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1,189,500 commits

Author SHA1 Message Date
Ricardo Koller
bd3ed7e1a4 KVM: selftests: Stash backing_src_type in struct userspace_mem_region
Add the backing_src_type into struct userspace_mem_region. This struct
already stores a lot of info about memory regions, except the backing
source type.  This info will be used by a future commit in order to
determine the method for punching a hole.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221017195834.2295901-7-ricarkol@google.com
2022-11-10 19:10:27 +00:00
Ricardo Koller
590b949597 tools: Copy bitfield.h from the kernel sources
Copy bitfield.h from include/linux/bitfield.h.  A subsequent change will
make use of some FIELD_{GET,PREP} macros defined in this header.

The header was copied as-is, no changes needed.

Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221017195834.2295901-6-ricarkol@google.com
2022-11-10 19:10:27 +00:00
Ricardo Koller
41f5189ea9 KVM: selftests: aarch64: Construct DEFAULT_MAIR_EL1 using sysreg.h macros
Define macros for memory type indexes and construct DEFAULT_MAIR_EL1
with macros from asm/sysreg.h.  The index macros can then be used when
constructing PTEs (instead of using raw numbers).

Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221017195834.2295901-5-ricarkol@google.com
2022-11-10 19:10:27 +00:00
Ricardo Koller
b6b03b86c0 KVM: selftests: Add missing close and munmap in __vm_mem_region_delete()
Deleting a memslot (when freeing a VM) is not closing the backing fd,
nor it's unmapping the alias mapping. Fix by adding the missing close
and munmap.

Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Reviewed-by: Oliver Upton <oupton@google.com>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221017195834.2295901-4-ricarkol@google.com
2022-11-10 19:10:27 +00:00
Ricardo Koller
228f324dc7 KVM: selftests: aarch64: Add virt_get_pte_hva() library function
Add a library function to get the PTE (a host virtual address) of a
given GVA.  This will be used in a future commit by a test to clear and
check the access flag of a particular page.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Andrew Jones <andrew.jones@linux.dev>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221017195834.2295901-3-ricarkol@google.com
2022-11-10 19:10:27 +00:00
Ricardo Koller
a93871d0ea KVM: selftests: Add a userfaultfd library
Move the generic userfaultfd code out of demand_paging_test.c into a
common library, userfaultfd_util. This library consists of a setup and a
stop function. The setup function starts a thread for handling page
faults using the handler callback function. This setup returns a
uffd_desc object which is then used in the stop function (to wait and
destroy the threads).

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Reviewed-by: Ben Gardon <bgardon@google.com>
Signed-off-by: Ricardo Koller <ricarkol@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221017195834.2295901-2-ricarkol@google.com
2022-11-10 19:10:27 +00:00
Reiji Watanabe
ebb8cc1031 KVM: arm64: selftests: Test with every breakpoint/watchpoint
Currently, the debug-exceptions test always uses only
{break,watch}point#0 and the highest numbered context-aware
breakpoint. Modify the test to use all {break,watch}points and
context-aware breakpoints supported on the system.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-10-reijiw@google.com
2022-11-10 19:03:54 +00:00
Reiji Watanabe
5ced4e533b KVM: arm64: selftests: Add a test case for a linked watchpoint
Currently, the debug-exceptions test doesn't have a test case for
a linked watchpoint. Add a test case for the linked watchpoint to
the test. The new test case uses the highest numbered context-aware
breakpoint (for Context ID match), and the watchpoint#0, which is
linked to the context-aware breakpoint.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-9-reijiw@google.com
2022-11-10 19:03:54 +00:00
Reiji Watanabe
142365932f KVM: arm64: selftests: Add a test case for a linked breakpoint
Currently, the debug-exceptions test doesn't have a test case for
a linked breakpoint. Add a test case for the linked breakpoint to
the test. The new test case uses a pair of breakpoints. One is the
higiest numbered context-aware breakpoint (for Context ID match),
and the other one is the breakpoint#0 (for Address Match), which
is linked to the context-aware breakpoint.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-8-reijiw@google.com
2022-11-10 19:03:54 +00:00
Reiji Watanabe
5dd544e882 KVM: arm64: selftests: Change debug_version() to take ID_AA64DFR0_EL1
Change debug_version() to take the ID_AA64DFR0_EL1 value instead of
vcpu as an argument, and change its callsite to read ID_AA64DFR0_EL1
(and pass it to debug_version()).
Subsequent patches will reuse the register value in the callsite.

