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2022-10-27perf: Fix missing raw data on tracepoint eventsJames Clark1-0/+1
Since commit 838d9bb62d13 ("perf: Use sample_flags for raw_data") raw data is not being output on tracepoints due to the PERF_SAMPLE_RAW field not being set. Fix this by setting it for tracepoint events. This fixes the following test failure: perf test "sched_switch" -vvv 35: Track with sched_switch --- start --- test child forked, pid 1828 ... Using CPUID 0x00000000410fd400 sched_switch: cpu: 2 prev_tid -14687 next_tid 0 sched_switch: cpu: 2 prev_tid -14687 next_tid 0 Missing sched_switch events 4613 events recorded test child finished with -1 ---- end ---- Track with sched_switch: FAILED! Fixes: 838d9bb62d13 ("perf: Use sample_flags for raw_data") Signed-off-by: James Clark <james.clark@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Namhyung Kim <namhyung@kernel.org> Tested-by: SeongJae Park <sj@kernel.org> Tested-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com> Link: https://lore.kernel.org/r/20221012143857.48198-1-james.clark@arm.com
2022-10-17perf: Fix missing SIGTRAPsPeter Zijlstra1-38/+113
Marco reported: Due to the implementation of how SIGTRAP are delivered if perf_event_attr::sigtrap is set, we've noticed 3 issues: 1. Missing SIGTRAP due to a race with event_sched_out() (more details below). 2. Hardware PMU events being disabled due to returning 1 from perf_event_overflow(). The only way to re-enable the event is for user space to first "properly" disable the event and then re-enable it. 3. The inability to automatically disable an event after a specified number of overflows via PERF_EVENT_IOC_REFRESH. The worst of the 3 issues is problem (1), which occurs when a pending_disable is "consumed" by a racing event_sched_out(), observed as follows: CPU0 | CPU1 --------------------------------+--------------------------- __perf_event_overflow() | perf_event_disable_inatomic() | pending_disable = CPU0 | ... | _perf_event_enable() | event_function_call() | task_function_call() | /* sends IPI to CPU0 */ <IPI> | ... __perf_event_enable() +--------------------------- ctx_resched() task_ctx_sched_out() ctx_sched_out() group_sched_out() event_sched_out() pending_disable = -1 </IPI> <IRQ-work> perf_pending_event() perf_pending_event_disable() /* Fails to send SIGTRAP because no pending_disable! */ </IRQ-work> In the above case, not only is that particular SIGTRAP missed, but also all future SIGTRAPs because 'event_limit' is not reset back to 1. To fix, rework pending delivery of SIGTRAP via IRQ-work by introduction of a separate 'pending_sigtrap', no longer using 'event_limit' and 'pending_disable' for its delivery. Additionally; and different to Marco's proposed patch: - recognise that pending_disable effectively duplicates oncpu for the case where it is set. As such, change the irq_work handler to use ->oncpu to target the event and use pending_* as boolean toggles. - observe that SIGTRAP targets the ctx->task, so the context switch optimization that carries contexts between tasks is invalid. If the irq_work were delayed enough to hit after a context switch the SIGTRAP would be delivered to the wrong task. - observe that if the event gets scheduled out (rotation/migration/context-switch/...) the irq-work would be insufficient to deliver the SIGTRAP when the event gets scheduled back in (the irq-work might still be pending on the old CPU). Therefore have event_sched_out() convert the pending sigtrap into a task_work which will deliver the signal at return_to_user. Fixes: 97ba62b27867 ("perf: Add support for SIGTRAP on perf events") Reported-by: Dmitry Vyukov <dvyukov@google.com> Debugged-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: Marco Elver <elver@google.com> Debugged-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Marco Elver <elver@google.com> Tested-by: Marco Elver <elver@google.com>
2022-10-10Merge tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mmLinus Torvalds1-1/+2
Pull MM updates from Andrew Morton: - Yu Zhao's Multi-Gen LRU patches are here. They've been under test in linux-next for a couple of months without, to my knowledge, any negative reports (or any positive ones, come to that). - Also the Maple Tree from Liam Howlett. An overlapping range-based tree for vmas. It it apparently slightly more efficient in its own right, but is mainly targeted at enabling work to reduce mmap_lock contention. Liam has identified a number of other tree users in the kernel which could be beneficially onverted to mapletrees. Yu Zhao has identified a hard-to-hit but "easy to fix" lockdep splat at [1]. This has yet to be addressed due to Liam's unfortunately timed vacation. He is now back and we'll get this fixed up. - Dmitry Vyukov introduces KMSAN: the Kernel Memory Sanitizer. It uses clang-generated instrumentation to detect used-unintialized bugs down to the single bit level. KMSAN keeps finding bugs. New ones, as well as the legacy ones. - Yang Shi adds a userspace mechanism (madvise) to induce a collapse of memory into THPs. - Zach O'Keefe has expanded Yang Shi's madvise(MADV_COLLAPSE) to support file/shmem-backed pages. - userfaultfd updates from Axel Rasmussen - zsmalloc cleanups from Alexey Romanov - cleanups from Miaohe Lin: vmscan, hugetlb_cgroup, hugetlb and memory-failure - Huang Ying adds enhancements to NUMA balancing memory tiering mode's page promotion, with a new way of detecting hot pages. - memcg updates from Shakeel Butt: charging optimizations and reduced memory consumption. - memcg cleanups from Kairui Song. - memcg fixes and cleanups from Johannes Weiner. - Vishal Moola provides more folio conversions - Zhang Yi removed ll_rw_block() :( - migration enhancements from Peter Xu - migration error-path bugfixes from Huang Ying - Aneesh Kumar added ability for a device driver to alter the memory tiering promotion paths. For optimizations by PMEM drivers, DRM drivers, etc. - vma merging improvements from Jakub Matěn. - NUMA hinting cleanups from David Hildenbrand. - xu xin added aditional userspace visibility into KSM merging activity. - THP & KSM code consolidation from Qi Zheng. - more folio work from Matthew Wilcox. - KASAN updates from Andrey Konovalov. - DAMON cleanups from Kaixu Xia. - DAMON work from SeongJae Park: fixes, cleanups. - hugetlb sysfs cleanups from Muchun Song. - Mike Kravetz fixes locking issues in hugetlbfs and in hugetlb core. Link: https://lkml.kernel.org/r/CAOUHufZabH85CeUN-MEMgL8gJGzJEWUrkiM58JkTbBhh-jew0Q@mail.gmail.com [1] * tag 'mm-stable-2022-10-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (555 commits) hugetlb: allocate vma lock for all sharable vmas hugetlb: take hugetlb vma_lock when clearing vma_lock->vma pointer hugetlb: fix vma lock handling during split vma and range unmapping mglru: mm/vmscan.c: fix imprecise comments mm/mglru: don't sync disk for each aging cycle mm: memcontrol: drop dead CONFIG_MEMCG_SWAP config symbol mm: memcontrol: use do_memsw_account() in a few more places mm: memcontrol: deprecate swapaccounting=0 mode mm: memcontrol: don't allocate cgroup swap arrays when memcg is disabled mm/secretmem: remove reduntant return value mm/hugetlb: add available_huge_pages() func mm: remove unused inline functions from include/linux/mm_inline.h selftests/vm: add selftest for MADV_COLLAPSE of uffd-minor memory selftests/vm: add file/shmem MADV_COLLAPSE selftest for cleared pmd selftests/vm: add thp collapse shmem testing selftests/vm: add thp collapse file and tmpfs testing selftests/vm: modularize thp collapse memory operations selftests/vm: dedup THP helpers mm/khugepaged: add tracepoint to hpage_collapse_scan_file() mm/madvise: add file and shmem support to MADV_COLLAPSE ...
