linux/kernel/events/core.c, branch v6.4

perf/core: Fix perf_sample_data not properly initialized for different swevents in perf_tp_event()

2023-05-08T08:58:26Z

data->sample_flags may be modified in perf_prepare_sample(), in perf_tp_event(), different swevents use the same on-stack perf_sample_data, the previous swevent may change sample_flags in perf_prepare_sample(), as a result, some members of perf_sample_data are not correctly initialized when next swevent_event preparing sample (for example data->id, the value varies according to swevent). A simple scenario triggers this problem is as follows: # perf record -e sched:sched_switch --switch-output-event sched:sched_switch -a sleep 1 [ perf record: dump data: Woken up 0 times ] [ perf record: Dump perf.data.2023041209014396 ] [ perf record: dump data: Woken up 0 times ] [ perf record: Dump perf.data.2023041209014662 ] [ perf record: dump data: Woken up 0 times ] [ perf record: Dump perf.data.2023041209014910 ] [ perf record: Woken up 0 times to write data ] [ perf record: Dump perf.data.2023041209015164 ] [ perf record: Captured and wrote 0.069 MB perf.data. ] # ls -l total 860 -rw------- 1 root root 95694 Apr 12 09:01 perf.data.2023041209014396 -rw------- 1 root root 606430 Apr 12 09:01 perf.data.2023041209014662 -rw------- 1 root root 82246 Apr 12 09:01 perf.data.2023041209014910 -rw------- 1 root root 82342 Apr 12 09:01 perf.data.2023041209015164 # perf script -i perf.data.2023041209014396 0x11d58 [0x80]: failed to process type: 9 [Bad address] Solution: Re-initialize perf_sample_data after each event is processed. Note that data->raw->frag.data may be accessed in perf_tp_event_match(). Therefore, need to init sample_data and then go through swevent hlist to prevent reference of NULL pointer, reported by [1]. After fix: # perf record -e sched:sched_switch --switch-output-event sched:sched_switch -a sleep 1 [ perf record: dump data: Woken up 0 times ] [ perf record: Dump perf.data.2023041209442259 ] [ perf record: dump data: Woken up 0 times ] [ perf record: Dump perf.data.2023041209442514 ] [ perf record: dump data: Woken up 0 times ] [ perf record: Dump perf.data.2023041209442760 ] [ perf record: Woken up 0 times to write data ] [ perf record: Dump perf.data.2023041209443003 ] [ perf record: Captured and wrote 0.069 MB perf.data. ] # ls -l total 864 -rw------- 1 root root 100166 Apr 12 09:44 perf.data.2023041209442259 -rw------- 1 root root 606438 Apr 12 09:44 perf.data.2023041209442514 -rw------- 1 root root 82246 Apr 12 09:44 perf.data.2023041209442760 -rw------- 1 root root 82342 Apr 12 09:44 perf.data.2023041209443003 # perf script -i perf.data.2023041209442259 | head -n 5 perf 232 [000] 66.846217: sched:sched_switch: prev_comm=perf prev_pid=232 prev_prio=120 prev_state=D ==> next_comm=perf next_pid=234 next_prio=120 perf 234 [000] 66.846449: sched:sched_switch: prev_comm=perf prev_pid=234 prev_prio=120 prev_state=S ==> next_comm=perf next_pid=232 next_prio=120 perf 232 [000] 66.846546: sched:sched_switch: prev_comm=perf prev_pid=232 prev_prio=120 prev_state=R ==> next_comm=perf next_pid=234 next_prio=120 perf 234 [000] 66.846606: sched:sched_switch: prev_comm=perf prev_pid=234 prev_prio=120 prev_state=S ==> next_comm=perf next_pid=232 next_prio=120 perf 232 [000] 66.846646: sched:sched_switch: prev_comm=perf prev_pid=232 prev_prio=120 prev_state=R ==> next_comm=perf next_pid=234 next_prio=120 [1] Link: https://lore.kernel.org/oe-lkp/202304250929.efef2caa-yujie.liu@intel.com Fixes: bb447c27a467 ("perf/core: Set data->sample_flags in perf_prepare_sample()") Signed-off-by: Yang Jihong Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20230425103217.130600-1-yangjihong1@huawei.com

Merge tag 'perf-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2023-04-28T21:41:53Z

