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2024-04-14perf/ring_buffer: Trigger IO signals for watermark_wakeupKyle Huey
perf_output_wakeup() already marks the perf event fd available for polling. Trigger IO signals with FASYNC too. Signed-off-by: Kyle Huey <khuey@kylehuey.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240413141618.4160-3-khuey@kylehuey.com
2024-04-14perf: Move perf_event_fasync() to perf_event.hKyle Huey
This will allow it to be called from perf_output_wakeup(). Signed-off-by: Kyle Huey <khuey@kylehuey.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240413141618.4160-2-khuey@kylehuey.com
2024-04-14Merge branch 'linus' into perf/core, to pick up perf/urgent fixesIngo Molnar
Pick up perf/urgent fixes that are upstream already, but not yet in the perf/core development branch. Signed-off-by: Ingo Molnar <mingo@kernel.org>
2024-04-14Merge tag 'x86-urgent-2024-04-14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull misc x86 fixes from Ingo Molnar: - Follow up fixes for the BHI mitigations code - Fix !SPECULATION_MITIGATIONS bug not turning off mitigations as expected - Work around an APIC emulation bug when the kernel is built with Clang and run as a SEV guest - Follow up x86 topology fixes * tag 'x86-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu/amd: Move TOPOEXT enablement into the topology parser x86/cpu/amd: Make the NODEID_MSR union actually work x86/cpu/amd: Make the CPUID 0x80000008 parser correct x86/bugs: Replace CONFIG_SPECTRE_BHI_{ON,OFF} with CONFIG_MITIGATION_SPECTRE_BHI x86/bugs: Remove CONFIG_BHI_MITIGATION_AUTO and spectre_bhi=auto x86/bugs: Clarify that syscall hardening isn't a BHI mitigation x86/bugs: Fix BHI handling of RRSBA x86/bugs: Rename various 'ia32_cap' variables to 'x86_arch_cap_msr' x86/bugs: Cache the value of MSR_IA32_ARCH_CAPABILITIES x86/bugs: Fix BHI documentation x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n x86/topology: Don't update cpu_possible_map in topo_set_cpuids() x86/bugs: Fix return type of spectre_bhi_state() x86/apic: Force native_apic_mem_read() to use the MOV instruction
2024-04-14Merge tag 'timers-urgent-2024-04-14' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Ingo Molnar: - Address a (valid) W=1 build warning - Fix timer self-tests - Annotate a KCSAN warning wrt. accesses to the tick_do_timer_cpu global variable - Address a !CONFIG_BUG build warning * tag 'timers-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: selftests: kselftest: Fix build failure with NOLIBC selftests: timers: Fix abs() warning in posix_timers test selftests: kselftest: Mark functions that unconditionally call exit() as __noreturn selftests: timers: Fix posix_timers ksft_print_msg() warning selftests: timers: Fix valid-adjtimex signed left-shift undefined behavior bug: Fix no-return-statement warning with !CONFIG_BUG timekeeping: Use READ/WRITE_ONCE() for tick_do_timer_cpu selftests/timers/posix_timers: Reimplement check_timer_distribution() irqflags: Explicitly ignore lockdep_hrtimer_exit() argument
2024-04-14Merge tag 'dma-maping-6.9-2024-04-14' of ↵Linus Torvalds
git://git.infradead.org/users/hch/dma-mapping Pull dma-mapping fixes from Christoph Hellwig: - fix up swiotlb buffer padding even more (Petr Tesarik) - fix for partial dma_sync on swiotlb (Michael Kelley) - swiotlb debugfs fix (Dexuan Cui) * tag 'dma-maping-6.9-2024-04-14' of git://git.infradead.org/users/hch/dma-mapping: swiotlb: do not set total_used to 0 in swiotlb_create_debugfs_files() swiotlb: fix swiotlb_bounce() to do partial sync's correctly swiotlb: extend buffer pre-padding to alloc_align_mask if necessary
2024-04-12bpf: Fix a verifier verbose messageAnton Protopopov
Long ago a map file descriptor in a pseudo ldimm64 instruction could only be present as an immediate value insn[0].imm, and thus this value was used in a verbose verifier message printed when the file descriptor wasn't valid. Since addition of BPF_PSEUDO_MAP_IDX_VALUE/BPF_PSEUDO_MAP_IDX the insn[0].imm field can also contain an index pointing to the file descriptor in the attr.fd_array array. However, if the file descriptor is invalid, the verifier still prints the verbose message containing value of insn[0].imm. Patch the verifier message to always print the actual file descriptor value. Fixes: 387544bfa291 ("bpf: Introduce fd_idx") Signed-off-by: Anton Protopopov <aspsk@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20240412141100.3562942-1-aspsk@isovalent.com