No functional change intended.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-7-reijiw@google.com
2022-11-10 19:03:54 +00:00
Reiji Watanabe
948f439c9d KVM: arm64: selftests: Stop unnecessary test stage tracking of debug-exceptions
Currently, debug-exceptions test unnecessarily tracks some test stages
using GUEST_SYNC().  The code for it needs to be updated as test cases
are added or removed.  Stop doing the unnecessary stage tracking,
as they are not so useful and are a bit pain to maintain.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-6-reijiw@google.com
2022-11-10 19:03:54 +00:00
Reiji Watanabe
152880d8ed KVM: arm64: selftests: Add helpers to enable debug exceptions
Add helpers to enable breakpoint and watchpoint exceptions.
No functional change intended.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-5-reijiw@google.com
2022-11-10 19:03:54 +00:00
Reiji Watanabe
700b8860e0 KVM: arm64: selftests: Remove the hard-coded {b,w}pn#0 from debug-exceptions
Remove the hard-coded {break,watch}point #0 from the guest_code() in
debug-exceptions to allow {break,watch}point number to be specified.
Change reset_debug_state() to zeroing all dbg{b,w}{c,v}r_el0 registers
so that guest_code() can use the function to reset those registers
even when non-zero {break,watch}points are specified for guest_code().
Subsequent patches will add test cases for non-zero {break,watch}points.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-4-reijiw@google.com
2022-11-10 19:03:54 +00:00
Reiji Watanabe
f6d02aa28a KVM: arm64: selftests: Add write_dbg{b,w}{c,v}r helpers in debug-exceptions
Introduce helpers in the debug-exceptions test to write to
dbg{b,w}{c,v}r registers. Those helpers will be useful for
test cases that will be added to the test in subsequent patches.

No functional change intended.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Ricardo Koller <ricarkol@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-3-reijiw@google.com
2022-11-10 19:03:54 +00:00
Reiji Watanabe
1a6182033f KVM: arm64: selftests: Use FIELD_GET() to extract ID register fields
Use FIELD_GET() macro to extract ID register fields for existing
aarch64 selftests code. No functional change intended.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020054202.2119018-2-reijiw@google.com
2022-11-10 19:03:54 +00:00
Anthony DeRossi
e806e22362 vfio/pci: Check the device set open count on reset
vfio_pci_dev_set_needs_reset() inspects the open_count of every device
in the set to determine whether a reset is allowed. The current device
always has open_count == 1 within vfio_pci_core_disable(), effectively
disabling the reset logic. This field is also documented as private in
vfio_device, so it should not be used to determine whether other devices
in the set are open.

Checking for vfio_device_set_open_count() > 1 on the device set fixes
both issues.

After commit 2cd8b14aaa ("vfio/pci: Move to the device set
infrastructure"), failure to create a new file for a device would cause
the reset to be skipped due to open_count being decremented after
calling close_device() in the error path.

After commit eadd86f835 ("vfio: Remove calls to
vfio_group_add_container_user()"), releasing a device would always skip
the reset due to an ordering change in vfio_device_fops_release().

Failing to reset the device leaves it in an unknown state, potentially
causing errors when it is accessed later or bound to a different driver.

This issue was observed with a Radeon RX Vega 56 [1002:687f] (rev c3)
assigned to a Windows guest. After shutting down the guest, unbinding
the device from vfio-pci, and binding the device to amdgpu:

[  548.007102] [drm:psp_hw_start [amdgpu]] *ERROR* PSP create ring failed!
[  548.027174] [drm:psp_hw_init [amdgpu]] *ERROR* PSP firmware loading failed
[  548.027242] [drm:amdgpu_device_fw_loading [amdgpu]] *ERROR* hw_init of IP block <psp> failed -22
[  548.027306] amdgpu 0000:0a:00.0: amdgpu: amdgpu_device_ip_init failed
[  548.027308] amdgpu 0000:0a:00.0: amdgpu: Fatal error during GPU init

Fixes: 2cd8b14aaa ("vfio/pci: Move to the device set infrastructure")
Fixes: eadd86f835 ("vfio: Remove calls to vfio_group_add_container_user()")
Signed-off-by: Anthony DeRossi <ajderossi@gmail.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20221110014027.28780-4-ajderossi@gmail.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-11-10 12:03:36 -07:00
Anthony DeRossi
5cd189e410 vfio: Export the device set open count
The open count of a device set is the sum of the open counts of all
devices in the set. Drivers can use this value to determine whether
shared resources are in use without tracking them manually or accessing
the private open_count in vfio_device.

Signed-off-by: Anthony DeRossi <ajderossi@gmail.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20221110014027.28780-3-ajderossi@gmail.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-11-10 12:03:36 -07:00
Anthony DeRossi
7fdba00111 vfio: Fix container device registration life cycle
In vfio_device_open(), vfio_device_container_register() is always called
when open_count == 1. On error, vfio_device_container_unregister() is
only called when open_count == 1 and close_device is set. This leaks a
registration for devices without a close_device implementation.

In vfio_device_fops_release(), vfio_device_container_unregister() is
called unconditionally. This can cause a device to be unregistered
multiple times.

