linux-toradex.git/arch/s390/oprofile/init.c, branch v3.0.84

oprofile: Fix uninitialized memory access when writing to writing to oprofilefs

2012-01-06T22:13:51+00:00

commit 913050b91eb94f194392dd797b1ff3779f606ac0 upstream.

If oprofilefs_ulong_from_user() is called with count equals
zero, *val remains unchanged. Depending on the implementation it
might be uninitialized.

Change oprofilefs_ulong_from_user()'s interface to return count
on success. Thus, we are able to return early if count equals
zero which avoids using *val uninitialized. Fixing all users of
oprofilefs_ulong_ from_user().

This follows write syscall implementation when count is zero:
"If count is zero ... [and if] no errors are detected, 0 will be
returned without causing any other effect." (man 2 write)

Reported-By: Mike Waychison 
Signed-off-by: Robert Richter 
Cc: Andrew Morton 
Cc: oprofile-list 
Link: http://lkml.kernel.org/r/20111219153830.GH16765@erda.amd.com
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

[S390] hwsampler: Set a sane default sampling rate

2011-06-22T14:24:20+00:00

The sampling interval for the hardware sampler is specified in cycles.
(see SA23-2260-01 The Load-Program-Parameter and the CPU-Measurement
Facilities)
The current default value will therefore result in millions of samples.
This patch changes the default sampling interval to 4M, which will
result in ~1500 samples per second on a z196 reducing the overhead
of sampling.

Signed-off-by: Christian Borntraeger 
Signed-off-by: Martin Schwidefsky

[S390] s390: enforce HW limits for the initial sampling rate

2011-06-22T14:24:20+00:00

On specific configurations with hwsampler opcontrol --start returns an
error on "echo 1 >/dev/oprofile/enable". Turns out that the hw sampling
interval is not checked against the hardware limits.

Signed-off-by: Christian Borntraeger 
Signed-off-by: Martin Schwidefsky

[S390] oprofile: fix min/max interval query checks

2011-05-10T15:13:43+00:00

oprofile_min_interval and oprofile_max_interval are unsigned, checking
for negative values doesn't work. Change hwsampler_query_min_interval
and hwsampler_query_max_interval to return an unsigned long and
check for a zero value instead.

Reported-by: Nicolas Kaiser 
Acked-by: Robert Richter 
Signed-off-by: Martin Schwidefsky

[S390] oprofile: disable hw sampling for CONFIG_32BIT

2011-03-23T09:15:14+00:00

Doesn't work and build for CONFIG_32BIT. So disable it.

Signed-off-by: Heiko Carstens 
Signed-off-by: Martin Schwidefsky

oprofile, s390: Cleanups

2011-03-16T13:30:40+00:00

Remove unused HAVE_HWSAMPLER config option. It is not used anymore,
removing it.

Also make some functions static and some coding style fixes.

Signed-off-by: Robert Richter

oprofile, s390: Remove hwsampler_files.c and merge it into init.c

2011-03-16T13:05:35+00:00

Merge the contents of hwsampler_files.c into
arch/s390/oprofile/init.c.

Signed-off-by: Mahesh Salgaonkar 
Signed-off-by: Heinz Graalfs 
Signed-off-by: Robert Richter

oprofile, s390: Rework hwsampler implementation

2011-02-15T10:10:20+00:00

This patch is a rework of the hwsampler oprofile implementation that
has been applied recently. Now there are less non-architectural
changes. The only changes are:

* introduction of oprofile_add_ext_hw_sample(), and
* removal of section attributes of oprofile_timer_init/_exit().

To setup hwsampler for oprofile we need to modify start()/stop()
callbacks and additional hwsampler control files in oprofilefs. We do
not reinitialize the timer or hwsampler mode by restarting calling
init/exit() anymore, instead hwsampler_running is used to switch the
mode directly in oprofile_hwsampler_start/_stop(). For locking reasons
there is also hwsampler_file that reflects the value in oprofilefs.

The overall diffstat of the oprofile s390 hwsampler implemenation
shows the low impact to non-architectural code:

 arch/Kconfig                         |    3 +
 arch/s390/Kconfig                    |    1 +
 arch/s390/oprofile/Makefile          |    2 +-
 arch/s390/oprofile/hwsampler.c       | 1256 ++++++++++++++++++++++++++++++++++
 arch/s390/oprofile/hwsampler.h       |  113 +++
 arch/s390/oprofile/hwsampler_files.c |  162 +++++
 arch/s390/oprofile/init.c            |    6 +-
 drivers/oprofile/cpu_buffer.c        |   24 +-
 drivers/oprofile/timer_int.c         |    4 +-
 include/linux/oprofile.h             |    7 +
 10 files changed, 1567 insertions(+), 11 deletions(-)

Acked-by: Heiko Carstens 
Signed-off-by: Robert Richter

oprofile, s390: Enhance OProfile to support System zs hardware sampling feature

2011-02-15T10:08:50+00:00

OProfile is enhanced to export all files for controlling System z's
hardware sampling, and to invoke hwsampler exported functions to
initialize and use System z's hardware sampling.

The patch invokes hwsampler_setup() during oprofile init and exports
following hwsampler files under oprofilefs if hwsampler's setup
succeeded:

A new directory for hardware sampling based files

 /dev/oprofile/hwsampling/

The userland daemon must explicitly write to the following files
to disable (or enable) hardware based sampling

 /dev/oprofile/hwsampling/hwsampler

to modify the actual sampling rate

 /dev/oprofile/hwsampling/hw_interval

to modify the amount of sampling memory (measured in 4K pages)

 /dev/oprofile/hwsampling/hw_sdbt_blocks

The following files are read only and show
the possible minimum sampling rate

 /dev/oprofile/hwsampling/hw_min_interval

the possible maximum sampling rate

 /dev/oprofile/hwsampling/hw_max_interval

The patch splits the oprofile_timer_[init/exit] function so that it
can be also called through user context (oprofilefs) to avoid kernel
oops.

Applied with following changes:
* whitespace changes in Makefile and timer_int.c

Signed-off-by: Mahesh Salgaonkar 
Signed-off-by: Maran Pakkirisamy 
Signed-off-by: Heinz Graalfs 
Acked-by: Heiko Carstens 
Signed-off-by: Robert Richter

[PATCH] s390: add oprofile callgraph support

2006-01-06T16:33:50+00:00

Signed-off-by: Andreas Krebbel 
Signed-off-by: Martin Schwidefsky 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds