures, it still did it the old way where the function graph tracer
handle was called by the function tracer trampoline. The handler then had
to check the hash to see if the registered handlers wanted to be called by
that function or not.

In order to speed up the function graph tracer that used ftrace_ops, if
only one callback was registered with function graph, it would call its
function directly via a static call.

Now, if the architecture does not support the use of using ftrace_ops and
still has the ftrace function trampoline calling the function graph
handler, then by doing a direct call it removes the check against the
handler's hash (list of functions it wants callbacks to), and it may call
that handler for functions that the handler did not request calls for.

On 32bit x86, which does not support the ftrace_ops use with function
graph tracer, it shows the issue:

 ~# trace-cmd start -p function -l schedule
 ~# trace-cmd show
 # tracer: function_graph
 #
 # CPU  DURATION                  FUNCTION CALLS
 # |     |   |                     |   |   |   |
  2) * 11898.94 us |  schedule();
  3) # 1783.041 us |  schedule();
  1)               |  schedule() {
  ------------------------------------------
  1)   bash-8369    =>  kworker-7669
  ------------------------------------------
  1)               |        schedule() {
  ------------------------------------------
  1)  kworker-7669  =>   bash-8369
  ------------------------------------------
  1) + 97.004 us   |  }
  1)               |  schedule() {
 [..]

Now by starting the function tracer is another instance:

 ~# trace-cmd start -B foo -p function

This causes the function graph tracer to trace all functions (because the
function trace calls the function graph tracer for each on, and the
function graph trace is doing a direct call):

 ~# trace-cmd show
 # tracer: function_graph
 #
 # CPU  DURATION                  FUNCTION CALLS
 # |     |   |                     |   |   |   |
  1)   1.669 us    |          } /* preempt_count_sub */
  1) + 10.443 us   |        } /* _raw_spin_unlock_irqrestore */
  1)               |        tick_program_event() {
  1)               |          clockevents_program_event() {
  1)   1.044 us    |            ktime_get();
  1)   6.481 us    |            lapic_next_event();
  1) + 10.114 us   |          }
  1) + 11.790 us   |        }
  1) ! 181.223 us  |      } /* hrtimer_interrupt */
  1) ! 184.624 us  |    } /* __sysvec_apic_timer_interrupt */
  1)               |    irq_exit_rcu() {
  1)   0.678 us    |      preempt_count_sub();

When it should still only be tracing the schedule() function.

To fix this, add a macro FGRAPH_NO_DIRECT to be set to 0 when the
architecture does not support function graph use of ftrace_ops, and set to
1 otherwise. Then use this macro to know to allow function graph tracer to
call the handlers directly or not.

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Link: https://patch.msgid.link/20260218104244.5f14dade@gandalf.local.home
Fixes: cc60ee813b ("function_graph: Use static_call and branch to optimize entry function")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-19 15:21:22 -05:00
Masami Hiramatsu (Google) 912b0ee248 tracing: ring-buffer: Fix to check event length before using
Check the event length before adding it for accessing next index in
rb_read_data_buffer(). Since this function is used for validating
possibly broken ring buffers, the length of the event could be broken.
In that case, the new event (e + len) can point a wrong address.
To avoid invalid memory access at boot, check whether the length of
each event is in the possible range before using it.

Cc: stable@vger.kernel.org
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Fixes: 5f3b6e839f ("ring-buffer: Validate boot range memory events")
Link: https://patch.msgid.link/177123421541.142205.9414352170164678966.stgit@devnote2
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-19 15:21:12 -05:00
Daniil Dulov f154777940 ring-buffer: Fix possible dereference of uninitialized pointer
There is a pointer head_page in rb_meta_validate_events() which is not
initialized at the beginning of a function. This pointer can be dereferenced
if there is a failure during reader page validation. In this case the control
is passed to "invalid" label where the pointer is dereferenced in a loop.

