kernel.git/arch/powerpc/perf, branch linux-6.14.y

arch/powerpc/perf: Check the instruction type before creating sample with perf_mem_data_src

2025-05-29T09:13:33Z

[ Upstream commit 2ffb26afa64261139e608bf087a0c1fe24d76d4d ] perf mem report aborts as below sometimes (during some corner case) in powerpc: # ./perf mem report 1>out *** stack smashing detected ***: terminated Aborted (core dumped) The backtrace is as below: __pthread_kill_implementation () raise () abort () __libc_message __fortify_fail __stack_chk_fail hist_entry.lvl_snprintf __sort__hpp_entry __hist_entry__snprintf hists.fprintf cmd_report cmd_mem Snippet of code which triggers the issue from tools/perf/util/sort.c static int hist_entry__lvl_snprintf(struct hist_entry *he, char *bf, size_t size, unsigned int width) { char out[64]; perf_mem__lvl_scnprintf(out, sizeof(out), he->mem_info); return repsep_snprintf(bf, size, "%-*s", width, out); } The value of "out" is filled from perf_mem_data_src value. Debugging this further showed that for some corner cases, the value of "data_src" was pointing to wrong value. This resulted in bigger size of string and causing stack check fail. The perf mem data source values are captured in the sample via isa207_get_mem_data_src function. The initial check is to fetch the type of sampled instruction. If the type of instruction is not valid (not a load/store instruction), the function returns. Since 'commit e16fd7f2cb1a ("perf: Use sample_flags for data_src")', data_src field is not initialized by the perf_sample_data_init() function. If the PMU driver doesn't set the data_src value to zero if type is not valid, this will result in uninitailised value for data_src. The uninitailised value of data_src resulted in stack check fail followed by abort for "perf mem report". When requesting for data source information in the sample, the instruction type is expected to be load or store instruction. In ISA v3.0, due to hardware limitation, there are corner cases where the instruction type other than load or store is observed. In ISA v3.0 and before values "0" and "7" are considered reserved. In ISA v3.1, value "7" has been used to indicate "larx/stcx". Drop the sample if instruction type has reserved values for this field with a ISA version check. Initialize data_src to zero in isa207_get_mem_data_src if the instruction type is not load/store. Reported-by: Disha Goel Signed-off-by: Athira Rajeev Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20250121131621.39054-1-atrajeev@linux.vnet.ibm.com Signed-off-by: Sasha Levin

powerpc/perf: Fix ref-counting on the PMU 'vpa_pmu'

2025-04-10T12:44:19Z

[ Upstream commit ff99d5b6a246715f2257123cdf6c4a29cb33aa78 ] Commit 176cda0619b6 ("powerpc/perf: Add perf interface to expose vpa counters") introduced 'vpa_pmu' to expose Book3s-HV nested APIv2 provided L1<->L2 context switch latency counters to L1 user-space via perf-events. However the newly introduced PMU named 'vpa_pmu' doesn't assign ownership of the PMU to the module 'vpa_pmu'. Consequently the module 'vpa_pmu' can be unloaded while one of the perf-events are still active, which can lead to kernel oops and panic of the form below on a Pseries-LPAR: BUG: Kernel NULL pointer dereference on read at 0x00000058 NIP [c000000000506cb8] event_sched_out+0x40/0x258 LR [c00000000050e8a4] __perf_remove_from_context+0x7c/0x2b0 Call Trace: [c00000025fc3fc30] [c00000025f8457a8] 0xc00000025f8457a8 (unreliable) [c00000025fc3fc80] [fffffffffffffee0] 0xfffffffffffffee0 [c00000025fc3fcd0] [c000000000501e70] event_function+0xa8/0x120 Kernel panic - not syncing: Aiee, killing interrupt handler! Fix this by adding the module ownership to 'vpa_pmu' so that the module 'vpa_pmu' is ref-counted and prevented from being unloaded when perf-events are initialized. Fixes: 176cda0619b6 ("powerpc/perf: Add perf interface to expose vpa counters") Signed-off-by: Vaibhav Jain Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20250204153527.125491-1-vaibhav@linux.ibm.com Signed-off-by: Sasha Levin

perf: Supply task information to sched_task()

