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2025-03-04perf/core: Fix perf_mmap() failure pathPeter Zijlstra
When f_ops->mmap() returns failure, m_ops->close() is *not* called. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lore.kernel.org/r/20241104135519.248358497@infradead.org
2025-03-04perf/core: Detach 'struct perf_cpu_pmu_context' and 'struct pmu' lifetimesPeter Zijlstra
In prepration for being able to unregister a PMU with existing events, it becomes important to detach struct perf_cpu_pmu_context lifetimes from that of struct pmu. Notably struct perf_cpu_pmu_context embeds a struct perf_event_pmu_context that can stay referenced until the last event goes. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lore.kernel.org/r/20241104135518.760214287@infradead.org
2025-03-04perf/core: Lift event->mmap_mutex in perf_mmap()Peter Zijlstra
This puts 'all' of perf_mmap() under single event->mmap_mutex. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lore.kernel.org/r/20241104135519.582252957@infradead.org
2025-03-04perf/core: Remove retry loop from perf_mmap()Peter Zijlstra
AFAICT there is no actual benefit from the mutex drop on re-try. The 'worst' case scenario is that we instantly re-gain the mutex without perf_mmap_close() getting it. So might as well make that the normal case. Reflow the code to make the ring buffer detach case naturally flow into the no ring buffer case. [ mingo: Forward ported it ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lore.kernel.org/r/20241104135519.463607258@infradead.org
2025-03-04perf/core: Further simplify perf_mmap()Peter Zijlstra
Perform CSE and such. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lore.kernel.org/r/20241104135519.354909594@infradead.org
2025-03-04perf/core: Simplify the perf_mmap() control flowPeter Zijlstra
Identity-transform: if (c) { X1; } else { Y; goto l; } X2; l: into the simpler: if (c) { X1; X2; } else { Y; } [ mingo: Forward ported it ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lore.kernel.org/r/20241104135519.095904637@infradead.org
2025-03-04perf/bpf: Robustify perf_event_free_bpf_prog()Peter Zijlstra
Ensure perf_event_free_bpf_prog() is safe to call a second time; notably without making any references to event->pmu when there is no prog left. Note: perf_event_detach_bpf_prog() might leave a stale event->prog Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20241104135518.978956692@infradead.org
2025-03-04perf/core: Introduce perf_free_addr_filters()Peter Zijlstra
Replace _free_event()'s use of perf_addr_filters_splice()s use with an explicit perf_free_addr_filters() with the explicit propery that it is able to be called a second time without ill effect. Most notable, referencing event->pmu must be avoided when there are no filters left (from eg a previous call). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lore.kernel.org/r/20241104135518.868460518@infradead.org
2025-03-04perf/core: Add this_cpc() helperPeter Zijlstra
As a preparation for adding yet another indirection. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lore.kernel.org/r/20241104135518.650051565@infradead.org
2025-03-04perf/core: Merge struct pmu::pmu_disable_count into struct ↵Peter Zijlstra
perf_cpu_pmu_context::pmu_disable_count Because it makes no sense to have two per-cpu allocations per pmu. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lore.kernel.org/r/20241104135518.518730578@infradead.org
2025-03-04perf/core: Simplify perf_event_alloc()Peter Zijlstra
Using the previous simplifications, transition perf_event_alloc() to the cleanup way of things -- reducing error path magic. [ mingo: Ported it to recent kernels. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lore.kernel.org/r/20241104135518.410755241@infradead.org
2025-03-04perf/core: Simplify perf_init_event()Peter Zijlstra
Use the <linux/cleanup.h> guard() and scoped_guard() infrastructure to simplify the control flow. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20241104135518.302444446@infradead.org
2025-03-04perf/core: Simplify perf_pmu_register()Peter Zijlstra
Using the previously introduced perf_pmu_free() and a new IDR helper, simplify the perf_pmu_register error paths. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lore.kernel.org/r/20241104135518.198937277@infradead.org
2025-03-04perf/core: Simplify the perf_pmu_register() error pathPeter Zijlstra
The error path of perf_pmu_register() is of course very similar to a subset of perf_pmu_unregister(). Extract this common part in perf_pmu_free() and simplify things. [ mingo: Forward ported it ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lore.kernel.org/r/20241104135518.090915501@infradead.org
2025-03-04perf/core: Simplify the perf_event_alloc() error pathPeter Zijlstra
The error cleanup sequence in perf_event_alloc() is a subset of the existing _free_event() function (it must of course be). Split this out into __free_event() and simplify the error path. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com> Link: https://lore.kernel.org/r/20241104135517.967889521@infradead.org