To fix the issue initialize orig_head and head_page before calling
rb_validate_buffer.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Cc: stable@vger.kernel.org
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Link: https://patch.msgid.link/20260213100130.2013839-1-d.dulov@aladdin.ru
Closes: https://lore.kernel.org/r/202406130130.JtTGRf7W-lkp@intel.com/
Fixes: 5f3b6e839f ("ring-buffer: Validate boot range memory events")
Signed-off-by: Daniil Dulov <d.dulov@aladdin.ru>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-19 15:20:41 -05:00
Linus Torvalds 4f13d0dabc Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Pull bpf fixes from Alexei Starovoitov:

 - Fix invalid write loop logic in libbpf's bpf_linker__add_buf() (Amery
   Hung)

 - Fix a potential use-after-free of BTF object (Anton Protopopov)

 - Add feature detection to libbpf and avoid moving arena global
   variables on older kernels (Emil Tsalapatis)

 - Remove extern declaration of bpf_stream_vprintk() from libbpf headers
   (Ihor Solodrai)

 - Fix truncated netlink dumps in bpftool (Jakub Kicinski)

 - Fix map_kptr grace period wait in bpf selftests (Kumar Kartikeya
   Dwivedi)

 - Remove hexdump dependency while building bpf selftests (Matthieu
   Baerts)

 - Complete fsession support in BPF trampolines on riscv (Menglong Dong)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Remove hexdump dependency
  libbpf: Remove extern declaration of bpf_stream_vprintk()
  selftests/bpf: Use vmlinux.h in test_xdp_meta
  bpftool: Fix truncated netlink dumps
  libbpf: Delay feature gate check until object prepare time
  libbpf: Do not use PROG_TYPE_TRACEPOINT program for feature gating
  bpf: Add a map/btf from a fd array more consistently
  selftests/bpf: Fix map_kptr grace period wait
  selftests/bpf: enable fsession_test on riscv64
  selftests/bpf: Adjust selftest due to function rename
  bpf, riscv: add fsession support for trampolines
  bpf: Fix a potential use-after-free of BTF object
  bpf, riscv: introduce emit_store_stack_imm64() for trampoline
  libbpf: Fix invalid write loop logic in bpf_linker__add_buf()
  libbpf: Add gating for arena globals relocation feature
2026-02-19 10:36:54 -08:00
Linus Torvalds 2b7a25df82 Merge tag 'mm-nonmm-stable-2026-02-18-19-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more non-MM updates from Andrew Morton:

 - "two fixes in kho_populate()" fixes a couple of not-major issues in
   the kexec handover code (Ran Xiaokai)

 - misc singletons

* tag 'mm-nonmm-stable-2026-02-18-19-56' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  lib/group_cpus: handle const qualifier from clusters allocation type
  kho: remove unnecessary WARN_ON(err) in kho_populate()
  kho: fix missing early_memunmap() call in kho_populate()
  scripts/gdb: implement x86_page_ops in mm.py
  objpool: fix the overestimation of object pooling metadata size
  selftests/memfd: use IPC semaphore instead of SIGSTOP/SIGCONT
  delayacct: fix build regression on accounting tool
2026-02-18 21:40:16 -08:00
Linus Torvalds eeccf287a2 Merge tag 'mm-stable-2026-02-18-19-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more MM  updates from Andrew Morton:

 - "mm/vmscan: fix demotion targets checks in reclaim/demotion" fixes a
   couple of issues in the demotion code - pages were failed demotion
   and were finding themselves demoted into disallowed nodes (Bing Jiao)

 - "Remove XA_ZERO from error recovery of dup_mmap()" fixes a rare
   mapledtree race and performs a number of cleanups (Liam Howlett)

 - "mm: add bitmap VMA flag helpers and convert all mmap_prepare to use
   them" implements a lot of cleanups following on from the conversion
   of the VMA flags into a bitmap (Lorenzo Stoakes)

 - "support batch checking of references and unmapping for large folios"
   implements batching to greatly improve the performance of reclaiming
   clean file-backed large folios (Baolin Wang)

 - "selftests/mm: add memory failure selftests" does as claimed (Miaohe
   Lin)

* tag 'mm-stable-2026-02-18-19-48' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (36 commits)
  mm/page_alloc: clear page->private in free_pages_prepare()
  selftests/mm: add memory failure dirty pagecache test
  selftests/mm: add memory failure clean pagecache test
  selftests/mm: add memory failure anonymous page test
  mm: rmap: support batched unmapping for file large folios
  arm64: mm: implement the architecture-specific clear_flush_young_ptes()
  arm64: mm: support batch clearing of the young flag for large folios
  arm64: mm: factor out the address and ptep alignment into a new helper
  mm: rmap: support batched checks of the references for large folios
  tools/testing/vma: add VMA userland tests for VMA flag functions
  tools/testing/vma: separate out vma_internal.h into logical headers
  tools/testing/vma: separate VMA userland tests into separate files
  mm: make vm_area_desc utilise vma_flags_t only
  mm: update all remaining mmap_prepare users to use vma_flags_t
  mm: update shmem_[kernel]_file_*() functions to use vma_flags_t
  mm: update secretmem to use VMA flags on mmap_prepare
  mm: update hugetlbfs to use VMA flags on mmap_prepare
  mm: add basic VMA flag operation helper functions
  tools: bitmap: add missing bitmap_[subset(), andnot()]
  mm: add mk_vma_flags() bitmap flag macro helper
  ...
2026-02-18 20:50:32 -08:00
Linus Torvalds 23b0f90ba8 Merge tag 'sysctl-7.00-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl
Pull sysctl updates from Joel Granados:

 - Remove macros from proc handler converters

   Replace the proc converter macros with "regular" functions. Though it
   is more verbose than the macro version, it helps when debugging and
   better aligns with coding-style.rst.

 - General cleanup

   Remove superfluous ctl_table forward declarations. Const qualify the
   memory_allocation_profiling_sysctl and loadpin_sysctl_table arrays.
   Add missing kernel doc to proc_dointvec_conv.

 - Testing

   This series was run through sysctl selftests/kunit test suite in
   x86_64. And went into linux-next after rc4, giving it a good 3 weeks
   of testing

* tag 'sysctl-7.00-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
  sysctl: replace SYSCTL_INT_CONV_CUSTOM macro with functions
  sysctl: Replace unidirectional INT converter macros with functions
  sysctl: Add kernel doc to proc_douintvec_conv
  sysctl: Replace UINT converter macros with functions
  sysctl: Add CONFIG_PROC_SYSCTL guards for converter macros
  sysctl: clarify proc_douintvec_minmax doc
  sysctl: Return -ENOSYS from proc_douintvec_conv when CONFIG_PROC_SYSCTL=n
  sysctl: Remove unused ctl_table forward declarations
  loadpin: Implement custom proc_handler for enforce
  alloc_tag: move memory_allocation_profiling_sysctls into .rodata
  sysctl: Add missing kernel-doc for proc_dointvec_conv
2026-02-18 10:45:36 -08:00
Linus Torvalds d295082ea6 Merge tag 'spdx-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx
Pull SPDX updates from Greg KH:
 "Here are two small changes that add some missing SPDX license lines to
  some core kernel files. These are:

   - adding SPDX license lines to kdb files

   - adding SPDX license lines to the remaining kernel/ files

  Both of these have been in linux-next for a while with no reported
  issues"

* tag 'spdx-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx:
  kernel: debug: Add SPDX license ids to kdb files
  kernel: add SPDX-License-Identifier lines
2026-02-17 09:46:03 -08:00
Linus Torvalds 99dfe2d4da Merge tag 'block-7.0-20260216' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull more block updates from Jens Axboe:

 - Fix partial IOVA mapping cleanup in error handling

 - Minor prep series ignoring discard return value, as
   the inline value is always known

 - Ensure BLK_FEAT_STABLE_WRITES is set for drbd

 - Fix leak of folio in bio_iov_iter_bounce_read()

 - Allow IOC_PR_READ_* for read-only open

 - Another debugfs deadlock fix

 - A few doc updates

* tag 'block-7.0-20260216' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  blk-mq: use NOIO context to prevent deadlock during debugfs creation
  blk-stat: convert struct blk_stat_callback to kernel-doc
  block: fix enum descriptions kernel-doc
  block: update docs for bio and bvec_iter
  block: change return type to void
  nvmet: ignore discard return value
  md: ignore discard return value
  block: fix partial IOVA mapping cleanup in blk_rq_dma_map_iova
  block: fix folio leak in bio_iov_iter_bounce_read()
  block: allow IOC_PR_READ_* ioctls with BLK_OPEN_READ
  drbd: always set BLK_FEAT_STABLE_WRITES
2026-02-17 08:48:45 -08:00
Linus Torvalds 543b9b6339 Merge tag 'kernel-7.0-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull pidfs updates from Christian Brauner:

 - pid: introduce task_ppid_vnr() helper

 - pidfs: convert rb-tree to rhashtable

   Mateusz reported performance penalties during task creation because
   pidfs uses pidmap_lock to add elements into the rbtree. Switch to an
   rhashtable to have separate fine-grained locking and to decouple from
   pidmap_lock moving all heavy manipulations outside of it

   Also move inode allocation outside of pidmap_lock. With this there's
   nothing happening for pidfs under pidmap_lock

 - pid: reorder fields in pid_namespace to reduce false sharing

 - Revert "pid: make __task_pid_nr_ns(ns => NULL) safe for zombie
   callers"

 - ipc: Add SPDX license id to mqueue.c

* tag 'kernel-7.0-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  pid: introduce task_ppid_vnr() helper
  pidfs: implement ino allocation without the pidmap lock
  Revert "pid: make __task_pid_nr_ns(ns => NULL) safe for zombie callers"
  pid: reorder fields in pid_namespace to reduce false sharing
  pidfs: convert rb-tree to rhashtable
  ipc: Add SPDX license id to mqueue.c
2026-02-16 12:37:13 -08:00
Yu Kuai dfe48ea179 blk-mq: use NOIO context to prevent deadlock during debugfs creation
Creating debugfs entries can trigger fs reclaim, which can enter back
into the block layer request_queue. This can cause deadlock if the
queue is frozen.

Previously, a WARN_ON_ONCE check was used in debugfs_create_files()
to detect this condition, but it was racy since the queue can be frozen
from another context at any time.

Introduce blk_debugfs_lock()/blk_debugfs_unlock() helpers that combine
the debugfs_mutex with memalloc_noio_save()/restore() to prevent fs
reclaim from triggering block I/O. Also add blk_debugfs_lock_nomemsave()
and blk_debugfs_unlock_nomemrestore() variants for callers that don't
need NOIO protection (e.g., debugfs removal or read-only operations).

Replace all raw debugfs_mutex lock/unlock pairs with these helpers,
using the _nomemsave/_nomemrestore variants where appropriate.

Reported-by: Yi Zhang <yi.zhang@redhat.com>
Closes: https://lore.kernel.org/all/CAHj4cs9gNKEYAPagD9JADfO5UH+OiCr4P7OO2wjpfOYeM-RV=A@mail.gmail.com/
Reported-by: Shinichiro Kawasaki <shinichiro.kawasaki@wdc.com>
Closes: https://lore.kernel.org/all/aYWQR7CtYdk3K39g@shinmob/
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yu Kuai <yukuai@fnnas.com>
Reviewed-by: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-02-16 10:47:25 -07:00
Linus Torvalds 2d10a48871 Merge tag 'probes-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull kprobes updates from Masami Hiramatsu:

 - Use a dedicated kernel thread to optimize the kprobes instead of
   using workqueue thread. Since the kprobe optimizer waits a long time
   for synchronize_rcu_task(), it can block other workers in the same
   queue if it uses a workqueue.

 - kprobe-events: return immediately if no new probe events are
   specified on the kernel command line at boot time. This shortens
   the kernel boot time.

 - When a kprobe is fully removed from the kernel code, retry optimizing
   another kprobe which is blocked by that kprobe.

* tag 'probes-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  kprobes: Use dedicated kthread for kprobe optimizer
  tracing: kprobe-event: Return directly when trace kprobes is empty
  kprobes: retry blocked optprobe in do_free_cleaned_kprobes
2026-02-16 07:04:01 -08:00
Sebastian Andrzej Siewior 8e9bf8b9e8 printk, vt, fbcon: Remove console_conditional_schedule()
do_con_write(), fbcon_redraw.*() invoke console_conditional_schedule()
which is a conditional scheduling point based on printk's internal
variables console_may_schedule. It may only be used if the console lock
is acquired for instance via console_lock() or console_trylock().

Prinkt sets the internal variable to 1 (and allows to schedule)
if the console lock has been acquired via console_lock(). The trylock
does not allow it.

The console_conditional_schedule() invocation in do_con_write() is
invoked shortly before console_unlock().
The console_conditional_schedule() invocation in fbcon_redraw.*()
original from fbcon_scroll() / vt's con_scroll() which originate from a
line feed.

In console_unlock() the variable is set to 0 (forbids to schedule) and
it tries to schedule while making progress printing. This is brand new
compared to when console_conditional_schedule() was added in v2.4.9.11.

In v2.6.38-rc3, console_unlock() (started its existence) iterated over
all consoles and flushed them with disabled interrupts. A scheduling
attempt here was not possible, it relied that a long print scheduled
before console_unlock().

Since commit 8d91f8b153 ("printk: do cond_resched() between lines
while outputting to consoles"), which appeared in v4.5-rc1,
console_unlock() attempts to schedule if it was allowed to schedule
while during console_lock(). Each record is idealy one line so after
every line feed.

This console_conditional_schedule() is also only relevant on
PREEMPT_NONE and PREEMPT_VOLUNTARY builds. In other configurations
cond_resched() becomes a nop and has no impact.

