linux.git/arch/arm/kernel/perf_event.c, branch v3.14.29

Revert "ARM: 7556/1: perf: fix updated event period in response to PERF_EVENT_IOC_PERIOD"

2013-12-17T14:21:35+00:00

This reverts commit 3581fe0ef37ce12ac7a4f74831168352ae848edc.

Fixes to the handling of PERF_EVENT_IOC_PERIOD in the core code mean
we no longer have to play this horrible game.

Signed-off-by: Will Deacon 
Signed-off-by: Peter Zijlstra 
Link: http://lkml.kernel.org/r/1385560479-11014-2-git-send-email-will.deacon@arm.com
Signed-off-by: Ingo Molnar

ARM: perf: fix group validation for mixed software and hardware groups

2013-10-09T13:33:07+00:00

Since software events can always be scheduled, perf allows software and
hardware events to be mixed together in the same event group. There are
two ways in which this can come about:

  (1) A SW event is added to a HW group. This validates using the HW PMU
      of the group leader.

  (2) A HW event is added to a SW group. This inserts the SW events and
      the new HW event into a HW context, but the SW event remains the
      group leader.

When validating the latter case, we would ideally compare the PMU of
each event in the group with the relevant HW PMU. The problem is, in the
face of potentially multiple HW PMUs, we don't have a handle on the
relevant structure. Commit 7b9f72c62ed0 ("ARM: perf: clean up event
group validation") attempting to resolve this issue, but actually made
things *worse* by comparing with the leader PMU. If the leader is a SW
event, then we automatically `pass' all the HW events during validation!

This patch removes the check against the leader PMU. Whilst this will
allow events from multiple HW PMUs to be grouped together, that should
probably be dealt with in perf core as the result of a later patch.

Acked-by: Mark Rutland 
Signed-off-by: Will Deacon

ARM: 7810/1: perf: Fix array out of bounds access in armpmu_map_hw_event()

2013-08-13T19:21:44+00:00

Vince Weaver reports an oops in the ARM perf event code while
running his perf_fuzzer tool on a pandaboard running v3.11-rc4.

Unable to handle kernel paging request at virtual address 73fd14cc
pgd = eca6c000
[73fd14cc] *pgd=00000000
Internal error: Oops: 5 [#1] SMP ARM
Modules linked in: snd_soc_omap_hdmi omapdss snd_soc_omap_abe_twl6040 snd_soc_twl6040 snd_soc_omap snd_soc_omap_hdmi_card snd_soc_omap_mcpdm snd_soc_omap_mcbsp snd_soc_core snd_compress regmap_spi snd_pcm snd_page_alloc snd_timer snd soundcore
CPU: 1 PID: 2790 Comm: perf_fuzzer Not tainted 3.11.0-rc4 #6
task: eddcab80 ti: ed892000 task.ti: ed892000
PC is at armpmu_map_event+0x20/0x88
LR is at armpmu_event_init+0x38/0x280
pc : []    lr : []    psr: 60000013
sp : ed893e40  ip : ecececec  fp : edfaec00
r10: 00000000  r9 : 00000000  r8 : ed8c3ac0
r7 : ed8c3b5c  r6 : edfaec00  r5 : 00000000  r4 : 00000000
r3 : 000000ff  r2 : c0496144  r1 : c049611c  r0 : edfaec00
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
Control: 10c5387d  Table: aca6c04a  DAC: 00000015
Process perf_fuzzer (pid: 2790, stack limit = 0xed892240)
Stack: (0xed893e40 to 0xed894000)
3e40: 00000800 c001c17c 00000002 c008a748 00000001 00000000 00000000 c00bf078
3e60: 00000000 edfaee50 00000000 00000000 00000000 edfaec00 ed8c3ac0 edfaec00
3e80: 00000000 c073ffac ed893f20 c00bf180 00000001 00000000 c00bf078 ed893f20
3ea0: 00000000 ed8c3ac0 00000000 00000000 00000000 c0cb0818 eddcab80 c00bf440
3ec0: ed893f20 00000000 eddcab80 eca76800 00000000 eca76800 00000000 00000000
3ee0: 00000000 ec984c80 eddcab80 c00bfe68 00000000 00000000 00000000 00000080
3f00: 00000000 ed892000 00000000 ed892030 00000004 ecc7e3c8 ecc7e3c8 00000000
3f20: 00000000 00000048 ecececec 00000000 00000000 00000000 00000000 00000000
3f40: 00000000 00000000 00297810 00000000 00000000 00000000 00000000 00000000
3f60: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
3f80: 00000002 00000002 000103a4 00000002 0000016c c00128e8 ed892000 00000000
3fa0: 00090998 c0012700 00000002 000103a4 00090ab8 00000000 00000000 0000000f
3fc0: 00000002 000103a4 00000002 0000016c 00090ab0 00090ab8 000107a0 00090998
3fe0: bed92be0 bed92bd0 0000b785 b6e8f6d0 40000010 00090ab8 00000000 00000000
[] (armpmu_map_event+0x20/0x88) from [] (armpmu_event_init+0x38/0x280)
[] (armpmu_event_init+0x38/0x280) from [] (perf_init_event+0x108/0x180)
[] (perf_init_event+0x108/0x180) from [] (perf_event_alloc+0x248/0x40c)
[] (perf_event_alloc+0x248/0x40c) from [] (SyS_perf_event_open+0x4f4/0x8fc)
[] (SyS_perf_event_open+0x4f4/0x8fc) from [] (ret_fast_syscall+0x0/0x48)
Code: 0a000005 e3540004 0a000016 e3540000 (0791010c)