Treating container device registration/unregistration uniformly (always
when open_count == 1) fixes both issues.

Fixes: ce4b4657ff ("vfio: Replace the DMA unmapping notifier with a callback")
Signed-off-by: Anthony DeRossi <ajderossi@gmail.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Yi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20221110014027.28780-2-ajderossi@gmail.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-11-10 12:03:36 -07:00
Gavin Shan
a69170c65a KVM: selftests: memslot_perf_test: Report optimal memory slots
The memory area in each slot should be aligned to host page size.
Otherwise, the test will fail. For example, the following command
fails with the following messages with 64KB-page-size-host and
4KB-pae-size-guest. It's not user friendly to abort the test.
Lets do something to report the optimal memory slots, instead of
failing the test.

  # ./memslot_perf_test -v -s 1000
  Number of memory slots: 999
  Testing map performance with 1 runs, 5 seconds each
  Adding slots 1..999, each slot with 8 pages + 216 extra pages last
  ==== Test Assertion Failure ====
    lib/kvm_util.c:824: vm_adjust_num_guest_pages(vm->mode, npages) == npages
    pid=19872 tid=19872 errno=0 - Success
       1  0x00000000004065b3: vm_userspace_mem_region_add at kvm_util.c:822
       2  0x0000000000401d6b: prepare_vm at memslot_perf_test.c:273
       3  (inlined by) test_execute at memslot_perf_test.c:756
       4  (inlined by) test_loop at memslot_perf_test.c:994
       5  (inlined by) main at memslot_perf_test.c:1073
       6  0x0000ffff7ebb4383: ?? ??:0
       7  0x00000000004021ff: _start at :?
    Number of guest pages is not compatible with the host. Try npages=16

Report the optimal memory slots instead of failing the test when
the memory area in each slot isn't aligned to host page size. With
this applied, the optimal memory slots is reported.

  # ./memslot_perf_test -v -s 1000
  Number of memory slots: 999
  Testing map performance with 1 runs, 5 seconds each
  Memslot count too high for this test, decrease the cap (max is 514)

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020071209.559062-7-gshan@redhat.com
2022-11-10 18:56:15 +00:00
Gavin Shan
88a64e6548 KVM: selftests: memslot_perf_test: Consolidate memory
The addresses and sizes passed to vm_userspace_mem_region_add() and
madvise() should be aligned to host page size, which can be 64KB on
aarch64. So it's wrong by passing additional fixed 4KB memory area
to various tests.

Fix it by passing additional fixed 64KB memory area to various tests.
We also add checks to ensure that none of host/guest page size exceeds
64KB. MEM_TEST_MOVE_SIZE is fixed up to 192KB either.

With this, the following command works fine on 64KB-page-size-host and
4KB-page-size-guest.

  # ./memslot_perf_test -v -s 512

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020071209.559062-6-gshan@redhat.com
2022-11-10 18:56:15 +00:00
Gavin Shan
8675c6f226 KVM: selftests: memslot_perf_test: Support variable guest page size
The test case is obviously broken on aarch64 because non-4KB guest
page size is supported. The guest page size on aarch64 could be 4KB,
16KB or 64KB.

This supports variable guest page size, mostly for aarch64.

  - The host determines the guest page size when virtual machine is
    created. The value is also passed to guest through the synchronization
    area.

  - The number of guest pages are unknown until the virtual machine
    is to be created. So all the related macros are dropped. Instead,
    their values are dynamically calculated based on the guest page
    size.

  - The static checks on memory sizes and pages becomes dependent
    on guest page size, which is unknown until the virtual machine
    is about to be created. So all the static checks are converted
    to dynamic checks, done in check_memory_sizes().

  - As the address passed to madvise() should be aligned to host page,
    the size of page chunk is automatically selected, other than one
    page.

  - MEM_TEST_MOVE_SIZE has fixed and non-working 64KB. It will be
    consolidated in next patch. However, the comments about how
    it's calculated has been correct.

  - All other changes included in this patch are almost mechanical
    replacing '4096' with 'guest_page_size'.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020071209.559062-5-gshan@redhat.com
2022-11-10 18:56:15 +00:00
Gavin Shan
34396437b1 KVM: selftests: memslot_perf_test: Probe memory slots for once
prepare_vm() is called in every iteration and run. The allowed memory
slots (KVM_CAP_NR_MEMSLOTS) are probed for multiple times. It's not
free and unnecessary.

Move the probing logic for the allowed memory slots to parse_args()
for once, which is upper layer of prepare_vm().

No functional change intended.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020071209.559062-4-gshan@redhat.com
2022-11-10 18:56:15 +00:00
Gavin Shan
2aae5e6795 KVM: selftests: memslot_perf_test: Consolidate loop conditions in prepare_vm()
There are two loops in prepare_vm(), which have different conditions.
'slot' is treated as meory slot index in the first loop, but index of
the host virtual address array in the second loop. It makes it a bit
hard to understand the code.

