When a system call that can copy user space addresses into the ring
buffer, it can copy up to 511 bytes of data. This can waste precious ring
buffer space if the user isn't interested in the output. Add a new file
"syscall_user_buf_size" that gets initialized to a new config
CONFIG_SYSCALL_BUF_SIZE_DEFAULT that defaults to 63.
The config also is used to limit how much perf can read from user space.
Also lower the max down to 165, as this isn't to record everything that a
system call may be passing through to the kernel. 165 is more than enough.
The reason for 165 is because adding one for the nul terminating byte, as
well as possibly needing to append the "..." string turns it into 170
bytes. As this needs to save up to 3 arguments and 3 * 170 is 510 which
fits nicely in 512 bytes (a power of 2).
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Takaya Saeki <takayas@google.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Douglas Raillard <douglas.raillard@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Link: https://lore.kernel.org/20251028231148.260068913@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Allow more than one field of a syscall trace event to read user space.
Build on top of the user_mask by allowing more than one bit to be set that
corresponds to the @args array of the syscall metadata. For each argument
in the @args array that is to be read, it will have a dynamic array/string
field associated to it.
Note that multiple fields to be read from user space is not supported if
the user_arg_size field is set in the syscall metada. That field can only
be used if only one field is being read from user space as that field is a
number representing the size field of the syscall event that holds the
size of the data to read from user space. It becomes ambiguous if the
system call reads more than one field. Currently this is not an issue.
If a syscall event happens to enable two events to read user space and
sets the user_arg_size field, it will trigger a warning at boot and the
user_arg_size field will be cleared.
The per CPU buffer that is used to read the user space addresses is now
broken up into 3 sections, each of 168 bytes. The reason for 168 is that
it is the biggest portion of 512 bytes divided by 3 that is 8 byte aligned.
The max amount copied into the ring buffer from user space is now only 128
bytes, which is plenty. When reading user space, it still reads 167
(168-1) bytes and uses the remaining to know if it should append the extra
"..." to the end or not.
This will allow the event to look like this:
sys_renameat2(olddfd: 0xffffff9c, oldname: 0x7ffe02facdff "/tmp/x", newdfd: 0xffffff9c, newname: 0x7ffe02face06 "/tmp/y", flags: 1)
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Takaya Saeki <takayas@google.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Douglas Raillard <douglas.raillard@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Link: https://lore.kernel.org/20251028231148.095789277@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
As of commit 654ced4a13 ("tracing: Introduce tracepoint_is_faultable()")
system call trace events allow faulting in user space memory. Have some of
the system call trace events take advantage of this.
Use the trace_user_fault_read() logic to read the user space buffer from
user space and instead of just saving the pointer to the buffer in the
system call event, also save the string that is passed in.
The syscall event has its nb_args shorten from an int to a short (where
even u8 is plenty big enough) and the freed two bytes are used for
"user_mask". The new "user_mask" field is used to store the index of the
"args" field array that has the address to read from user space. This
value is set to 0 if the system call event does not need to read user
space for a field. This mask can be used to know if the event may fault or
not. Only one bit set in user_mask is supported at this time.
This allows the output to look like this:
sys_access(filename: 0x7f8c55368470 "/etc/ld.so.preload", mode: 4)
sys_execve(filename: 0x564ebcf5a6b8 "/usr/bin/emacs", argv: 0x7fff357c0300, envp: 0x564ebc4a4820)
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Takaya Saeki <takayas@google.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Douglas Raillard <douglas.raillard@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Link: https://lore.kernel.org/20251028231147.261867956@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
The write to the trace_marker file is a critical section where it cannot
take locks nor allocate memory. To read from user space, it allocates a per
CPU buffer when the trace_marker file is opened, and then when the write
system call is performed, it uses the following method to read from user
space:
preempt_disable();
buffer = per_cpu_ptr(cpu_buffers, cpu);
do {
cnt = nr_context_switches_cpu();
migrate_disable();
preempt_enable();
ret = copy_from_user(buffer, ptr, len);
preempt_disable();
migrate_enable();
} while (!ret && cnt != nr_context_switches_cpu());
if (!ret)
ring_buffer_write(buffer);
preempt_enable();
It records the number of context switches for the current CPU, enables
preemption, copies from user space, disable preemption and then checks if
the number of context switches changed. If it did not, then the buffer is
valid, otherwise the buffer may have been corrupted and the read from user
space must be tried again.