2025-04-10T12:43:58Z

[ Upstream commit d57e94f5b891925e4f2796266eba31edd5a01903 ] To save/restore LBR call stack data in system-wide mode, the task_struct information is required. Extend the parameters of sched_task() to supply task_struct information. When schedule in, the LBR call stack data for new task will be restored. When schedule out, the LBR call stack data for old task will be saved. Only need to pass the required task_struct information. Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Link: https://lore.kernel.org/r/20250314172700.438923-4-kan.liang@linux.intel.com Stable-dep-of: 3cec9fd03543 ("perf/x86/lbr: Fix shorter LBRs call stacks for the system-wide mode") Signed-off-by: Sasha Levin

Merge tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2024-11-23T18:44:31Z

Pull powerpc updates from Michael Ellerman: - Rework kfence support for the HPT MMU to work on systems with >= 16TB of RAM. - Remove the powerpc "maple" platform, used by the "Yellow Dog Powerstation". - Add support for DYNAMIC_FTRACE_WITH_CALL_OPS, DYNAMIC_FTRACE_WITH_DIRECT_CALLS & BPF Trampolines. - Add support for running KVM nested guests on Power11. - Other small features, cleanups and fixes. Thanks to Amit Machhiwal, Arnd Bergmann, Christophe Leroy, Costa Shulyupin, David Hunter, David Wang, Disha Goel, Gautam Menghani, Geert Uytterhoeven, Hari Bathini, Julia Lawall, Kajol Jain, Keith Packard, Lukas Bulwahn, Madhavan Srinivasan, Markus Elfring, Michal Suchanek, Ming Lei, Mukesh Kumar Chaurasiya, Nathan Chancellor, Naveen N Rao, Nicholas Piggin, Nysal Jan K.A, Paulo Miguel Almeida, Pavithra Prakash, Ritesh Harjani (IBM), Rob Herring (Arm), Sachin P Bappalige, Shen Lichuan, Simon Horman, Sourabh Jain, Thomas Weißschuh, Thorsten Blum, Thorsten Leemhuis, Venkat Rao Bagalkote, Zhang Zekun, and zhang jiao. * tag 'powerpc-6.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (89 commits) EDAC/powerpc: Remove PPC_MAPLE drivers powerpc/perf: Add per-task/process monitoring to vpa_pmu driver powerpc/kvm: Add vpa latency counters to kvm_vcpu_arch docs: ABI: sysfs-bus-event_source-devices-vpa-pmu: Document sysfs event format entries for vpa_pmu powerpc/perf: Add perf interface to expose vpa counters MAINTAINERS: powerpc: Mark Maddy as "M" powerpc/Makefile: Allow overriding CPP powerpc-km82xx.c: replace of_node_put() with __free ps3: Correct some typos in comments powerpc/kexec: Fix return of uninitialized variable macintosh: Use common error handling code in via_pmu_led_init() powerpc/powermac: Use of_property_match_string() in pmac_has_backlight_type() powerpc: remove dead config options for MPC85xx platform support powerpc/xive: Use cpumask_intersects() selftests/powerpc: Remove the path after initialization. powerpc/xmon: symbol lookup length fixed powerpc/ep8248e: Use %pa to format resource_size_t powerpc/ps3: Reorganize kerneldoc parameter names KVM: PPC: Book3S HV: Fix kmv -> kvm typo powerpc/sstep: make emulate_vsx_load and emulate_vsx_store static ...