2022-10-10Merge tag 'perf-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-29/+59
Pull perf events updates from Ingo Molnar: "PMU driver updates: - Add AMD Last Branch Record Extension Version 2 (LbrExtV2) feature support for Zen 4 processors. - Extend the perf ABI to provide branch speculation information, if available, and use this on CPUs that have it (eg. LbrExtV2). - Improve Intel PEBS TSC timestamp handling & integration. - Add Intel Raptor Lake S CPU support. - Add 'perf mem' and 'perf c2c' memory profiling support on AMD CPUs by utilizing IBS tagged load/store samples. - Clean up & optimize various x86 PMU details. HW breakpoints: - Big rework to optimize the code for systems with hundreds of CPUs and thousands of breakpoints: - Replace the nr_bp_mutex global mutex with the bp_cpuinfo_sem per-CPU rwsem that is read-locked during most of the key operations. - Improve the O(#cpus * #tasks) logic in toggle_bp_slot() and fetch_bp_busy_slots(). - Apply micro-optimizations & cleanups. - Misc cleanups & enhancements" * tag 'perf-core-2022-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (75 commits) perf/hw_breakpoint: Annotate tsk->perf_event_mutex vs ctx->mutex perf: Fix pmu_filter_match() perf: Fix lockdep_assert_event_ctx() perf/x86/amd/lbr: Adjust LBR regardless of filtering perf/x86/utils: Fix uninitialized var in get_branch_type() perf/uapi: Define PERF_MEM_SNOOPX_PEER in kernel header file perf/x86/amd: Support PERF_SAMPLE_PHY_ADDR perf/x86/amd: Support PERF_SAMPLE_ADDR perf/x86/amd: Support PERF_SAMPLE_{WEIGHT|WEIGHT_STRUCT} perf/x86/amd: Support PERF_SAMPLE_DATA_SRC perf/x86/amd: Add IBS OP_DATA2 DataSrc bit definitions perf/mem: Introduce PERF_MEM_LVLNUM_{EXTN_MEM|IO} perf/x86/uncore: Add new Raptor Lake S support perf/x86/cstate: Add new Raptor Lake S support perf/x86/msr: Add new Raptor Lake S support perf/x86: Add new Raptor Lake S support bpf: Check flags for branch stack in bpf_read_branch_records helper perf, hw_breakpoint: Fix use-after-free if perf_event_open() fails perf: Use sample_flags for raw_data perf: Use sample_flags for addr ...
2022-10-04perf: Fix pmu_filter_match()Peter Zijlstra1-3/+9
Mark reported that the new for_each_sibling_event() assertion triggers in pmu_filter_match() -- which isn't always called with IRQs disabled or ctx->mutex held. Fixes: f3c0eba28704 ("perf: Add a few assertions") Reported-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/YvvJq2f/7eFVcnNy@FVFF77S0Q05N
2022-09-29perf/x86/amd: Support PERF_SAMPLE_PHY_ADDRRavi Bangoria1-1/+2
IBS_DC_PHYSADDR provides the physical data address for the tagged load/ store operation. Populate perf sample physical address using it. Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220928095805.596-7-ravi.bangoria@amd.com
2022-09-27perf, hw_breakpoint: Fix use-after-free if perf_event_open() failsMarco Elver1-3/+1
Local testing revealed that we can trigger a use-after-free during rhashtable lookup as follows: | BUG: KASAN: use-after-free in memcmp lib/string.c:757 | Read of size 8 at addr ffff888107544dc0 by task perf-rhltable-n/1293 | | CPU: 0 PID: 1293 Comm: perf-rhltable-n Not tainted 6.0.0-rc3-00014-g85260862789c #46 | Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-4 04/01/2014 | Call Trace: | <TASK> | memcmp lib/string.c:757 | rhashtable_compare include/linux/rhashtable.h:577 [inline] | __rhashtable_lookup include/linux/rhashtable.h:602 [inline] | rhltable_lookup include/linux/rhashtable.h:688 [inline] | task_bp_pinned kernel/events/hw_breakpoint.c:324 | toggle_bp_slot kernel/events/hw_breakpoint.c:462 | __release_bp_slot kernel/events/hw_breakpoint.c:631 [inline] | release_bp_slot kernel/events/hw_breakpoint.c:639 | register_perf_hw_breakpoint kernel/events/hw_breakpoint.c:742 | hw_breakpoint_event_init kernel/events/hw_breakpoint.c:976 | perf_try_init_event kernel/events/core.c:11261 | perf_init_event kernel/events/core.c:11325 [inline] | perf_event_alloc kernel/events/core.c:11619 | __do_sys_perf_event_open kernel/events/core.c:12157 | do_syscall_x64 arch/x86/entry/common.c:50 [inline] | do_syscall_64 arch/x86/entry/common.c:80 | entry_SYSCALL_64_after_hwframe | </TASK> | | Allocated by task 1292: | perf_event_alloc kernel/events/core.c:11505 | __do_sys_perf_event_open kernel/events/core.c:12157 | do_syscall_x64 arch/x86/entry/common.c:50 [inline] | do_syscall_64 arch/x86/entry/common.c:80 | entry_SYSCALL_64_after_hwframe | | Freed by task 1292: | perf_event_alloc kernel/events/core.c:11716 | __do_sys_perf_event_open kernel/events/core.c:12157 | do_syscall_x64 arch/x86/entry/common.c:50 [inline] | do_syscall_64 arch/x86/entry/common.c:80 | entry_SYSCALL_64_after_hwframe | | The buggy address belongs to the object at ffff888107544c00 | which belongs to the cache perf_event of size 1352 | The buggy address is located 448 bytes inside of | 1352-byte region [ffff888107544c00, ffff888107545148) This happens because the first perf_event_open() managed to reserve a HW breakpoint slot, however, later fails for other reasons and returns. The second perf_event_open() runs concurrently, and during rhltable_lookup() looks up an entry which is being freed: since rhltable_lookup() may run concurrently (under the RCU read lock) with rhltable_remove(), we may end up with a stale entry, for which memory may also have already been freed when being accessed. To fix, only free the failed perf_event after an RCU grace period. This allows subsystems that store references to an event to always access it concurrently under the RCU read lock, even if initialization will fail. Given failure is unlikely and a slow-path, turning the immediate free into a call_rcu()-wrapped free does not affect performance elsewhere. Fixes: 0370dc314df3 ("perf/hw_breakpoint: Optimize list of per-task breakpoints") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220927172025.1636995-1-elver@google.com
2022-09-27perf: Use sample_flags for raw_dataNamhyung Kim1-1/+2
Use the new sample_flags to indicate whether the raw data field is filled by the PMU driver. Although it could check with the NULL, follow the same rule with other fields. Remove the raw field from the perf_sample_data_init() to minimize the number of cache lines touched. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220921220032.2858517-2-namhyung@kernel.org
2022-09-27perf: Use sample_flags for addrNamhyung Kim1-0/+5
Use the new sample_flags to indicate whether the addr field is filled by the PMU driver. As most PMU drivers pass 0, it can set the flag only if it has a non-zero value. And use 0 in perf_sample_output() if it's not filled already. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220921220032.2858517-1-namhyung@kernel.org
2022-09-26perf: use VMA iteratorMatthew Wilcox (Oracle)1-1/+2
The VMA iterator is faster than the linked list and removing the linked list will shrink the vm_area_struct. Link: https://lkml.kernel.org/r/20220906194824.2110408-48-Liam.Howlett@oracle.com Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Tested-by: Yu Zhao <yuzhao@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: David Hildenbrand <david@redhat.com> Cc: David Howells <dhowells@redhat.com> Cc: SeongJae Park <sj@kernel.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-21perf/core: Convert snprintf() to scnprintf()Jules Irenge1-3/+3