The system call trace events are now faultable and have the same
restrictions as the trace_marker write. For system calls to read the user
space buffer (for example to read the file of the openat system call), it
needs the same logic. Instead of copying the code over to the system call
trace events, make the code generic to allow the system call trace events to
use the same code. The following API is added internally to the tracing sub
system (these are only exposed within the tracing subsystem and not to be
used outside of it):
trace_user_fault_init() - initializes a trace_user_buf_info descriptor
that will allocate the per CPU buffers to copy from user space into.
trace_user_fault_destroy() - used to free the allocations made by
trace_user_fault_init().
trace_user_fault_get() - update the ref count of the info descriptor to
allow more than one user to use the same descriptor.
trace_user_fault_put() - decrement the ref count.
trace_user_fault_read() - performs the above action to read user space
into the per CPU buffer. The preempt_disable() is expected before
calling this function and preemption must remain disabled while the
buffer returned is in use.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Takaya Saeki <takayas@google.com>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ian Rogers <irogers@google.com>
Cc: Douglas Raillard <douglas.raillard@arm.com>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Link: https://lore.kernel.org/20251028231147.096570057@kernel.org
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
ddf7233fca ("sched/ext: Fix invalid task state transitions on class
switch") added tryget_task_struct() test during scx_enable()'s class
switching loop. The reason for the addition was to avoid enabling tasks which
skipped prep in the previous loop due to being dead.
While tryget_task_struct() does work for this purpose as tasks that fail
tryget always will fail it, it's a bit roundabout. A more direct way is
testing whether the task is in READY state. Switch to testing SCX_TASK_READY
directly.
Cc: Andrea Righi <arighi@nvidia.com>
Acked-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
A later commit will reduce the size of the RCU watching counter to free up
some bits for another purpose. Paul suggested adding a config option to
test the extreme case where the counter is reduced to its minimum usable
width for rcutorture to poke at, so do that.
Make it only configurable under RCU_EXPERT. While at it, add a comment to
explain the layout of context_tracking->state.
Link: http://lore.kernel.org/r/4c2cb573-168f-4806-b1d9-164e8276e66a@paulmck-laptop
Suggested-by: Paul E. McKenney <paulmck@kernel.org>
Signed-off-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Extract the duplicated maximum allowed depth computation for stack
traces stored in BPF stacks from bpf_get_stackid() and __bpf_get_stack()
into a dedicated stack_map_calculate_max_depth() helper function.
This unifies the logic for:
- The max depth computation
- Enforcing the sysctl_perf_event_max_stack limit
No functional changes for existing code paths.
Signed-off-by: Arnaud Lecomte <contact@arnaud-lcm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20251025192858.31424-1-contact@arnaud-lcm.com
Commit abfc01077d ("sched: Fix do_set_cpus_allowed() locking")
overlooked that __balance_push_cpu_stop() calls select_fallback_rq()
with rq->lock held. This makes that set_cpus_allowed_force() will
recursively take rq->lock and the machine locks up.
Run select_fallback_rq() earlier, without holding rq->lock. This opens
up a race window where a task could get migrated out from under us, but
that is harmless, we want the task migrated.
select_fallback_rq() itself will not be subject to concurrency as it
will be fully serialized by p->pi_lock, so there is no chance of
set_cpus_allowed_force() getting called with different arguments and
selecting different fallback CPUs for one task.
Fixes: abfc01077d ("sched: Fix do_set_cpus_allowed() locking")
Reported-by: Jan Polensky <japo@linux.ibm.com>
Reported-by: kernel test robot <oliver.sang@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Jan Polensky <japo@linux.ibm.com>
Closes: https://lore.kernel.org/oe-lkp/202510271206.24495a68-lkp@intel.com
Link: https://patch.msgid.link/20251027110133.GI3245006@noisy.programming.kicks-ass.net
The ftrace blktrace path allocates buffers and writes trace events but
was using the wrong recording function. After
commit 4d8bc7bd4f ("blktrace: move ftrace blk_io_tracer to blk_io_trace2"),
the ftrace interface was moved to use blk_io_trace2 format, but
__blk_add_trace() still called record_blktrace_event() which writes in
blk_io_trace (v1) format.