2024-04-12Merge tag 'trace-v6.9-rc3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix the buffer_percent accounting as it is dependent on three variables: 1) pages_read - number of subbuffers read 2) pages_lost - number of subbuffers lost due to overwrite 3) pages_touched - number of pages that a writer entered These three counters only increment, and to know how many active pages there are on the buffer at any given time, the pages_read and pages_lost are subtracted from pages_touched. But the pages touched was incremented whenever any writer went to the next subbuffer even if it wasn't the only one, so it was incremented more than it should be causing the counter for how many subbuffers currently have content incorrect, which caused the buffer_percent that holds waiters until the ring buffer is filled to a given percentage to wake up early. - Fix warning of unused functions when PERF_EVENTS is not configured in - Replace bad tab with space in Kconfig for FTRACE_RECORD_RECURSION_SIZE - Fix to some kerneldoc function comments in eventfs code. * tag 'trace-v6.9-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Only update pages_touched when a new page is touched tracing: hide unused ftrace_event_id_fops tracing: Fix FTRACE_RECORD_RECURSION_SIZE Kconfig entry eventfs: Fix kernel-doc comments to functions
2024-04-12watchdog/softlockup: Report the most frequent interruptsBitao Hu
When the watchdog determines that the current soft lockup is due to an interrupt storm based on CPU utilization, reporting the most frequent interrupts could be good enough for further troubleshooting. Below is an example of interrupt storm. The call tree does not provide useful information, but analyzing which interrupt caused the soft lockup by comparing the counts of interrupts during the lockup period allows to identify the culprit. [ 638.870231] watchdog: BUG: soft lockup - CPU#9 stuck for 26s! [swapper/9:0] [ 638.870825] CPU#9 Utilization every 4s during lockup: [ 638.871194] #1: 0% system, 0% softirq, 100% hardirq, 0% idle [ 638.871652] #2: 0% system, 0% softirq, 100% hardirq, 0% idle [ 638.872107] #3: 0% system, 0% softirq, 100% hardirq, 0% idle [ 638.872563] #4: 0% system, 0% softirq, 100% hardirq, 0% idle [ 638.873018] #5: 0% system, 0% softirq, 100% hardirq, 0% idle [ 638.873494] CPU#9 Detect HardIRQ Time exceeds 50%. Most frequent HardIRQs: [ 638.873994] #1: 330945 irq#7 [ 638.874236] #2: 31 irq#82 [ 638.874493] #3: 10 irq#10 [ 638.874744] #4: 2 irq#89 [ 638.874992] #5: 1 irq#102 ... [ 638.875313] Call trace: [ 638.875315] __do_softirq+0xa8/0x364 Signed-off-by: Bitao Hu <yaoma@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Liu Song <liusong@linux.alibaba.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20240411074134.30922-6-yaoma@linux.alibaba.com
2024-04-12watchdog/softlockup: Low-overhead detection of interrupt stormBitao Hu
The following softlockup is caused by interrupt storm, but it cannot be identified from the call tree. Because the call tree is just a snapshot and doesn't fully capture the behavior of the CPU during the soft lockup. watchdog: BUG: soft lockup - CPU#28 stuck for 23s! [fio:83921] ... Call trace: __do_softirq+0xa0/0x37c __irq_exit_rcu+0x108/0x140 irq_exit+0x14/0x20 __handle_domain_irq+0x84/0xe0 gic_handle_irq+0x80/0x108 el0_irq_naked+0x50/0x58 Therefore, it is necessary to report CPU utilization during the softlockup_threshold period (report once every sample_period, for a total of 5 reportings), like this: watchdog: BUG: soft lockup - CPU#28 stuck for 23s! [fio:83921] CPU#28 Utilization every 4s during lockup: #1: 0% system, 0% softirq, 100% hardirq, 0% idle #2: 0% system, 0% softirq, 100% hardirq, 0% idle #3: 0% system, 0% softirq, 100% hardirq, 0% idle #4: 0% system, 0% softirq, 100% hardirq, 0% idle #5: 0% system, 0% softirq, 100% hardirq, 0% idle ... This is helpful in determining whether an interrupt storm has occurred or in identifying the cause of the softlockup. The criteria for determination are as follows: a. If the hardirq utilization is high, then interrupt storm should be considered and the root cause cannot be determined from the call tree. b. If the softirq utilization is high, then the call might not necessarily point at the root cause. c. If the system utilization is high, then analyzing the root cause from the call tree is possible in most cases. The mechanism requires a considerable amount of global storage space when configured for the maximum number of CPUs. Therefore, adding a SOFTLOCKUP_DETECTOR_INTR_STORM Kconfig knob that defaults to "yes" if the max number of CPUs is <= 128. Signed-off-by: Bitao Hu <yaoma@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Douglas Anderson <dianders@chromium.org> Reviewed-by: Liu Song <liusong@linux.alibaba.com> Link: https://lore.kernel.org/r/20240411074134.30922-5-yaoma@linux.alibaba.com
2024-04-12genirq: Avoid summation loops for /proc/interruptsBitao Hu
show_interrupts() unconditionally accumulates the per CPU interrupt statistics to determine whether an interrupt was ever raised. This can be avoided for all interrupts which are not strictly per CPU and not of type NMI because those interrupts provide already an accumulated counter. The required logic is already implemented in kstat_irqs(). Split the inner access logic out of kstat_irqs() and use it for kstat_irqs() and show_interrupts() to avoid the accumulation loop when possible. Originally-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Bitao Hu <yaoma@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Liu Song <liusong@linux.alibaba.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Link: https://lore.kernel.org/r/20240411074134.30922-4-yaoma@linux.alibaba.com
