tracing: Fix build breakage without CONFIG_PERF_EVENTS (again)

Today's -next fails to link for me:

kernel/built-in.o:(.data+0x178e50): undefined reference to `perf_ftrace_event_register'

It looks like multiple fixes have been merged for the issue fixed by
commit fa73dc9 (tracing: Fix build breakage without CONFIG_PERF_EVENTS)
though I can't identify the other changes that have gone in at the
minute, it's possible that the changes which caused the breakage fixed
by the previous commit got dropped but the fix made it in.

Link: http://lkml.kernel.org/r/1334307179-21255-1-git-send-email-broonie@opensource.wolfsonmicro.com

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
perf report: Fix crash showing warning related to kernel maps

While testing https://lkml.org/lkml/2012/4/10/123 I hit this crash:

(gdb) bt
 0  0x000000000042000f in __cmd_report (rep=0x7fff80cec580) at builtin-report.c:380
 1  cmd_report (argc=0, argv=<optimized out>, prefix=<optimized out>) at builtin-report.c:759
 2  0x0000000000414513 in run_builtin (p=0x7724a8, argc=3, argv=0x7fff80ceca70) at perf.c:273
 3  0x0000000000413d41 in handle_internal_command (argv=0x7fff80ceca70, argc=3) at perf.c:345
 4  run_argv (argv=0x7fff80cec880, argcp=0x7fff80cec88c) at perf.c:389
 5  main (argc=3, argv=0x7fff80ceca70) at perf.c:487

kernel_map can be NULL, so need to handle it while dumping a warning
to user.

v2:
- fixed RB_EMPTY_ROOT check -- desc takes the altnerative output when RB_EMPTY_ROOT is false.

Signed-off-by: David Ahern <dsahern@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Namhyung Kim <namhyung.kim@lge.com>
Link: http://lkml.kernel.org/r/1334544855-55021-1-git-send-email-dsahern@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
perf tools: Drop CROSS_COMPILE from flex and bison calls

The flex and bison tools generate arch-independent C code so its
binaries are not prefixed with the target-arch prefix. With this patch
the Linux 3.4-rc2 can be successfuly build on OE-Core.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Link: http://lkml.kernel.org/r/1334148270-13139-1-git-send-email-otavio@ossystems.com.br
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
tracing: Fix regression with tracing_on

The change to make tracing_on affect only the ftrace ring buffer, caused
a bug where it wont affect any ring buffer. The problem was that the buffer
of the trace_array was passed to the write function and not the trace array
itself.

The trace_array can change the buffer when running a latency tracer. If this
happens, then the buffer being disabled may not be the buffer currently used
by ftrace. This will cause the tracing_on file to become useless.

The simple fix is to pass the trace_array to the write function instead of
the buffer. Then the actual buffer may be changed.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
perf tools: Add 'G' and 'H' modifiers to event parsing

They were dropped during conversion of event parser. Add test case to
make sure this will not happen again.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/20120417111345.GK11918@redhat.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
rcu: Permit call_rcu() from CPU_DYING notifiers

As of:

  29494be71afe ("rcu,cleanup: simplify the code when cpu is dying")

RCU adopts callbacks from the dying CPU in its CPU_DYING notifier,
which means that any callbacks posted by later CPU_DYING notifiers
are ignored until the CPU comes back online.

A WARN_ON_ONCE() was added to __call_rcu() by:

  e56014000816 ("rcu: Simplify offline processing")

to check for this condition.  Although this condition did not trigger
(at least as far as I know) during -next testing, it did recently
trigger in mainline:

  https://lkml.org/lkml/2012/4/2/34

What is needed longer term is for RCU's CPU_DEAD notifier to adopt any
callbacks that were posted by CPU_DYING notifiers, however, the Linux
kernel has been running with this sort of thing happening for quite
some time.  So the only thing that qualifies as a regression is the
WARN_ON_ONCE(), which this commit removes.

Making RCU's CPU_DEAD notifier adopt callbacks posted by CPU_DYING
notifiers is a topic for the 3.5 release of the Linux kernel.

Reported-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
spi/pl022: Fix range checking for bits per word

pl022 ssp controller supports word lengths from 4 to 16 (or 32) bits.
Currently implemented checks were incorrect. It has following check

if (pl022->vendor->max_bpw >= 32)

which must be checking for <=.

Also error print message is incorrect, that prints "range is from 1 to
16".

Fix both these issues.