This causes critical data corruption:
- blk_io_trace (v1) has 32-bit 'action' field at offset 28
- blk_io_trace2 (v2) has 32-bit 'pid' at offset 28 and 64-bit 'action'
at offset 32
- When record_blktrace_event() writes to a v2 buffer:
* Writing pid (offset 32 in v1) corrupts the v2 action field
* Writing action (offset 28 in v1) corrupts the v2 pid field
* The 64-bit action is truncated to 32-bit via lower_32_bits()
Fix by:
1. Adding version switch to select correct format (v1 vs v2)
2. Calling appropriate recording function based on version
3. Defaulting to v2 for ftrace (as intended by commit 4d8bc7bd4f)
4. Adding WARN_ONCE for unexpected version values
Without this patch :-
linux-block (for-next) # sh reproduce_blktrace_bug.sh
dd-14242 [033] d..1. 3903.022308: Unknown action 36a2
dd-14242 [033] d..1. 3903.022333: Unknown action 36a2
dd-14242 [033] d..1. 3903.022365: Unknown action 36a2
dd-14242 [033] d..1. 3903.022366: Unknown action 36a2
dd-14242 [033] d..1. 3903.022369: Unknown action 36a2
The action field is corrupted because:
- ftrace allocated blk_io_trace2 buffer (64 bytes)
- But called record_blktrace_event() (writes v1, 48 bytes)
- Field offsets don't match, causing corruption
The hex value shown 0x30e3 is actually a PID, not an action code!
linux-block (for-next) #
linux-block (for-next) #
linux-block (for-next) # sh reproduce_blktrace_bug.sh
Trace output looks correct:
dd-2420 [019] d..1. 59.641742: 251,0 Q RS 0 + 8 [dd]
dd-2420 [019] d..1. 59.641775: 251,0 G RS 0 + 8 [dd]
dd-2420 [019] d..1. 59.641784: 251,0 P N [dd]
dd-2420 [019] d..1. 59.641785: 251,0 U N [dd] 1
dd-2420 [019] d..1. 59.641788: 251,0 D RS 0 + 8 [dd]
Fixes: 4d8bc7bd4f ("blktrace: move ftrace blk_io_tracer to blk_io_trace2")
Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The WARN_ON_ONCE introduced in
commit f9ee38bbf7 ("blktrace: add block trace commands for zone operations")
triggers kernel warnings when zone operations are traced with blktrace
version 1. This can spam the kernel log during normal operation with
zoned block devices when userspace is using the legacy blktrace
protocol.
Currently blktrace implementation drops newly added REQ_OP_ZONE_XXX
when blktrace userspce version is set to 1.
Remove the WARN_ON_ONCE and quietly filter these events. Add a
rate-limited debug message to help diagnose potential issues without
flooding the kernel log. The debug message can be enabled via dynamic
debug when needed for troubleshooting.
This approach is more appropriate as encountering zone operations with
blktrace v1 is an expected condition that should be handled gracefully
rather than warned about, since users may be running older blktrace
userspace tools that only support version 1 of the protocol.