Coccinelle reports a warning: WARNING: use scnprintf or sprintf This LWN article explains the rationale for this change: https: //lwn.net/Articles/69419/ Ie. snprintf() returns what *would* be the resulting length, while scnprintf() returns the actual length. Adding to that, there has also been some slow migration from snprintf to scnprintf, here's the shift in usage in the past 3.5 years, in all fs/ files: v5.0 v6.0-rc6 -------------------------------------- snprintf() uses: 63 213 scnprintf() uses: 374 186 No intended change in behavior. [ mingo: Improved the changelog & reviewed the usage sites. ] Signed-off-by: Jules Irenge <jbi.octave@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2022-09-13perf/bpf: Always use perf callchains if existNamhyung Kim1-2/+10
If the perf_event has PERF_SAMPLE_CALLCHAIN, BPF can use it for stack trace. The problematic cases like PEBS and IBS already handled in the PMU driver and they filled the callchain info in the sample data. For others, we can call perf_callchain() before the BPF handler. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220908214104.3851807-2-namhyung@kernel.org
2022-09-13perf: Use sample_flags for callchainNamhyung Kim1-1/+1
So that it can call perf_callchain() only if needed. Historically it used __PERF_SAMPLE_CALLCHAIN_EARLY but we can do that with sample_flags in the struct perf_sample_data. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220908214104.3851807-1-namhyung@kernel.org
2022-09-07perf: Add a few assertionsPeter Zijlstra1-0/+2
While auditing 6b959ba22d34 ("perf/core: Fix reentry problem in perf_output_read_group()") a few spots were found that wanted assertions. Notable for_each_sibling_event() relies on exclusion from modification. This would normally be holding either ctx->lock or ctx->mutex, however due to how things are constructed disabling IRQs is a valid and sufficient substitute for ctx->lock. Another possible site to add assertions would be the various pmu::{add,del,read,..}() methods, but that's not trivially expressable in C -- the best option is wrappers, but those are easy enough to forget. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
2022-09-07perf: Consolidate branch sample filter helpersAnshuman Khandual1-7/+2
Besides the branch type filtering requests, 'event.attr.branch_sample_type' also contains various flags indicating which additional information should be captured, along with the base branch record. These flags help configure the underlying hardware, and capture the branch records appropriately when required e.g after PMU interrupt. But first, this moves an existing helper perf_sample_save_hw_index() into the header before adding some more helpers for other branch sample filter flags. Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220906084414.396220-1-anshuman.khandual@arm.com
2022-09-06perf: Use sample_flags for txnKan Liang1-0/+3
Use the new sample_flags to indicate whether the txn field is filled by the PMU driver. Remove the txn field from the perf_sample_data_init() to minimize the number of cache lines touched. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220901130959.1285717-7-kan.liang@linux.intel.com
2022-09-06perf: Use sample_flags for data_srcKan Liang1-0/+3
Use the new sample_flags to indicate whether the data_src field is filled by the PMU driver. Remove the data_src field from the perf_sample_data_init() to minimize the number of cache lines touched. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220901130959.1285717-6-kan.liang@linux.intel.com
2022-09-06perf: Use sample_flags for weightKan Liang1-0/+3
Use the new sample_flags to indicate whether the weight field is filled by the PMU driver. Remove the weight field from the perf_sample_data_init() to minimize the number of cache lines touched. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220901130959.1285717-5-kan.liang@linux.intel.com
2022-09-06perf: Use sample_flags for branch stackKan Liang1-2/+2
Use the new sample_flags to indicate whether the branch stack is filled by the PMU driver. Remove the br_stack from the perf_sample_data_init() to minimize the number of cache lines touched. Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220901130959.1285717-4-kan.liang@linux.intel.com
2022-09-06perf: Add sample_flags to indicate the PMU-filled sample dataKan Liang1-6/+11
On some platforms, some data e.g., timestamps, can be retrieved from the PMU driver. Usually, the data from the PMU driver is more accurate. The current perf kernel should output the PMU-filled sample data if it's available. To check the availability of the PMU-filled sample data, the current perf kernel initializes the related fields in the perf_sample_data_init(). When outputting a sample, the perf checks whether the field is updated by the PMU driver. If yes, the updated value will be output. If not, the perf uses an SW way to calculate the value or just outputs the initialized value if an SW way is unavailable either. With more and more data being provided by the PMU driver, more fields has to be initialized in the perf_sample_data_init(). That will increase the number of cache lines touched in perf_sample_data_init() and be harmful to the performance. Add new "sample_flags" to indicate the PMU-filled sample data. The PMU driver should set the corresponding PERF_SAMPLE_ flag when the field is updated. The initialization of the corresponding field is not required anymore. The following patches will make use of it and remove the corresponding fields from the perf_sample_data_init(), which will further minimize the number of cache lines touched. Only clear the sample flags that have already been done by the PMU driver in the perf_prepare_sample() for the PERF_RECORD_SAMPLE. For the other PERF_RECORD_ event type, the sample data is not available. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Kan Liang <kan.liang@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220901130959.1285717-2-kan.liang@linux.intel.com
2022-09-06perf/core: Fix reentry problem in perf_output_read_group()Yang Jihong1-0/+9
perf_output_read_group may respond to IPI request of other cores and invoke __perf_install_in_context function. As a result, hwc configuration is modified. causing inconsistency and unexpected consequences. Interrupts are not disabled when perf_output_read_group reads PMU counter. In this case, IPI request may be received from other cores. As a result, PMU configuration is modified and an error occurs when reading PMU counter: CPU0 CPU1 __se_sys_perf_event_open perf_install_in_context perf_output_read_group smp_call_function_single for_each_sibling_event(sub, leader) { generic_exec_single if ((sub != event) && remote_function (sub->state == PERF_EVENT_STATE_ACTIVE)) | <enter IPI handler: __perf_install_in_context> <----RAISE IPI-----+ __perf_install_in_context ctx_resched event_sched_out armpmu_del ... hwc->idx = -1; // event->hwc.idx is set to -1 ... <exit IPI> sub->pmu->read(sub); armpmu_read armv8pmu_read_counter armv8pmu_read_hw_counter int idx = event->hw.idx; // idx = -1 u64 val = armv8pmu_read_evcntr(idx); u32 counter = ARMV8_IDX_TO_COUNTER(idx); // invalid counter = 30 read_pmevcntrn(counter) // undefined instruction Signed-off-by: Yang Jihong <yangjihong1@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220902082918.179248-1-yangjihong1@huawei.com
2022-08-06Merge tag 'perf-urgent-2022-08-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-1/+1
Pull perf fixes from Ingo Molnar: "Misc fixes to kprobes and the faddr2line script, plus a cleanup" * tag 'perf-urgent-2022-08-06' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/core: Fix ';;' typo scripts/faddr2line: Add CONFIG_DEBUG_INFO check scripts/faddr2line: Fix vmlinux detection on arm64 x86/kprobes: Update kcb status flag after singlestepping kprobes: Forbid probing on trampoline and BPF code areas
2022-08-04perf/core: Fix ';;' typoSlark Xiao1-1/+1
Remove double ';;'. Signed-off-by: Slark Xiao <slark_xiao@163.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20220720091220.14200-1-slark_xiao@163.com
2022-08-03Merge tag 'net-next-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextLinus Torvalds1-6/+10
Pull networking changes from Paolo Abeni: "Core: - Refactor the forward memory allocation to better cope with memory pressure with many open sockets, moving from a per socket cache to a per-CPU one - Replace rwlocks with RCU for better fairness in ping, raw sockets and IP multicast router. - Network-side support for IO uring zero-copy send. - A few skb drop reason improvements, including codegen the source file with string mapping instead of using macro magic. - Rename reference tracking helpers to a more consistent netdev_* schema. - Adapt u64_stats_t type to address load/store tearing issues. - Refine debug helper usage to reduce the log noise caused by bots. BPF: - Improve socket map performance, avoiding skb cloning on read operation. - Add support for 64 bits enum, to match types exposed by kernel. - Introduce support for sleepable uprobes program. - Introduce support for enum textual representation in libbpf. - New helpers to implement synproxy with eBPF/XDP. - Improve loop performances, inlining indirect calls when possible. - Removed all the deprecated libbpf APIs. - Implement new eBPF-based LSM flavor. - Add type match support, which allow accurate queries to the eBPF used types. - A few TCP congetsion control framework usability improvements. - Add new infrastructure to manipulate CT entries via eBPF programs. - Allow for livepatch (KLP) and BPF trampolines to attach to the same kernel function. Protocols: - Introduce per network namespace lookup tables for unix sockets, increasing scalability and reducing contention. - Preparation work for Wi-Fi 7 Multi-Link Operation (MLO) support. - Add support to forciby close TIME_WAIT TCP sockets via user-space tools. - Significant performance improvement for the TLS 1.3 receive path, both for zero-copy and not-zero-copy. - Support for changing the initial MTPCP subflow priority/backup status - Introduce virtually contingus buffers for sockets over RDMA, to cope better with memory pressure. - Extend CAN ethtool support with timestamping capabilities - Refactor CAN build infrastructure to allow building only the needed features. Driver API: - Remove devlink mutex to allow parallel commands on multiple links. - Add support for pause stats in distributed switch. - Implement devlink helpers to query and flash line cards. - New helper for phy mode to register conversion. New hardware / drivers: - Ethernet DSA driver for the rockchip mt7531 on BPI-R2 Pro. - Ethernet DSA driver for the Renesas RZ/N1 A5PSW switch. - Ethernet DSA driver for the Microchip LAN937x switch. - Ethernet PHY driver for the Aquantia AQR113C EPHY. - CAN driver for the OBD-II ELM327 interface. - CAN driver for RZ/N1 SJA1000 CAN controller. - Bluetooth: Infineon CYW55572 Wi-Fi plus Bluetooth combo device. Drivers: - Intel Ethernet NICs: - i40e: add support for vlan pruning - i40e: add support for XDP framented packets - ice: improved vlan offload support - ice: add support for PPPoE offload - Mellanox Ethernet (mlx5) - refactor packet steering offload for performance and scalability - extend support for TC offload - refactor devlink code to clean-up the locking schema - support stacked vlans for bridge offloads - use TLS objects pool to improve connection rate - Netronome Ethernet NICs (nfp): - extend support for IPv6 fields mangling offload - add support for vepa mode in HW bridge - better support for virtio data path acceleration (VDPA) - enable TSO by default - Microsoft vNIC driver (mana) - add support for XDP redirect - Others Ethernet drivers: - bonding: add per-port priority support - microchip lan743x: extend phy support - Fungible funeth: support UDP segmentation offload and XDP xmit - Solarflare EF100: add support for virtual function representors - MediaTek SoC: add XDP support - Mellanox Ethernet/IB switch (mlxsw): - dropped support for unreleased H/W (XM router). - improved stats accuracy - unified bridge model coversion improving scalability (parts 1-6) - support for PTP in Spectrum-2 asics - Broadcom PHYs - add PTP support for BCM54210E - add support for the BCM53128 internal PHY - Marvell Ethernet switches (prestera): - implement support for multicast forwarding offload - Embedded Ethernet switches: - refactor OcteonTx MAC filter for better scalability - improve TC H/W offload for the Felix driver - refactor the Microchip ksz8 and ksz9477 drivers to share the probe code (parts 1, 2), add support for phylink mac configuration - Other WiFi: - Microchip wilc1000: diable WEP support and enable WPA3 - Atheros ath10k: encapsulation offload support Old code removal: - Neterion vxge ethernet driver: this is untouched since more than 10 years" * tag 'net-next-6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1890 commits) doc: sfp-phylink: Fix a broken reference wireguard: selftests: support UML wireguard: allowedips: don't corrupt stack when detecting overflow wireguard: selftests: update config fragments wireguard: ratelimiter: use hrtimer in selftest net/mlx5e: xsk: Discard unaligned XSK frames on striding RQ net: usb: ax88179_178a: Bind only to vendor-specific interface selftests: net: fix IOAM test skip return code net: usb: make USB_RTL8153_ECM non user configurable net: marvell: prestera: remove reduntant code octeontx2-pf: Reduce minimum mtu size to 60 net: devlink: Fix missing mutex_unlock() call net/tls: Remove redundant workqueue flush before destroy net: txgbe: Fix an error handling path in txgbe_probe() net: dsa: Fix spelling mistakes and cleanup code Documentation: devlink: add add devlink-selftests to the table of contents dccp: put dccp_qpolicy_full() and dccp_qpolicy_push() in the same lock net: ionic: fix error check for vlan flags in ionic_set_nic_features() net: ice: fix error NETIF_F_HW_VLAN_CTAG_FILTER check in ice_vsi_sync_fltr() nfp: flower: add support for tunnel offload without key ID ...
