| Commit message (Collapse) | Author | Age | Files | Lines |
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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 <markovicbudimir@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/ZBFzvQV9tEqoHEtH@gentoo
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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 <song@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/r/20230313171608.298734-1-song@kernel.org
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perf_event_bpf_output
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 <yangjihong1@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20230314044735.56551-1-yangjihong1@huawei.com
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
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()
...
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We need the char-misc driver fixes in here as other patches depend on
them.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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CoreSight trace being updated to use the perf_report_aux_output_id()
in a similar way to intel-pt.
This function in needs export visibility to allow it to be called from
kernel loadable modules, which CoreSight may configured to be built as.
Signed-off-by: Mike Leach <mike.leach@linaro.org>
Acked-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20230116124928.5440-12-mike.leach@linaro.org
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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
...
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Replace direct modifications to vma->vm_flags with calls to modifier
functions to be able to track flag changes and to keep vma locking
correctness.
[akpm@linux-foundation.org: fix drivers/misc/open-dice.c, per Hyeonggon Yoo]
Link: https://lkml.kernel.org/r/20230126193752.297968-5-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Acked-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@Oracle.com>
Reviewed-by: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Laurent Dufour <ldufour@linux.ibm.com>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Peter Oskolkov <posk@google.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Punit Agrawal <punit.agrawal@bytedance.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Inline the work of __vma_adjust() into vma_merge(). This reduces code
size and has the added benefits of the comments for the cases being
located with the code.
Change the comments referencing vma_adjust() accordingly.
[Liam.Howlett@oracle.com: fix vma_merge() offset when expanding the next vma]
Link: https://lkml.kernel.org/r/20230130195713.2881766-1-Liam.Howlett@oracle.com
Link: https://lkml.kernel.org/r/20230120162650.984577-49-Liam.Howlett@oracle.com
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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All callers now have a folio and can call munlock_vma_folio(). Update the
documentation to refer to munlock_vma_folio().
Link: https://lkml.kernel.org/r/20230116192827.2146732-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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mmu_notifier_range_update_to_read_only() was originally introduced in
commit c6d23413f81b ("mm/mmu_notifier:
mmu_notifier_range_update_to_read_only() helper") as an optimisation for
device drivers that know a range has only been mapped read-only. However
there are no users of this feature so remove it. As it is the only user
of the struct mmu_notifier_range.vma field remove that also.
Link: https://lkml.kernel.org/r/20230110025722.600912-1-apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Ralph Campbell <rcampbell@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
- Optimize perf_sample_data layout
- Prepare sample data handling for BPF integration
- Update the x86 PMU driver for Intel Meteor Lake
- Restructure the x86 uncore code to fix a SPR (Sapphire Rapids)
discovery breakage
- Fix the x86 Zhaoxin PMU driver
- Cleanups
* tag 'perf-core-2023-02-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
perf/x86/intel/uncore: Add Meteor Lake support
x86/perf/zhaoxin: Add stepping check for ZXC
perf/x86/intel/ds: Fix the conversion from TSC to perf time
perf/x86/uncore: Don't WARN_ON_ONCE() for a broken discovery table
perf/x86/uncore: Add a quirk for UPI on SPR
perf/x86/uncore: Ignore broken units in discovery table
perf/x86/uncore: Fix potential NULL pointer in uncore_get_alias_name
perf/x86/uncore: Factor out uncore_device_to_die()
perf/core: Call perf_prepare_sample() before running BPF
perf/core: Introduce perf_prepare_header()
perf/core: Do not pass header for sample ID init
perf/core: Set data->sample_flags in perf_prepare_sample()
perf/core: Add perf_sample_save_brstack() helper
perf/core: Add perf_sample_save_raw_data() helper
perf/core: Add perf_sample_save_callchain() helper
perf/core: Save the dynamic parts of sample data size
x86/kprobes: Use switch-case for 0xFF opcodes in prepare_emulation
perf/core: Change the layout of perf_sample_data
perf/x86/msr: Add Meteor Lake support
perf/x86/cstate: Add Meteor Lake support
...
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As BPF can access sample data, it needs to populate the data. Also
remove the logic to get the callchain specifically as it's covered by
the perf_prepare_sample() now.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230118060559.615653-9-namhyung@kernel.org
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Factor out perf_prepare_header() so that it can call
perf_prepare_sample() without a header if not needed.
Also it checks the filtered_sample_type to avoid duplicate
work when perf_prepare_sample() is called twice (or more).