With this patch :-
linux-block (for-next) # git log -1
commit c8966006a0971d2b4bf94c0426eb7e4407c6853f (HEAD -> for-next)
Author: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
Date: Mon Oct 27 19:26:53 2025 -0700
blktrace: use debug print to report dropped events
linux-block (for-next) # cdblktests
blktests (master) # ./check blktrace
blktrace/001 (blktrace zone management command tracing) [passed]
runtime 3.805s ... 3.889s
blktests (master) # dmesg -c
blktests (master) # echo "file kernel/trace/blktrace.c +p" > /sys/kernel/debug/dynamic_debug/control
blktests (master) # ./check blktrace
blktrace/001 (blktrace zone management command tracing) [passed]
runtime 3.889s ... 3.881s
blktests (master) # dmesg -c
[ 77.826237] blktrace: blktrace v1 cannot trace zone operation 0x1000190001
[ 77.826260] blktrace: blktrace v1 cannot trace zone operation 0x1000190004
[ 77.826282] blktrace: blktrace v1 cannot trace zone operation 0x1001490007
[ 77.826288] blktrace: blktrace v1 cannot trace zone operation 0x1001890008
[ 77.826343] blktrace: blktrace v1 cannot trace zone operation 0x1000190001
[ 77.826347] blktrace: blktrace v1 cannot trace zone operation 0x1000190004
[ 77.826350] blktrace: blktrace v1 cannot trace zone operation 0x1001490007
[ 77.826354] blktrace: blktrace v1 cannot trace zone operation 0x1001890008
[ 77.826373] blktrace: blktrace v1 cannot trace zone operation 0x1000190001
[ 77.826377] blktrace: blktrace v1 cannot trace zone operation 0x1000190004
blktests (master) # echo "file kernel/trace/blktrace.c -p" > /sys/kernel/debug/dynamic_debug/control
blktests (master) # ./check blktrace
blktrace/001 (blktrace zone management command tracing) [passed]
runtime 3.881s ... 3.824s
blktests (master) # dmesg -c
blktests (master) #
Reported-by: syzbot+153e64c0aa875d7e4c37@syzkaller.appspotmail.com
Fixes: f9ee38bbf7 ("blktrace: add block trace commands for zone operations")
Signed-off-by: Chaitanya Kulkarni <ckulkarnilinux@gmail.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull sched_ext fixes from Tejun Heo:
- Fix scx_kick_pseqs corruption when multiple schedulers are loaded
concurrently
- Allocate scx_kick_cpus_pnt_seqs lazily using kvzalloc() to handle
systems with large CPU counts
- Defer queue_balance_callback() until after ops.dispatch to fix
callback ordering issues
- Sync error_irq_work before freeing scx_sched to prevent
use-after-free
- Mark scx_bpf_dsq_move_set_[slice|vtime]() with KF_RCU for proper RCU
protection
- Fix flag check for deferred callbacks
* tag 'sched_ext-for-6.18-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext:
sched_ext: fix flag check for deferred callbacks
sched_ext: Fix scx_kick_pseqs corruption on concurrent scheduler loads
sched_ext: Allocate scx_kick_cpus_pnt_seqs lazily using kvzalloc()
sched_ext: defer queue_balance_callback() until after ops.dispatch
sched_ext: Sync error_irq_work before freeing scx_sched
sched_ext: Mark scx_bpf_dsq_move_set_[slice|vtime]() with KF_RCU
File dynptr reads may sleep when the requested folios are not in
the page cache. To avoid sleeping in non-sleepable contexts while still
supporting valid sleepable use, given that dynptrs are non-sleepable by
default, enable sleeping only when bpf_dynptr_from_file() is invoked
from a sleepable context.
This change:
* Introduces a sleepable constructor: bpf_dynptr_from_file_sleepable()
* Override non-sleepable constructor with sleepable if it's always
called in sleepable context
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251026203853.135105-10-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Move kfunc specialization (function address substitution) to later stage
of verification to support a new use case, where we need to take into
consideration whether kfunc is called in sleepable context.
Minor refactoring in add_kfunc_call(), making sure that if function
fails, kfunc desc is not added to tab->descs (previously it could be
added or not, depending on what failed).
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251026203853.135105-9-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add support for file dynptr.
Introduce struct bpf_dynptr_file_impl to hold internal state for file
dynptrs, with 64-bit size and offset support.
Introduce lifecycle management kfuncs:
- bpf_dynptr_from_file() for initialization
- bpf_dynptr_file_discard() for destruction
Extend existing helpers to support file dynptrs in:
- bpf_dynptr_read()
- bpf_dynptr_slice()
Write helpers (bpf_dynptr_write() and bpf_dynptr_data()) are not
modified, as file dynptr is read-only.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251026203853.135105-8-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add the necessary verifier plumbing for the new file-backed dynptr type.
Introduce two kfuncs for its lifecycle management:
* bpf_dynptr_from_file() for initialization
* bpf_dynptr_file_discard() for destruction
Currently there is no mechanism for kfunc to release dynptr, this patch
add one:
* Dynptr release function sets meta->release_regno
* Call unmark_stack_slots_dynptr() if meta->release_regno is set and
dynptr ref_obj_id is set as well.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251026203853.135105-7-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Dynptr currently caps size and offset at 24 bits, which isn’t sufficient
for file-backed use cases; even 32 bits can be limiting. Refactor dynptr
helpers/kfuncs to use 64-bit size and offset, ensuring consistency
across the APIs.
This change does not affect internals of xdp, skb or other dynptrs,
which continue to behave as before. Also it does not break binary
compatibility.
The widening enables large-file access support via dynptr, implemented
in the next patches.
Signed-off-by: Mykyta Yatsenko <yatsenko@meta.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20251026203853.135105-3-mykyta.yatsenko5@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Interrupt sharing for percpu-devid interrupts is forbidden, and for good
reasons. These are interrupts generated *from* a CPU and handled by itself
(timer, for example). Nobody in their right mind would put two devices on
the same pin (and if they have, they get to keep the pieces...).
But this also prevents more benign cases, where devices are connected
to groups of CPUs, and for which the affinities are not overlapping.
Effectively, the only thing they share is the interrupt number, and
nothing else.
Tweak the definition of IRQF_SHARED applied to percpu_devid interrupts to
allow this particular use case. This results in extra validation at the
point of the interrupt being setup and freed, as well as a tiny bit of
extra complexity for interrupts at handling time (to pick the correct
irqaction).
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20251020122944.3074811-17-maz@kernel.org
Add an affinity field to both the irqaction structure and the interrupt
request primitives. Nothing is making use of it yet, and the only value
used it NULL, which is used as a shorthand for cpu_possible_mask.
This will shortly get used with actual affinities.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20251020122944.3074811-15-maz@kernel.org
Move the code creating a per-cpu irqaction into its own helper, so that
future changes to this code can be kept localised.
At the same time, fix the documentation which appears to say the wrong
thing when it comes to interrupts being automatically enabled
(percpu_devid interrupts never are).
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Will Deacon <will@kernel.org>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20251020122944.3074811-14-maz@kernel.org
Add an irqdomain callback to report firmware-provided information that is
otherwise not available in a generic way. This is reported using a new data
structure (struct irq_fwspec_info).
This callback is optional and the only information that can be reported
currently is the affinity of an interrupt. However, the containing
structure is designed to be extensible, allowing other potentially relevant
information to be reported in the future.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Will Deacon <will@kernel.org>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20251020122944.3074811-2-maz@kernel.org
Pull irq fixes from Borislav Petkov:
- Restore the original buslock locking in a couple of places in the irq
core subsystem after a rework
* tag 'irq_urgent_for_v6.18_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq/manage: Add buslock back in to enable_irq()
genirq/manage: Add buslock back in to __disable_irq_nosync()
genirq/chip: Add buslock back in to irq_set_handler()
Pull scheduler fix from Borislav Petkov:
- Make sure a CFS runqueue on a throttled hierarchy has its PELT clock
throttled otherwise task movement and manipulation would lead to
dangling cfs_rq references and an eventual crash
* tag 'sched_urgent_for_v6.18_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/fair: Start a cfs_rq on throttled hierarchy with PELT clock throttled
Pull timer fix from Borislav Petkov:
- Do not create more than eight (max supported) AUX clocks sysfs
hierarchies
* tag 'timers_urgent_for_v6.18_rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping: Fix aux clocks sysfs initialization loop bound
Clang is not happy with set but unused variable (this is visible
with `make W=1` build:
kernel/sched/sched.h:3744:18: error: variable 'cpumask' set but not used [-Werror,-Wunused-but-set-variable]
It seems like the variable was never used along with the assignment
that does not have side effects as far as I can see. Remove those
altogether.
Fixes: 223baf9d17 ("sched: Fix performance regression introduced by mm_cid")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Eric Biggers <ebiggers@kernel.org>
Reviewed-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When removing a task from a FIFO DSQ, we must delete it from the list
before updating dsq->first_task, otherwise the following lookup will
just re-read the same task, leaving first_task pointing to removed
entry.