2025-03-04perf/hw_breakpoint: Return EOPNOTSUPP for unsupported breakpoint typeSaket Kumar Bhaskar
Currently, __reserve_bp_slot() returns -ENOSPC for unsupported breakpoint types on the architecture. For example, powerpc does not support hardware instruction breakpoints. This causes the perf_skip BPF selftest to fail, as neither ENOENT nor EOPNOTSUPP is returned by perf_event_open for unsupported breakpoint types. As a result, the test that should be skipped for this arch is not correctly identified. To resolve this, hw_breakpoint_event_init() should exit early by checking for unsupported breakpoint types using hw_breakpoint_slots_cached() and return the appropriate error (-EOPNOTSUPP). Signed-off-by: Saket Kumar Bhaskar <skb99@linux.ibm.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Marco Elver <elver@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ian Rogers <irogers@google.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Link: https://lore.kernel.org/r/20250303092451.1862862-1-skb99@linux.ibm.com
2025-03-03genirq/msi: Expose MSI message data in debugfsHans Zhang
When debugging MSI-related hardware issues (e.g. interrupt delivery failures), developers currently need to either: 1. Recompile the kernel with dynamic debug for tracing msi_desc. 2. Manually read device registers through low-level tools. Both approaches become challenging in production environments where dynamic debugging is often disabled. The interrupt core provides a debugfs interface for inspection of interrupt related data, which contains the per interrupt information in the view of the hierarchical interrupt domains. Though this interface does not expose the MSI address/data pair, which is important information to: - Verify whether the MSI configuration matches the hardware expectations - Diagnose interrupt routing errors (e.g., mismatched destination ID) - Validate remapping behavior in virtualized environments Implement the debug_show() callback for the generic MSI interrupt domains, and use it to expose the MSI address/data pair in the per interrupt diagnostics. Sample output: address_hi: 0x00000000 address_lo: 0xfe670040 msg_data: 0x00000001 [ tglx: Massaged change log. Use irq_data_get_msi_desc() to avoid pointless lookup. ] Signed-off-by: Hans Zhang <18255117159@163.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/all/20250303121008.309265-1-18255117159@163.com
2025-03-03Merge tag 'v6.14-rc5' into x86/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-03-03sched_ext: Merge branch 'for-6.14-fixes' into for-6.15Tejun Heo
Pull for-6.14-fixes to receive: 9360dfe4cbd6 ("sched_ext: Validate prev_cpu in scx_bpf_select_cpu_dfl()") which conflicts with: 337d1b354a29 ("sched_ext: Move built-in idle CPU selection policy to a separate file") Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-03sched_ext: Validate prev_cpu in scx_bpf_select_cpu_dfl()Andrea Righi
If a BPF scheduler provides an invalid CPU (outside the nr_cpu_ids range) as prev_cpu to scx_bpf_select_cpu_dfl() it can cause a kernel crash. To prevent this, validate prev_cpu in scx_bpf_select_cpu_dfl() and trigger an scx error if an invalid CPU is specified. Fixes: f0e1a0643a59b ("sched_ext: Implement BPF extensible scheduler class") Cc: stable@vger.kernel.org # v6.12+ Signed-off-by: Andrea Righi <arighi@nvidia.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2025-03-03Merge tag 'probes-fixes-v6.14-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull probe events fixes from Masami Hiramatsu: - probe-events: Remove unused MAX_ARG_BUF_LEN macro - it is not used - fprobe-events: Log error for exceeding the number of entry args. Since the max number of entry args is limited, it should be checked and rejected when the parser detects it. - tprobe-events: Reject invalid tracepoint name If a user specifies an invalid tracepoint name (e.g. including '/') then the new event is not defined correctly in the eventfs. - tprobe-events: Fix a memory leak when tprobe defined with $retval There is a memory leak if tprobe is defined with $retval. * tag 'probes-fixes-v6.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: tracing: probe-events: Remove unused MAX_ARG_BUF_LEN macro tracing: fprobe-events: Log error for exceeding the number of entry args tracing: tprobe-events: Reject invalid tracepoint name tracing: tprobe-events: Fix a memory leak when tprobe with $retval
2025-03-03PM: hibernate: Avoid deadlock in hibernate_compressor_param_set()Lizhi Xu