Change the usage of 'slot' in the second loop, to treat it as the
memory slot index either.

No functional change intended.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020071209.559062-3-gshan@redhat.com
2022-11-10 18:56:15 +00:00
Gavin Shan
3bfadb2325 KVM: selftests: memslot_perf_test: Use data->nslots in prepare_vm()
In prepare_vm(), 'data->nslots' is assigned with 'max_mem_slots - 1'
at the beginning, meaning they are interchangeable.

Use 'data->nslots' isntead of 'max_mem_slots - 1'. With this, it
becomes easier to move the logic of probing number of slots into
upper layer in subsequent patches.

No functional change intended.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Maciej S. Szmigiero <maciej.szmigiero@oracle.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221020071209.559062-2-gshan@redhat.com
2022-11-10 18:56:14 +00:00
James Clark
612a5337ae perf vendor events: Add Arm Neoverse V2 PMU events
Rename the neoverse-n2 folder to make it clear that it includes V2, and
add V2 to mapfile.csv. V2 has the same events as N2, visible by running
the following command in the ARM-software/data github repo [1]:

  diff pmu/neoverse-v2.json pmu/neoverse-n2.json | grep code

Testing:

  $ perf test pmu

  10: PMU events                                           :
  10.1: PMU event table sanity                             : Ok
  10.2: PMU event map aliases                              : Ok
  10.3: Parsing of PMU event table metrics                 : Ok
  10.4: Parsing of PMU event table metrics with fake PMUs  : Ok

[1]: https://github.com/ARM-software/data

Reviewed-by: Nick Forrington <nick.forrington@arm.com>
Signed-off-by: James Clark <james.clark@arm.com>
Cc: Al Grant <al.grant@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.garry@huawei.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20221020134512.1345013-1-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-11-10 15:41:18 -03:00
Kang Minchul
cf9f67b363 perf print-events: Remove redundant comparison with zero
Since variable npmus is unsigned int, comparing with 0 is unnecessary.

Signed-off-by: Kang Minchul <tegongkang@gmail.com>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221105135932.81612-1-tegongkang@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-11-10 15:39:02 -03:00
Dmitrii Dolgov
9d895e4684 perf data: Add tracepoint fields when converting to JSON
When converting recorded data into JSON format, perf data omits probe
variables. Add them to the output in the format "field name": "field value"
using tep_print_field:

    $ perf data convert --to-json output.json

    // output.json
    {
        "linux-perf-json-version": 1,
        "headers": { ... },
        "samples": [
            {
            "timestamp": 29182079082999,
            "pid": 309194,
                    [...]
            "__probe_ip": "0x93ee35",
            "query_string_string": "select 2;",
            "nxids": "0"
            }
        ]
    }

Signed-off-by: Dmitrii Dolgov <9erthalion6@gmail.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20221109103932.65675-1-9erthalion6@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-11-10 15:35:37 -03:00
Namhyung Kim
30b331d2e3 perf lock: Allow concurrent record and report
To support live monitoring of kernel lock contention without BPF,
it should support something like below:

  # perf lock record -a -o- sleep 1 | perf lock contention -i-
   contended   total wait     max wait     avg wait         type   caller

           2     10.27 us      6.17 us      5.13 us     spinlock   load_balance+0xc03
           1      5.29 us      5.29 us      5.29 us     rwlock:W   ep_scan_ready_list+0x54
           1      4.12 us      4.12 us      4.12 us     spinlock   smpboot_thread_fn+0x116
           1      3.28 us      3.28 us      3.28 us        mutex   pipe_read+0x50

To do that, it needs to handle HEAD_ATTR, HEADER_EVENT_UPDATE and
HEADER_TRACING_DATA which are generated only for the pipe mode.
And setting event handler also should be delayed until it gets the
event information.

Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20221104051440.220989-1-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-11-10 15:34:19 -03:00
Eric Farman
913447d06f vfio: Remove vfio_free_device
With the "mess" sorted out, we should be able to inline the
vfio_free_device call introduced by commit cb9ff3f3b8
("vfio: Add helpers for unifying vfio_device life cycle")
and remove them from driver release callbacks.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>	# vfio-ap part
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221104142007.1314999-8-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-11-10 11:30:23 -07:00
Eric Farman
d1104f9327 vfio/ccw: replace vfio_init_device with _alloc_
Now that we have a reasonable separation of structs that follow
the subchannel and mdev lifecycles, there's no reason we can't
call the official vfio_alloc_device routine for our private data,
and behave like everyone else.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221104142007.1314999-7-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-11-10 11:30:23 -07:00
Arnaldo Carvalho de Melo
6ac7382099 perf trace: Add augmenter for clock_gettime's rqtp timespec arg
One more before going the BTF way:

  # perf trace -e /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o,*nanosleep
         ? pool-gsd-smart/2893  ... [continued]: clock_nanosleep())    = 0
         ? gpm/1042  ... [continued]: clock_nanosleep())    = 0
     1.232 pool-gsd-smart/2893 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f64d7ffec50) ...
     1.232 pool-gsd-smart/2893  ... [continued]: clock_nanosleep())    = 0
   327.329 gpm/1042 clock_nanosleep(rqtp: { .tv_sec: 2, .tv_nsec: 0 }, rmtp: 0x7ffddfd1cf20) ...
  1002.482 pool-gsd-smart/2893 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f64d7ffec50) = 0
   327.329 gpm/1042  ... [continued]: clock_nanosleep())    = 0
  2003.947 pool-gsd-smart/2893 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f64d7ffec50) ...
  2003.947 pool-gsd-smart/2893  ... [continued]: clock_nanosleep())    = 0
  2327.858 gpm/1042 clock_nanosleep(rqtp: { .tv_sec: 2, .tv_nsec: 0 }, rmtp: 0x7ffddfd1cf20) ...
         ? crond/1384  ... [continued]: clock_nanosleep())    = 0
  3005.382 pool-gsd-smart/2893 clock_nanosleep(rqtp: { .tv_sec: 1, .tv_nsec: 0 }, rmtp: 0x7f64d7ffec50) ...
  3005.382 pool-gsd-smart/2893  ... [continued]: clock_nanosleep())    = 0
  3675.633 crond/1384 clock_nanosleep(rqtp: { .tv_sec: 60, .tv_nsec: 0 }, rmtp: 0x7ffcc02b66b0) ...
^C#

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-11-10 15:30:10 -03:00
Christoph Hellwig
ee9d55210c blk-mq: simplify blk_mq_realloc_tag_set_tags
Use set->nr_hw_queues for the current number of tags, and remove the
duplicate set->nr_hw_queues update in the caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20221109100811.2413423-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-10 11:18:09 -07:00
Christoph Hellwig
5ee20298ff blk-mq: remove blk_mq_alloc_tag_set_tags
There is no point in trying to share any code with the realloc case when
all that is needed by the initial tagset allocation is a simple
kcalloc_node.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20221109100811.2413423-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-10 11:18:09 -07:00
Rafał Miłecki
2a5796e63e ARM: dts: BCM5301X: Correct description of TP-Link partitions
TP-Link routers have flash space partitioned according to the partitions
table. It may look like fixed partitioning but those partitions can be
actually reorganized. New can be added (or some removed), offsets and
sizes may change.

Fix DT to use binding for the TP-Link SafeLoader partitioning method.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20221108110708.13693-1-zajec5@gmail.com
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
2022-11-10 10:15:21 -08:00
Linus Walleij
566656dd1a ARM: dts: bcm47094: Add devicetree for D-Link DIR-890L
This adds a device tree for the D-Link DIR-890L. This device
is very similar to D-Link DIR-885L, the differences are detailed
as a comment in the DTS file.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20221107134104.1422169-2-linus.walleij@linaro.org
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
2022-11-10 10:15:21 -08:00
Linus Walleij
45174541c9 dt-bindings: ARM: add bindings for the D-Link DIR-890L
The DIR-890L is a router similar to DIR-885L just a bit different.

Cc: devicetree@vger.kernel.org
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20221107134104.1422169-1-linus.walleij@linaro.org
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
2022-11-10 10:15:20 -08:00
Maxime Ripard
27ab05e1b7 ARM: dts: bcm2835-rpi: Use firmware clocks for display
We've experienced a number of issues around the cohabitation between the
"real" clock driver in Linux and the one backed by the firmware.

One solution around this is to follow what the RaspberryPi foundation
in its downstream clock, which is also what we've been doing on the
RaspberryPi4: to use the clocks exposed by the firmware.

Link: https://lore.kernel.org/linux-clk/20221021140505.kjmw5x4s6qhnrfif@houat/
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20221026-rpi-display-fw-clk-v1-2-5c29b7a3d8b0@cerno.tech
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
2022-11-10 10:15:15 -08:00
Maxime Ripard
9d9491b641 ARM: dts: bcm283x: Remove bcm2835-rpi-common.dtsi from SoC DTSI
According to the commit log of the commit 3ac395a5b3 ("ARM: dts:
bcm283x: Use firmware PM driver for V3D"), the initial intent behind the
bcm2835-rpi-common DTSI was to share data between the RaspberryPies
based on the BCM2835, 36 and 37.

However, it was included by these SoCs' main DTSI. This is creating an
improper layering.

On top of that, bcm2835.dtsi is being included by bcm2711.dtsi, which
means that, even though the bcm2835-rpi-common DTSI wasn't actually
meant to contain data for the BCM2711, it actually leaks into the
BCM2711 DTSI.

In order to remove both issues, let's remove the include of
bcm2835-rpi-common.dtsi from bcm283{5-7}.dtsi and put them into the
bcm283{6,7}-rpi.dtsi.

BCM2835 has to be handled with special care due to the fact that
bcm2835.dtsi is being included by bcm2711.dtsi. Thus, we chose to
include bcm2835-rpi-common.dtsi directly into the board DTS. This will
be more error-prone, but given that it's a fairly old SoC by now, the
chance that we will get more BCM2835 boards is fairly low.

BCM2711 isn't modified since the content of bcm2835-rpi-common.dtsi was
only a power-domain for the v3d that was overridden anyway.

Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20221026-rpi-display-fw-clk-v1-1-5c29b7a3d8b0@cerno.tech
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
2022-11-10 10:15:08 -08:00
Guilherme G. Piccoli
727209376f x86/split_lock: Add sysctl to control the misery mode
Commit b041b525da ("x86/split_lock: Make life miserable for split lockers")
changed the way the split lock detector works when in "warn" mode;
basically, it not only shows the warn message, but also intentionally
introduces a slowdown through sleeping plus serialization mechanism
on such task. Based on discussions in [0], seems the warning alone
wasn't enough motivation for userspace developers to fix their
applications.

This slowdown is enough to totally break some proprietary (aka.
unfixable) userspace[1].

Happens that originally the proposal in [0] was to add a new mode
which would warns + slowdown the "split locking" task, keeping the
old warn mode untouched. In the end, that idea was discarded and
the regular/default "warn" mode now slows down the applications. This
is quite aggressive with regards proprietary/legacy programs that
basically are unable to properly run in kernel with this change.
While it is understandable that a malicious application could DoS
by split locking, it seems unacceptable to regress old/proprietary
userspace programs through a default configuration that previously
worked. An example of such breakage was reported in [1].

Add a sysctl to allow controlling the "misery mode" behavior, as per
Thomas suggestion on [2]. This way, users running legacy and/or
proprietary software are allowed to still execute them with a decent
performance while still observing the warning messages on kernel log.

[0] https://lore.kernel.org/lkml/20220217012721.9694-1-tony.luck@intel.com/
[1] https://github.com/doitsujin/dxvk/issues/2938
[2] https://lore.kernel.org/lkml/87pmf4bter.ffs@tglx/

[ dhansen: minor changelog tweaks, including clarifying the actual
  	   problem ]

Fixes: b041b525da ("x86/split_lock: Make life miserable for split lockers")
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Tested-by: Andre Almeida <andrealmeid@igalia.com>
Link: https://lore.kernel.org/all/20221024200254.635256-1-gpiccoli%40igalia.com
2022-11-10 10:14:22 -08:00
Eric Farman
f4da83f7e3 vfio/ccw: remove release completion
There's enough separation between the parent and private structs now,
that it is fine to remove the release completion hack.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221104142007.1314999-6-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-11-10 11:11:26 -07:00
Eric Farman
3d62fe18b6 vfio/ccw: move private to mdev lifecycle
Now that the mdev parent data is split out into its own struct,
it is safe to move the remaining private data to follow the
mdev probe/remove lifecycle. The mdev parent data will remain
where it is, and follow the subchannel and the css driver
interfaces.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221104142007.1314999-5-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-11-10 11:11:25 -07:00
Eric Farman
06caaa27df vfio/ccw: move private initialization to callback
There's already a device initialization callback that is used to
initialize the release completion workaround that was introduced
by commit ebb72b765f ("vfio/ccw: Use the new device life cycle
helpers").

Move the other elements of the vfio_ccw_private struct that
require distinct initialization over to that routine.

With that done, the vfio_ccw_alloc_private routine only does a
kzalloc, so fold it inline.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221104142007.1314999-4-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-11-10 11:11:25 -07:00
Eric Farman
008a011d68 vfio/ccw: remove private->sch
These places all rely on the ability to jump from a private
struct back to the subchannel struct. Rather than keeping a
copy in our back pocket, let's use the relationship provided
by the vfio_device embedded within the private.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221104142007.1314999-3-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-11-10 11:11:25 -07:00
Eric Farman
9e6f07cd1e vfio/ccw: create a parent struct
Move the stuff associated with the mdev parent (and thus the
subchannel struct) into its own struct, and leave the rest in
the existing private structure.

The subchannel will point to the parent, and the parent will point
to the private, for the areas where one or both are needed. Further
separation of these structs will follow.