I'm bringing this all up just proof that it is not required anymore. It
becomes a problem on a PREEMPT_RT build with debug code enabled because
that might_sleep() in cond_resched() remains and triggers a warnings.
This is due to

 legacy_kthread_func-> console_flush_one_record ->  vt_console_print-> lf
   -> con_scroll -> fbcon_scroll

and vt_console_print() acquires a spinlock_t which does not allow a
voluntary schedule. There is no need to fb_scroll() to schedule since
console_flush_one_record() attempts to schedule after each line.
!PREEMPT_RT is not affected because the legacy printing thread is only
enabled on PREEMPT_RT builds.

Therefore I suggest to remove console_conditional_schedule().

Cc: Simona Vetter <simona@ffwll.ch>
Cc: Helge Deller <deller@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: dri-devel@lists.freedesktop.org
Fixes: 5f53ca3ff8 ("printk: Implement legacy printer kthread for PREEMPT_RT")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Petr Mladek <pmladek@suse.com> # from printk() POV
Signed-off-by: Helge Deller <deller@gmx.de>
2026-02-14 11:09:47 +01:00
Linus Torvalds 3c6e577d5a Merge tag 'trace-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
 "User visible changes:

   - Add an entry into MAINTAINERS file for RUST versions of code

     There's now RUST code for tracing and static branches. To
     differentiate that code from the C code, add entries in for the
     RUST version (with "[RUST]" around it) so that the right
     maintainers get notified on changes.

   - New bitmask-list option added to tracefs

     When this is set, bitmasks in trace event are not displayed as hex
     numbers, but instead as lists: e.g. 0-5,7,9 instead of 0000015f

   - New show_event_filters file in tracefs

     Instead of having to search all events/*/*/filter for any active
     filters enabled in the trace instance, the file show_event_filters
     will list them so that there's only one file that needs to be
     examined to see if any filters are active.

   - New show_event_triggers file in tracefs

     Instead of having to search all events/*/*/trigger for any active
     triggers enabled in the trace instance, the file
     show_event_triggers will list them so that there's only one file
     that needs to be examined to see if any triggers are active.

   - Have traceoff_on_warning disable trace pintk buffer too

     Recently recording of trace_printk() could go to other trace
     instances instead of the top level instance. But if
     traceoff_on_warning triggers, it doesn't stop the buffer with
     trace_printk() and that data can easily be lost by being
     overwritten. Have traceoff_on_warning also disable the instance
     that has trace_printk() being written to it.

   - Update the hist_debug file to show what function the field uses

     When CONFIG_HIST_TRIGGERS_DEBUG is enabled, a hist_debug file
     exists for every event. This displays the internal data of any
     histogram enabled for that event. But it is lacking the function
     that is called to process one of its fields. This is very useful
     information that was missing when debugging histograms.

   - Up the histogram stack size from 16 to 31

     Stack traces can be used as keys for event histograms. Currently
     the size of the stack that is stored is limited to just 16 entries.
     But the storage space in the histogram is 256 bytes, meaning that
     it can store up to 31 entries (plus one for the count of entries).
     Instead of letting that space go to waste, up the limit from 16 to
     31. This makes the keys much more useful.

   - Fix permissions of per CPU file buffer_size_kb

     The per CPU file of buffer_size_kb was incorrectly set to read only
     in a previous cleanup. It should be writable.

   - Reset "last_boot_info" if the persistent buffer is cleared

     The last_boot_info shows address information of a persistent ring
     buffer if it contains data from a previous boot. It is cleared when
     recording starts again, but it is not cleared when the buffer is
     reset. The data is useless after a reset so clear it on reset too.

  Internal changes:

   - A change was made to allow tracepoint callbacks to have preemption
     enabled, and instead be protected by SRCU. This required some
     updates to the callbacks for perf and BPF.

     perf needed to disable preemption directly in its callback because
     it expects preemption disabled in the later code.

     BPF needed to disable migration, as its code expects to run
     completely on the same CPU.

   - Have irq_work wake up other CPU if current CPU is "isolated"

     When there's a waiter waiting on ring buffer data and a new event
     happens, an irq work is triggered to wake up that waiter. This is
     noisy on isolated CPUs (running NO_HZ_FULL). Trigger an IPI to a
     house keeping CPU instead.

   - Use proper free of trigger_data instead of open coding it in.

   - Remove redundant call of event_trigger_reset_filter()

     It was called immediately in a function that was called right after
     it.

   - Workqueue cleanups

   - Report errors if tracing_update_buffers() were to fail.

   - Make the enum update workqueue generic for other parts of tracing

     On boot up, a work queue is created to convert enum names into
     their numbers in the trace event format files. This work queue can
     also be used for other aspects of tracing that takes some time and
     shouldn't be called by the init call code.