2024-04-12genirq: Provide a snapshot mechanism for interrupt statisticsBitao Hu
The soft lockup detector lacks a mechanism to identify interrupt storms as root cause of a lockup. To enable this the detector needs a mechanism to snapshot the interrupt count statistics on a CPU when the detector observes a potential lockup scenario and compare that against the interrupt count when it warns about the lockup later on. The number of interrupts in that period give a hint whether the lockup might have been caused by an interrupt storm. Instead of having extra storage in the lockup detector and accessing the internals of the interrupt descriptor directly, add a snapshot member to the per CPU irq_desc::kstat_irq structure and provide interfaces to take a snapshot of all interrupts on the current CPU and to retrieve the delta of a specific interrupt later on. Originally-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Bitao Hu <yaoma@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240411074134.30922-3-yaoma@linux.alibaba.com
2024-04-12genirq: Convert kstat_irqs to a structBitao Hu
The irq_desc::kstat_irqs member is a per-CPU variable of type int, which is only capable of counting. A snapshot mechanism for interrupt statistics will be added soon, which requires an additional variable to store the snapshot. To facilitate expansion, convert kstat_irqs here to a struct containing only the count. Originally-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Bitao Hu <yaoma@linux.alibaba.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20240411074134.30922-2-yaoma@linux.alibaba.com
2024-04-12perf/bpf: Change the !CONFIG_BPF_SYSCALL stubs to static inlinesIngo Molnar
Otherwise the compiler will be unhappy if they go unused, which they do on allnoconfigs. Signed-off-by: Ingo Molnar <mingo@kernel.org> Cc: Kyle Huey <me@kylehuey.com> Link: https://lore.kernel.org/r/ZhkE9F4dyfR2dH2D@gmail.com
2024-04-12perf/bpf: Allow a BPF program to suppress all sample side effectsKyle Huey
Returning zero from a BPF program attached to a perf event already suppresses any data output. Return early from __perf_event_overflow() in this case so it will also suppress event_limit accounting, SIGTRAP generation, and F_ASYNC signalling. Signed-off-by: Kyle Huey <khuey@kylehuey.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Song Liu <song@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240412015019.7060-7-khuey@kylehuey.com
2024-04-12perf/bpf: Call BPF handler directly, not through overflow machineryKyle Huey
To ultimately allow BPF programs attached to perf events to completely suppress all of the effects of a perf event overflow (rather than just the sample output, as they do today), call bpf_overflow_handler() from __perf_event_overflow() directly rather than modifying struct perf_event's overflow_handler. Return the BPF program's return value from bpf_overflow_handler() so that __perf_event_overflow() knows how to proceed. Remove the now unnecessary orig_overflow_handler from struct perf_event. This patch is solely a refactoring and results in no behavior change. Suggested-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Kyle Huey <khuey@kylehuey.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Acked-by: Song Liu <song@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/r/20240412015019.7060-5-khuey@kylehuey.com
2024-04-12perf/bpf: Create bpf_overflow_handler() stub for !CONFIG_BPF_SYSCALLKyle Huey
This will allow __perf_event_overflow() (which is independent of CONFIG_BPF_SYSCALL) to call bpf_overflow_handler(). Signed-off-by: Kyle Huey <khuey@kylehuey.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240412015019.7060-3-khuey@kylehuey.com
2024-04-12perf/bpf: Reorder bpf_overflow_handler() ahead of __perf_event_overflow()Kyle Huey
This will allow __perf_event_overflow() to call bpf_overflow_handler(). Signed-off-by: Kyle Huey <khuey@kylehuey.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20240412015019.7060-2-khuey@kylehuey.com
2024-04-12locking/pvqspinlock: Use try_cmpxchg() in qspinlock_paravirt.hUros Bizjak
Use try_cmpxchg(*ptr, &old, new) instead of cmpxchg(*ptr, old, new) == old in qspinlock_paravirt.h x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after cmpxchg. No functional change intended. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Waiman Long <longman@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20240411192317.25432-2-ubizjak@gmail.com
2024-04-12locking/pvqspinlock: Use try_cmpxchg_acquire() in trylock_clear_pending()Uros Bizjak
Replace this pattern in trylock_clear_pending(): cmpxchg_acquire(*ptr, old, new) == old ... with the simpler and faster: try_cmpxchg_acquire(*ptr, &old, new) The x86 CMPXCHG instruction returns success in the ZF flag, so this change saves a compare after the CMPXCHG. Also change the return type of the function to bool and streamline the control flow in the _Q_PENDING_BITS == 8 variant a bit. No functional change intended. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Waiman Long <longman@redhat.com> Reviewed-by: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20240325140943.815051-1-ubizjak@gmail.com
