linux-stable.git/arch/arm/kernel/perf_event.c, branch linux-3.2.y Linux kernel stable tree perf/arm: Fix armpmu_map_hw_event() 2013-09-10T00:57:23+00:00 Stephen Boyd sboyd@codeaurora.org 2013-08-07T23:18:08+00:00 1cf253ee0a4a3102a1dc89a3001abb31a8b60c00 commit b88a2595b6d8aedbd275c07dfa784657b4f757eb upstream. Fix constraint check in armpmu_map_hw_event(). Reported-and-tested-by: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit b88a2595b6d8aedbd275c07dfa784657b4f757eb upstream.

Fix constraint check in armpmu_map_hw_event().

Reported-and-tested-by: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ARM: 7809/1: perf: fix event validation for software group leaders 2013-09-10T00:57:23+00:00 Will Deacon will.deacon@arm.com 2013-08-07T22:39:41+00:00 5fff965ef7b5b2a3715b1a4005e6515716e49305 commit c95eb3184ea1a3a2551df57190c81da695e2144b upstream. It is possible to construct an event group with a software event as a group leader and then subsequently add a hardware event to the group. This results in the event group being validated by adding all members of the group to a fake PMU and attempting to allocate each event on their respective PMU. Unfortunately, for software events wthout a corresponding arm_pmu, this results in a kernel crash attempting to dereference the ->get_event_idx function pointer. This patch fixes the problem by checking explicitly for software events and ignoring those in event validation (since they can always be scheduled). We will probably want to revisit this for 3.12, since the validation checks don't appear to work correctly when dealing with multiple hardware PMUs anyway. Reported-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Vince Weaver <vincent.weaver@maine.edu> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit c95eb3184ea1a3a2551df57190c81da695e2144b upstream.

It is possible to construct an event group with a software event as a
group leader and then subsequently add a hardware event to the group.
This results in the event group being validated by adding all members
of the group to a fake PMU and attempting to allocate each event on
their respective PMU.

Unfortunately, for software events wthout a corresponding arm_pmu, this
results in a kernel crash attempting to dereference the ->get_event_idx
function pointer.

This patch fixes the problem by checking explicitly for software events
and ignoring those in event validation (since they can always be
scheduled). We will probably want to revisit this for 3.12, since the
validation checks don't appear to work correctly when dealing with
multiple hardware PMUs anyway.

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Vince Weaver <vincent.weaver@maine.edu>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ARM: 7765/1: perf: Record the user-mode PC in the call chain. 2013-07-27T04:34:16+00:00 Jed Davis jld@mozilla.com 2013-06-20T09:16:29+00:00 8c7c7cec2608c2a9cfbc4153a79b0dbae9d7a801 commit c5f927a6f62196226915f12194c9d0df4e2210d7 upstream. With this change, we no longer lose the innermost entry in the user-mode part of the call chain. See also the x86 port, which includes the ip. It's possible to partially work around this problem by post-processing the data to use the PERF_SAMPLE_IP value, but this works only if the CPU wasn't in the kernel when the sample was taken. Signed-off-by: Jed Davis <jld@mozilla.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit c5f927a6f62196226915f12194c9d0df4e2210d7 upstream.

With this change, we no longer lose the innermost entry in the user-mode
part of the call chain.  See also the x86 port, which includes the ip.

It's possible to partially work around this problem by post-processing
the data to use the PERF_SAMPLE_IP value, but this works only if the CPU
wasn't in the kernel when the sample was taken.

Signed-off-by: Jed Davis <jld@mozilla.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ARM: 7698/1: perf: fix group validation when using enable_on_exec 2013-04-25T19:25:41+00:00 Will Deacon will.deacon@arm.com 2013-04-12T18:04:19+00:00 e23d55ac7a8d76509ded2fd8f6e75e6d2c912e5c commit cb2d8b342aa084d1f3ac29966245dec9163677fb upstream. Events may be created with attr->disabled == 1 and attr->enable_on_exec == 1, which confuses the group validation code because events with the PERF_EVENT_STATE_OFF are not considered candidates for scheduling, which may lead to failure at group scheduling time. This patch fixes the validation check for ARM, so that events in the OFF state are still considered when enable_on_exec is true. Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Jiri Olsa <jolsa@redhat.com> Reported-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Ben Hutchings <ben@decadent.org.uk> 
commit cb2d8b342aa084d1f3ac29966245dec9163677fb upstream.

Events may be created with attr->disabled == 1 and attr->enable_on_exec
== 1, which confuses the group validation code because events with the
PERF_EVENT_STATE_OFF are not considered candidates for scheduling, which
may lead to failure at group scheduling time.

This patch fixes the validation check for ARM, so that events in the
OFF state are still considered when enable_on_exec is true.

Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Reported-by: Sudeep KarkadaNagesha <Sudeep.KarkadaNagesha@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
ARM: 7354/1: perf: limit sample_period to half max_period in non-sampling mode 2012-03-12T19:31:38+00:00 Will Deacon will.deacon@arm.com 2012-03-06T16:33:17+00:00 14e84b15bcd96521190c5566c440c56553e66fc9 commit 5727347180ebc6b4a866fcbe00dcb39cc03acb37 upstream. On ARM, the PMU does not stop counting after an overflow and therefore IRQ latency affects the new counter value read by the kernel. This is significant for non-sampling runs where it is possible for the new value to overtake the previous one, causing the delta to be out by up to max_period events. Commit a737823d ("ARM: 6835/1: perf: ensure overflows aren't missed due to IRQ latency") attempted to fix this problem by allowing interrupt handlers to pass an overflow flag to the event update function, causing the overflow calculation to assume that the counter passed through zero when going from prev to new. Unfortunately, this doesn't work when overflow occurs on the perf_task_tick path because we have the flag cleared and end up computing a large negative delta. This patch removes the overflow flag from armpmu_event_update and instead limits the sample_period to half of the max_period for non-sampling profiling runs. Signed-off-by: Ming Lei <ming.lei@canonical.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5727347180ebc6b4a866fcbe00dcb39cc03acb37 upstream.

On ARM, the PMU does not stop counting after an overflow and therefore
IRQ latency affects the new counter value read by the kernel. This is
significant for non-sampling runs where it is possible for the new value
to overtake the previous one, causing the delta to be out by up to
max_period events.

Commit a737823d ("ARM: 6835/1: perf: ensure overflows aren't missed due
to IRQ latency") attempted to fix this problem by allowing interrupt
handlers to pass an overflow flag to the event update function, causing
the overflow calculation to assume that the counter passed through zero
when going from prev to new. Unfortunately, this doesn't work when
overflow occurs on the perf_task_tick path because we have the flag
cleared and end up computing a large negative delta.

This patch removes the overflow flag from armpmu_event_update and
instead limits the sample_period to half of the max_period for
non-sampling profiling runs.

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ARM: 7185/1: perf: don't assign platform_device on unsupported CPUs 2011-12-06T12:48:01+00:00 Will Deacon will.deacon@arm.com 2011-12-02T17:16:01+00:00 6bd054096dce061560cee0e016e292e588dc438f In the unlikely case that a platform registers a PMU platform_device when running on a CPU that is unsupported by perf, we will encounter a NULL dereference when trying to assign the platform_device to the cpu_pmu structure. This patch checks that the CPU is supported by perf before assigning the platform_device. Reported-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> 
In the unlikely case that a platform registers a PMU platform_device
when running on a CPU that is unsupported by perf, we will encounter a
NULL dereference when trying to assign the platform_device to the
cpu_pmu structure.

This patch checks that the CPU is supported by perf before assigning
the platform_device.

Reported-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2011-12-06T00:54:00+00:00 Linus Torvalds torvalds@linux-foundation.org 2011-12-06T00:54:00+00:00 232ea344550c4a099d35d9df552509d6748a31c0 * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf: Fix loss of notification with multi-event perf, x86: Force IBS LVT offset assignment for family 10h perf, x86: Disable PEBS on SandyBridge chips trace_events_filter: Use rcu_assign_pointer() when setting ftrace_event_call->filter perf session: Fix crash with invalid CPU list perf python: Fix undefined symbol problem perf/x86: Enable raw event access to Intel offcore events perf: Don't use -ENOSPC for out of PMU resources perf: Do not set task_ctx pointer in cpuctx if there are no events in the context perf/x86: Fix PEBS instruction unwind oprofile, x86: Fix crash when unloading module (nmi timer mode) oprofile: Fix crash when unloading module (hr timer mode) 
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf: Fix loss of notification with multi-event
  perf, x86: Force IBS LVT offset assignment for family 10h
  perf, x86: Disable PEBS on SandyBridge chips
  trace_events_filter: Use rcu_assign_pointer() when setting ftrace_event_call->filter
  perf session: Fix crash with invalid CPU list
  perf python: Fix undefined symbol problem
  perf/x86: Enable raw event access to Intel offcore events
  perf: Don't use -ENOSPC for out of PMU resources
  perf: Do not set task_ctx pointer in cpuctx if there are no events in the context
  perf/x86: Fix PEBS instruction unwind
  oprofile, x86: Fix crash when unloading module (nmi timer mode)
  oprofile: Fix crash when unloading module (hr timer mode)
ARM: perf: check that we have a platform device when reserving PMU 2011-11-22T18:01:46+00:00 Will Deacon will.deacon@arm.com 2011-11-22T18:01:46+00:00 e5a21327644adba32816f74a415114d11c57f2e9 Attempting to use a hardware counter on a platform with a supported PMU but where the platform_device (defining the interrupts) has not been registered results in a NULL pointer dereference. This patch fixes the problem by checking that we actually have a platform device registered before attempting to grab the interrupts. Reported-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> 
Attempting to use a hardware counter on a platform with a supported PMU
but where the platform_device (defining the interrupts) has not been
registered results in a NULL pointer dereference.

This patch fixes the problem by checking that we actually have a platform
device registered before attempting to grab the interrupts.

Reported-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
ARM: perf: initialise used_mask for fake PMU during validation 2011-11-17T15:20:03+00:00 Will Deacon will.deacon@arm.com 2011-11-17T15:05:14+00:00 bce34d14428d35d9a06ddc10cd46ecef311764c9 When validating an event group, we call pmu->get_event_idx for each group member in order to check that the group can be scheduled as a unit on an empty PMU. As a result of 3fc2c830 ("ARM: perf: remove event limit from pmu_hw_events"), the used_mask member of struct cpu_hw_events must be setup explicitly, something which we don't do for the fake cpu_hw_events used for validation. This patch sets up an empty used_mask for the fake validation cpu_hw_events, preventing NULL deferences when trying to get the event index. Reported-by: Pawel Moll <pawel.moll@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> 
When validating an event group, we call pmu->get_event_idx for each
group member in order to check that the group can be scheduled as a
unit on an empty PMU.

As a result of 3fc2c830 ("ARM: perf: remove event limit from
pmu_hw_events"), the used_mask member of struct cpu_hw_events must be
setup explicitly, something which we don't do for the fake cpu_hw_events
used for validation.

This patch sets up an empty used_mask for the fake validation
cpu_hw_events, preventing NULL deferences when trying to get the event
index.

Reported-by: Pawel Moll <pawel.moll@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
perf: Don't use -ENOSPC for out of PMU resources 2011-11-14T12:01:24+00:00 Peter Zijlstra a.p.zijlstra@chello.nl 2011-11-09T16:56:37+00:00 aa2bc1ade59003a379ffc485d6da2d92ea3370a6 People (Linus) objected to using -ENOSPC to signal not having enough resources on the PMU to satisfy the request. Use -EINVAL. Requested-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Stephane Eranian <eranian@google.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com> Cc: David Daney <david.daney@cavium.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/n/tip-xv8geaz2zpbjhlx0svmpp28n@git.kernel.org [ merged to newer kernel, fixed up MIPS impact ] Signed-off-by: Ingo Molnar <mingo@elte.hu> 
People (Linus) objected to using -ENOSPC to signal not having enough
resources on the PMU to satisfy the request. Use -EINVAL.

Requested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: David Daney <david.daney@cavium.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-xv8geaz2zpbjhlx0svmpp28n@git.kernel.org
[ merged to newer kernel, fixed up MIPS impact ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>