2022-08-01Merge tag 'perf-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-3/+18
Pull perf events updates from Ingo Molnar: - Fix Intel Alder Lake PEBS memory access latency & data source profiling info bugs. - Use Intel large-PEBS hardware feature in more circumstances, to reduce PMI overhead & reduce sampling data. - Extend the lost-sample profiling output with the PERF_FORMAT_LOST ABI variant, which tells tooling the exact number of samples lost. - Add new IBS register bits definitions. - AMD uncore events: Add PerfMonV2 DF (Data Fabric) enhancements. * tag 'perf-core-2022-08-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/ibs: Add new IBS register bits into header perf/x86/intel: Fix PEBS data source encoding for ADL perf/x86/intel: Fix PEBS memory access info encoding for ADL perf/core: Add a new read format to get a number of lost samples perf/x86/amd/uncore: Add PerfMonV2 RDPMC assignments perf/x86/amd/uncore: Add PerfMonV2 DF event format perf/x86/amd/uncore: Detect available DF counters perf/x86/amd/uncore: Use attr_update for format attributes perf/x86/amd/uncore: Use dynamic events array x86/events/intel/ds: Enable large PEBS for PERF_SAMPLE_WEIGHT_TYPE
2022-07-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-14/+31
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-07-13perf/core: Fix data race between perf_event_set_output() and perf_mmap_close()Peter Zijlstra1-14/+31
Yang Jihing reported a race between perf_event_set_output() and perf_mmap_close(): CPU1 CPU2 perf_mmap_close(e2) if (atomic_dec_and_test(&e2->rb->mmap_count)) // 1 - > 0 detach_rest = true ioctl(e1, IOC_SET_OUTPUT, e2) perf_event_set_output(e1, e2) ... list_for_each_entry_rcu(e, &e2->rb->event_list, rb_entry) ring_buffer_attach(e, NULL); // e1 isn't yet added and // therefore not detached ring_buffer_attach(e1, e2->rb) list_add_rcu(&e1->rb_entry, &e2->rb->event_list) After this; e1 is attached to an unmapped rb and a subsequent perf_mmap() will loop forever more: again: mutex_lock(&e->mmap_mutex); if (event->rb) { ... if (!atomic_inc_not_zero(&e->rb->mmap_count)) { ... mutex_unlock(&e->mmap_mutex); goto again; } } The loop in perf_mmap_close() holds e2->mmap_mutex, while the attach in perf_event_set_output() holds e1->mmap_mutex. As such there is no serialization to avoid this race. Change perf_event_set_output() to take both e1->mmap_mutex and e2->mmap_mutex to alleviate that problem. Additionally, have the loop in perf_mmap() detach the rb directly, this avoids having to wait for the concurrent perf_mmap_close() to get around to doing it to make progress. Fixes: 9bb5d40cd93c ("perf: Fix mmap() accounting hole") Reported-by: Yang Jihong <yangjihong1@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Tested-by: Yang Jihong <yangjihong1@huawei.com> Link: https://lkml.kernel.org/r/YsQ3jm2GR38SW7uD@worktop.programming.kicks-ass.net
2022-06-28perf/core: Add a new read format to get a number of lost samplesNamhyung Kim1-3/+18
Sometimes we want to know an accurate number of samples even if it's lost. Currenlty PERF_RECORD_LOST is generated for a ring-buffer which might be shared with other events. So it's hard to know per-event lost count. Add event->lost_samples field and PERF_FORMAT_LOST to retrieve it from userspace. Original-patch-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220616180623.1358843-1-namhyung@kernel.org
2022-06-17Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski1-6/+10
Daniel Borkmann says: ==================== pull-request: bpf-next 2022-06-17 We've added 72 non-merge commits during the last 15 day(s) which contain a total of 92 files changed, 4582 insertions(+), 834 deletions(-). The main changes are: 1) Add 64 bit enum value support to BTF, from Yonghong Song. 2) Implement support for sleepable BPF uprobe programs, from Delyan Kratunov. 3) Add new BPF helpers to issue and check TCP SYN cookies without binding to a socket especially useful in synproxy scenarios, from Maxim Mikityanskiy. 4) Fix libbpf's internal USDT address translation logic for shared libraries as well as uprobe's symbol file offset calculation, from Andrii Nakryiko. 5) Extend libbpf to provide an API for textual representation of the various map/prog/attach/link types and use it in bpftool, from Daniel Müller. 6) Provide BTF line info for RV64 and RV32 JITs, and fix a put_user bug in the core seen in 32 bit when storing BPF function addresses, from Pu Lehui. 7) Fix libbpf's BTF pointer size guessing by adding a list of various aliases for 'long' types, from Douglas Raillard. 8) Fix bpftool to readd setting rlimit since probing for memcg-based accounting has been unreliable and caused a regression on COS, from Quentin Monnet. 9) Fix UAF in BPF cgroup's effective program computation triggered upon BPF link detachment, from Tadeusz Struk. 10) Fix bpftool build bootstrapping during cross compilation which was pointing to the wrong AR process, from Shahab Vahedi. 11) Fix logic bug in libbpf's is_pow_of_2 implementation, from Yuze Chi. 12) BPF hash map optimization to avoid grabbing spinlocks of all CPUs when there is no free element. Also add a benchmark as reproducer, from Feng Zhou. 13) Fix bpftool's codegen to bail out when there's no BTF, from Michael Mullin. 14) Various minor cleanup and improvements all over the place. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (72 commits) bpf: Fix bpf_skc_lookup comment wrt. return type bpf: Fix non-static bpf_func_proto struct definitions selftests/bpf: Don't force lld on non-x86 architectures selftests/bpf: Add selftests for raw syncookie helpers in TC mode bpf: Allow the new syncookie helpers to work with SKBs selftests/bpf: Add selftests for raw syncookie helpers bpf: Add helpers to issue and check SYN cookies in XDP bpf: Allow helpers to accept pointers with a fixed size bpf: Fix documentation of th_len in bpf_tcp_{gen,check}_syncookie selftests/bpf: add tests for sleepable (uk)probes libbpf: add support for sleepable uprobe programs bpf: allow sleepable uprobe programs to attach bpf: implement sleepable uprobes by chaining gps bpf: move bpf_prog to bpf.h libbpf: Fix internal USDT address translation logic for shared libraries samples/bpf: Check detach prog exist or not in xdp_fwd selftests/bpf: Avoid skipping certain subtests selftests/bpf: Fix test_varlen verification failure with latest llvm bpftool: Do not check return value from libbpf_set_strict_mode() Revert "bpftool: Use libbpf 1.0 API mode instead of RLIMIT_MEMLOCK" ... ==================== Link: https://lore.kernel.org/r/20220617220836.7373-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-06-16bpf: allow sleepable uprobe programs to attachDelyan Kratunov1-6/+10
uprobe and kprobe programs have the same program type, KPROBE, which is currently not allowed to load sleepable programs. To avoid adding a new UPROBE type, instead allow sleepable KPROBE programs to load and defer the is-it-actually-a-uprobe-program check to attachment time, where there's already validation of the corresponding perf_event. A corollary of this patch is that you can now load a sleepable kprobe program but cannot attach it. Acked-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Delyan Kratunov <delyank@fb.com> Link: https://lore.kernel.org/r/fcd44a7cd204f372f6bb03ef794e829adeaef299.1655248076.git.delyank@fb.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-05-27perf/core: Remove unused local variableHaowen Bai1-1/+0