syzbot reported a deadlock in lock_system_sleep() (see below). The write operation to "/sys/module/hibernate/parameters/compressor" conflicts with the registration of ieee80211 device, resulting in a deadlock when attempting to acquire system_transition_mutex under param_lock. To avoid this deadlock, change hibernate_compressor_param_set() to use mutex_trylock() for attempting to acquire system_transition_mutex and return -EBUSY when it fails. Task flags need not be saved or adjusted before calling mutex_trylock(&system_transition_mutex) because the caller is not going to end up waiting for this mutex and if it runs concurrently with system suspend in progress, it will be frozen properly when it returns to user space. syzbot report: syz-executor895/5833 is trying to acquire lock: ffffffff8e0828c8 (system_transition_mutex){+.+.}-{4:4}, at: lock_system_sleep+0x87/0xa0 kernel/power/main.c:56 but task is already holding lock: ffffffff8e07dc68 (param_lock){+.+.}-{4:4}, at: kernel_param_lock kernel/params.c:607 [inline] ffffffff8e07dc68 (param_lock){+.+.}-{4:4}, at: param_attr_store+0xe6/0x300 kernel/params.c:586 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (param_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 ieee80211_rate_control_ops_get net/mac80211/rate.c:220 [inline] rate_control_alloc net/mac80211/rate.c:266 [inline] ieee80211_init_rate_ctrl_alg+0x18d/0x6b0 net/mac80211/rate.c:1015 ieee80211_register_hw+0x20cd/0x4060 net/mac80211/main.c:1531 mac80211_hwsim_new_radio+0x304e/0x54e0 drivers/net/wireless/virtual/mac80211_hwsim.c:5558 init_mac80211_hwsim+0x432/0x8c0 drivers/net/wireless/virtual/mac80211_hwsim.c:6910 do_one_initcall+0x128/0x700 init/main.c:1257 do_initcall_level init/main.c:1319 [inline] do_initcalls init/main.c:1335 [inline] do_basic_setup init/main.c:1354 [inline] kernel_init_freeable+0x5c7/0x900 init/main.c:1568 kernel_init+0x1c/0x2b0 init/main.c:1457 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #2 (rtnl_mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 wg_pm_notification drivers/net/wireguard/device.c:80 [inline] wg_pm_notification+0x49/0x180 drivers/net/wireguard/device.c:64 notifier_call_chain+0xb7/0x410 kernel/notifier.c:85 notifier_call_chain_robust kernel/notifier.c:120 [inline] blocking_notifier_call_chain_robust kernel/notifier.c:345 [inline] blocking_notifier_call_chain_robust+0xc9/0x170 kernel/notifier.c:333 pm_notifier_call_chain_robust+0x27/0x60 kernel/power/main.c:102 snapshot_open+0x189/0x2b0 kernel/power/user.c:77 misc_open+0x35a/0x420 drivers/char/misc.c:179 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0x735/0x1c40 fs/open.c:956 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x1e88/0x2d80 fs/namei.c:3989 do_filp_open+0x20c/0x470 fs/namei.c:4016 do_sys_openat2+0x17a/0x1e0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 ((pm_chain_head).rwsem){++++}-{4:4}: down_read+0x9a/0x330 kernel/locking/rwsem.c:1524 blocking_notifier_call_chain_robust kernel/notifier.c:344 [inline] blocking_notifier_call_chain_robust+0xa9/0x170 kernel/notifier.c:333 pm_notifier_call_chain_robust+0x27/0x60 kernel/power/main.c:102 snapshot_open+0x189/0x2b0 kernel/power/user.c:77 misc_open+0x35a/0x420 drivers/char/misc.c:179 chrdev_open+0x237/0x6a0 fs/char_dev.c:414 do_dentry_open+0x735/0x1c40 fs/open.c:956 vfs_open+0x82/0x3f0 fs/open.c:1086 do_open fs/namei.c:3830 [inline] path_openat+0x1e88/0x2d80 fs/namei.c:3989 do_filp_open+0x20c/0x470 fs/namei.c:4016 do_sys_openat2+0x17a/0x1e0 fs/open.c:1428 do_sys_open fs/open.c:1443 [inline] __do_sys_openat fs/open.c:1459 [inline] __se_sys_openat fs/open.c:1454 [inline] __x64_sys_openat+0x175/0x210 fs/open.c:1454 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (system_transition_mutex){+.+.}-{4:4}: check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain kernel/locking/lockdep.c:3906 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 lock_system_sleep+0x87/0xa0 kernel/power/main.c:56 hibernate_compressor_param_set+0x1c/0x210 kernel/power/hibernate.c:1452 param_attr_store+0x18f/0x300 kernel/params.c:588 module_attr_store+0x55/0x80 kernel/params.c:924 sysfs_kf_write+0x117/0x170 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x33d/0x500 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:586 [inline] vfs_write+0x5ae/0x1150 fs/read_write.c:679 ksys_write+0x12b/0x250 fs/read_write.c:731 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: system_transition_mutex --> rtnl_mutex --> param_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(param_lock); lock(rtnl_mutex); lock(param_lock); lock(system_transition_mutex); *** DEADLOCK *** Reported-by: syzbot+ace60642828c074eb913@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=ace60642828c074eb913 Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com> Link: https://patch.msgid.link/20250224013139.3994500-1-lizhi.xu@windriver.com [ rjw: New subject matching the code changes, changelog edits ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2025-03-03tracing: probe-events: Remove unused MAX_ARG_BUF_LEN macroMasami Hiramatsu (Google)
Commit 18b1e870a496 ("tracing/probes: Add $arg* meta argument for all function args") introduced MAX_ARG_BUF_LEN but it is not used. Remove it. Link: https://lore.kernel.org/all/174055075876.4079315.8805416872155957588.stgit@mhiramat.tok.corp.google.com/ Fixes: 18b1e870a496 ("tracing/probes: Add $arg* meta argument for all function args") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-03-01Merge branch 'perf/urgent' into perf/core, to pick up dependent patches and ↵Ingo Molnar