Merge tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2024-11-23T17:58:07Z

Pull MM updates from Andrew Morton: - The series "zram: optimal post-processing target selection" from Sergey Senozhatsky improves zram's post-processing selection algorithm. This leads to improved memory savings. - Wei Yang has gone to town on the mapletree code, contributing several series which clean up the implementation: - "refine mas_mab_cp()" - "Reduce the space to be cleared for maple_big_node" - "maple_tree: simplify mas_push_node()" - "Following cleanup after introduce mas_wr_store_type()" - "refine storing null" - The series "selftests/mm: hugetlb_fault_after_madv improvements" from David Hildenbrand fixes this selftest for s390. - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng implements some rationaizations and cleanups in the page mapping code. - The series "mm: optimize shadow entries removal" from Shakeel Butt optimizes the file truncation code by speeding up the handling of shadow entries. - The series "Remove PageKsm()" from Matthew Wilcox completes the migration of this flag over to being a folio-based flag. - The series "Unify hugetlb into arch_get_unmapped_area functions" from Oscar Salvador implements a bunch of consolidations and cleanups in the hugetlb code. - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain takes away the wp-fault time practice of turning a huge zero page into small pages. Instead we replace the whole thing with a THP. More consistent cleaner and potentiall saves a large number of pagefaults. - The series "percpu: Add a test case and fix for clang" from Andy Shevchenko enhances and fixes the kernel's built in percpu test code. - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett optimizes mremap() by avoiding doing things which we didn't need to do. - The series "Improve the tmpfs large folio read performance" from Baolin Wang teaches tmpfs to copy data into userspace at the folio size rather than as individual pages. A 20% speedup was observed. - The series "mm/damon/vaddr: Fix issue in damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON splitting. - The series "memcg-v1: fully deprecate charge moving" from Shakeel Butt removes the long-deprecated memcgv2 charge moving feature. - The series "fix error handling in mmap_region() and refactor" from Lorenzo Stoakes cleanup up some of the mmap() error handling and addresses some potential performance issues. - The series "x86/module: use large ROX pages for text allocations" from Mike Rapoport teaches x86 to use large pages for read-only-execute module text. - The series "page allocation tag compression" from Suren Baghdasaryan is followon maintenance work for the new page allocation profiling feature. - The series "page->index removals in mm" from Matthew Wilcox remove most references to page->index in mm/. A slow march towards shrinking struct page. - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs interface tests" from Andrew Paniakin performs maintenance work for DAMON's self testing code. - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar improves zswap's batching of compression and decompression. It is a step along the way towards using Intel IAA hardware acceleration for this zswap operation. - The series "kasan: migrate the last module test to kunit" from Sabyrzhan Tasbolatov completes the migration of the KASAN built-in tests over to the KUnit framework. - The series "implement lightweight guard pages" from Lorenzo Stoakes permits userapace to place fault-generating guard pages within a single VMA, rather than requiring that multiple VMAs be created for this. Improved efficiencies for userspace memory allocators are expected. - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses tracepoints to provide increased visibility into memcg stats flushing activity. - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky fixes a zram buglet which potentially affected performance. - The series "mm: add more kernel parameters to control mTHP" from Maíra Canal enhances our ability to control/configuremultisize THP from the kernel boot command line. - The series "kasan: few improvements on kunit tests" from Sabyrzhan Tasbolatov has a couple of fixups for the KASAN KUnit tests. - The series "mm/list_lru: Split list_lru lock into per-cgroup scope" from Kairui Song optimizes list_lru memory utilization when lockdep is enabled. * tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits) cma: enforce non-zero pageblock_order during cma_init_reserved_mem() mm/kfence: add a new kunit test test_use_after_free_read_nofault() zram: fix NULL pointer in comp_algorithm_show() memcg/hugetlb: add hugeTLB counters to memcg vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount zram: ZRAM_DEF_COMP should depend on ZRAM MAINTAINERS/MEMORY MANAGEMENT: add document files for mm Docs/mm/damon: recommend academic papers to read and/or cite mm: define general function pXd_init() kmemleak: iommu/iova: fix transient kmemleak false positive mm/list_lru: simplify the list_lru walk callback function mm/list_lru: split the lock to per-cgroup scope mm/list_lru: simplify reparenting and initial allocation mm/list_lru: code clean up for reparenting mm/list_lru: don't export list_lru_add mm/list_lru: don't pass unnecessary key parameters kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols ...

powerpc/perf: Add per-task/process monitoring to vpa_pmu driver

2024-11-19T03:11:30Z

Enhance the vpa_pmu driver with a feature to observe context switch latency event for both per-task (tid) and per-pid (pid) option. Couple of new helper functions are added to hide the abstraction of reading the context switch latency counter from kvm_vcpu_arch struct and these helper functions are defined in the "kvm/book3s_hv.c". "PERF_ATTACH_TASK" flag is used to decide whether to read the counter values from lppaca or kvm_vcpu_arch struct. Signed-off-by: Kajol Jain Co-developed-by: Madhavan Srinivasan Signed-off-by: Madhavan Srinivasan Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/20241118114114.208964-4-kjain@linux.ibm.com