Drop LIST_HEAD() where the variable it declares is never used. Compiler probably never warned us, because the LIST_HEAD() initializer is technically 'usage'. [ mingo: Tweak changelog. ] Signed-off-by: Haowen Bai <baihaowen@meizu.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/1653645835-29206-1-git-send-email-baihaowen@meizu.com
2022-05-24Merge tag 'perf-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-2/+2
Pull perf events updates from Ingo Molnar: "Platform PMU changes: - x86/intel: - Add new Intel Alder Lake and Raptor Lake support - x86/amd: - AMD Zen4 IBS extensions support - Add AMD PerfMonV2 support - Add AMD Fam19h Branch Sampling support Generic changes: - signal: Deliver SIGTRAP on perf event asynchronously if blocked Perf instrumentation can be driven via SIGTRAP, but this causes a problem when SIGTRAP is blocked by a task & terminate the task. Allow user-space to request these signals asynchronously (after they get unblocked) & also give the information to the signal handler when this happens: "To give user space the ability to clearly distinguish synchronous from asynchronous signals, introduce siginfo_t::si_perf_flags and TRAP_PERF_FLAG_ASYNC (opted for flags in case more binary information is required in future). The resolution to the problem is then to (a) no longer force the signal (avoiding the terminations), but (b) tell user space via si_perf_flags if the signal was synchronous or not, so that such signals can be handled differently (e.g. let user space decide to ignore or consider the data imprecise). " - Unify/standardize the /sys/devices/cpu/events/* output format. - Misc fixes & cleanups" * tag 'perf-core-2022-05-23' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits) perf/x86/amd/core: Fix reloading events for SVM perf/x86/amd: Run AMD BRS code only on supported hw perf/x86/amd: Fix AMD BRS period adjustment perf/x86/amd: Remove unused variable 'hwc' perf/ibs: Fix comment perf/amd/ibs: Advertise zen4_ibs_extensions as pmu capability attribute perf/amd/ibs: Add support for L3 miss filtering perf/amd/ibs: Use ->is_visible callback for dynamic attributes perf/amd/ibs: Cascade pmu init functions' return value perf/x86/uncore: Add new Alder Lake and Raptor Lake support perf/x86/uncore: Clean up uncore_pci_ids[] perf/x86/cstate: Add new Alder Lake and Raptor Lake support perf/x86/msr: Add new Alder Lake and Raptor Lake support perf/x86: Add new Alder Lake and Raptor Lake support perf/amd/ibs: Use interrupt regs ip for stack unwinding perf/x86/amd/core: Add PerfMonV2 overflow handling perf/x86/amd/core: Add PerfMonV2 counter control perf/x86/amd/core: Detect available counters perf/x86/amd/core: Detect PerfMonV2 support x86/msr: Add PerfCntrGlobal* registers ...
2022-05-20perf: Fix sys_perf_event_open() race against selfPeter Zijlstra1-0/+14
Norbert reported that it's possible to race sys_perf_event_open() such that the looser ends up in another context from the group leader, triggering many WARNs. The move_group case checks for races against itself, but the !move_group case doesn't, seemingly relying on the previous group_leader->ctx == ctx check. However, that check is racy due to not holding any locks at that time. Therefore, re-check the result after acquiring locks and bailing if they no longer match. Additionally, clarify the not_move_group case from the move_group-vs-move_group race. Fixes: f63a8daa5812 ("perf: Fix event->ctx locking") Reported-by: Norbert Slusarek <nslusarek@gmx.net> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2022-05-11Merge branch 'v5.18-rc5'Peter Zijlstra1-158/+56
Obtain the new INTEL_FAM6 stuff required. Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2022-04-22signal: Deliver SIGTRAP on perf event asynchronously if blockedMarco Elver1-2/+2
With SIGTRAP on perf events, we have encountered termination of processes due to user space attempting to block delivery of SIGTRAP. Consider this case: <set up SIGTRAP on a perf event> ... sigset_t s; sigemptyset(&s); sigaddset(&s, SIGTRAP | <and others>); sigprocmask(SIG_BLOCK, &s, ...); ... <perf event triggers> When the perf event triggers, while SIGTRAP is blocked, force_sig_perf() will force the signal, but revert back to the default handler, thus terminating the task. This makes sense for error conditions, but not so much for explicitly requested monitoring. However, the expectation is still that signals generated by perf events are synchronous, which will no longer be the case if the signal is blocked and delivered later. To give user space the ability to clearly distinguish synchronous from asynchronous signals, introduce siginfo_t::si_perf_flags and TRAP_PERF_FLAG_ASYNC (opted for flags in case more binary information is required in future). The resolution to the problem is then to (a) no longer force the signal (avoiding the terminations), but (b) tell user space via si_perf_flags if the signal was synchronous or not, so that such signals can be handled differently (e.g. let user space decide to ignore or consider the data imprecise). The alternative of making the kernel ignore SIGTRAP on perf events if the signal is blocked may work for some usecases, but likely causes issues in others that then have to revert back to interception of sigprocmask() (which we want to avoid). [ A concrete example: when using breakpoint perf events to track data-flow, in a region of code where signals are blocked, data-flow can no longer be tracked accurately. When a relevant asynchronous signal is received after unblocking the signal, the data-flow tracking logic needs to know its state is imprecise. ] Fixes: 97ba62b27867 ("perf: Add support for SIGTRAP on perf events") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Dmitry Vyukov <dvyukov@google.com> Link: https://lore.kernel.org/r/20220404111204.935357-1-elver@google.com
2022-04-19perf/core: Fix perf_mmap fail when CONFIG_PERF_USE_VMALLOC enabledZhipeng Xie1-1/+1
This problem can be reproduced with CONFIG_PERF_USE_VMALLOC enabled on both x86_64 and aarch64 arch when using sysdig -B(using ebpf)[1]. sysdig -B works fine after rebuilding the kernel with CONFIG_PERF_USE_VMALLOC disabled. I tracked it down to the if condition event->rb->nr_pages != nr_pages in perf_mmap is true when CONFIG_PERF_USE_VMALLOC is enabled where event->rb->nr_pages = 1 and nr_pages = 2048 resulting perf_mmap to return -EINVAL. This is because when CONFIG_PERF_USE_VMALLOC is enabled, rb->nr_pages is always equal to 1. Arch with CONFIG_PERF_USE_VMALLOC enabled by default: arc/arm/csky/mips/sh/sparc/xtensa Arch with CONFIG_PERF_USE_VMALLOC disabled by default: x86_64/aarch64/... Fix this problem by using data_page_nr() [1] https://github.com/draios/sysdig Fixes: 906010b2134e ("perf_event: Provide vmalloc() based mmap() backing") Signed-off-by: Zhipeng Xie <xiezhipeng1@huawei.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220209145417.6495-1-xiezhipeng1@huawei.com
2022-04-05perf/core: Always set cpuctx cgrp when enable cgroup eventChengming Zhou1-16/+2
When enable a cgroup event, cpuctx->cgrp setting is conditional on the current task cgrp matching the event's cgroup, so have to do it for every new event. It brings complexity but no advantage. To keep it simple, this patch would always set cpuctx->cgrp when enable the first cgroup event, and reset to NULL when disable the last cgroup event. Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220329154523.86438-5-zhouchengming@bytedance.com
2022-04-05perf/core: Fix perf_cgroup_switch()Chengming Zhou1-107/+25
There is a race problem that can trigger WARN_ON_ONCE(cpuctx->cgrp) in perf_cgroup_switch(). CPU1 CPU2 perf_cgroup_sched_out(prev, next) cgrp1 = perf_cgroup_from_task(prev) cgrp2 = perf_cgroup_from_task(next) if (cgrp1 != cgrp2) perf_cgroup_switch(prev, PERF_CGROUP_SWOUT) cgroup_migrate_execute() task->cgroups = ? perf_cgroup_attach() task_function_call(task, __perf_cgroup_move) perf_cgroup_sched_in(prev, next) cgrp1 = perf_cgroup_from_task(prev) cgrp2 = perf_cgroup_from_task(next) if (cgrp1 != cgrp2) perf_cgroup_switch(next, PERF_CGROUP_SWIN) __perf_cgroup_move() perf_cgroup_switch(task, PERF_CGROUP_SWOUT | PERF_CGROUP_SWIN) The commit a8d757ef076f ("perf events: Fix slow and broken cgroup context switch code") want to skip perf_cgroup_switch() when the perf_cgroup of "prev" and "next" are the same. But task->cgroups can change in concurrent with context_switch() in cgroup_migrate_execute(). If cgrp1 == cgrp2 in sched_out(), cpuctx won't do sched_out. Then task->cgroups changed cause cgrp1 != cgrp2 in sched_in(), cpuctx will do sched_in. So trigger WARN_ON_ONCE(cpuctx->cgrp). Even though __perf_cgroup_move() will be synchronized as the context switch disables the interrupt, context_switch() still can see the task->cgroups is changing in the middle, since task->cgroups changed before sending IPI. So we have to combine perf_cgroup_sched_in() into perf_cgroup_sched_out(), unified into perf_cgroup_switch(), to fix the incosistency between perf_cgroup_sched_out() and perf_cgroup_sched_in(). But we can't just compare prev->cgroups with next->cgroups to decide whether to skip cpuctx sched_out/in since the prev->cgroups is changing too. For example: CPU1 CPU2 cgroup_migrate_execute() prev->cgroups = ? perf_cgroup_attach() task_function_call(task, __perf_cgroup_move) perf_cgroup_switch(task) cgrp1 = perf_cgroup_from_task(prev) cgrp2 = perf_cgroup_from_task(next) if (cgrp1 != cgrp2) cpuctx sched_out/in ... task_function_call() will return -ESRCH In the above example, prev->cgroups changing cause (cgrp1 == cgrp2) to be true, so skip cpuctx sched_out/in. And later task_function_call() would return -ESRCH since the prev task isn't running on cpu anymore. So we would leave perf_events of the old prev->cgroups still sched on the CPU, which is wrong. The solution is that we should use cpuctx->cgrp to compare with the next task's perf_cgroup. Since cpuctx->cgrp can only be changed on local CPU, and we have irq disabled, we can read cpuctx->cgrp to compare without holding ctx lock. Fixes: a8d757ef076f ("perf events: Fix slow and broken cgroup context switch code") Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220329154523.86438-4-zhouchengming@bytedance.com
2022-04-05perf/core: Use perf_cgroup_info->active to check if cgroup is activeChengming Zhou1-5/+2
Since we use perf_cgroup_set_timestamp() to start cgroup time and set active to 1, then use update_cgrp_time_from_cpuctx() to stop cgroup time and set active to 0. We can use info->active directly to check if cgroup is active. Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220329154523.86438-3-zhouchengming@bytedance.com
2022-04-05perf/core: Don't pass task around when ctx sched inChengming Zhou1-32/+26
The current code pass task around for ctx_sched_in(), only to get perf_cgroup of the task, then update the timestamp of it and its ancestors and set them to active. But we can use cpuctx->cgrp to get active perf_cgroup and its ancestors since cpuctx->cgrp has been set before ctx_sched_in(). This patch remove the task argument in ctx_sched_in() and cleanup related code. Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220329154523.86438-2-zhouchengming@bytedance.com
2022-04-05perf/core: Inherit event_capsNamhyung Kim1-0/+3
It was reported that some perf event setup can make fork failed on ARM64. It was the case of a group of mixed hw and sw events and it failed in perf_event_init_task() due to armpmu_event_init(). The ARM PMU code checks if all the events in a group belong to the same PMU except for software events. But it didn't set the event_caps of inherited events and no longer identify them as software events. Therefore the test failed in a child process. A simple reproducer is: $ perf stat -e '{cycles,cs,instructions}' perf bench sched messaging # Running 'sched/messaging' benchmark: perf: fork(): Invalid argument The perf stat was fine but the perf bench failed in fork(). Let's inherit the event caps from the parent. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: <stable@vger.kernel.org> Link: https://lkml.kernel.org/r/20220328200112.457740-1-namhyung@kernel.org
2022-03-23Merge tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-genericLinus Torvalds1-3/+0
Pull asm-generic updates from Arnd Bergmann: "There are three sets of updates for 5.18 in the asm-generic tree: - The set_fs()/get_fs() infrastructure gets removed for good. This was already gone from all major architectures, but now we can finally remove it everywhere, which loses some particularly tricky and error-prone code. There is a small merge conflict against a parisc cleanup, the solution is to use their new version. - The nds32 architecture ends its tenure in the Linux kernel. The hardware is still used and the code is in reasonable shape, but the mainline port is not actively maintained any more, as all remaining users are thought to run vendor kernels that would never be updated to a future release. - A series from Masahiro Yamada cleans up some of the uapi header files to pass the compile-time checks" * tag 'asm-generic-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/asm-generic: (27 commits) nds32: Remove the architecture uaccess: remove CONFIG_SET_FS ia64: remove CONFIG_SET_FS support sh: remove CONFIG_SET_FS support sparc64: remove CONFIG_SET_FS support lib/test_lockup: fix kernel pointer check for separate address spaces uaccess: generalize access_ok() uaccess: fix type mismatch warnings from access_ok() arm64: simplify access_ok() m68k: fix access_ok for coldfire MIPS: use simpler access_ok() MIPS: Handle address errors for accesses above CPU max virtual user address uaccess: add generic __{get,put}_kernel_nofault nios2: drop access_ok() check from __put_user() x86: use more conventional access_ok() definition x86: remove __range_not_ok() sparc64: add __{get,put}_kernel_nofault() nds32: fix access_ok() checks in get/put_user uaccess: fix nios2 and microblaze get_user_8() sparc64: fix building assembly files ...