2024-04-12ftrace: Choose RCU Tasks based on TASKS_RCU rather than PREEMPTIONPaul E. McKenney
The advent of CONFIG_PREEMPT_AUTO, AKA lazy preemption, will mean that even kernels built with CONFIG_PREEMPT_NONE or CONFIG_PREEMPT_VOLUNTARY might see the occasional preemption, and that this preemption just might happen within a trampoline. Therefore, update ftrace_shutdown() to invoke synchronize_rcu_tasks() based on CONFIG_TASKS_RCU instead of CONFIG_PREEMPTION. [ paulmck: Apply Steven Rostedt feedback. ] Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Ankur Arora <ankur.a.arora@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <linux-trace-kernel@vger.kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-12bpf: Choose RCU Tasks based on TASKS_RCU rather than PREEMPTIONPaul E. McKenney
The advent of CONFIG_PREEMPT_AUTO, AKA lazy preemption, will mean that even kernels built with CONFIG_PREEMPT_NONE or CONFIG_PREEMPT_VOLUNTARY might see the occasional preemption, and that this preemption just might happen within a trampoline. Therefore, update bpf_tramp_image_put() to choose call_rcu_tasks() based on CONFIG_TASKS_RCU instead of CONFIG_PREEMPTION. This change might enable further simplifications, but the goal of this effort is to make the code safe, not necessarily optimal. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: John Fastabend <john.fastabend@gmail.com> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Song Liu <song@kernel.org> Cc: Yonghong Song <yonghong.song@linux.dev> Cc: KP Singh <kpsingh@kernel.org> Cc: Stanislav Fomichev <sdf@google.com> Cc: Hao Luo <haoluo@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Ankur Arora <ankur.a.arora@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: <bpf@vger.kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-12mm: replace set_pte_at_notify() with just set_pte_at()Paolo Bonzini
With the demise of the .change_pte() MMU notifier callback, there is no notification happening in set_pte_at_notify(). It is a synonym of set_pte_at() and can be replaced with it. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Message-ID: <20240405115815.3226315-5-pbonzini@redhat.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2024-04-12padata: Disable BH when taking works lock on MT pathHerbert Xu
As the old padata code can execute in softirq context, disable softirqs for the new padata_do_mutithreaded code too as otherwise lockdep will get antsy. Reported-by: syzbot+0cb5bb0f4bf9e79db3b3@syzkaller.appspotmail.com Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Acked-by: Daniel Jordan <daniel.m.jordan@oracle.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2024-04-11ring-buffer: Only update pages_touched when a new page is touchedSteven Rostedt (Google)
The "buffer_percent" logic that is used by the ring buffer splice code to only wake up the tasks when there's no data after the buffer is filled to the percentage of the "buffer_percent" file is dependent on three variables that determine the amount of data that is in the ring buffer: 1) pages_read - incremented whenever a new sub-buffer is consumed 2) pages_lost - incremented every time a writer overwrites a sub-buffer 3) pages_touched - incremented when a write goes to a new sub-buffer The percentage is the calculation of: (pages_touched - (pages_lost + pages_read)) / nr_pages Basically, the amount of data is the total number of sub-bufs that have been touched, minus the number of sub-bufs lost and sub-bufs consumed. This is divided by the total count to give the buffer percentage. When the percentage is greater than the value in the "buffer_percent" file, it wakes up splice readers waiting for that amount. It was observed that over time, the amount read from the splice was constantly decreasing the longer the trace was running. That is, if one asked for 60%, it would read over 60% when it first starts tracing, but then it would be woken up at under 60% and would slowly decrease the amount of data read after being woken up, where the amount becomes much less than the buffer percent. This was due to an accounting of the pages_touched incrementation. This value is incremented whenever a writer transfers to a new sub-buffer. But the place where it was incremented was incorrect. If a writer overflowed the current sub-buffer it would go to the next one. If it gets preempted by an interrupt at that time, and the interrupt performs a trace, it too will end up going to the next sub-buffer. But only one should increment the counter. Unfortunately, that was not the case. Change the cmpxchg() that does the real switch of the tail-page into a try_cmpxchg(), and on success, perform the increment of pages_touched. This will only increment the counter once for when the writer moves to a new sub-buffer, and not when there's a race and is incremented for when a writer and its preempting writer both move to the same new sub-buffer. Link: https://lore.kernel.org/linux-trace-kernel/20240409151309.0d0e5056@gandalf.local.home Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Fixes: 2c2b0a78b3739 ("ring-buffer: Add percentage of ring buffer full to wake up reader") Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-04-11tracing: hide unused ftrace_event_id_fopsArnd Bergmann