     The blk_trace initialization takes a bit of time. Have the
     initialization code moved to the new tracing generic work queue
     function.

   - Skip kprobe boot event creation call if there's no kprobes defined
     on cmdline

     The kprobe initialization to set up kprobes if they are defined on
     the cmdline requires taking the event_mutex lock. This can be held
     by other tracing code doing initialization for a long time. Since
     kprobes added to the kernel command line need to be setup
     immediately, as they may be tracing early initialization code, they
     cannot be postponed in a work queue and must be setup in the
     initcall code.

     If there's no kprobe on the kernel cmdline, there's no reason to
     take the mutex and slow down the boot up code waiting to get the
     lock only to find out there's nothing to do. Simply exit out early
     if there's no kprobes on the kernel cmdline.

     If there are kprobes on the cmdline, then someone cares more about
     tracing over the speed of boot up.

   - Clean up the trigger code a bit

   - Move code out of trace.c and into their own files

     trace.c is now over 11,000 lines of code and has become more
     difficult to maintain. Start splitting it up so that related code
     is in their own files.

     Move all the trace_printk() related code into trace_printk.c.

     Move the __always_inline stack functions into trace.h.

     Move the pid filtering code into a new trace_pid.c file.

   - Better define the max latency and snapshot code

     The latency tracers have a "max latency" buffer that is a copy of
     the main buffer and gets swapped with it when a new high latency is
     detected. This keeps the trace up to the highest latency around
     where this max_latency buffer is never written to. It is only used
     to save the last max latency trace.

     A while ago a snapshot feature was added to tracefs to allow user
     space to perform the same logic. It could also enable events to
     trigger a "snapshot" if one of their fields hit a new high. This
     was built on top of the latency max_latency buffer logic.

     Because snapshots came later, they were dependent on the latency
     tracers to be enabled. In reality, the latency tracers depend on
     the snapshot code and not the other way around. It was just that
     they came first.

     Restructure the code and the kconfigs to have the latency tracers
     depend on snapshot code instead. This actually simplifies the logic
     a bit and allows to disable more when the latency tracers are not
     defined and the snapshot code is.

   - Fix a "false sharing" in the hwlat tracer code

     The loop to search for latency in hardware was using a variable
     that could be changed by user space for each sample. If the user
     change this variable, it could cause a bus contention, and reading
     that variable can show up as a large latency in the trace causing a
     false positive. Read this variable at the start of the sample with
     a READ_ONCE() into a local variable and keep the code from sharing
     cache lines with readers.

   - Fix function graph tracer static branch optimization code

     When only one tracer is defined for function graph tracing, it uses
     a static branch to call that tracer directly. When another tracer
     is added, it goes into loop logic to call all the registered
     callbacks.

     The code was incorrect when going back to one tracer and never
     re-enabled the static branch again to do the optimization code.

   - And other small fixes and cleanups"

* tag 'trace-v7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (46 commits)
  function_graph: Restore direct mode when callbacks drop to one
  tracing: Fix indentation of return statement in print_trace_fmt()
  tracing: Reset last_boot_info if ring buffer is reset
  tracing: Fix to set write permission to per-cpu buffer_size_kb
  tracing: Fix false sharing in hwlat get_sample()
  tracing: Move d_max_latency out of CONFIG_FSNOTIFY protection
  tracing: Better separate SNAPSHOT and MAX_TRACE options
  tracing: Add tracer_uses_snapshot() helper to remove #ifdefs
  tracing: Rename trace_array field max_buffer to snapshot_buffer
  tracing: Move pid filtering into trace_pid.c
  tracing: Move trace_printk functions out of trace.c and into trace_printk.c
  tracing: Use system_state in trace_printk_init_buffers()
  tracing: Have trace_printk functions use flags instead of using global_trace
  tracing: Make tracing_update_buffers() take NULL for global_trace
  tracing: Make printk_trace global for tracing system
  tracing: Move ftrace_trace_stack() out of trace.c and into trace.h
  tracing: Move __trace_buffer_{un}lock_*() functions to trace.h
  tracing: Make tracing_selftest_running global to the tracing subsystem
  tracing: Make tracing_disabled global for tracing system
  tracing: Clean up use of trace_create_maxlat_file()
  ...
2026-02-13 19:25:16 -08:00
Linus Torvalds 72f05009d8 Merge tag 'dma-mapping-7.0-2026-02-13' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux
Pull dma-mapping update from Marek Szyprowski:
 "A small code cleanup for the DMA-mapping subsystem: removal of unused
  hooks (Robin Murphy)"