2022-03-22Merge tag 'perf-core-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds1-2/+3
Pull x86 perf event updates from Ingo Molnar: - Fix address filtering for Intel/PT,ARM/CoreSight - Enable Intel/PEBS format 5 - Allow more fixed-function counters for x86 - Intel/PT: Enable not recording Taken-Not-Taken packets - Add a few branch-types * tag 'perf-core-2022-03-21' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel/uncore: Fix the build on !CONFIG_PHYS_ADDR_T_64BIT perf: Add irq and exception return branch types perf/x86/intel/uncore: Make uncore_discovery clean for 64 bit addresses perf/x86/intel/pt: Add a capability and config bit for disabling TNTs perf/x86/intel/pt: Add a capability and config bit for event tracing perf/x86/intel: Increase max number of the fixed counters KVM: x86: use the KVM side max supported fixed counter perf/x86/intel: Enable PEBS format 5 perf/core: Allow kernel address filter when not filtering the kernel perf/x86/intel/pt: Fix address filter config for 32-bit kernel perf/core: Fix address filter parser for multiple filters x86: Share definition of __is_canonical_address() perf/x86/intel/pt: Relax address filter validation
2022-02-25uaccess: remove CONFIG_SET_FSArnd Bergmann1-3/+0
There are no remaining callers of set_fs(), so CONFIG_SET_FS can be removed globally, along with the thread_info field and any references to it. This turns access_ok() into a cheaper check against TASK_SIZE_MAX. As CONFIG_SET_FS is now gone, drop all remaining references to set_fs()/get_fs(), mm_segment_t, user_addr_max() and uaccess_kernel(). Acked-by: Sam Ravnborg <sam@ravnborg.org> # for sparc32 changes Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Tested-by: Sergey Matyukevich <sergey.matyukevich@synopsys.com> # for arc changes Acked-by: Stafford Horne <shorne@gmail.com> # [openrisc, asm-generic] Acked-by: Dinh Nguyen <dinguyen@kernel.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2022-02-06perf: Fix list corruption in perf_cgroup_switch()Song Liu1-2/+2
There's list corruption on cgrp_cpuctx_list. This happens on the following path: perf_cgroup_switch: list_for_each_entry(cgrp_cpuctx_list) cpu_ctx_sched_in ctx_sched_in ctx_pinned_sched_in merge_sched_in perf_cgroup_event_disable: remove the event from the list Use list_for_each_entry_safe() to allow removing an entry during iteration. Fixes: 058fe1c0440e ("perf/core: Make cgroup switch visit only cpuctxs with cgroup events") Signed-off-by: Song Liu <song@kernel.org> Reviewed-by: Rik van Riel <riel@surriel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220204004057.2961252-1-song@kernel.org
2022-02-02perf/core: Allow kernel address filter when not filtering the kernelAdrian Hunter1-2/+0
The so-called 'kernel' address filter can also be useful for filtering fixed addresses in user space. Allow that. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220131072453.2839535-6-adrian.hunter@intel.com
2022-02-02perf/core: Fix address filter parser for multiple filtersAdrian Hunter1-0/+3
Reset appropriate variables in the parser loop between parsing separate filters, so that they do not interfere with parsing the next filter. Fixes: 375637bc524952 ("perf/core: Introduce address range filtering") Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lore.kernel.org/r/20220131072453.2839535-4-adrian.hunter@intel.com
2022-02-02perf: Copy perf_event_attr::sig_data on modificationMarco Elver1-0/+16
The intent has always been that perf_event_attr::sig_data should also be modifiable along with PERF_EVENT_IOC_MODIFY_ATTRIBUTES, because it is observable by user space if SIGTRAP on events is requested. Currently only PERF_TYPE_BREAKPOINT is modifiable, and explicitly copies relevant breakpoint-related attributes in hw_breakpoint_copy_attr(). This misses copying perf_event_attr::sig_data. Since sig_data is not specific to PERF_TYPE_BREAKPOINT, introduce a helper to copy generic event-type-independent attributes on modification. Fixes: 97ba62b27867 ("perf: Add support for SIGTRAP on perf events") Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Link: https://lore.kernel.org/r/20220131103407.1971678-1-elver@google.com
2022-01-26perf/core: Fix cgroup event list managementNamhyung Kim1-2/+9
The active cgroup events are managed in the per-cpu cgrp_cpuctx_list. This list is only accessed from current cpu and not protected by any locks. But from the commit ef54c1a476ae ("perf: Rework perf_event_exit_event()"), it's possible to access (actually modify) the list from another cpu. In the perf_remove_from_context(), it can remove an event from the context without an IPI when the context is not active. This is not safe with cgroup events which can have some active events in the context even if ctx->is_active is 0 at the moment. The target cpu might be in the middle of list iteration at the same time. If the event is enabled when it's about to be closed, it might call perf_cgroup_event_disable() and list_del() with the cgrp_cpuctx_list on a different cpu. This resulted in a crash due to an invalid list pointer access during the cgroup list traversal on the cpu which the event belongs to. Let's fallback to IPI to access the cgrp_cpuctx_list from that cpu. Similarly, perf_install_in_context() should use IPI for the cgroup events too. Fixes: ef54c1a476ae ("perf: Rework perf_event_exit_event()") Signed-off-by: Namhyung Kim <namhyung@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20220124195808.2252071-1-namhyung@kernel.org
2022-01-26perf: Always wake the parent eventJames Clark1-2/+10
When using per-process mode and event inheritance is set to true, forked processes will create a new perf events via inherit_event() -> perf_event_alloc(). But these events will not have ring buffers assigned to them. Any call to wakeup will be dropped if it's called on an event with no ring buffer assigned because that's the object that holds the wakeup list. If the child event is disabled due to a call to perf_aux_output_begin() or perf_aux_output_end(), the wakeup is dropped leaving userspace hanging forever on the poll. Normally the event is explicitly re-enabled by userspace after it wakes up to read the aux data, but in this case it does not get woken up so the event remains disabled. This can be reproduced when using Arm SPE and 'stress' which forks once before running the workload. By looking at the list of aux buffers read, it's apparent that they stop after the fork: perf record -e arm_spe// -vvv -- stress -c 1 With this patch applied they continue to be printed. This behaviour doesn't happen when using systemwide or per-cpu mode. Reported-by: Ruben Ayrapetyan <Ruben.Ayrapetyan@arm.com> Signed-off-by: James Clark <james.clark@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20211206113840.130802-2-james.clark@arm.com