Suggested-by: Peter Zijlstr <peterz@infradead.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230118060559.615653-8-namhyung@kernel.org
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The only thing it does for header in __perf_event_header__init_id() is
to update the header size with event->id_header_size. We can do this
outside and get rid of the argument for the later change.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230118060559.615653-7-namhyung@kernel.org
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The perf_prepare_sample() function sets the perf_sample_data according
to the attr->sample_type before copying it to the ring buffer. But BPF
also wants to access the sample data so it needs to prepare the sample
even before the regular path.
That means perf_prepare_sample() can be called more than once. Set
the data->sample_flags consistently so that it can indicate which fields
are set already and skip them if sets.
Also update the filtered_sample_type to have the dependent flags to
reduce the number of branches.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230118060559.615653-6-namhyung@kernel.org
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When we saves the branch stack to the perf sample data, we needs to
update the sample flags and the dynamic size. To make sure this is
done consistently, add the perf_sample_save_brstack() helper and
convert all call sites.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230118060559.615653-5-namhyung@kernel.org
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When we save the raw_data to the perf sample data, we need to update
the sample flags and the dynamic size. To make sure this is done
consistently, add the perf_sample_save_raw_data() helper and convert
all call sites.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230118060559.615653-4-namhyung@kernel.org
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When we save the callchain to the perf sample data, we need to update
the sample flags and the dynamic size. To ensure this is done consistently,
add the perf_sample_save_callchain() helper and convert all call sites.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230118060559.615653-3-namhyung@kernel.org
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The perf sample data can be divided into parts. The event->header_size
and event->id_header_size keep the static part of the sample data which
is determined by the sample_type flags.
But other parts like CALLCHAIN and BRANCH_STACK are changing dynamically
so it needs to see the actual data. In preparation of handling repeated
calls for perf_prepare_sample(), it can save the dynamic size to the
perf sample data to avoid the duplicate work.
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230118060559.615653-2-namhyung@kernel.org
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Syzkaller triggered a WARN in put_pmu_ctx().
WARNING: CPU: 1 PID: 2245 at kernel/events/core.c:4925 put_pmu_ctx+0x1f0/0x278
This is because there is no locking around the access of "if
(!epc->ctx)" in find_get_pmu_context() and when it is set to NULL in
put_pmu_ctx().
The decrement of the reference count in put_pmu_ctx() also happens
outside of the spinlock, leading to the possibility of this order of
events, and the context being cleared in put_pmu_ctx(), after its
refcount is non zero:
CPU0 CPU1
find_get_pmu_context()
if (!epc->ctx) == false
put_pmu_ctx()
atomic_dec_and_test(&epc->refcount) == true
epc->refcount == 0
atomic_inc(&epc->refcount);
epc->refcount == 1
list_del_init(&epc->pmu_ctx_entry);
epc->ctx = NULL;
Another issue is that WARN_ON for no active PMU events in put_pmu_ctx()
is outside of the lock. If the perf_event_pmu_context is an embedded
one, even after clearing it, it won't be deleted and can be re-used. So
the warning can trigger. For this reason it also needs to be moved
inside the lock.
The above warning is very quick to trigger on Arm by running these two
commands at the same time:
while true; do perf record -- ls; done
while true; do perf record -- ls; done
[peterz: atomic_dec_and_raw_lock*()]
Fixes: bd2756811766 ("perf: Rewrite core context handling")
Reported-by: syzbot+697196bc0265049822bd@syzkaller.appspotmail.com
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/r/20230127143141.1782804-2-james.clark@arm.com
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It passes the attr struct to the security_perf_event_open() but it's
not initialized yet.
Fixes: da97e18458fb ("perf_event: Add support for LSM and SELinux checks")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20221220223140.4020470-1-namhyung@kernel.org
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The syscall error path has a use-after-free; put_pmu_ctx() will
reference ctx, therefore we must ensure ctx is destroyed after pmu_ctx
is.