Pull perf updates from Ingo Molnar: - Add Intel Granite Rapids support - Add uncore events for Intel SPR IMC PMU - Fix perf IRQ throttling bug * tag 'perf-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel/uncore: Add events for Intel SPR IMC PMU perf/core: Fix hardlockup failure caused by perf throttle perf/x86/cstate: Add Granite Rapids support perf/x86/msr: Add Granite Rapids perf/x86/intel: Add Granite Rapids

perf/core: Fix hardlockup failure caused by perf throttle

2023-04-14T14:08:22Z

commit e050e3f0a71bf ("perf: Fix broken interrupt rate throttling") introduces a change in throttling threshold judgment. Before this, compare hwc->interrupts and max_samples_per_tick, then increase hwc->interrupts by 1, but this commit reverses order of these two behaviors, causing the semantics of max_samples_per_tick to change. In literal sense of "max_samples_per_tick", if hwc->interrupts == max_samples_per_tick, it should not be throttled, therefore, the judgment condition should be changed to "hwc->interrupts > max_samples_per_tick". In fact, this may cause the hardlockup to fail, The minimum value of max_samples_per_tick may be 1, in this case, the return value of __perf_event_account_interrupt function is 1. As a result, nmi_watchdog gets throttled, which would stop PMU (Use x86 architecture as an example, see x86_pmu_handle_irq). Fixes: e050e3f0a71b ("perf: Fix broken interrupt rate throttling") Signed-off-by: Yang Jihong Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20230227023508.102230-1-yangjihong1@huawei.com

perf/core: Fix the same task check in perf_event_set_output

2023-04-05T07:58:46Z

The same task check in perf_event_set_output has some potential issues for some usages. For the current perf code, there is a problem if using of perf_event_open() to have multiple samples getting into the same mmap’d memory when they are both attached to the same process. https://lore.kernel.org/all/92645262-D319-4068-9C44-2409EF44888E@gmail.com/ Because the event->ctx is not ready when the perf_event_set_output() is invoked in the perf_event_open(). Besides the above issue, before the commit bd2756811766 ("perf: Rewrite core context handling"), perf record can errors out when sampling with a hardware event and a software event as below. $ perf record -e cycles,dummy --per-thread ls failed to mmap with 22 (Invalid argument) That's because that prior to the commit a hardware event and a software event are from different task context. The problem should be a long time issue since commit c3f00c70276d ("perk: Separate find_get_context() from event initialization"). The task struct is stored in the event->hw.target for each per-thread event. It is a more reliable way to determine whether two events are attached to the same task. The event->hw.target was also introduced several years ago by the commit 50f16a8bf9d7 ("perf: Remove type specific target pointers"). It can not only be used to fix the issue with the current code, but also back port to fix the issues with an older kernel. Note: The event->hw.target was introduced later than commit c3f00c70276d. The patch may cannot be applied between the commit c3f00c70276d and commit 50f16a8bf9d7. Anybody that wants to back-port this at that period may have to find other solutions. Fixes: c3f00c70276d ("perf: Separate find_get_context() from event initialization") Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Zhengjun Xing Link: https://lkml.kernel.org/r/20230322202449.512091-1-kan.liang@linux.intel.com

perf: Optimize perf_pmu_migrate_context()

2023-04-05T07:58:46Z

Thomas reported that offlining CPUs spends a lot of time in synchronize_rcu() as called from perf_pmu_migrate_context() even though he's not actually using uncore events. Turns out, the thing is unconditionally waiting for RCU, even if there's no actual events to migrate. Fixes: 0cda4c023132 ("perf: Introduce perf_pmu_migrate_context()") Reported-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Tested-by: Thomas Gleixner Reviewed-by: Thomas Gleixner Reviewed-by: Paul E. McKenney Link: https://lkml.kernel.org/r/20230403090858.GT4253@hirez.programming.kicks-ass.net

perf: Fix check before add_event_to_groups() in perf_group_detach()

2023-03-15T20:49:47Z

Events should only be added to a groups rb tree if they have not been removed from their context by list_del_event(). Since remove_on_exec made it possible to call list_del_event() on individual events before they are detached from their group, perf_group_detach() should check each sibling's attach_state before calling add_event_to_groups() on it. Fixes: 2e498d0a74e5 ("perf: Add support for event removal on exec") Signed-off-by: Budimir Markovic Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/ZBFzvQV9tEqoHEtH@gentoo

perf: fix perf_event_context->time

2023-03-15T20:49:46Z

Time readers rely on perf_event_context->[time|timestamp|timeoffset] to get accurate time_enabled and time_running for an event. The difference between ctx->timestamp and ctx->time is the among of time when the context is not enabled. __update_context_time(ctx, false) is used to increase timestamp, but not time. Therefore, it should only be called in ctx_sched_in() when EVENT_TIME was not enabled. Fixes: 09f5e7dc7ad7 ("perf: Fix perf_event_read_local() time") Signed-off-by: Song Liu Signed-off-by: Peter Zijlstra (Intel) Acked-by: Namhyung Kim Link: https://lkml.kernel.org/r/20230313171608.298734-1-song@kernel.org

perf/core: Fix perf_output_begin parameter is incorrectly invoked in perf_event_bpf_output