This is because event->attr.config in armpmu_event_init()
contains a very large number copied directly from userspace and
is never checked against the size of the array indexed in
armpmu_map_hw_event(). Fix the problem by checking the value of
config before indexing the array and rejecting invalid config
values.

Reported-by: Vince Weaver 
Tested-by: Vince Weaver 
Acked-by: Will Deacon 
Signed-off-by: Stephen Boyd 
Signed-off-by: Russell King

ARM: 7809/1: perf: fix event validation for software group leaders

2013-08-13T19:21:43+00:00

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.

Cc: 
Reported-by: Vince Weaver 
Tested-by: Vince Weaver 
Tested-by: Mark Rutland 
Signed-off-by: Will Deacon 
Signed-off-by: Russell King

ARM: 7765/1: perf: Record the user-mode PC in the call chain.

2013-06-24T14:23:29+00:00

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.

Cc: 
Signed-off-by: Jed Davis 
Signed-off-by: Will Deacon 
Signed-off-by: Russell King

ARM: 7698/1: perf: fix group validation when using enable_on_exec

2013-04-17T15:54:07+00:00

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: stable@vger.kernel.org
Cc: Peter Zijlstra 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Reported-by: Sudeep KarkadaNagesha 
Signed-off-by: Will Deacon 
Signed-off-by: Russell King

ARM: 7667/1: perf: Fix section mismatch on armpmu_init()

2013-03-06T23:45:43+00:00

WARNING: vmlinux.o(.text+0xfb80): Section mismatch in reference
from the function armpmu_register() to the function
.init.text:armpmu_init()
The function armpmu_register() references
the function __init armpmu_init().
This is often because armpmu_register lacks a __init
annotation or the annotation of armpmu_init is wrong.

Just drop the __init marking on armpmu_init() because
armpmu_register() no longer has an __init marking.

Acked-by: Will Deacon 
Signed-off-by: Stephen Boyd 
Signed-off-by: Russell King

ARM: 7664/1: perf: remove erroneous semicolon from event initialisation

2013-03-03T22:54:17+00:00

Commit 9dcbf466559f ("ARM: perf: simplify __hw_perf_event_init err
handling") tidied up the error handling code for perf event
initialisation on ARM, but a copy-and-paste error left a dangling
semicolon at the end of an if statement.

This patch removes the broken semicolon, restoring the old group
validation semantics.

Cc: Mark Rutland 
Acked-by: Dirk Behme 
Signed-off-by: Chen Gang 
Signed-off-by: Will Deacon 
Signed-off-by: Russell King

ARM: perf: simplify __hw_perf_event_init err handling

2013-01-18T16:54:30+00:00

Currently __hw_perf_event_init has an err variable that's ignored right
until the end, where it's initialised, conditionally set, and then used
as a boolean flag deciding whether to return another error code.

This patch removes the err variable and simplifies the associated error
handling logic.

Signed-off-by: Mark Rutland 
Signed-off-by: Will Deacon

ARM: perf: remove unnecessary checks for idx < 0

2013-01-18T13:46:09+00:00

We currently check for hwx->idx < 0 in armpmu_read and armpmu_del
unnecessarily. The only case where hwc->idx < 0 is when armpmu_add
fails, in which case the event's state is set to
PERF_EVENT_STATE_INACTIVE.

The perf core will not attempt to read from an event in
PERF_EVENT_STATE_INACTIVE, and so the check in armpmu_read is
unnecessary. Similarly, if perf core cannot add an event it will not
attempt to delete it, so the WARN_ON in armpmu_del is unnecessary.

This patch removes these two redundant checks.

Signed-off-by: Mark Rutland 
Signed-off-by: Will Deacon