* tag 'dma-mapping-7.0-2026-02-13' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
  dma-mapping: Remove dma_mark_clean (again)
2026-02-13 14:51:39 -08:00
Anton Protopopov b0b1a8583d bpf: Add a map/btf from a fd array more consistently
The add_fd_from_fd_array() function takes a file descriptor as a
parameter and tries to add either map or btf to the corresponding
list of used objects. As was reported by Dan Carpenter, since the
commit c81e4322acf0 ("bpf: Fix a potential use-after-free of BTF
object"), the fdget() is called twice on the file descriptor, and
thus userspace, potentially, can replace the file pointed to by the
file descriptor in between the two calls. On practice, this shouldn't
break anything on the kernel side, but for consistency fix the code
such that only one fdget() is executed.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/r/aY689z7gHNv8rgVO@stanley.mountain/
Fixes: ccd2d799ed ("bpf: Fix a potential use-after-free of BTF object")
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Link: https://lore.kernel.org/r/20260213212949.759321-1-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-13 14:37:02 -08:00
Anton Protopopov ccd2d799ed bpf: Fix a potential use-after-free of BTF object
Refcounting in the check_pseudo_btf_id() function is incorrect:
the __check_pseudo_btf_id() function might get called with a zero
refcounted btf. Fix this, and patch related code accordingly.

v3: rephrase a comment (AI)
v2: fix a refcount leak introduced in v1 (AI)

Reported-by: syzbot+5a0f1995634f7c1dadbf@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=5a0f1995634f7c1dadbf
Fixes: 76145f7255 ("bpf: Refactor check_pseudo_btf_id")
Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com>
Link: https://lore.kernel.org/r/20260209132904.63908-1-a.s.protopopov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-02-13 14:14:27 -08:00
Linus Torvalds a353e7260b Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Pull virtio updates from Michael Tsirkin:

 - in-order support in virtio core

 - multiple address space support in vduse

 - fixes, cleanups all over the place, notably dma alignment fixes for
   non-cache-coherent systems

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (59 commits)
  vduse: avoid adding implicit padding
  vhost: fix caching attributes of MMIO regions by setting them explicitly
  vdpa/mlx5: update MAC address handling in mlx5_vdpa_set_attr()
  vdpa/mlx5: reuse common function for MAC address updates
  vdpa/mlx5: update mlx_features with driver state check
  crypto: virtio: Replace package id with numa node id
  crypto: virtio: Remove duplicated virtqueue_kick in virtio_crypto_skcipher_crypt_req
  crypto: virtio: Add spinlock protection with virtqueue notification
  Documentation: Add documentation for VDUSE Address Space IDs
  vduse: bump version number
  vduse: add vq group asid support
  vduse: merge tree search logic of IOTLB_GET_FD and IOTLB_GET_INFO ioctls
  vduse: take out allocations from vduse_dev_alloc_coherent
  vduse: remove unused vaddr parameter of vduse_domain_free_coherent
  vduse: refactor vdpa_dev_add for goto err handling
  vhost: forbid change vq groups ASID if DRIVER_OK is set
  vdpa: document set_group_asid thread safety
  vduse: return internal vq group struct as map token
  vduse: add vq group support
  vduse: add v1 API definition
  ...
2026-02-13 12:02:18 -08:00
Shengming Hu 53b2fae90f function_graph: Restore direct mode when callbacks drop to one
When registering a second fgraph callback, direct path is disabled and
array loop is used instead.  When ftrace_graph_active falls back to one,
we try to re-enable direct mode via ftrace_graph_enable_direct(true, ...).
But ftrace_graph_enable_direct() incorrectly disables the static key
rather than enabling it.  This leaves fgraph_do_direct permanently off
after first multi-callback transition, so direct fast mode is never
restored.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260213142932519cuWSpEXeS4-UnCvNXnK2P@zte.com.cn
Fixes: cc60ee813b ("function_graph: Use static_call and branch to optimize entry function")
Signed-off-by: Shengming Hu <hu.shengming@zte.com.cn>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2026-02-13 09:33:14 -05:00
Linus Torvalds cee73b1e84 Merge tag 'riscv-for-linus-7.0-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V updates from Paul Walmsley:

 - Add support for control flow integrity for userspace processes.