Signed-off-by: Eric Farman <farman@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20221104142007.1314999-2-farman@linux.ibm.com
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
2022-11-10 11:11:25 -07:00
Jim Cromie
2f465b921b vmlinux.lds.h: place optional header space in BOUNDED_SECTION
Extend recently added BOUNDED_SECTION(_name) macro by adding a
KEEP(*(.gnu.linkonce.##_name)) before the KEEP(*(_name)).

This does nothing by itself, vmlinux is the same before and after this
patch.  But if a developer adds a .gnu.linkonce.foo record, that
record is placed in the front of the section, where it can be used as
a header for the table.

The intent is to create an up-link to another organizing struct, from
where related tables can be referenced.  And since every item in a
table has a known offset from its header, that same offset can be used
to fetch records from the related tables.

By itself, this doesnt gain much, unless maybe the pattern of access
is to scan 1 or 2 fields in each fat record, but with 2 16 bit .map*
fields added, we could de-duplicate 2 related tables.

The use case here is struct _ddebug, which has 3 pointers (function,
file, module) with substantial repetition; respectively 53%, 90%, and
the module column is fully recoverable after dynamic_debug_init()
splits the table into a linked list of "module" chunks.

On a DYNAMIC_DEBUG=y kernel with 5k pr_debugs, the memory savings
should be ~100 KiB.

Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20221022225637.1406715-3-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-10 19:08:38 +01:00
Jim Cromie
9b351be253 vmlinux.lds.h: add BOUNDED_SECTION* macros
vmlinux.lds.h has ~45 occurrences of this general pattern:

  __start_foo = .;
  KEEP(*(foo))
  __stop_foo = .;

Reduce this pattern to a (group of 4) macros, and use them to reduce
linecount.  This was inspired by the codetag patchset.

no functional change.

CC: Suren Baghdasaryan <surenb@google.com>
CC: Kent Overstreet <kent.overstreet@linux.dev>
Signed-off-by: Jim Cromie <jim.cromie@gmail.com>
Link: https://lore.kernel.org/r/20221022225637.1406715-2-jim.cromie@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-10 19:08:38 +01:00
Jens Axboe
3851d25c75 io_uring: check for rollover of buffer ID when providing buffers
We already check if the chosen starting offset for the buffer IDs fit
within an unsigned short, as 65535 is the maximum value for a provided
buffer. But if the caller asks to add N buffers at offset M, and M + N
would exceed the size of the unsigned short, we simply add buffers with
wrapping around the ID.

This is not necessarily a bug and could in fact be a valid use case, but
it seems confusing and inconsistent with the initial check for starting
offset. Let's check for wrap consistently, and error the addition if we
do need to wrap.

Reported-by: Olivier Langlois <olivier@trillion01.com>
Link: https://github.com/axboe/liburing/issues/726
Cc: stable@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-11-10 11:07:41 -07:00
Thomas Weißschuh
d3d76fbde1 kernel/ksysfs.c: export kernel cpu byteorder
Certain files in procfs are formatted in byteorder-dependent formats.
For example the IP addresses in /proc/net/udp.

When using emulation like qemu-user, applications are not guaranteed to
be using the same byteorder as the kernel.
Therefore the kernel needs to provide a way for applications to discover
the byteorder used in API-filesystems.
Using systemcalls is not enough because these are intercepted and
translated by the emulation.

Also this makes it easier for non-compiled applications like
shellscripts to discover the byteorder.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Link: https://lore.kernel.org/r/20221103152407.3348-1-linux@weissschuh.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-10 19:07:31 +01:00
Christophe JAILLET
0d4a030b3d greybus: svc: Use kstrtobool() instead of strtobool()
strtobool() is the same as kstrtobool().
However, the latter is more used within the kernel.

In order to remove strtobool() and slightly simplify kstrtox.h, switch to
the other function name.

While at it, include the corresponding header file (<linux/kstrtox.h>)

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Alex Elder <elder@linaro.org>
Link: https://lore.kernel.org/r/ebf1e6988a53a455990230a37cf759ee542ea7ec.1667336095.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-10 19:03:58 +01:00
Tejun Heo
1edfe4ea16 kernfs: Fix spurious lockdep warning in kernfs_find_and_get_node_by_id()
c25491747b ("kernfs: Add KERNFS_REMOVING flags") made
kernfs_find_and_get_node_by_id() test kernfs_active() instead of
KERNFS_ACTIVATED. kernfs_find_and_get_by_id() is called without holding the
kernfs_rwsem triggering the following lockdep warning.