fixes Signed-off-by: Ingo Molnar <mingo@kernel.org>
2025-03-01perf/core: Fix perf_pmu_register() vs. perf_init_event()Peter Zijlstra
There is a fairly obvious race between perf_init_event() doing idr_find() and perf_pmu_register() doing idr_alloc() with an incompletely initialized PMU pointer. Avoid by doing idr_alloc() on a NULL pointer to register the id, and swizzling the real struct pmu pointer at the end using idr_replace(). Also making sure to not set struct pmu members after publishing the struct pmu, duh. [ introduce idr_cmpxchg() in order to better handle the idr_replace() error case -- if it were to return an unexpected pointer, it will already have replaced the value and there is no going back. ] Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20241104135517.858805880@infradead.org
2025-03-01perf/core: Fix pmus_lock vs. pmus_srcu orderingPeter Zijlstra
Commit a63fbed776c7 ("perf/tracing/cpuhotplug: Fix locking order") placed pmus_lock inside pmus_srcu, this makes perf_pmu_unregister() trip lockdep. Move the locking about such that only pmu_idr and pmus (list) are modified while holding pmus_lock. This avoids doing synchronize_srcu() while holding pmus_lock and all is well again. Fixes: a63fbed776c7 ("perf/tracing/cpuhotplug: Fix locking order") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20241104135517.679556858@infradead.org
2025-03-01Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull kvm fixes from Paolo Bonzini: "ARM: - Fix TCR_EL2 configuration to not use the ASID in TTBR1_EL2 and not mess-up T1SZ/PS by using the HCR_EL2.E2H==0 layout. - Bring back the VMID allocation to the vcpu_load phase, ensuring that we only setup VTTBR_EL2 once on VHE. This cures an ugly race that would lead to running with an unallocated VMID. RISC-V: - Fix hart status check in SBI HSM extension - Fix hart suspend_type usage in SBI HSM extension - Fix error returned by SBI IPI and TIME extensions for unsupported function IDs - Fix suspend_type usage in SBI SUSP extension - Remove unnecessary vcpu kick after injecting interrupt via IMSIC guest file x86: - Fix an nVMX bug where KVM fails to detect that, after nested VM-Exit, L1 has a pending IRQ (or NMI). - To avoid freeing the PIC while vCPUs are still around, which would cause a NULL pointer access with the previous patch, destroy vCPUs before any VM-level destruction. - Handle failures to create vhost_tasks" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: kvm: retry nx_huge_page_recovery_thread creation vhost: return task creation error instead of NULL KVM: nVMX: Process events on nested VM-Exit if injectable IRQ or NMI is pending KVM: x86: Free vCPUs before freeing VM state riscv: KVM: Remove unnecessary vcpu kick KVM: arm64: Ensure a VMID is allocated before programming VTTBR_EL2 KVM: arm64: Fix tcr_el2 initialisation in hVHE mode riscv: KVM: Fix SBI sleep_type use riscv: KVM: Fix SBI TIME error generation riscv: KVM: Fix SBI IPI error generation riscv: KVM: Fix hart suspend_type use riscv: KVM: Fix hart suspend status check
2025-03-01watch_queue: fix pipe accounting mismatchEric Sandeen
Currently, watch_queue_set_size() modifies the pipe buffers charged to user->pipe_bufs without updating the pipe->nr_accounted on the pipe itself, due to the if (!pipe_has_watch_queue()) test in pipe_resize_ring(). This means that when the pipe is ultimately freed, we decrement user->pipe_bufs by something other than what than we had charged to it, potentially leading to an underflow. This in turn can cause subsequent too_many_pipe_buffers_soft() tests to fail with -EPERM. To remedy this, explicitly account for the pipe usage in watch_queue_set_size() to match the number set via account_pipe_buffers() (It's unclear why watch_queue_set_size() does not update nr_accounted; it may be due to intentional overprovisioning in watch_queue_set_size()?) Fixes: e95aada4cb93d ("pipe: wakeup wr_wait after setting max_usage") Signed-off-by: Eric Sandeen <sandeen@redhat.com> Link: https://lore.kernel.org/r/206682a8-0604-49e5-8224-fdbe0c12b460@redhat.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-03-01vhost: return task creation error instead of NULLKeith Busch
Lets callers distinguish why the vhost task creation failed. No one currently cares why it failed, so no real runtime change from this patch, but that will not be the case for long. Signed-off-by: Keith Busch <kbusch@kernel.org> Message-ID: <20250227230631.303431-2-kbusch@meta.com> Reviewed-by: Mike Christie <michael.christie@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2025-02-28Merge tag 'sched-urgent-2025-02-28' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fix from Ingo Molnar: "Prevent cond_resched() based preemption when interrupts are disabled, on PREEMPT_NONE and PREEMPT_VOLUNTARY kernels" * tag 'sched-urgent-2025-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/core: Prevent rescheduling when interrupts are disabled