2023-03-15T20:49:46Z

syzkaller reportes a KASAN issue with stack-out-of-bounds. The call trace is as follows: dump_stack+0x9c/0xd3 print_address_description.constprop.0+0x19/0x170 __kasan_report.cold+0x6c/0x84 kasan_report+0x3a/0x50 __perf_event_header__init_id+0x34/0x290 perf_event_header__init_id+0x48/0x60 perf_output_begin+0x4a4/0x560 perf_event_bpf_output+0x161/0x1e0 perf_iterate_sb_cpu+0x29e/0x340 perf_iterate_sb+0x4c/0xc0 perf_event_bpf_event+0x194/0x2c0 __bpf_prog_put.constprop.0+0x55/0xf0 __cls_bpf_delete_prog+0xea/0x120 [cls_bpf] cls_bpf_delete_prog_work+0x1c/0x30 [cls_bpf] process_one_work+0x3c2/0x730 worker_thread+0x93/0x650 kthread+0x1b8/0x210 ret_from_fork+0x1f/0x30 commit 267fb27352b6 ("perf: Reduce stack usage of perf_output_begin()") use on-stack struct perf_sample_data of the caller function. However, perf_event_bpf_output uses incorrect parameter to convert small-sized data (struct perf_bpf_event) into large-sized data (struct perf_sample_data), which causes memory overwriting occurs in __perf_event_header__init_id. Fixes: 267fb27352b6 ("perf: Reduce stack usage of perf_output_begin()") Signed-off-by: Yang Jihong Signed-off-by: Peter Zijlstra (Intel) Link: https://lkml.kernel.org/r/20230314044735.56551-1-yangjihong1@huawei.com

Merge tag 'char-misc-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc

2023-02-24T20:47:33Z

Pull char/misc and other driver subsystem updates from Greg KH: "Here is the large set of driver changes for char/misc drivers and other smaller driver subsystems that flow through this git tree. Included in here are: - New IIO drivers and features and improvments in that subsystem - New hwtracing drivers and additions to that subsystem - lots of interconnect changes and new drivers as that subsystem seems under very active development recently. This required also merging in the icc subsystem changes through this tree. - FPGA driver updates - counter subsystem and driver updates - MHI driver updates - nvmem driver updates - documentation updates - Other smaller driver updates and fixes, full details in the shortlog All of these have been in linux-next for a while with no reported problems" * tag 'char-misc-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (223 commits) scripts/tags.sh: fix incompatibility with PCRE2 firmware: coreboot: Remove GOOGLE_COREBOOT_TABLE_ACPI/OF Kconfig entries mei: lower the log level for non-fatal failed messages mei: bus: disallow driver match while dismantling device misc: vmw_balloon: fix memory leak with using debugfs_lookup() nvmem: stm32: fix OPTEE dependency dt-bindings: nvmem: qfprom: add IPQ8074 compatible nvmem: qcom-spmi-sdam: register at device init time nvmem: rave-sp-eeprm: fix kernel-doc bad line warning nvmem: stm32: detect bsec pta presence for STM32MP15x nvmem: stm32: add OP-TEE support for STM32MP13x nvmem: core: use nvmem_add_one_cell() in nvmem_add_cells_from_of() nvmem: core: add nvmem_add_one_cell() nvmem: core: drop the removal of the cells in nvmem_add_cells() nvmem: core: move struct nvmem_cell_info to nvmem-provider.h nvmem: core: add an index parameter to the cell of: property: add #nvmem-cell-cells property of: property: make #.*-cells optional for simple props of: base: add of_parse_phandle_with_optional_args() net: add helper eth_addr_add() ...