Fixes: bd2756811766 ("perf: Rewrite core context handling")
Reported-by: syzbot+b8e8c01c8ade4fe6e48f@syzkaller.appspotmail.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Chengming Zhou <zhouchengming@bytedance.com>
Link: https://lkml.kernel.org/r/Y6B3xEgkbmFUCeni@hirez.programming.kicks-ass.net
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We encounter perf warnings when using cgroup events like:
cd /sys/fs/cgroup
mkdir test
perf stat -e cycles -a -G test
Which then triggers:
WARNING: CPU: 0 PID: 690 at kernel/events/core.c:849 perf_cgroup_switch+0xb2/0xc0
Call Trace:
<TASK>
__schedule+0x4ae/0x9f0
? _raw_spin_unlock_irqrestore+0x23/0x40
? __cond_resched+0x18/0x20
preempt_schedule_common+0x2d/0x70
__cond_resched+0x18/0x20
wait_for_completion+0x2f/0x160
? cpu_stop_queue_work+0x9e/0x130
affine_move_task+0x18a/0x4f0
WARNING: CPU: 0 PID: 690 at kernel/events/core.c:829 ctx_sched_in+0x1cf/0x1e0
Call Trace:
<TASK>
? ctx_sched_out+0xb7/0x1b0
perf_cgroup_switch+0x88/0xc0
__schedule+0x4ae/0x9f0
? _raw_spin_unlock_irqrestore+0x23/0x40
? __cond_resched+0x18/0x20
preempt_schedule_common+0x2d/0x70
__cond_resched+0x18/0x20
wait_for_completion+0x2f/0x160
? cpu_stop_queue_work+0x9e/0x130
affine_move_task+0x18a/0x4f0
The above two warnings are not complete here since I remove other
unimportant information. The problem is caused by the perf cgroup
events tracking:
CPU0 CPU1
perf_event_open()
perf_event_alloc()
account_event()
account_event_cpu()
atomic_inc(perf_cgroup_events)
__perf_event_task_sched_out()
if (atomic_read(perf_cgroup_events))
perf_cgroup_switch()
// kernel/events/core.c:849
WARN_ON_ONCE(cpuctx->ctx.nr_cgroups == 0)
if (READ_ONCE(cpuctx->cgrp) == cgrp) // false
return
perf_ctx_lock()
ctx_sched_out()
cpuctx->cgrp = cgrp
ctx_sched_in()
perf_cgroup_set_timestamp()
// kernel/events/core.c:829
WARN_ON_ONCE(!ctx->nr_cgroups)
perf_ctx_unlock()
perf_install_in_context()
cpu_function_call()
__perf_install_in_context()
add_event_to_ctx()
list_add_event()
perf_cgroup_event_enable()
ctx->nr_cgroups++
cpuctx->cgrp = X
We can see from above that we wrongly use percpu atomic perf_cgroup_events
to check if we need to perf_cgroup_switch(), which should only be used
when we know this CPU has cgroup events enabled.
The commit bd2756811766 ("perf: Rewrite core context handling") change
to have only one context per-CPU, so we can just use cpuctx->cgrp to
check if this CPU has cgroup events enabled.
So percpu atomic perf_cgroup_events is not needed.
Fixes: bd2756811766 ("perf: Rewrite core context handling")
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lkml.kernel.org/r/20221207124023.66252-1-zhouchengming@bytedance.com
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inherit_event() returns NULL only when it finds orphaned events
otherwise it returns either valid child_event pointer or an error
pointer. Follow the same when it fails to find pmu_ctx.
Fixes: bd2756811766 ("perf: Rewrite core context handling")
Reported-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221118051539.820-1-ravi.bangoria@amd.com
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm updates from Dave Hansen:
"New Feature:
- Randomize the per-cpu entry areas
Cleanups:
- Have CR3_ADDR_MASK use PHYSICAL_PAGE_MASK instead of open coding it
- Move to "native" set_memory_rox() helper
- Clean up pmd_get_atomic() and i386-PAE
- Remove some unused page table size macros"
* tag 'x86_mm_for_6.2_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits)
x86/mm: Ensure forced page table splitting
x86/kasan: Populate shadow for shared chunk of the CPU entry area
x86/kasan: Add helpers to align shadow addresses up and down
x86/kasan: Rename local CPU_ENTRY_AREA variables to shorten names
x86/mm: Populate KASAN shadow for entire per-CPU range of CPU entry area
x86/mm: Recompute physical address for every page of per-CPU CEA mapping
x86/mm: Rename __change_page_attr_set_clr(.checkalias)
x86/mm: Inhibit _PAGE_NX changes from cpa_process_alias()
x86/mm: Untangle __change_page_attr_set_clr(.checkalias)
x86/mm: Add a few comments
x86/mm: Fix CR3_ADDR_MASK
x86/mm: Remove P*D_PAGE_MASK and P*D_PAGE_SIZE macros
mm: Convert __HAVE_ARCH_P..P_GET to the new style
mm: Remove pointless barrier() after pmdp_get_lockless()
x86/mm/pae: Get rid of set_64bit()
x86_64: Remove pointless set_64bit() usage
x86/mm/pae: Be consistent with pXXp_get_and_clear()
x86/mm/pae: Use WRITE_ONCE()
x86/mm/pae: Don't (ab)use atomic64
mm/gup: Fix the lockless PMD access
...