2025-02-28Merge tag 'perf-urgent-2025-02-28' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf event fixes from Ingo Molnar: "Miscellaneous perf events fixes and a minor HW enablement change: - Fix missing RCU protection in perf_iterate_ctx() - Fix pmu_ctx_list ordering bug - Reject the zero page in uprobes - Fix a family of bugs related to low frequency sampling - Add Intel Arrow Lake U CPUs to the generic Arrow Lake RAPL support table - Fix a lockdep-assert false positive in uretprobes" * tag 'perf-urgent-2025-02-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: uprobes: Remove too strict lockdep_assert() condition in hprobe_expire() perf/x86/rapl: Add support for Intel Arrow Lake U perf/x86/intel: Use better start period for frequency mode perf/core: Fix low freq setting via IOC_PERIOD perf/x86: Fix low freqency setting issue uprobes: Reject the shared zeropage in uprobe_write_opcode() perf/core: Order the PMU list to fix warning about unordered pmu_ctx_list perf/core: Add RCU read lock protection to perf_iterate_ctx()
2025-02-28Merge tag 'trace-v6.14-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix crash from bad histogram entry An error path in the histogram creation could leave an entry in a link list that gets freed. Then when a new entry is added it can cause a u-a-f bug. This is fixed by restructuring the code so that the histogram is consistent on failure and everything is cleaned up appropriately. - Fix fprobe self test The fprobe self test relies on no function being attached by ftrace. BPF programs can attach to functions via ftrace and systemd now does so. This causes those functions to appear in the enabled_functions list which holds all functions attached by ftrace. The selftest also uses that file to see if functions are being connected correctly. It counts the functions in the file, but if there's already functions in the file, it fails. Instead, add the number of functions in the file at the start of the test to all the calculations during the test. - Fix potential division by zero of the function profiler stddev The calculated divisor that calculates the standard deviation of the function times can overflow. If the overflow happens to land on zero, that can cause a division by zero. Check for zero from the calculation before doing the division. TODO: Catch when it ever overflows and report it accordingly. For now, just prevent the system from crashing. * tag 'trace-v6.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ftrace: Avoid potential division by zero in function_stat_show() selftests/ftrace: Let fprobe test consider already enabled functions tracing: Fix bad hist from corrupting named_triggers list
2025-02-28Merge tag 'for-joerg' of ↵Joerg Roedel
git://git.kernel.org/pub/scm/linux/kernel/git/jgg/iommufd into core iommu shared branch with iommufd The three dependent series on a shared branch: - Change the iommufd fault handle into an always present hwpt handle in the domain - Give iommufd its own SW_MSI implementation along with some IRQ layer rework - Improvements to the handle attach API
2025-02-27ftrace: Avoid potential division by zero in function_stat_show()Nikolay Kuratov
Check whether denominator expression x * (x - 1) * 1000 mod {2^32, 2^64} produce zero and skip stddev computation in that case. For now don't care about rec->counter * rec->counter overflow because rec->time * rec->time overflow will likely happen earlier. Cc: stable@vger.kernel.org Cc: Wen Yang <wenyang@linux.alibaba.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20250206090156.1561783-1-kniv@yandex-team.ru Fixes: e31f7939c1c27 ("ftrace: Avoid potential division by zero in function profiler") Signed-off-by: Nikolay Kuratov <kniv@yandex-team.ru> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-02-27tracing: Fix bad hist from corrupting named_triggers listSteven Rostedt
The following commands causes a crash: ~# cd /sys/kernel/tracing/events/rcu/rcu_callback ~# echo 'hist:name=bad:keys=common_pid:onmax(bogus).save(common_pid)' > trigger bash: echo: write error: Invalid argument ~# echo 'hist:name=bad:keys=common_pid' > trigger Because the following occurs: event_trigger_write() { trigger_process_regex() { event_hist_trigger_parse() { data = event_trigger_alloc(..); event_trigger_register(.., data) { cmd_ops->reg(.., data, ..) [hist_register_trigger()] { data->ops->init() [event_hist_trigger_init()] { save_named_trigger(name, data) { list_add(&data->named_list, &named_triggers); } } } } ret = create_actions(); (return -EINVAL) if (ret) goto out_unreg; [..] ret = hist_trigger_enable(data, ...) { list_add_tail_rcu(&data->list, &file->triggers); <<<---- SKIPPED!!! (this is important!) [..] out_unreg: event_hist_unregister(.., data) { cmd_ops->unreg(.., data, ..) [hist_unregister_trigger()] { list_for_each_entry(iter, &file->triggers, list) { if (!hist_trigger_match(data, iter, named_data, false)) <- never matches continue; [..] test = iter; } if (test && test->ops->free) <<<-- test is NULL test->ops->free(test) [event_hist_trigger_free()] { [..] if (data->name) del_named_trigger(data) { list_del(&data->named_list); <<<<-- NEVER