   This is based on the standard RISC-V ISA extensions Zicfiss and
   Zicfilp

 - Improve ptrace behavior regarding vector registers, and add some
   selftests

 - Optimize our strlen() assembly

 - Enable the ISO-8859-1 code page as built-in, similar to ARM64, for
   EFI volume mounting

 - Clean up some code slightly, including defining copy_user_page() as
   copy_page() rather than memcpy(), aligning us with other
   architectures; and using max3() to slightly simplify an expression
   in riscv_iommu_init_check()

* tag 'riscv-for-linus-7.0-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (42 commits)
  riscv: lib: optimize strlen loop efficiency
  selftests: riscv: vstate_exec_nolibc: Use the regular prctl() function
  selftests: riscv: verify ptrace accepts valid vector csr values
  selftests: riscv: verify ptrace rejects invalid vector csr inputs
  selftests: riscv: verify syscalls discard vector context
  selftests: riscv: verify initial vector state with ptrace
  selftests: riscv: test ptrace vector interface
  riscv: ptrace: validate input vector csr registers
  riscv: csr: define vtype register elements
  riscv: vector: init vector context with proper vlenb
  riscv: ptrace: return ENODATA for inactive vector extension
  kselftest/riscv: add kselftest for user mode CFI
  riscv: add documentation for shadow stack
  riscv: add documentation for landing pad / indirect branch tracking
  riscv: create a Kconfig fragment for shadow stack and landing pad support
  arch/riscv: add dual vdso creation logic and select vdso based on hw
  arch/riscv: compile vdso with landing pad and shadow stack note
  riscv: enable kernel access to shadow stack memory via the FWFT SBI call
  riscv: add kernel command line option to opt out of user CFI
  riscv/hwprobe: add zicfilp / zicfiss enumeration in hwprobe
  ...
2026-02-12 19:17:44 -08:00
Linus Torvalds e812928be2 Merge tag 'cxl-for-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl
Pull CXL updates from Dave Jiang:

 - Introduce cxl_memdev_attach and pave way for soft reserved handling,
   type2 accelerator enabling, and LSA 2.0 enabling. All these series
   require the endpoint driver to settle before continuing the memdev
   driver probe.

 - Address CXL port error protocol handling and reporting.

   The large patch series was split into three parts. The first two
   parts are included here with the final part coming later.

   The first part consists of a series of code refactoring to PCI AER
   sub-system that addresses CXL and also CXL RAS code to prepare for
   port error handling.

   The second part refactors the CXL code to move management of
   component registers to cxl_port objects to allow all CXL AER errors
   to be handled through the cxl_port hierarchy.

 - Provide AMD Zen5 platform address translation for CXL using ACPI
   PRMT. This includes a conventions document to explain why this is
   needed and how it's implemented.

 - Misc CXL patches of fixes, cleanups, and updates. Including CXL
   address translation for unaligned MOD3 regions.

[ TLA service: CXL is "Compute Express Link" ]

* tag 'cxl-for-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/cxl/cxl: (59 commits)
  cxl: Disable HPA/SPA translation handlers for Normalized Addressing
  cxl/region: Factor out code into cxl_region_setup_poison()
  cxl/atl: Lock decoders that need address translation
  cxl: Enable AMD Zen5 address translation using ACPI PRMT
  cxl/acpi: Prepare use of EFI runtime services
  cxl: Introduce callback for HPA address ranges translation
  cxl/region: Use region data to get the root decoder
  cxl/region: Add @hpa_range argument to function cxl_calc_interleave_pos()
  cxl/region: Separate region parameter setup and region construction
  cxl: Simplify cxl_root_ops allocation and handling
  cxl/region: Store HPA range in struct cxl_region
  cxl/region: Store root decoder in struct cxl_region
  cxl/region: Rename misleading variable name @hpa to @hpa_range
  Documentation/driver-api/cxl: ACPI PRM Address Translation Support and AMD Zen5 enablement
  cxl, doc: Moving conventions in separate files
  cxl, doc: Remove isonum.txt inclusion
  cxl/port: Unify endpoint and switch port lookup
  cxl/port: Move endpoint component register management to cxl_port
  cxl/port: Map Port RAS registers
  cxl/port: Move dport RAS setup to dport add time
  ...
2026-02-12 16:33:05 -08:00
Ran Xiaokai f7a553b813 kho: remove unnecessary WARN_ON(err) in kho_populate()
The following pr_warn() provides detailed error and location information,
WARN_ON(err) adds no additional debugging value, so remove the redundant
WARN_ON() call.

Link: https://lkml.kernel.org/r/20260212111146.210086-3-ranxiaokai627@163.com
Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Mike Rapoport <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-02-12 15:45:58 -08:00