When CONFIG_PERF_EVENTS, a 'make W=1' build produces a warning about the unused ftrace_event_id_fops variable: kernel/trace/trace_events.c:2155:37: error: 'ftrace_event_id_fops' defined but not used [-Werror=unused-const-variable=] 2155 | static const struct file_operations ftrace_event_id_fops = { Hide this in the same #ifdef as the reference to it. Link: https://lore.kernel.org/linux-trace-kernel/20240403080702.3509288-7-arnd@kernel.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Zheng Yejian <zhengyejian1@huawei.com> Cc: Kees Cook <keescook@chromium.org> Cc: Ajay Kaher <akaher@vmware.com> Cc: Jinjie Ruan <ruanjinjie@huawei.com> Cc: Clément Léger <cleger@rivosinc.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: "Tzvetomir Stoyanov (VMware)" <tz.stoyanov@gmail.com> Fixes: 620a30e97feb ("tracing: Don't pass file_operations array to event_create_dir()") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-04-11tracing: Fix FTRACE_RECORD_RECURSION_SIZE Kconfig entryPrasad Pandit
Fix FTRACE_RECORD_RECURSION_SIZE entry, replace tab with a space character. It helps Kconfig parsers to read file without error. Link: https://lore.kernel.org/linux-trace-kernel/20240322121801.1803948-1-ppandit@redhat.com Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Fixes: 773c16705058 ("ftrace: Add recording of functions that caused recursion") Signed-off-by: Prasad Pandit <pjp@fedoraproject.org> Reviewed-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-04-11Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR. Conflicts: net/unix/garbage.c 47d8ac011fe1 ("af_unix: Fix garbage collector racing against connect()") 4090fa373f0e ("af_unix: Replace garbage collection algorithm.") Adjacent changes: drivers/net/ethernet/broadcom/bnxt/bnxt.c faa12ca24558 ("bnxt_en: Reset PTP tx_avail after possible firmware reset") b3d0083caf9a ("bnxt_en: Support RSS contexts in ethtool .{get|set}_rxfh()") drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c 7ac10c7d728d ("bnxt_en: Fix possible memory leak in bnxt_rdma_aux_device_init()") 194fad5b2781 ("bnxt_en: Refactor bnxt_rdma_aux_device_init/uninit functions") drivers/net/ethernet/mellanox/mlx5/core/en_ethtool.c 958f56e48385 ("net/mlx5e: Un-expose functions in en.h") 49e6c9387051 ("net/mlx5e: RSS, Block XOR hash with over 128 channels") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2024-04-11Merge tag 'pm-6.9-rc4' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management fix from Rafael Wysocki: "Fix the suspend-to-idle core code to guarantee that timers queued on CPUs other than the one that has first left the idle state, which should expire directly after resume, will be handled (Anna-Maria Behnsen)" * tag 'pm-6.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: PM: s2idle: Make sure CPUs will wakeup directly on resume
2024-04-11locking/mutex: Introduce devm_mutex_init()George Stark
Using of devm API leads to a certain order of releasing resources. So all dependent resources which are not devm-wrapped should be deleted with respect to devm-release order. Mutex is one of such objects that often is bound to other resources and has no own devm wrapping. Since mutex_destroy() actually does nothing in non-debug builds frequently calling mutex_destroy() is just ignored which is safe for now but wrong formally and can lead to a problem if mutex_destroy() will be extended so introduce devm_mutex_init(). Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu> Signed-off-by: George Stark <gnstark@salutedevices.com> Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu> Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com> Reviewed-by: Marek Behún <kabel@kernel.org> Acked-by: Waiman Long <longman@redhat.com> Link: https://lore.kernel.org/r/20240411161032.609544-2-gnstark@salutedevices.com Signed-off-by: Lee Jones <lee@kernel.org>
2024-04-11tracing: Select new NEED_TASKS_RCU Kconfig optionPaul E. McKenney
Currently, if a Kconfig option depends on TASKS_RCU, it conditionally does "select TASKS_RCU if PREEMPTION". This works, but requires any change in this enablement logic to be replicated across all such "select" clauses. A new NEED_TASKS_RCU Kconfig option has been created to allow this enablement logic to be in one place in kernel/rcu/Kconfig. Therefore, select the new NEED_TASKS_RCU Kconfig option instead of the old TASKS_RCU option. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: <linux-trace-kernel@vger.kernel.org> Cc: Ankur Arora <ankur.a.arora@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-11rcu: Add data structures for synchronize_rcu()Uladzislau Rezki (Sony)