This issue only affects DSQs operating in FIFO mode, as priority DSQs
correctly update the rbtree before re-evaluating the new first task.
Remove the item from the list before refreshing the first task to
guarantee the correct behavior in FIFO DSQs.
Fixes: 44f5c8ec5b ("sched_ext: Add lockless peek operation for DSQs")
Signed-off-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Move nmi_watchdog into the watchdog_sysctls array to prevent it from
unnecessary modification. This move effectively moves it inside the
.rodata section.
Initially moved out into its own non-const array in commit 9ec272c586
("watchdog/hardlockup: keep kernel.nmi_watchdog sysctl as 0444 if probe
fails"), which made it writable only when watchdog_hardlockup_available
was true. Moving it back to watchdog_sysctl keeps this behavior as
writing to nmi_watchdog still fails when watchdog_hardlockup_available
is false.
Reviewed-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
Function kdb_msg_write was calling con->write for any found console,
but it won't work on NBCON consoles. In this case we should acquire the
ownership of the console using NBCON_PRIO_EMERGENCY, since printing
kdb messages should only be interrupted by a panic.
At this point, the console is required to use the atomic callback. The
console is skipped if the write_atomic callback is not set or if the
context could not be acquired. The validation of NBCON is done by the
console_is_usable helper. The context is released right after
write_atomic finishes.
The oops_in_progress handling is only needed in the legacy consoles,
so it was moved around the con->write callback.
Suggested-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Link: https://patch.msgid.link/20251016-nbcon-kgdboc-v6-5-866aac60a80e@suse.com
[pmladek@suse.com: Fixed compilation with !CONFIG_PRINTK.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
KDB can interrupt any console to execute the "mirrored printing" at any
time, so add an exception to nbcon_context_try_acquire_direct to allow
to get the context if the current CPU is the same as kdb_printf_cpu.
This change will be necessary for the next patch, which fixes
kdb_msg_write to work with NBCON consoles by calling ->write_atomic on
such consoles. But to print it first needs to acquire the ownership of
the console, so nbcon_context_try_acquire_direct is fixed here.
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://patch.msgid.link/20251016-nbcon-kgdboc-v6-3-866aac60a80e@suse.com
[pmladek@suse.com: Fix compilation with !CONFIG_KGDB_KDB.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
These helpers will be used when calling console->write_atomic on
KDB code in the next patch. It's basically the same implementation
as nbcon_device_try_acquire, but using NBCON_PRIO_EMERGENCY when
acquiring the context.
If the acquire succeeds, the message and message length are assigned to
nbcon_write_context so ->write_atomic can print the message.
After release try to flush the console since there may be a backlog of
messages in the ringbuffer. The kthread console printers do not get a
chance to run while kdb is active.
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Signed-off-by: Marcos Paulo de Souza <mpdesouza@suse.com>
Link: https://patch.msgid.link/20251016-nbcon-kgdboc-v6-2-866aac60a80e@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Pull tracing fixes from Steven Rostedt:
"A couple of fixes for Runtime Verification:
- A bug caused a kernel panic when reading enabled_monitors was
reported.
Change callback functions to always use list_head iterators and by
doing so, fix the wrong pointer that was leading to the panic.
- The rtapp/pagefault monitor relies on the MMU to be present
(pagefaults exist) but that was not enforced via kconfig, leading
to potential build errors on systems without an MMU.
Add that kconfig dependency"
* tag 'trace-rv-v6.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
rv: Make rtapp/pagefault monitor depends on CONFIG_MMU
rv: Fully convert enabled_monitors to use list_head as iterator
The legacy printer kthread uses console_lock and
__console_flush_and_unlock to flush records to the console. This
approach results in the console_lock being held for the entire
duration of a flush. This can result in large waiting times for
those waiting for console_lock especially where there is a large
volume of records or where the console is slow (e.g. serial). This
contention is observed during boot, as the call to filp_open in
console_on_rootfs will delay progression to userspace until any
in-flight flush is completed.
Let's instead use console_flush_one_record and release/reacquire
the console_lock between records.