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On architectures where the PTE/PMD is larger than the native word size
(i386-PAE for example), READ_ONCE() can do the wrong thing. Use
pmdp_get_lockless() just like we use ptep_get_lockless().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221022114424.906110403%40infradead.org
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf events updates from Ingo Molnar:
- Thoroughly rewrite the data structures that implement perf task
context handling, with the goal of fixing various quirks and
unfeatures both in already merged, and in upcoming proposed code.
The old data structure is the per task and per cpu
perf_event_contexts:
task_struct::perf_events_ctxp[] <-> perf_event_context <-> perf_cpu_context
^ | ^ | ^
`---------------------------------' | `--> pmu ---'
v ^
perf_event ------'
In this new design this is replaced with a single task context and a
single CPU context, plus intermediate data-structures:
task_struct::perf_event_ctxp -> perf_event_context <- perf_cpu_context
^ | ^ ^
`---------------------------' | |
| | perf_cpu_pmu_context <--.
| `----. ^ |
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| v v |
| ,--> perf_event_pmu_context |
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v v |
perf_event ---> pmu ----------------'
[ See commit bd2756811766 for more details. ]
This rewrite was developed by Peter Zijlstra and Ravi Bangoria.
- Optimize perf_tp_event()
- Update the Intel uncore PMU driver, extending it with UPI topology
discovery on various hardware models.
- Misc fixes & cleanups
* tag 'perf-core-2022-12-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (25 commits)
perf/x86/intel/uncore: Fix reference count leak in __uncore_imc_init_box()
perf/x86/intel/uncore: Fix reference count leak in snr_uncore_mmio_map()
perf/x86/intel/uncore: Fix reference count leak in hswep_has_limit_sbox()
perf/x86/intel/uncore: Fix reference count leak in sad_cfg_iio_topology()
perf/x86/intel/uncore: Make set_mapping() procedure void
perf/x86/intel/uncore: Update sysfs-devices-mapping file
perf/x86/intel/uncore: Enable UPI topology discovery for Sapphire Rapids
perf/x86/intel/uncore: Enable UPI topology discovery for Icelake Server
perf/x86/intel/uncore: Get UPI NodeID and GroupID
perf/x86/intel/uncore: Enable UPI topology discovery for Skylake Server
perf/x86/intel/uncore: Generalize get_topology() for SKX PMUs
perf/x86/intel/uncore: Disable I/O stacks to PMU mapping on ICX-D
perf/x86/intel/uncore: Clear attr_update properly
perf/x86/intel/uncore: Introduce UPI topology type
perf/x86/intel/uncore: Generalize IIO topology support
perf/core: Don't allow grouping events from different hw pmus
perf/amd/ibs: Make IBS a core pmu
perf: Fix function pointer case
perf/x86/amd: Remove the repeated declaration
perf: Fix possible memleak in pmu_dev_alloc()
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Event group from different hw pmus does not make sense and thus perf
has never allowed it. However, with recent rewrite that restriction
has been inadvertently removed. Fix it.
Fixes: bd2756811766 ("perf: Rewrite core context handling")
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221122080326.228-1-ravi.bangoria@amd.com
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With the advent of CFI it is no longer acceptible to cast function
pointers.
The robot complains thusly:
kernel-events-core.c:warning:cast-from-int-(-)(struct-perf_cpu_pmu_context-)-to-remote_function_f-(aka-int-(-)(void-)-)-converts-to-incompatible-function-type
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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In pmu_dev_alloc(), when dev_set_name() failed, it will goto free_dev
and call put_device(pmu->dev) to release it.
However pmu->dev->release is assigned after this, which makes warning
and memleak.
Call dev_set_name() after pmu->dev->release = pmu_dev_release to fix it.
Device '(null)' does not have a release() function...
WARNING: CPU: 2 PID: 441 at drivers/base/core.c:2332 device_release+0x1b9/0x240
...
Call Trace:
<TASK>
kobject_put+0x17f/0x460
put_device+0x20/0x30
pmu_dev_alloc+0x152/0x400
perf_pmu_register+0x96b/0xee0
...
kmemleak: 1 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
unreferenced object 0xffff888014759000 (size 2048):
comm "modprobe", pid 441, jiffies 4294931444 (age 38.332s)
backtrace:
[<0000000005aed3b4>] kmalloc_trace+0x27/0x110
[<000000006b38f9b8>] pmu_dev_alloc+0x50/0x400
[<00000000735f17be>] perf_pmu_register+0x96b/0xee0
[<00000000e38477f1>] 0xffffffffc0ad8603
[<000000004e162216>] do_one_initcall+0xd0/0x4e0
...