The synchronize_rcu() call is going to be reworked, thus this patch adds dedicated fields into the rcu_state structure. Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-11treewide: Use sysfs_bin_attr_simple_read() helperLukas Wunner
Deduplicate ->read() callbacks of bin_attributes which are backed by a simple buffer in memory: Use the newly introduced sysfs_bin_attr_simple_read() helper instead, either by referencing it directly or by declaring such bin_attributes with BIN_ATTR_SIMPLE_RO() or BIN_ATTR_SIMPLE_ADMIN_RO(). Aside from a reduction of LoC, this shaves off a few bytes from vmlinux (304 bytes on an x86_64 allyesconfig). No functional change intended. Signed-off-by: Lukas Wunner <lukas@wunner.de> Acked-by: Zhi Wang <zhiwang@kernel.org> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/92ee0a0e83a5a3f3474845db6c8575297698933a.1712410202.git.lukas@wunner.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-11locking/qspinlock: Use atomic_try_cmpxchg_relaxed() in xchg_tail()Uros Bizjak
Use atomic_try_cmpxchg_relaxed(*ptr, &old, new) instead of atomic_cmpxchg_relaxed (*ptr, old, new) == old in xchg_tail(). x86 CMPXCHG instruction returns success in ZF flag, so this change saves a compare after CMPXCHG. No functional change intended. Since this code requires NR_CPUS >= 16k, I have tested it by unconditionally setting _Q_PENDING_BITS to 1 in <asm-generic/qspinlock_types.h>. Signed-off-by: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Waiman Long <longman@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20240321195309.484275-1-ubizjak@gmail.com
2024-04-11printk: Add function to replay kernel log on consolesSreenath Vijayan
Add a generic function console_replay_all() for replaying the kernel log on consoles, in any context. It would allow viewing the logs on an unresponsive terminal via sysrq. Reuse the existing code from console_flush_on_panic() for resetting the sequence numbers, by introducing a new helper function __console_rewind_all(). It is safe to be called under console_lock(). Try to acquire lock on the console subsystem without waiting. If successful, reset the sequence number to oldest available record on all consoles and call console_unlock() which will automatically flush the messages to the consoles. Suggested-by: John Ogness <john.ogness@linutronix.de> Suggested-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Shimoyashiki Taichi <taichi.shimoyashiki@sony.com> Reviewed-by: John Ogness <john.ogness@linutronix.de> Signed-off-by: Sreenath Vijayan <sreenath.vijayan@sony.com> Link: https://lore.kernel.org/r/90ee131c643a5033d117b556c0792de65129d4c3.1710220326.git.sreenath.vijayan@sony.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-10bpf: Add bpf_link support for sk_msg and sk_skb progsYonghong Song
Add bpf_link support for sk_msg and sk_skb programs. We have an internal request to support bpf_link for sk_msg programs so user space can have a uniform handling with bpf_link based libbpf APIs. Using bpf_link based libbpf API also has a benefit which makes system robust by decoupling prog life cycle and attachment life cycle. Reviewed-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Yonghong Song <yonghong.song@linux.dev> Link: https://lore.kernel.org/r/20240410043527.3737160-1-yonghong.song@linux.dev Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-04-10kprobes: Fix possible use-after-free issue on kprobe registrationZheng Yejian
When unloading a module, its state is changing MODULE_STATE_LIVE -> MODULE_STATE_GOING -> MODULE_STATE_UNFORMED. Each change will take a time. `is_module_text_address()` and `__module_text_address()` works with MODULE_STATE_LIVE and MODULE_STATE_GOING. If we use `is_module_text_address()` and `__module_text_address()` separately, there is a chance that the first one is succeeded but the next one is failed because module->state becomes MODULE_STATE_UNFORMED between those operations. In `check_kprobe_address_safe()`, if the second `__module_text_address()` is failed, that is ignored because it expected a kernel_text address. But it may have failed simply because module->state has been changed to MODULE_STATE_UNFORMED. In this case, arm_kprobe() will try to modify non-exist module text address (use-after-free). To fix this problem, we should not use separated `is_module_text_address()` and `__module_text_address()`, but use only `__module_text_address()` once and do `try_module_get(module)` which is only available with MODULE_STATE_LIVE. Link: https://lore.kernel.org/all/20240410015802.265220-1-zhengyejian1@huawei.com/ Fixes: 28f6c37a2910 ("kprobes: Forbid probing on trampoline and BPF code areas") Cc: stable@vger.kernel.org Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2024-04-10x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=nSean Christopherson