Merge tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2023-02-24T01:09:35Z

Pull MM updates from Andrew Morton: - Daniel Verkamp has contributed a memfd series ("mm/memfd: add F_SEAL_EXEC") which permits the setting of the memfd execute bit at memfd creation time, with the option of sealing the state of the X bit. - Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset() thread-safe for pmd unshare") which addresses a rare race condition related to PMD unsharing. - Several folioification patch serieses from Matthew Wilcox, Vishal Moola, Sidhartha Kumar and Lorenzo Stoakes - Johannes Weiner has a series ("mm: push down lock_page_memcg()") which does perform some memcg maintenance and cleanup work. - SeongJae Park has added DAMOS filtering to DAMON, with the series "mm/damon/core: implement damos filter". These filters provide users with finer-grained control over DAMOS's actions. SeongJae has also done some DAMON cleanup work. - Kairui Song adds a series ("Clean up and fixes for swap"). - Vernon Yang contributed the series "Clean up and refinement for maple tree". - Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It adds to MGLRU an LRU of memcgs, to improve the scalability of global reclaim. - David Hildenbrand has added some userfaultfd cleanup work in the series "mm: uffd-wp + change_protection() cleanups". - Christoph Hellwig has removed the generic_writepages() library function in the series "remove generic_writepages". - Baolin Wang has performed some maintenance on the compaction code in his series "Some small improvements for compaction". - Sidhartha Kumar is doing some maintenance work on struct page in his series "Get rid of tail page fields". - David Hildenbrand contributed some cleanup, bugfixing and generalization of pte management and of pte debugging in his series "mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with swap PTEs". - Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation flag in the series "Discard __GFP_ATOMIC". - Sergey Senozhatsky has improved zsmalloc's memory utilization with his series "zsmalloc: make zspage chain size configurable". - Joey Gouly has added prctl() support for prohibiting the creation of writeable+executable mappings. The previous BPF-based approach had shortcomings. See "mm: In-kernel support for memory-deny-write-execute (MDWE)". - Waiman Long did some kmemleak cleanup and bugfixing in the series "mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF". - T.J. Alumbaugh has contributed some MGLRU cleanup work in his series "mm: multi-gen LRU: improve". - Jiaqi Yan has provided some enhancements to our memory error statistics reporting, mainly by presenting the statistics on a per-node basis. See the series "Introduce per NUMA node memory error statistics". - Mel Gorman has a second and hopefully final shot at fixing a CPU-hog regression in compaction via his series "Fix excessive CPU usage during compaction". - Christoph Hellwig does some vmalloc maintenance work in the series "cleanup vfree and vunmap". - Christoph Hellwig has removed block_device_operations.rw_page() in ths series "remove ->rw_page". - We get some maple_tree improvements and cleanups in Liam Howlett's series "VMA tree type safety and remove __vma_adjust()". - Suren Baghdasaryan has done some work on the maintainability of our vm_flags handling in the series "introduce vm_flags modifier functions". - Some pagemap cleanup and generalization work in Mike Rapoport's series "mm, arch: add generic implementation of pfn_valid() for FLATMEM" and "fixups for generic implementation of pfn_valid()" - Baoquan He has done some work to make /proc/vmallocinfo and /proc/kcore better represent the real state of things in his series "mm/vmalloc.c: allow vread() to read out vm_map_ram areas". - Jason Gunthorpe rationalized the GUP system's interface to the rest of the kernel in the series "Simplify the external interface for GUP". - SeongJae Park wishes to migrate people from DAMON's debugfs interface over to its sysfs interface. To support this, we'll temporarily be printing warnings when people use the debugfs interface. See the series "mm/damon: deprecate DAMON debugfs interface". - Andrey Konovalov provided the accurately named "lib/stackdepot: fixes and clean-ups" series. - Huang Ying has provided a dramatic reduction in migration's TLB flush IPI rates with the series "migrate_pages(): batch TLB flushing". - Arnd Bergmann has some objtool fixups in "objtool warning fixes". * tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits) include/linux/migrate.h: remove unneeded externs mm/memory_hotplug: cleanup return value handing in do_migrate_range() mm/uffd: fix comment in handling pte markers mm: change to return bool for isolate_movable_page() mm: hugetlb: change to return bool for isolate_hugetlb() mm: change to return bool for isolate_lru_page() mm: change to return bool for folio_isolate_lru() objtool: add UACCESS exceptions for __tsan_volatile_read/write kmsan: disable ftrace in kmsan core code kasan: mark addr_has_metadata __always_inline mm: memcontrol: rename memcg_kmem_enabled() sh: initialize max_mapnr m68k/nommu: add missing definition of ARCH_PFN_OFFSET mm: percpu: fix incorrect size in pcpu_obj_full_size() maple_tree: reduce stack usage with gcc-9 and earlier mm: page_alloc: call panic() when memoryless node allocation fails mm: multi-gen LRU: avoid futile retries migrate_pages: move THP/hugetlb migration support check to simplify code migrate_pages: batch flushing TLB migrate_pages: share more code between _unmap and _move ...