  WARNING: CPU: 1 PID: 6191 at fs/kernfs/dir.c:36 kernfs_active+0xe8/0x120 fs/kernfs/dir.c:38
  Modules linked in:
  CPU: 1 PID: 6191 Comm: syz-executor.1 Not tainted 6.0.0-syzkaller-09413-g4899a36f91a9 #0
  Hardware name: linux,dummy-virt (DT)
  pstate: 10000005 (nzcV daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : kernfs_active+0xe8/0x120 fs/kernfs/dir.c:36
  lr : lock_is_held include/linux/lockdep.h:283 [inline]
  lr : kernfs_active+0x94/0x120 fs/kernfs/dir.c:36
  sp : ffff8000182c7a00
  x29: ffff8000182c7a00 x28: 0000000000000002 x27: 0000000000000001
  x26: ffff00000ee1f6a8 x25: 1fffe00001dc3ed5 x24: 0000000000000000
  x23: ffff80000ca1fba0 x22: ffff8000089efcb0 x21: 0000000000000001
  x20: ffff0000091181d0 x19: ffff0000091181d0 x18: ffff00006a9e6b88
  x17: 0000000000000000 x16: 0000000000000000 x15: ffff00006a9e6bc4
  x14: 1ffff00003058f0e x13: 1fffe0000258c816 x12: ffff700003058f39
  x11: 1ffff00003058f38 x10: ffff700003058f38 x9 : dfff800000000000
  x8 : ffff80000e482f20 x7 : ffff0000091d8058 x6 : ffff80000e482c60
  x5 : ffff000009402ee8 x4 : 1ffff00001bd1f46 x3 : 1fffe0000258c6d1
  x2 : 0000000000000003 x1 : 00000000000000c0 x0 : 0000000000000000
  Call trace:
   kernfs_active+0xe8/0x120 fs/kernfs/dir.c:38
   kernfs_find_and_get_node_by_id+0x6c/0x140 fs/kernfs/dir.c:708
   __kernfs_fh_to_dentry fs/kernfs/mount.c:102 [inline]
   kernfs_fh_to_dentry+0x88/0x1fc fs/kernfs/mount.c:128
   exportfs_decode_fh_raw+0x104/0x560 fs/exportfs/expfs.c:435
   exportfs_decode_fh+0x10/0x5c fs/exportfs/expfs.c:575
   do_handle_to_path fs/fhandle.c:152 [inline]
   handle_to_path fs/fhandle.c:207 [inline]
   do_handle_open+0x2a4/0x7b0 fs/fhandle.c:223
   __do_compat_sys_open_by_handle_at fs/fhandle.c:277 [inline]
   __se_compat_sys_open_by_handle_at fs/fhandle.c:274 [inline]
   __arm64_compat_sys_open_by_handle_at+0x6c/0x9c fs/fhandle.c:274
   __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
   invoke_syscall+0x6c/0x260 arch/arm64/kernel/syscall.c:52
   el0_svc_common.constprop.0+0xc4/0x254 arch/arm64/kernel/syscall.c:142
   do_el0_svc_compat+0x40/0x70 arch/arm64/kernel/syscall.c:212
   el0_svc_compat+0x54/0x140 arch/arm64/kernel/entry-common.c:772
   el0t_32_sync_handler+0x90/0x140 arch/arm64/kernel/entry-common.c:782
   el0t_32_sync+0x190/0x194 arch/arm64/kernel/entry.S:586
  irq event stamp: 232
  hardirqs last  enabled at (231): [<ffff8000081edf70>] raw_spin_rq_unlock_irq kernel/sched/sched.h:1367 [inline]
  hardirqs last  enabled at (231): [<ffff8000081edf70>] finish_lock_switch kernel/sched/core.c:4943 [inline]
  hardirqs last  enabled at (231): [<ffff8000081edf70>] finish_task_switch.isra.0+0x200/0x880 kernel/sched/core.c:5061
  hardirqs last disabled at (232): [<ffff80000c888bb4>] el1_dbg+0x24/0x80 arch/arm64/kernel/entry-common.c:404
  softirqs last  enabled at (228): [<ffff800008010938>] _stext+0x938/0xf58
  softirqs last disabled at (207): [<ffff800008019380>] ____do_softirq+0x10/0x20 arch/arm64/kernel/irq.c:79
  ---[ end trace 0000000000000000 ]---

The lockdep warning in kernfs_active() is there to ensure that the activated
state stays stable for the caller. For kernfs_find_and_get_node_by_id(), all
that's needed is ensuring that a node which has never been activated can't
be looked up and guaranteeing lookup success when the caller knows the node
to be active, both of which can be achieved by testing the active count
without holding the kernfs_rwsem.

Fix the spurious warning by introducing __kernfs_active() which doesn't have
the lockdep annotation.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: syzbot+590ce62b128e79cf0a35@syzkaller.appspotmail.com
Fixes: c25491747b ("kernfs: Add KERNFS_REMOVING flags")
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Link: https://lore.kernel.org/r/Y0SwqBsZ9BMmZv6x@slm.duckdns.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-11-10 19:03:42 +01:00