Fixes: abe43400579d ("perf: Sysfs enumeration")
Signed-off-by: Chen Zhongjin <chenzhongjin@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221111103653.91058-1-chenzhongjin@huawei.com
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The find_get_pmu_context() returns an ERR_PTR() on failure, we should use
IS_ERR() to check the return value.
Fixes: bd2756811766 ("perf: Rewrite core context handling")
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221114091833.1492575-1-cuigaosheng1@huawei.com
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The pointer task_ctx is being assigned a value that is not read, the
assignment is redundant and so is the pointer. Remove it
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221028122545.528999-1-colin.i.king@gmail.com
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Use the event group trees to iterate only perf_tracepoint events.
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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There have been various issues and limitations with the way perf uses
(task) contexts to track events. Most notable is the single hardware
PMU task context, which has resulted in a number of yucky things (both
proposed and merged).
Notably:
- HW breakpoint PMU
- ARM big.little PMU / Intel ADL PMU
- Intel Branch Monitoring PMU
- AMD IBS PMU
- S390 cpum_cf PMU
- PowerPC trace_imc PMU
*Current design:*
Currently we have a per task and per cpu perf_event_contexts:
task_struct::perf_events_ctxp[] <-> perf_event_context <-> perf_cpu_context
^ | ^ | ^
`---------------------------------' | `--> pmu ---'
v ^
perf_event ------'
Each task has an array of pointers to a perf_event_context. Each
perf_event_context has a direct relation to a PMU and a group of
events for that PMU. The task related perf_event_context's have a
pointer back to that task.
Each PMU has a per-cpu pointer to a per-cpu perf_cpu_context, which
includes a perf_event_context, which again has a direct relation to
that PMU, and a group of events for that PMU.
The perf_cpu_context also tracks which task context is currently
associated with that CPU and includes a few other things like the
hrtimer for rotation etc.
Each perf_event is then associated with its PMU and one
perf_event_context.
*Proposed design:*
New design proposed by this patch reduce to a single task context and
a single CPU context but adds some intermediate data-structures:
task_struct::perf_event_ctxp -> perf_event_context <- perf_cpu_context
^ | ^ ^
`---------------------------' | |
| | perf_cpu_pmu_context <--.
| `----. ^ |
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| v v |
| ,--> perf_event_pmu_context |
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v v |
perf_event ---> pmu ----------------'
With the new design, perf_event_context will hold all events for all
pmus in the (respective pinned/flexible) rbtrees. This can be achieved
by adding pmu to rbtree key:
{cpu, pmu, cgroup, group_index}
Each perf_event_context carries a list of perf_event_pmu_context which
is used to hold per-pmu-per-context state. For example, it keeps track
of currently active events for that pmu, a pmu specific task_ctx_data,
a flag to tell whether rotation is required or not etc.
Additionally, perf_cpu_pmu_context is used to hold per-pmu-per-cpu
state like hrtimer details to drive the event rotation, a pointer to
perf_event_pmu_context of currently running task and some other
ancillary information.
Each perf_event is associated to it's pmu, perf_event_context and
perf_event_pmu_context.
Further optimizations to current implementation are possible. For
example, ctx_resched() can be optimized to reschedule only single pmu
events.
Much thanks to Ravi for picking this up and pushing it towards
completion.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Co-developed-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221008062424.313-1-ravi.bangoria@amd.com
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fix from Borislav Petkov:
- Fix a use-after-free case where the perf pending task callback would
see an already freed event
* tag 'perf_urgent_for_v6.1_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf: Fix perf_pending_task() UaF
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Per syzbot it is possible for perf_pending_task() to run after the
event is free()'d. There are two related but distinct cases:
- the task_work was already queued before destroying the event;
- destroying the event itself queues the task_work.
The first cannot be solved using task_work_cancel() since
perf_release() itself might be called from a task_work (____fput),
which means the current->task_works list is already empty and
task_work_cancel() won't be able to find the perf_pending_task()
entry.
The simplest alternative is extending the perf_event lifetime to cover
the task_work.
The second is just silly, queueing a task_work while you know the
event is going away makes no sense and is easily avoided by
re-arranging how the event is marked STATE_DEAD and ensuring it goes
through STATE_OFF on the way down.
Reported-by: syzbot+9228d6098455bb209ec8@syzkaller.appspotmail.com
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Marco Elver <elver@google.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Jakub Kicinski:
"Including fixes from bpf, can and wifi.