gets removed! } } } } [..] kfree(data); <<<-- frees item but it is still on list The next time a hist with name is registered, it causes an u-a-f bug and the kernel can crash. Move the code around such that if event_trigger_register() succeeds, the next thing called is hist_trigger_enable() which adds it to the list. A bunch of actions is called if get_named_trigger_data() returns false. But that doesn't need to be called after event_trigger_register(), so it can be moved up, allowing event_trigger_register() to be called just before hist_trigger_enable() keeping them together and allowing the file->triggers to be properly populated. Cc: stable@vger.kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Link: https://lore.kernel.org/20250227163944.1c37f85f@gandalf.local.home Fixes: 067fe038e70f6 ("tracing: Add variable reference handling to hist triggers") Reported-by: Tomas Glozar <tglozar@redhat.com> Tested-by: Tomas Glozar <tglozar@redhat.com> Reviewed-by: Tom Zanussi <zanussi@kernel.org> Closes: https://lore.kernel.org/all/CAP4=nvTsxjckSBTz=Oe_UYh8keD9_sZC4i++4h72mJLic4_W4A@mail.gmail.com/ Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-02-27sched/core: Prevent rescheduling when interrupts are disabledThomas Gleixner
David reported a warning observed while loop testing kexec jump: Interrupts enabled after irqrouter_resume+0x0/0x50 WARNING: CPU: 0 PID: 560 at drivers/base/syscore.c:103 syscore_resume+0x18a/0x220 kernel_kexec+0xf6/0x180 __do_sys_reboot+0x206/0x250 do_syscall_64+0x95/0x180 The corresponding interrupt flag trace: hardirqs last enabled at (15573): [<ffffffffa8281b8e>] __up_console_sem+0x7e/0x90 hardirqs last disabled at (15580): [<ffffffffa8281b73>] __up_console_sem+0x63/0x90 That means __up_console_sem() was invoked with interrupts enabled. Further instrumentation revealed that in the interrupt disabled section of kexec jump one of the syscore_suspend() callbacks woke up a task, which set the NEED_RESCHED flag. A later callback in the resume path invoked cond_resched() which in turn led to the invocation of the scheduler: __cond_resched+0x21/0x60 down_timeout+0x18/0x60 acpi_os_wait_semaphore+0x4c/0x80 acpi_ut_acquire_mutex+0x3d/0x100 acpi_ns_get_node+0x27/0x60 acpi_ns_evaluate+0x1cb/0x2d0 acpi_rs_set_srs_method_data+0x156/0x190 acpi_pci_link_set+0x11c/0x290 irqrouter_resume+0x54/0x60 syscore_resume+0x6a/0x200 kernel_kexec+0x145/0x1c0 __do_sys_reboot+0xeb/0x240 do_syscall_64+0x95/0x180 This is a long standing problem, which probably got more visible with the recent printk changes. Something does a task wakeup and the scheduler sets the NEED_RESCHED flag. cond_resched() sees it set and invokes schedule() from a completely bogus context. The scheduler enables interrupts after context switching, which causes the above warning at the end. Quite some of the code paths in syscore_suspend()/resume() can result in triggering a wakeup with the exactly same consequences. They might not have done so yet, but as they share a lot of code with normal operations it's just a question of time. The problem only affects the PREEMPT_NONE and PREEMPT_VOLUNTARY scheduling models. Full preemption is not affected as cond_resched() is disabled and the preemption check preemptible() takes the interrupt disabled flag into account. Cure the problem by adding a corresponding check into cond_resched(). Reported-by: David Woodhouse <dwmw@amazon.co.uk> Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: David Woodhouse <dwmw@amazon.co.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: stable@vger.kernel.org Closes: https://lore.kernel.org/all/7717fe2ac0ce5f0a2c43fdab8b11f4483d54a2a4.camel@infradead.org
2025-02-27x86/bpf: Fix BPF percpu accessesBrian Gerst
Due to this recent commit in the x86 tree: 9d7de2aa8b41 ("Use relative percpu offsets") percpu addresses went from positive offsets from the GSBASE to negative kernel virtual addresses. The BPF verifier has an optimization for x86-64 that loads the address of cpu_number into a register, but was only doing a 32-bit load which truncates negative addresses. Change it to a 64-bit load so that the address is properly sign-extended. Fixes: 9d7de2aa8b41 ("Use relative percpu offsets") Signed-off-by: Brian Gerst <brgerst@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Uros Bizjak <ubizjak@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20250227195302.1667654-1-brgerst@gmail.com
2025-02-27Change inode_operations.mkdir to return struct dentry *NeilBrown
Some filesystems, such as NFS, cifs, ceph, and fuse, do not have complete control of sequencing on the actual filesystem (e.g. on a different server) and may find that the inode created for a mkdir request already exists in the icache and dcache by the time the mkdir request returns. For example, if the filesystem is mounted twice the directory could be visible on the other mount before it is on the original mount, and a pair of name_to_handle_at(), open_by_handle_at() calls could instantiate the directory inode with an IS_ROOT() dentry before the first mkdir returns. This means that the dentry passed to ->mkdir() may not be the one that is associated with the inode after the ->mkdir() completes. Some callers need to interact with the inode after the ->mkdir completes and they currently need to perform a lookup in the (rare) case that the dentry is no longer hashed. This lookup-after-mkdir requires that the directory remains locked to avoid races. Planned future patches to lock the dentry rather than the directory will mean that this lookup cannot be performed atomically with the mkdir. To remove this barrier, this patch changes ->mkdir to return the resulting dentry if it is different from the one passed in. Possible returns are: NULL - the directory was created and no other dentry was used ERR_PTR() - an error occurred non-NULL - this other dentry was spliced in This patch only changes file-systems to return "ERR_PTR(err)" instead of "err" or equivalent transformations. Subsequent patches will make further changes to some file-systems to return a correct dentry. Not all filesystems reliably result in a positive hashed dentry: - NFS, cifs, hostfs will sometimes need to perform a lookup of the name to get inode information. Races could result in this returning something different. Note that this lookup is non-atomic which is what we are trying to avoid. Placing the lookup in filesystem code means it only happens when the filesystem has no other option. - kernfs and tracefs leave the dentry negative and the ->revalidate operation ensures that lookup will be called to correctly populate the dentry. This could be fixed but I don't think it is important to any of the users of vfs_mkdir() which look at the dentry. The recommendation to use d_drop();d_splice_alias() is ugly but fits with current practice. A planned future patch will change this. Reviewed-by: Jeff Layton <jlayton@kernel.org> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: NeilBrown <neilb@suse.de> Link: https://lore.kernel.org/r/20250227013949.536172-2-neilb@suse.de Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.14-rc5). Conflicts: drivers/net/ethernet/cadence/macb_main.c fa52f15c745c ("net: cadence: macb: Synchronize stats calculations") 75696dd0fd72 ("net: cadence: macb: Convert to get_stats64") https://lore.kernel.org/20250224125848.68ee63e5@canb.auug.org.au Adjacent changes: drivers/net/ethernet/intel/ice/ice_sriov.c 79990cf5e7ad ("ice: Fix deinitializing VF in error path") a203163274a4 ("ice: simplify VF MSI-X managing") net/ipv4/tcp.c 18912c520674 ("tcp: devmem: don't write truncated dmabuf CMSGs to userspace") 297d389e9e5b ("net: prefix devmem specific helpers") net/mptcp/subflow.c 8668860b0ad3 ("mptcp: reset when MPTCP opts are dropped after join") c3349a22c200 ("mptcp: consolidate subflow cleanup") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-27bpf: Use try_alloc_pages() to allocate pages for bpf needs.Alexei Starovoitov
Use try_alloc_pages() and free_pages_nolock() for BPF needs when context doesn't allow using normal alloc_pages. This is a prerequisite for further work. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/r/20250222024427.30294-7-alexei.starovoitov@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-02-27cgroup/rstat: Fix forceidle time in cpu.statAbel Wu
The commit b824766504e4 ("cgroup/rstat: add force idle show helper") retrieves forceidle_time outside cgroup_rstat_lock for non-root cgroups which can be potentially inconsistent with other stats. Rather than reverting that commit, fix it in a way that retains the effort of cleaning up the ifdef-messes. Fixes: b824766504e4 ("cgroup/rstat: add force idle show helper") Signed-off-by: Abel Wu <wuyun.abel@bytedance.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2025-02-27bpf: cpumap: switch to napi_skb_cache_get_bulk()Alexander Lobakin
Now that cpumap uses GRO, which drops unused skb heads to the NAPI cache, use napi_skb_cache_get_bulk() to try to reuse cached entries and lower MM layer pressure. Always disable the BH before checking and running the cpumap-pinned XDP prog and don't re-enable it in between that and allocating an skb bulk, as we can access the NAPI caches only from the BH context. The better GRO aggregates packets, the less new skbs will be allocated. If an aggregated skb contains 16 frags, this means 15 skbs were returned to the cache, so next 15 skbs will be built without allocating anything. The same trafficgen UDP GRO test now shows: GRO off GRO on threaded GRO 2.3 4 Mpps thr bulk GRO 2.4 4.7 Mpps diff +4 +17 % Comparing to the baseline cpumap: baseline 2.7 N/A Mpps thr bulk GRO 2.4 4.7 Mpps diff -11 +74 % Tested-by: Daniel Xu <dxu@dxuuu.xyz> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-02-27bpf: cpumap: reuse skb array instead of a linked list to chain skbsAlexander Lobakin