Initialize cpu_mitigations to CPU_MITIGATIONS_OFF if the kernel is built with CONFIG_SPECULATION_MITIGATIONS=n, as the help text quite clearly states that disabling SPECULATION_MITIGATIONS is supposed to turn off all mitigations by default. │ If you say N, all mitigations will be disabled. You really │ should know what you are doing to say so. As is, the kernel still defaults to CPU_MITIGATIONS_AUTO, which results in some mitigations being enabled in spite of SPECULATION_MITIGATIONS=n. Fixes: f43b9876e857 ("x86/retbleed: Add fine grained Kconfig knobs") Signed-off-by: Sean Christopherson <seanjc@google.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Daniel Sneddon <daniel.sneddon@linux.intel.com> Cc: stable@vger.kernel.org Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/r/20240409175108.1512861-2-seanjc@google.com
2024-04-10timekeeping: Use READ/WRITE_ONCE() for tick_do_timer_cpuThomas Gleixner
tick_do_timer_cpu is used lockless to check which CPU needs to take care of the per tick timekeeping duty. This is done to avoid a thundering herd problem on jiffies_lock. The read and writes are not annotated so KCSAN complains about data races: BUG: KCSAN: data-race in tick_nohz_idle_stop_tick / tick_nohz_next_event write to 0xffffffff8a2bda30 of 4 bytes by task 0 on cpu 26: tick_nohz_idle_stop_tick+0x3b1/0x4a0 do_idle+0x1e3/0x250 read to 0xffffffff8a2bda30 of 4 bytes by task 0 on cpu 16: tick_nohz_next_event+0xe7/0x1e0 tick_nohz_get_sleep_length+0xa7/0xe0 menu_select+0x82/0xb90 cpuidle_select+0x44/0x60 do_idle+0x1c2/0x250 value changed: 0x0000001a -> 0xffffffff Annotate them with READ/WRITE_ONCE() to document the intentional data race. Reported-by: Mirsad Todorovac <mirsad.todorovac@alu.unizg.hr> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Sean Anderson <sean.anderson@seco.com> Link: https://lore.kernel.org/r/87cyqy7rt3.ffs@tglx
2024-04-10perf/core: Reduce PMU access to adjust sample freqNamhyung Kim
In perf_adjust_freq_unthr_context(), it first starts the event and then stop unnecessarily to adjust the sampling frequency if the event is throttled. For a throttled non-frequency event, it doesn't have a freq so no need to adjust. Just starting the event would be ok. For a frequency event, whether it's throttled or not, it needs to stop before adjusting the frequency. That means it should not start the even if it was throttled. I tried to skip calling the stop callback, but it didn't work well since the event count might not be up to date. It should call the stop callback with PERF_EF_UPDATE anyway. However not calling start would prevent unnecessary MSR accesses (which can be costly) for already stopped events as stop state is saved in the hw config. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Ian Rogers <irogers@google.com> Reviewed-by: Kan Liang <kan.liang@linux.intel.com> Link: https://lore.kernel.org/r/20240207050545.2727923-2-namhyung@kernel.org
2024-04-10perf/core: Optimize perf_adjust_freq_unthr_context()Namhyung Kim
It was unnecessarily disabling and enabling PMUs for each event. It should be done at PMU level. Add pmu_ctx->nr_freq counter to check it at each PMU. As PMU context has separate active lists for pinned group and flexible group, factor out a new function to do the job. Another minor optimization is that it can skip PMUs w/ CAP_NO_INTERRUPT even if it needs to unthrottle sampling events. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Ingo Molnar <mingo@kernel.org> Tested-by: Mingwei Zhang <mizhang@google.com> Reviewed-by: Ian Rogers <irogers@google.com> Reviewed-by: Kan Liang <kan.liang@linux.intel.com> Link: https://lore.kernel.org/r/20240207050545.2727923-1-namhyung@kernel.org
2024-04-09bpf: Add support for certain atomics in bpf_arena to x86 JITAlexei Starovoitov
Support atomics in bpf_arena that can be JITed as a single x86 instruction. Instructions that are JITed as loops are not supported at the moment, since they require more complex extable and loop logic. JITs can choose to do smarter things with bpf_jit_supports_insn(). Like arm64 may decide to support all bpf atomics instructions when emit_lse_atomic is available and none in ll_sc mode. bpf_jit_supports_percpu_insn(), bpf_jit_supports_ptr_xchg() and other such callbacks can be replaced with bpf_jit_supports_insn() in the future. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20240405231134.17274-1-alexei.starovoitov@gmail.com Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2024-04-09printk: Flag register_console() if console is set on command lineTony Lindgren
If add_preferred_console() is not called early in setup_console(), we can end up having register_console() call try_enable_default_console() before a console device has called add_preferred_console(). Let's set console_set_on_cmdline flag in console_setup() to prevent this from happening. Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20240327110021.59793-4-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09printk: Don't try to parse DEVNAME:0.0 console optionsTony Lindgren
Currently console_setup() tries to make a console index out of any digits passed in the kernel command line for console. In the DEVNAME:0.0 case, the name can contain a device IO address, so bail out on console names with a ':'. Signed-off-by: Tony Lindgren <tony@atomide.com> Link: https://lore.kernel.org/r/20240327110021.59793-3-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09printk: Save console options for add_preferred_console_match()Tony Lindgren