Current release - new code bugs:
- eth: mlx5e:
- use kvfree() in mlx5e_accel_fs_tcp_create()
- MACsec, fix RX data path 16 RX security channel limit
- MACsec, fix memory leak when MACsec device is deleted
- MACsec, fix update Rx secure channel active field
- MACsec, fix add Rx security association (SA) rule memory leak
Previous releases - regressions:
- wifi: cfg80211: don't allow multi-BSSID in S1G
- stmmac: set MAC's flow control register to reflect current settings
- eth: mlx5:
- E-switch, fix duplicate lag creation
- fix use-after-free when reverting termination table
Previous releases - always broken:
- ipv4: fix route deletion when nexthop info is not specified
- bpf: fix a local storage BPF map bug where the value's spin lock
field can get initialized incorrectly
- tipc: re-fetch skb cb after tipc_msg_validate
- wifi: wilc1000: fix Information Element parsing
- packet: do not set TP_STATUS_CSUM_VALID on CHECKSUM_COMPLETE
- sctp: fix memory leak in sctp_stream_outq_migrate()
- can: can327: fix potential skb leak when netdev is down
- can: add number of missing netdev freeing on error paths
- aquantia: do not purge addresses when setting the number of rings
- wwan: iosm:
- fix incorrect skb length leading to truncated packet
- fix crash in peek throughput test due to skb UAF"
* tag 'net-6.1-rc8-2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (79 commits)
net: ethernet: renesas: ravb: Fix promiscuous mode after system resumed
MAINTAINERS: Update maintainer list for chelsio drivers
ionic: update MAINTAINERS entry
sctp: fix memory leak in sctp_stream_outq_migrate()
packet: do not set TP_STATUS_CSUM_VALID on CHECKSUM_COMPLETE
net/mlx5: Lag, Fix for loop when checking lag
Revert "net/mlx5e: MACsec, remove replay window size limitation in offload path"
net: marvell: prestera: Fix a NULL vs IS_ERR() check in some functions
net: tun: Fix use-after-free in tun_detach()
net: mdiobus: fix unbalanced node reference count
net: hsr: Fix potential use-after-free
tipc: re-fetch skb cb after tipc_msg_validate
mptcp: fix sleep in atomic at close time
mptcp: don't orphan ssk in mptcp_close()
dsa: lan9303: Correct stat name
ipv4: Fix route deletion when nexthop info is not specified
net: wwan: iosm: fix incorrect skb length
net: wwan: iosm: fix crash in peek throughput test
net: wwan: iosm: fix dma_alloc_coherent incompatible pointer type
net: wwan: iosm: fix kernel test robot reported error
...
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Since commit bfea9a8574f3 ("bpf: Add name to struct bpf_ksym"), when
reporting subprog ksymbol to perf, prog name instead of subprog name is
used. The backtrace of bpf program with subprogs will be incorrect as
shown below:
ffffffffc02deace bpf_prog_e44a3057dcb151f8_overwrite+0x66
ffffffffc02de9f7 bpf_prog_e44a3057dcb151f8_overwrite+0x9f
ffffffffa71d8d4e trace_call_bpf+0xce
ffffffffa71c2938 perf_call_bpf_enter.isra.0+0x48
overwrite is the entry program and it invokes the overwrite_htab subprog
through bpf_loop, but in above backtrace, overwrite program just jumps
inside itself.
Fixing it by using subprog name when reporting subprog ksymbol. After
the fix, the output of perf script will be correct as shown below:
ffffffffc031aad2 bpf_prog_37c0bec7d7c764a4_overwrite_htab+0x66
ffffffffc031a9e7 bpf_prog_c7eb827ef4f23e71_overwrite+0x9f
ffffffffa3dd8d4e trace_call_bpf+0xce
ffffffffa3dc2938 perf_call_bpf_enter.isra.0+0x48
Fixes: bfea9a8574f3 ("bpf: Add name to struct bpf_ksym")
Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20221114095733.158588-1-houtao@huaweicloud.com
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Some PMUs (notably the traditional hardware kind) have boundary issues
with the OS filter. Specifically, it is possible for
perf_event_attr::exclude_kernel=1 events to trigger in-kernel due to
SKID or errata.
This can upset the sigtrap logic some and trigger the WARN.
However, if this invalid sample is the first we must not loose the
SIGTRAP, OTOH if it is the second, it must not override the
pending_addr with a (possibly) invalid one.
Fixes: ca6c21327c6a ("perf: Fix missing SIGTRAPs")
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Marco Elver <elver@google.com>
Tested-by: Pengfei Xu <pengfei.xu@intel.com>
Link: https://lkml.kernel.org/r/Y3hDYiXwRnJr8RYG@xpf.sh.intel.com
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The perf_event_attr::sigtrap functionality relies on data->addr being
set. However commit 7b0846301531 ("perf: Use sample_flags for addr")
changed this to only initialize data->addr when not 0.