On a PocketBeagle 2, with the following boot args:
"console=ttyS2,9600 initcall_debug=1 loglevel=10"
Without this patch:
[ 5.613166] +console_on_rootfs/filp_open
[ 5.643473] mmc1: SDHCI controller on fa00000.mmc [fa00000.mmc] using ADMA 64-bit
[ 5.643823] probe of fa00000.mmc returned 0 after 258244 usecs
[ 5.710520] mmc1: new UHS-I speed SDR104 SDHC card at address 5048
[ 5.721976] mmcblk1: mmc1:5048 SD32G 29.7 GiB
[ 5.747258] mmcblk1: p1 p2
[ 5.753324] probe of mmc1:5048 returned 0 after 40002 usecs
[ 15.595240] ti_sci_pm_domains 44043000.system-controller:power-controller: sync_state() pending due to 30040000.pruss
[ 15.595282] ti_sci_pm_domains 44043000.system-controller:power-controller: sync_state() pending due to e010000.watchdog
[ 15.595297] ti_sci_pm_domains 44043000.system-controller:power-controller: sync_state() pending due to e000000.watchdog
[ 15.595437] ti_sci_pm_domains 44043000.system-controller:power-controller: sync_state() pending due to 30300000.crc
[ 146.275961] -console_on_rootfs/filp_open ...
and with:
[ 5.477122] +console_on_rootfs/filp_open
[ 5.595814] mmc1: SDHCI controller on fa00000.mmc [fa00000.mmc] using ADMA 64-bit
[ 5.596181] probe of fa00000.mmc returned 0 after 312757 usecs
[ 5.662813] mmc1: new UHS-I speed SDR104 SDHC card at address 5048
[ 5.674367] mmcblk1: mmc1:5048 SD32G 29.7 GiB
[ 5.699320] mmcblk1: p1 p2
[ 5.705494] probe of mmc1:5048 returned 0 after 39987 usecs
[ 6.418682] -console_on_rootfs/filp_open ...
...
[ 15.593509] ti_sci_pm_domains 44043000.system-controller:power-controller: sync_state() pending due to 30040000.pruss
[ 15.593551] ti_sci_pm_domains 44043000.system-controller:power-controller: sync_state() pending due to e010000.watchdog
[ 15.593566] ti_sci_pm_domains 44043000.system-controller:power-controller: sync_state() pending due to e000000.watchdog
[ 15.593704] ti_sci_pm_domains 44043000.system-controller:power-controller: sync_state() pending due to 30300000.crc
Where I've added a printk surrounding the call in console_on_rootfs
to filp_open.
Suggested-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Andrew Murray <amurray@thegoodpenguin.co.uk>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Link: https://patch.msgid.link/20251020-printk_legacy_thread_console_lock-v3-3-00f1f0ac055a@thegoodpenguin.co.uk
[pmladek@suse.com: Fixed ordering of variable definition suggested by John.]
Signed-off-by: Petr Mladek <pmladek@suse.com>
console_flush_one_record() and console_flush_all() duplicate several
checks. They both want to tell the caller that consoles are not
longer usable in this context because it has lost the lock or
the lock has to be reserved for the panic CPU.
Remove the duplication by changing the semantic of the function
console_flush_one_record() return value and parameters.
The function will return true when it is able to do the job. It means
that there is at least one usable console. And the flushing was
not interrupted by a takeover or panic_on_other_cpu().
Also replace the @any_usable parameter with @try_again. The @try_again
parameter will be set to true when the function could do the job
and at least one console made a progress.
Motivation:
The callers need to know when
+ they should continue flushing => @try_again
+ when the console is flushed => can_do_the_job(return) && !@try_again
+ when @next_seq is valid => same as flushed
+ when lost console_lock => @takeover
The proposed change makes it clear when the function can do
the job. It simplifies the answer for the other questions.
Also the return value from console_flush_one_record() can
be used as return value from console_flush_all().
Reviewed-by: John Ogness <john.ogness@linutronix.de>
Link: https://patch.msgid.link/20251020-printk_legacy_thread_console_lock-v3-2-00f1f0ac055a@thegoodpenguin.co.uk
[pmladek@suse.com: Fixed type of any_usable variable reported by John]
Signed-off-by: Petr Mladek <pmladek@suse.com>
