Vince's perf fuzzer uncovered the following issue on Alpha:
Unable to handle kernel paging request at virtual address fffffbfe4e46a0e8
CPU 0 perf_fuzzer(1278): Oops 0
pc = [<fffffc000031fbc0>] ra = [<fffffc000031ff54>] ps = 0007 Not tainted
pc is at alpha_perf_event_set_period+0x60/0xf0
ra is at alpha_pmu_enable+0x1a4/0x1c0
v0 = 0000000000000000 t0 = 00000000000fffff t1 = fffffc007b3f5800
t2 = fffffbff275faa94 t3 = ffffffffc9b9bd89 t4 = fffffbfe4e46a098
t5 = 0000000000000020 t6 = fffffbfe4e46a0b8 t7 = fffffc007f4c8000
s0 = 0000000000000000 s1 = fffffc0001b0c018 s2 = fffffc0001b0c020
s3 = fffffc007b3f5800 s4 = 0000000000000001 s5 = ffffffffc9b9bd85
s6 = 0000000000000001
a0 = 0000000000000006 a1 = fffffc007b3f5908 a2 = fffffbfe4e46a098
a3 = 00000005000108c0 a4 = 0000000000000000 a5 = 0000000000000000
t8 = 0000000000000001 t9 = 0000000000000001 t10= 0000000027829f6f
t11= 0000000000000020 pv = fffffc000031fb60 at = fffffc0000950900
gp = fffffc0000940900 sp = fffffc007f4cbca8
Disabling lock debugging due to kernel taint
Trace:
[<fffffc000031ff54>] alpha_pmu_enable+0x1a4/0x1c0
[<fffffc000039f4e8>] perf_pmu_enable+0x48/0x60
[<fffffc00003a0d6c>] __perf_install_in_context+0x15c/0x230
[<fffffc000039d1f0>] remote_function+0x80/0xa0
[<fffffc00003a0c10>] __perf_install_in_context+0x0/0x230
[<fffffc000037b7e4>] smp_call_function_single+0x1b4/0x1d0
[<fffffc000039bb70>] task_function_call+0x60/0x80
[<fffffc00003a0c10>] __perf_install_in_context+0x0/0x230
[<fffffc000039bb44>] task_function_call+0x34/0x80
[<fffffc000039d3fc>] perf_install_in_context+0x9c/0x150
[<fffffc00003a0c10>] __perf_install_in_context+0x0/0x230
[<fffffc00003a5100>] SYSC_perf_event_open+0x360/0xac0
[<fffffc00003110c4>] entSys+0xa4/0xc0
This is due to the raw event encoding being used as an index directly
into the ev67_mapping array, rather than being validated against the
ev67_pmc_event_type enumeration instead. Unlike other architectures,
which allow raw events to propagate into the hardware counters with
little interference, the limited number of events on Alpha and the
strict event <-> counter relationships mean that raw events actually
correspond to the Linux-specific Alpha events, rather than anything
defined by the architecture.
This patch adds a new callback to alpha_pmu_t for validating the raw
event encoding with the Linux event types for the PMU, preventing the
out-of-bounds array access.
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: Michael Cree <mcree@orcon.net.nz>
Acked-by: Matt Turner <mattst88@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
We always need to pass the last sample period to
perf_sample_data_init(), otherwise the event distribution will be
wrong. Thus, modifiyng the function interface with the required period
as argument. So basically a pattern like this:
perf_sample_data_init(&data, ~0ULL);
data.period = event->hw.last_period;
will now be like that:
perf_sample_data_init(&data, ~0ULL, event->hw.last_period);
Avoids unininitialized data.period and simplifies code.
Signed-off-by: Robert Richter <robert.richter@amd.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1333390758-10893-3-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This allows us to move duplicated code in <asm/atomic.h>
(atomic_inc_not_zero() for now) to <linux/atomic.h>
Signed-off-by: Arun Sharma <asharma@fb.com>
Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Acked-by: Mike Frysinger <vapier@gentoo.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The nmi parameter indicated if we could do wakeups from the current
context, if not, we would set some state and self-IPI and let the
resulting interrupt do the wakeup.
For the various event classes:
- hardware: nmi=0; PMI is in fact an NMI or we run irq_work_run from
the PMI-tail (ARM etc.)
- tracepoint: nmi=0; since tracepoint could be from NMI context.
- software: nmi=[0,1]; some, like the schedule thing cannot
perform wakeups, and hence need 0.
As one can see, there is very little nmi=1 usage, and the down-side of
not using it is that on some platforms some software events can have a
jiffy delay in wakeup (when arch_irq_work_raise isn't implemented).
The up-side however is that we can remove the nmi parameter and save a
bunch of conditionals in fast paths.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: Anton Blanchard <anton@samba.org>
Cc: Eric B Munson <emunson@mgebm.net>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Don Zickus <dzickus@redhat.com>
Link: http://lkml.kernel.org/n/tip-agjev8eu666tvknpb3iaj0fg@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Extend the perf_pmu_register() interface to allow for named and
dynamic pmu types.
Because we need to support the existing static types we cannot use
dynamic types for everything, hence provide a type argument.
If we want to enumerate the PMUs they need a name, provide one.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <20101117222056.259707703@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The perf hardware pmu got initialized at various points in the boot,
some before early_initcall() some after (notably arch_initcall).
The problem is that the NMI lockup detector is ran from early_initcall()
and expects the hardware pmu to be present.
Sanitize this by moving all architecture hardware pmu implementations to
initialize at early_initcall() and move the lockup detector to an explicit
initcall right after that.
Cc: paulus <paulus@samba.org>
Cc: davem <davem@davemloft.net>
Cc: Michael Cree <mcree@orcon.net.nz>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1290707759.2145.119.camel@laptop>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Also fix a few compile errors due to undefined and duplicated
variables.
Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1284269844-23251-1-git-send-email-mcree@orcon.net.nz>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Neither the overcommit nor the reservation sysfs parameter were
actually working, remove them as they'll only get in the way.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus <paulus@samba.org>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Replace pmu::{enable,disable,start,stop,unthrottle} with
pmu::{add,del,start,stop}, all of which take a flags argument.
The new interface extends the capability to stop a counter while
keeping it scheduled on the PMU. We replace the throttled state with
the generic stopped state.
This also allows us to efficiently stop/start counters over certain
code paths (like IRQ handlers).
It also allows scheduling a counter without it starting, allowing for
a generic frozen state (useful for rotating stopped counters).
The stopped state is implemented in two different ways, depending on
how the architecture implemented the throttled state:
1) We disable the counter:
a) the pmu has per-counter enable bits, we flip that
b) we program a NOP event, preserving the counter state
2) We store the counter state and ignore all read/overflow events
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus <paulus@samba.org>
Cc: stephane eranian <eranian@googlemail.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Yanmin <yanmin_zhang@linux.intel.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: Michael Cree <mcree@orcon.net.nz>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Simple registration interface for struct pmu, this provides the
infrastructure for removing all the weak functions.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: paulus <paulus@samba.org>
Cc: stephane eranian <eranian@googlemail.com>
Cc: Robert Richter <robert.richter@amd.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Cyrill Gorcunov <gorcunov@gmail.com>
Cc: Lin Ming <ming.m.lin@intel.com>
Cc: Yanmin <yanmin_zhang@linux.intel.com>
Cc: Deng-Cheng Zhu <dengcheng.zhu@gmail.com>
Cc: David Miller <davem@davemloft.net>
Cc: Michael Cree <mcree@orcon.net.nz>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Updates the Alpha perf_event code to match the changes
recently made to the core perf_event code in commit
e78505958c.
Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Signed-off-by: Matt Turner <mattst88@gmail.com>
This implements hardware performance events for the EV67 and later CPUs
within the Linux performance events subsystem. Only using the performance
monitoring unit in HP/Compaq's so called "Aggregrate mode" is supported.
The code has been implemented in a manner that makes extension to other
older Alpha CPUs relatively straightforward should some mug wish to
indulge themselves.
Signed-off-by: Michael Cree <mcree@orcon.net.nz>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jay Estabrook <jay.estabrook@hp.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Will Deacon