Driver subsystems may need to translate the preferred console name to the character device name used. We already do some of this in console_setup() with a few hardcoded names, but that does not scale well. The console options are parsed early in console_setup(), and the consoles are added with __add_preferred_console(). At this point we don't know much about the character device names and device drivers getting probed. To allow driver subsystems to set up a preferred console, let's save the kernel command line console options. To add a preferred console from a driver subsystem with optional character device name translation, let's add a new function add_preferred_console_match(). This allows the serial core layer to support console=DEVNAME:0.0 style hardware based addressing in addition to the current console=ttyS0 style naming. And we can start moving console_setup() character device parsing to the driver subsystem specific code. We use a separate array from the console_cmdline array as the character device name and index may be unknown at the console_setup() time. And eventually there's no need to call __add_preferred_console() until the subsystem is ready to handle the console. Adding the console name in addition to the character device name, and a flag for an added console, could be added to the struct console_cmdline. And the console_cmdline array handling could be modified accordingly. But that complicates things compared saving the console options, and then adding the consoles when the subsystems handling the consoles are ready. Co-developed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Link: https://lore.kernel.org/r/20240327110021.59793-2-tony@atomide.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-04-09bpf: Select new NEED_TASKS_RCU Kconfig optionPaul E. McKenney
Currently, if a Kconfig option depends on TASKS_RCU, it conditionally does "select TASKS_RCU if PREEMPTION". This works, but requires any change in this enablement logic to be replicated across all such "select" clauses. A new NEED_TASKS_RCU Kconfig option has been created to allow this enablement logic to be in one place in kernel/rcu/Kconfig. Therefore, make BPF select the new NEED_TASKS_RCU Kconfig option. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: Andrii Nakryiko <andrii@kernel.org> Cc: Martin KaFai Lau <martin.lau@linux.dev> Cc: Song Liu <song@kernel.org> Cc: Yonghong Song <yonghong.song@linux.dev> Cc: John Fastabend <john.fastabend@gmail.com> Cc: KP Singh <kpsingh@kernel.org> Cc: Stanislav Fomichev <sdf@google.com> Cc: Hao Luo <haoluo@google.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: <bpf@vger.kernel.org> Cc: Ankur Arora <ankur.a.arora@oracle.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Acked-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-09rcu-tasks: Make Tasks RCU wait idly for grace-period delaysPaul E. McKenney
Currently, all waits for grace periods sleep at TASK_UNINTERRUPTIBLE, regardless of RCU flavor. This has worked well, but there have been cases where a longer-than-average Tasks RCU grace period has triggered softlockup splats, many of them, before the Tasks RCU CPU stall warning appears. These softlockup splats unnecessarily consume console bandwidth and complicate diagnosis of the underlying problem. Plus a long but not pathologically long Tasks RCU grace period might trigger a few softlockup splats before completing normally, which generates noise for no good reason. This commit therefore causes Tasks RCU grace periods to sleep at TASK_IDLE priority. If there really is a persistent problem, the eventual Tasks RCU CPU stall warning will flag it, and without the extra noise. Reported-by: Breno Leitao <leitao@debian.org> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-09rcutorture: ASSERT_EXCLUSIVE_WRITER() for ->rtort_pipe_count updatesPaul E. McKenney
It turns out that only one CPU at a time will ever invoke rcu_torture_pipe_update_one() on a given rcu_torture structure. This commit therefore adds three ASSERT_EXCLUSIVE_WRITER() calls to enlist KCSAN's aid in checking this. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-09rcutorture: Dump GP kthread state on insufficient cb-flood launderingPaul E. McKenney
If a callback flood prevents grace period from completing, rcutorture does a WARN_ON(). Avoiding this WARN_ON() currently requires that at least three grace periods elapse during an eight-second callback-flood interval. Unfortunately, the current debug information does not include anything about the grace-period state. This commit therefore adds a call to cur_ops->gp_kthread_dbg(), if this function pointer is non-NULL. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
2024-04-09rcutorture: Dump # online CPUs on insufficient cb-flood launderingPaul E. McKenney
This commit adds the number of online CPUs to the state dump following an unsuccesful callback-flood test. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>