linux-stable.git/drivers/perf, branch linux-5.0.y

perf/arm-cci: Remove broken race mitigation

2019-05-31T13:45:01+00:00

[ Upstream commit 0d2e2a82d4de298d006bf8eddc86829e3c7da820 ]

Uncore PMU drivers face an awkward cyclic dependency wherein:

 - They have to pick a valid online CPU to associate with before
   registering the PMU device, since it will get exposed to userspace
   immediately.
 - The PMU registration has to be be at least partly complete before
   hotplug events can be handled, since trying to migrate an
   uninitialised context would be bad.
 - The hotplug handler has to be ready as soon as a CPU is chosen, lest
   it go offline without the user-visible cpumask value getting updated.

The arm-cci driver has tried to solve this by using get_cpu() to pick
the current CPU and prevent it from disappearing while both
registrations are performed, but that results in taking mutexes with
preemption disabled, which makes certain configurations very unhappy:

[ 1.983337] BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:2004
[ 1.983340] in_atomic(): 1, irqs_disabled(): 0, pid: 1, name: swapper/0
[ 1.983342] Preemption disabled at:
[ 1.983353] [] cci_pmu_probe+0x1dc/0x488
[ 1.983360] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.18.20-rt8-yocto-preempt-rt #1
[ 1.983362] Hardware name: ZynqMP ZCU102 Rev1.0 (DT)
[ 1.983364] Call trace:
[ 1.983369] dump_backtrace+0x0/0x158
[ 1.983372] show_stack+0x24/0x30
[ 1.983378] dump_stack+0x80/0xa4
[ 1.983383] ___might_sleep+0x138/0x160
[ 1.983386] __might_sleep+0x58/0x90
[ 1.983391] __rt_mutex_lock_state+0x30/0xc0
[ 1.983395] _mutex_lock+0x24/0x30
[ 1.983400] perf_pmu_register+0x2c/0x388
[ 1.983404] cci_pmu_probe+0x2bc/0x488
[ 1.983409] platform_drv_probe+0x58/0xa8

It is not feasible to resolve all the possible races outside of the perf
core itself, so address the immediate bug by following the example of
nearly every other PMU driver and not even trying to do so. Registering
the hotplug notifier first should minimise the window in which things
can go wrong, so that's about as much as we can reasonably do here. This
also revealed an additional race in assigning the global pointer too
late relative to the hotplug notifier, which gets fixed in the process.

Reported-by: Li, Meng 
Tested-by: Corentin Labbe 
Reviewed-by: Suzuki K Poulose 
Signed-off-by: Robin Murphy 
Signed-off-by: Will Deacon 
Signed-off-by: Sasha Levin

perf/aux: Make perf_event accessible to setup_aux()

2019-04-05T20:34:42+00:00

[ Upstream commit 840018668ce2d96783356204ff282d6c9b0e5f66 ]

When pmu::setup_aux() is called the coresight PMU needs to know which
sink to use for the session by looking up the information in the
event's attr::config2 field.

As such simply replace the cpu information by the complete perf_event
structure and change all affected customers.

Signed-off-by: Mathieu Poirier 
Reviewed-by: Suzuki Poulouse 
Acked-by: Peter Zijlstra 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Alexei Starovoitov 
Cc: Greg Kroah-Hartman 
Cc: H. Peter Anvin 
Cc: Heiko Carstens 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Martin Schwidefsky 
Cc: Namhyung Kim 
Cc: Thomas Gleixner 
Cc: Will Deacon 
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-s390@vger.kernel.org
Link: http://lkml.kernel.org/r/20190131184714.20388-2-mathieu.poirier@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

drivers/perf: hisi: Fixup one DDRC PMU register offset

2019-01-04T10:13:27+00:00

For DDRC PMU, each PMU counter is fixed-purpose. There is a mismatch
between perf list and driver definition on rw_chg event.
# perf list | grep chg
  hisi_sccl1_ddrc0/rnk_chg/                          [Kernel PMU event]
  hisi_sccl1_ddrc0/rw_chg/                           [Kernel PMU event]
But the register offset of rw_chg event is not defined in the driver,
meanwhile bnk_chg register offset is mis-defined, let's fixup it.

Fixes: 904dcf03f086 ("perf: hisi: Add support for HiSilicon SoC DDRC PMU driver")
Cc: stable@vger.kernel.org
Cc: John Garry 
Cc: Will Deacon 
Cc: Mark Rutland 
Reported-by: Weijian Huang 
Signed-off-by: Shaokun Zhang 
Signed-off-by: Will Deacon

drivers/perf: Add Cavium ThunderX2 SoC UNCORE PMU driver

2018-12-06T13:03:17+00:00

This patch adds a perf driver for the PMU UNCORE devices DDR4 Memory
Controller(DMC) and Level 3 Cache(L3C). Each PMU supports up to 4
counters. All counters lack overflow interrupt and are
sampled periodically.

Reviewed-by: Suzuki K Poulose 
Signed-off-by: Ganapatrao Kulkarni 
[will: consistent enum cpuhp_state naming]
Signed-off-by: Will Deacon

perf: arm_spe: handle devm_kasprintf() failure

2018-11-29T16:29:16+00:00

devm_kasprintf() may return NULL on failure of internal allocation
thus the assignment to 'name' is not safe if unchecked. If NULL
is passed in for name then perf_pmu_register() would not fail
but rather silently jump to skip_type which is not the intent
here. As perf_pmu_register() may also return -ENOMEM returning
-ENOMEM in the (unlikely) failure case of devm_kasprintf() should
be fine here as well.

Acked-by: Mark Rutland 
Fixes: d5d9696b0380 ("drivers/perf: Add support for ARMv8.2 Statistical Profiling Extension")
Signed-off-by: Nicholas Mc Guire 
[will: reworded error message]
Signed-off-by: Will Deacon

drivers/perf: xgene: Add CPU hotplug support

2018-11-21T16:28:00+00:00

If the CPU assigned to the xgene PMU is taken offline, then subsequent
perf invocations on the PMU will fail:

  # echo 0 > /sys/devices/system/cpu/cpu0/online
  # perf stat -a -e l3c0/cycle-count/,l3c0/write/ sleep 1
    Error:
    The sys_perf_event_open() syscall returned with 19 (No such device) for event (l3c0/cycle-count/).
    /bin/dmesg may provide additional information.
    No CONFIG_PERF_EVENTS=y kernel support configured?

This patch implements a hotplug notifier in the xgene PMU driver so that
the PMU context is migrated to another online CPU should its assigned
CPU disappear.

Acked-by: Mark Rutland 
Signed-off-by: Hoan Tran 
[will: Made naming of new cpuhp_state enum entry consistent]
Signed-off-by: Will Deacon

perf: arm_spe: Enable automatic DT loading

2018-11-21T13:16:34+00:00

When built as a module, the spe driver isn't automatically
loaded on DT systems. Add the MODULE_DEVICE_TABLE entry.

Reviewed-by: Sudeep Holla 
Signed-off-by: Jeremy Linton 
Signed-off-by: Will Deacon

Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2018-10-22T16:30:06+00:00

Pull arm64 updates from Catalin Marinas:
 "Apart from some new arm64 features and clean-ups, this also contains
  the core mmu_gather changes for tracking the levels of the page table
  being cleared and a minor update to the generic
  compat_sys_sigaltstack() introducing COMPAT_SIGMINSKSZ.

  Summary:

   - Core mmu_gather changes which allow tracking the levels of
     page-table being cleared together with the arm64 low-level flushing
     routines

   - Support for the new ARMv8.5 PSTATE.SSBS bit which can be used to
     mitigate Spectre-v4 dynamically without trapping to EL3 firmware

   - Introduce COMPAT_SIGMINSTKSZ for use in compat_sys_sigaltstack

   - Optimise emulation of MRS instructions to ID_* registers on ARMv8.4

   - Support for Common Not Private (CnP) translations allowing threads
     of the same CPU to share the TLB entries

   - Accelerated crc32 routines

   - Move swapper_pg_dir to the rodata section

   - Trap WFI instruction executed in user space

   - ARM erratum 1188874 workaround (arch_timer)

   - Miscellaneous fixes and clean-ups"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (78 commits)
  arm64: KVM: Guests can skip __install_bp_hardening_cb()s HYP work
  arm64: cpufeature: Trap CTR_EL0 access only where it is necessary
  arm64: cpufeature: Fix handling of CTR_EL0.IDC field
  arm64: cpufeature: ctr: Fix cpu capability check for late CPUs
  Documentation/arm64: HugeTLB page implementation
  arm64: mm: Use __pa_symbol() for set_swapper_pgd()
  arm64: Add silicon-errata.txt entry for ARM erratum 1188873
  Revert "arm64: uaccess: implement unsafe accessors"
  arm64: mm: Drop the unused cpu parameter
  MAINTAINERS: fix bad sdei paths
  arm64: mm: Use #ifdef for the __PAGETABLE_P?D_FOLDED defines
  arm64: Fix typo in a comment in arch/arm64/mm/kasan_init.c
  arm64: xen: Use existing helper to check interrupt status
  arm64: Use daifflag_restore after bp_hardening
  arm64: daifflags: Use irqflags functions for daifflags
  arm64: arch_timer: avoid unused function warning
  arm64: Trap WFI executed in userspace
  arm64: docs: Document SSBS HWCAP
  arm64: docs: Fix typos in ELF hwcaps
  arm64/kprobes: remove an extra semicolon in arch_prepare_kprobe
  ...

arm64: perf: Reject stand-alone CHAIN events for PMUv3

2018-10-12T14:25:17+00:00

It doesn't make sense for a perf event to be configured as a CHAIN event
in isolation, so extend the arm_pmu structure with a ->filter_match()
function to allow the backend PMU implementation to reject CHAIN events
early.

Cc: 
Reviewed-by: Suzuki K Poulose 
Signed-off-by: Will Deacon

perf: Convert to using %pOFn instead of device_node.name

2018-10-01T10:33:17+00:00

In preparation to remove the node name pointer from struct device_node,
convert printf users to use the %pOFn format specifier.

Cc: Mark Rutland 
Cc: linux-arm-kernel@lists.infradead.org
Acked-by: Will Deacon 
Signed-off-by: Rob Herring 
Signed-off-by: Catalin Marinas