powerpc/perf: Add perf interface to expose vpa counters

2024-11-19T03:11:06Z

To support performance measurement for KVM on PowerVM(KoP) feature, PowerVM hypervisor has added couple of new software counters in Virtual Process Area(VPA) of the partition. Commit e1f288d2f9c69 ("KVM: PPC: Book3S HV nestedv2: Add support for reading VPA counters for pseries guests") have updated the paca fields with corresponding changes. Proposed perf interface is to expose these new software counters for monitoring of context switch latencies and runtime aggregate. Perf interface driver is called "vpa_pmu" and it has dependency on KVM and perf, hence added new config called "VPA_PMU" which depends on "CONFIG_KVM_BOOK3S_64_HV" and "CONFIG_HV_PERF_CTRS". Since, kvm and kvm_host are currently compiled as built-in modules, this perf interface takes the same path and registered as a module. vpa_pmu perf interface needs access to some of the kvm functions and structures like kvmhv_get_l2_counters_status(), hence kvm_book3s_64.h and kvm_ppc.h are included. Below are the events added to monitor KoP: vpa_pmu/l1_to_l2_lat/ vpa_pmu/l2_to_l1_lat/ vpa_pmu/l2_runtime_agg/ and vpa_pmu driver supports only per-cpu monitoring with this patch. Example usage: [command]# perf stat -e vpa_pmu/l1_to_l2_lat/ -a -I 1000 1.001017682 727,200 vpa_pmu/l1_to_l2_lat/ 2.003540491 1,118,824 vpa_pmu/l1_to_l2_lat/ 3.005699458 1,919,726 vpa_pmu/l1_to_l2_lat/ 4.007827011 2,364,630 vpa_pmu/l1_to_l2_lat/ Signed-off-by: Kajol Jain Co-developed-by: Madhavan Srinivasan Signed-off-by: Madhavan Srinivasan Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/20241118114114.208964-1-kjain@linux.ibm.com

perf/powerpc: Use perf_arch_instruction_pointer()

2024-11-14T09:40:01Z

Make sure PowerPC uses the arch-specific function now that those have been reorganized. Signed-off-by: Colton Lewis Signed-off-by: Ingo Molnar Reviewed-by: Oliver Upton Acked-by: Madhavan Srinivasan Link: https://lore.kernel.org/r/20241113190156.2145593-4-coltonlewis@google.com

perf/core: Hoist perf_instruction_pointer() and perf_misc_flags()

2024-11-14T09:40:01Z

For clarity, rename the arch-specific definitions of these functions to perf_arch_* to denote they are arch-specifc. Define the generic-named functions in one place where they can call the arch-specific ones as needed. Signed-off-by: Colton Lewis Signed-off-by: Ingo Molnar Reviewed-by: Oliver Upton Acked-by: Thomas Richter Acked-by: Mark Rutland Acked-by: Madhavan Srinivasan Acked-by: Kan Liang Link: https://lore.kernel.org/r/20241113190156.2145593-3-coltonlewis@google.com

asm-generic: introduce text-patching.h

2024-11-07T22:25:15Z

Several architectures support text patching, but they name the header files that declare patching functions differently. Make all such headers consistently named text-patching.h and add an empty header in asm-generic for architectures that do not support text patching. Link: https://lkml.kernel.org/r/20241023162711.2579610-4-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) Reviewed-by: Christoph Hellwig Acked-by: Geert Uytterhoeven # m68k Acked-by: Arnd Bergmann Reviewed-by: Luis Chamberlain Tested-by: kdevops Cc: Andreas Larsson Cc: Andy Lutomirski Cc: Ard Biesheuvel Cc: Borislav Petkov (AMD) Cc: Brian Cain Cc: Catalin Marinas Cc: Christophe Leroy Cc: Dave Hansen Cc: Dinh Nguyen Cc: Guo Ren Cc: Helge Deller Cc: Huacai Chen Cc: Ingo Molnar Cc: Johannes Berg Cc: John Paul Adrian Glaubitz Cc: Kent Overstreet Cc: Liam R. Howlett Cc: Mark Rutland Cc: Masami Hiramatsu (Google) Cc: Matt Turner Cc: Max Filippov Cc: Michael Ellerman Cc: Michal Simek Cc: Oleg Nesterov Cc: Palmer Dabbelt Cc: Peter Zijlstra Cc: Richard Weinberger Cc: Russell King Cc: Song Liu Cc: Stafford Horne Cc: Steven Rostedt (Google) Cc: Suren Baghdasaryan Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Uladzislau Rezki (Sony) Cc: Vineet Gupta Cc: Will Deacon Signed-off-by: Andrew Morton