cpumap still uses linked lists to store a list of skbs to pass to the stack. Now that we don't use listified Rx in favor of napi_gro_receive(), linked list is now an unneeded overhead. Inside the polling loop, we already have an array of skbs. Let's reuse it for skbs passed to cpumap (generic XDP) and keep there in case of XDP_PASS when a program is installed to the map itself. Don't list regular xdp_frames after converting them to skbs as well; store them in the mentioned array (but *before* generic skbs as the latters have lower priority) and call gro_receive_skb() for each array element after they're done. Tested-by: Daniel Xu <dxu@dxuuu.xyz> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-02-27bpf: cpumap: switch to GRO from netif_receive_skb_list()Alexander Lobakin
cpumap has its own BH context based on kthread. It has a sane batch size of 8 frames per one cycle. GRO can be used here on its own. Adjust cpumap calls to the upper stack to use GRO API instead of netif_receive_skb_list() which processes skbs by batches, but doesn't involve GRO layer at all. In plenty of tests, GRO performs better than listed receiving even given that it has to calculate full frame checksums on the CPU. As GRO passes the skbs to the upper stack in the batches of @gro_normal_batch, i.e. 8 by default, and skb->dev points to the device where the frame comes from, it is enough to disable GRO netdev feature on it to completely restore the original behaviour: untouched frames will be being bulked and passed to the upper stack by 8, as it was with netif_receive_skb_list(). Tested-by: Daniel Xu <dxu@dxuuu.xyz> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-02-27Merge patch series "prep patches for my mkdir series"Christian Brauner
NeilBrown <neilb@suse.de> says: These two patches are cleanup are dependencies for my mkdir changes and subsequence directory locking changes. * patches from https://lore.kernel.org/r/20250226062135.2043651-1-neilb@suse.de: (2 commits) nfsd: drop fh_update() from S_IFDIR branch of nfsd_create_locked() nfs/vfs: discard d_exact_alias() Link: https://lore.kernel.org/r/20250226062135.2043651-1-neilb@suse.de Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-02-26trace/osnoise: Add trace events for samplesTomas Glozar
Add trace events that fire at osnoise and timerlat sample generation, in addition to the already existing noise and threshold events. This allows processing the samples directly in the kernel, either with ftrace triggers or with BPF. Cc: John Kacur <jkacur@redhat.com> Cc: Luis Goncalves <lgoncalv@redhat.com> Link: https://lore.kernel.org/20250203090418.1458923-1-tglozar@redhat.com Signed-off-by: Tomas Glozar <tglozar@redhat.com> Tested-by: Gabriele Monaco <gmonaco@redhat.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-02-27tracing: fprobe-events: Log error for exceeding the number of entry argsMasami Hiramatsu (Google)
Add error message when the number of entry argument exceeds the maximum size of entry data. This is currently checked when registering fprobe, but in this case no error message is shown in the error_log file. Link: https://lore.kernel.org/all/174055074269.4079315.17809232650360988538.stgit@mhiramat.tok.corp.google.com/ Fixes: 25f00e40ce79 ("tracing/probes: Support $argN in return probe (kprobe and fprobe)") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2025-02-27tracing: tprobe-events: Reject invalid tracepoint nameMasami Hiramatsu (Google)
Commit 57a7e6de9e30 ("tracing/fprobe: Support raw tracepoints on future loaded modules") allows user to set a tprobe on non-exist tracepoint but it does not check the tracepoint name is acceptable. So it leads tprobe has a wrong character for events (e.g. with subsystem prefix). In this case, the event is not shown in the events directory. Reject such invalid tracepoint name. The tracepoint name must consist of alphabet or digit or '_'. Link: https://lore.kernel.org/all/174055073461.4079315.15875502830565214255.stgit@mhiramat.tok.corp.google.com/ Fixes: 57a7e6de9e30 ("tracing/fprobe: Support raw tracepoints on future loaded modules") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: stable@vger.kernel.org
2025-02-27tracing: tprobe-events: Fix a memory leak when tprobe with $retvalMasami Hiramatsu (Google)
Fix a memory leak when a tprobe is defined with $retval. This combination is not allowed, but the parse_symbol_and_return() does not free the *symbol which should not be used if it returns the error. Thus, it leaks the *symbol memory in that error path. Link: https://lore.kernel.org/all/174055072650.4079315.3063014346697447838.stgit@mhiramat.tok.corp.google.com/ Fixes: ce51e6153f77 ("tracing: fprobe-event: Fix to check tracepoint event and return") Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org> Cc: stable@vger.kernel.org
2025-02-26Merge tag 'wq-for-6.14-rc4-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull workqueue update from Tejun Heo: "This contains a patch improve debug visibility. While it isn't a fix, the change carries virtually no risk and makes it substantially easier to chase down a class of problems" * tag 'wq-for-6.14-rc4-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: Log additional details when rejecting work