Fixes: 7b0846301531 ("perf: Use sample_flags for addr")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/Y3426b4OimE%2FI5po%40hirez.programming.kicks-ass.net
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To catch missing SIGTRAP we employ a WARN in __perf_event_overflow(),
which fires if pending_sigtrap was already set: returning to user space
without consuming pending_sigtrap, and then having the event fire again
would re-enter the kernel and trigger the WARN.
This, however, seemed to miss the case where some events not associated
with progress in the user space task can fire and the interrupt handler
runs before the IRQ work meant to consume pending_sigtrap (and generate
the SIGTRAP).
syzbot gifted us this stack trace:
| WARNING: CPU: 0 PID: 3607 at kernel/events/core.c:9313 __perf_event_overflow
| Modules linked in:
| CPU: 0 PID: 3607 Comm: syz-executor100 Not tainted 6.1.0-rc2-syzkaller-00073-g88619e77b33d #0
| Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
| RIP: 0010:__perf_event_overflow+0x498/0x540 kernel/events/core.c:9313
| <...>
| Call Trace:
| <TASK>
| perf_swevent_hrtimer+0x34f/0x3c0 kernel/events/core.c:10729
| __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
| __hrtimer_run_queues+0x1c6/0xfb0 kernel/time/hrtimer.c:1749
| hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
| local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline]
| __sysvec_apic_timer_interrupt+0x17c/0x640 arch/x86/kernel/apic/apic.c:1113
| sysvec_apic_timer_interrupt+0x40/0xc0 arch/x86/kernel/apic/apic.c:1107
| asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
| <...>
| </TASK>
In this case, syzbot produced a program with event type
PERF_TYPE_SOFTWARE and config PERF_COUNT_SW_CPU_CLOCK. The hrtimer
manages to fire again before the IRQ work got a chance to run, all while
never having returned to user space.
Improve the WARN to check for real progress in user space: approximate
this by storing a 32-bit hash of the current IP into pending_sigtrap,
and if an event fires while pending_sigtrap still matches the previous
IP, we assume no progress (false negatives are possible given we could
return to user space and trigger again on the same IP).
Fixes: ca6c21327c6a ("perf: Fix missing SIGTRAPs")
Reported-by: syzbot+b8ded3e2e2c6adde4990@syzkaller.appspotmail.com
Signed-off-by: Marco Elver <elver@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20221031093513.3032814-1-elver@google.com
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Running the test currently fails on non-SMP systems, despite being
enabled by default. This means that running the test with:
./tools/testing/kunit/kunit.py run --arch x86_64 hw_breakpoint
results in every hw_breakpoint test failing with:
# test_one_cpu: failed to initialize: -22
not ok 1 - test_one_cpu
Instead, use kunit_skip(), which will mark the test as skipped, and give
a more comprehensible message:
ok 1 - test_one_cpu # SKIP not enough cpus
This makes it more obvious that the test is not suited to the test
environment, and so wasn't run, rather than having run and failed.
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Daniel Latypov <dlatypov@google.com>
Acked-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20221026141040.1609203-1-davidgow@google.com
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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
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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>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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
...
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Add support for MADV_COLLAPSE to collapse shmem-backed and file-backed
memory into THPs (requires CONFIG_READ_ONLY_THP_FOR_FS=y).
On success, the backing memory will be a hugepage. For the memory range
and process provided, the page tables will synchronously have a huge pmd
installed, mapping the THP. Other mappings of the file extent mapped by
the memory range may be added to a set of entries that khugepaged will
later process and attempt update their page tables to map the THP by a
pmd.
This functionality unlocks two important uses:
(1) Immediately back executable text by THPs. Current support provided
by CONFIG_READ_ONLY_THP_FOR_FS may take a long time on a large
system which might impair services from serving at their full rated
load after (re)starting. Tricks like mremap(2)'ing text onto
anonymous memory to immediately realize iTLB performance prevents
page sharing and demand paging, both of which increase steady state
memory footprint. Now, we can have the best of both worlds: Peak
upfront performance and lower RAM footprints.
(2) userfaultfd-based live migration of virtual machines satisfy UFFD
faults by fetching native-sized pages over the network (to avoid
latency of transferring an entire hugepage). However, after guest
memory has been fully copied to the new host, MADV_COLLAPSE can
be used to immediately increase guest performance.
Since khugepaged is single threaded, this change now introduces
possibility of collapse contexts racing in file collapse path. There a
important few places to consider:
(1) hpage_collapse_scan_file(), when we xas_pause() and drop RCU.
We could have the memory collapsed out from under us, but
the next xas_for_each() iteration will correctly pick up the
hugepage. The hugepage might not be up to date (insofar as
copying of small page contents might not have completed - the
page still may be locked), but regardless what small page index
we were iterating over, we'll find the hugepage and identify it
as a suitably aligned compound page of order HPAGE_PMD_ORDER.
In khugepaged path, we locklessly check the value of the pmd,
and only add it to deferred collapse array if we find pmd
mapping pte table. This is fine, since other values that could
have raced in right afterwards denote failure, or that the
memory was successfully collapsed, so we don't need further
processing.
In madvise path, we'll take mmap_lock() in write to serialize
against page table updates and will know what to do based on the
true value of the pmd: recheck all ptes if we point to a pte table,
directly install the pmd, if the pmd has been cleared, but
memory not yet faulted, or nothing at all if we find a huge pmd.
It's worth putting emphasis here on how we treat the none pmd
here. If khugepaged has processed this mm's page tables
already, it will have left the pmd cleared (ready for refault by
the process). Depending on the VMA flags and sysfs settings,
amount of RAM on the machine, and the current load, could be a
relatively common occurrence - and as such is one we'd like to
handle successfully in MADV_COLLAPSE. When we see the none pmd
in collapse_pte_mapped_thp(), we've locked mmap_lock in write
and checked (a) huepaged_vma_check() to see if the backing
memory is appropriate still, along with VMA sizing and
appropriate hugepage alignment within the file, and (b) we've
found a hugepage head of order HPAGE_PMD_ORDER at the offset
in the file mapped by our hugepage-aligned virtual address.
Even though the common-case is likely race with khugepaged,
given these checks (regardless how we got here - we could be
operating on a completely different file than originally checked
in hpage_collapse_scan_file() for all we know) it should be safe
to directly make the pmd a huge pmd pointing to this hugepage.
(2) collapse_file() is mostly serialized on the same file extent by
lock sequence:
| lock hupepage
| lock mapping->i_pages
| lock 1st page
| unlock mapping->i_pages
| <page checks>
| lock mapping->i_pages
| page_ref_freeze(3)
| xas_store(hugepage)
| unlock mapping->i_pages
| page_ref_unfreeze(1)
| unlock 1st page
V unlock hugepage
Once a context (who already has their fresh hugepage locked)
locks mapping->i_pages exclusively, it will hold said lock
until it locks the first page, and it will hold that lock until
the after the hugepage has been added to the page cache (and
will unlock the hugepage after page table update, though that
isn't important here).
A racing context that loses the race for mapping->i_pages will
then lose the race to locking the first page. Here - depending
on how far the other racing context has gotten - we might find
the new hugepage (in which case we'll exit cleanly when we
check PageTransCompound()), or we'll find the "old" 1st small
page (in which we'll exit cleanly when we discover unexpected
refcount of 2 after isolate_lru_page()). This is assuming we
are able to successfully lock the page we find - in shmem path,
we could just fail the trylock and exit cleanly anyways.
Failure path in collapse_file() is similar: once we hold lock
on 1st small page, we are serialized against other collapse
contexts. Before the 1st small page is unlocked, we add it
back to the pagecache and unfreeze the refcount appropriately.
Contexts who lost the race to the 1st small page will then find
the same 1st small page with the correct refcount and will be
able to proceed.
[zokeefe@google.com: don't check pmd value twice in collapse_pte_mapped_thp()]
Link: https://lkml.kernel.org/r/20220927033854.477018-1-zokeefe@google.com
[shy828301@gmail.com: Delete hugepage_vma_revalidate_anon(), remove
check for multi-add in khugepaged_add_pte_mapped_thp()]
Link: https://lore.kernel.org/linux-mm/CAHbLzkrtpM=ic7cYAHcqkubah5VTR8N5=k5RT8MTvv5rN1Y91w@mail.gmail.com/
Link: https://lkml.kernel.org/r/20220907144521.3115321-4-zokeefe@google.com
Link: https://lkml.kernel.org/r/20220922224046.1143204-4-zokeefe@google.com
Signed-off-by: Zach O'Keefe <zokeefe@google.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Chris Kennelly <ckennelly@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: James Houghton <jthoughton@google.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rongwei Wang <rongwei.wang@linux.alibaba.com>
Cc: SeongJae Park <sj@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Saves several calls to compound_head().
Link: https://lkml.kernel.org/r/20220902194653.1739778-57-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Remove a few hidden calls to compound_head().
Link: https://lkml.kernel.org/r/20220902194653.1739778-45-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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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>
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