Signed-off-by: Vinit Shenoy <vinit.shenoy@st.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
powerpc: fix system.h fallout in sysdev/scom.c [chroma_defconfig]

The following shows up in chroma_defconfig:

 CC      arch/powerpc/sysdev/scom.o
arch/powerpc/sysdev/scom.c: In function 'scom_debug_init':
arch/powerpc/sysdev/scom.c:182:36: error: 'powerpc_debugfs_root' undeclared (first use in this function)
arch/powerpc/sysdev/scom.c:182:36: note: each undeclared identifier is reported only once for each function it appears in
make[2]: *** [arch/powerpc/sysdev/scom.o] Error 1
make[1]: *** [arch/powerpc/sysdev/scom.o] Error 2

A bisect leads to commit 9ffc93f203c18a70623f21950f1dd473c9ec48cd

    "Remove all #inclusions of asm/system.h"

Add the debug header which contains powerpc_debugfs_root.

Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
sh: Fix error synchronising kernel page tables

The problem is caused by the interaction of two features in the Linux
memory management code.

A processes address space is described by a struct mm_struct, and
every thread has a pointer to the mm it should run in. The exception
to this are kernel threads, which don't have an mm, and so borrow
the mm from the last thread which ran. The system is bootstrapped
by the initial kernel thread using init's mm (even though init hasn't
been created yet, its mm is the static init_mm).

The other feature is how the kernel handles the page table which
describes the portion of the address space which is only visible when
executing inside the kernel, and which is shared by all threads. On
the SH4 the only portion of the kernel's address space which described
using the page table is called P3, from 0xc0000000 to 0xdfffffff. This
portion of the address space is divided into three:
  - mappings for dma_alloc_coherent()
  - mappings for vmalloc() and ioremap()
  - fixmap mappings, primarily used in copy_user_pages() to create
    kernel mappings of user pages with the correct cache colour.

To optimise the TLB miss handler we don't want to add an additional
condition which checks whether the faulting address is in the user or
the kernel portion of the address space, and so all page tables have a
common portion which describes the kernel part of the address
space. As the SH4 uses a two level page table, only the kernel portion
of first level page table (the pgd entries) is duplicated. These all
point to the same second level entries (the pte's), and so no memory
is wasted.

The reference page table for the kernel is called the swapper_pg_dir,
and when a new page table is created for a new process the kernel
portion of the page table is copied from swapper_pg_dir. This works
fine when changes only occur in the second level of the kernel's page
table, or the first level entries are created before any new user
processes. However if a change occurs to the first level of the page
table, and there are existing processes which don't have this entry in
their page table, this new entry needs to be added. This is done on
demand, when the kernel accesses a P3 address which isn't mapped using
the current page table, the code in vmalloc_fault() copies the entry
from the reference page table (swapper_pg_dir) into the current
processes page table.

The bug which this patch addresses is that the code in vmalloc_fault()
was not copying addresses which fell in the dma_alloc_coherent()
portion of the address space, and it should have been copying any P3
address.

Why we hadn't seen this before, and what made this hard to reproduce,
is that normally the kernel will have called dma_alloc_coherent(), and
accessed the memory mapping created, before any user process
runs. Typically drivers such as USB or SATA will have created and used
mappings of this type during the kernel initialisation, when probing
for the attached devices, before init runs. Ethernet is slightly
different, as it normally only creates and accesses
dma_alloc_coherent() mappings when the network is brought up, but if
kernel level IP configuration is used this will also occur before any
user space process runs. So the first reproduction of this problem
which we saw was occurred when USB and SATA were removed from the
kernel, and then bring up Ethernet from user space using ifconfig.
I'd like to thank Joseph Bormolini who did the hard work reducing the
problem to this simple to reproduce criteria.

In your case the situation is slightly different, and turns out to
depends on the exact kernel configuration (which we had) and your
ramdisk contents (which we didn't - hence the need for some assumptions).

In this case the problem is a side effect of kernel level module
loading. Kernel subsystems sometimes trigger the load of kernel
modules directly, for example the crypto subsystem tries to load the
cryptomgr and MTD tries to load modules for Flash partitioning if
these are not built into the kernel. This is done by the kernel
creating a user process which runs insmod to try and load the
appropriate module.

In order for this to cause problems the system must be running with a
initrd or initramfs, which contains an insmod executable - if the
kernel can't find an insmod to run, no user process is created, and
the problem doesn't occur.  If an insmod is found, a process is
created to run it, which will inherit the kernel portion of the
swapper_pg_dir first level page table. It doesn't matter whether the
inmod is successful or not, but when the the kernel scheduler context
switches back to the kernel initialisation thread, the insmod's mm is
'borrowed' by the kernel thread, as it doesn't have an address space
of its own. (Reference counting is used to ensure this mm is not
destroyed, even though the user process which caused its creation may no
longer exist.) If this address space doesn't have a first level page
table entry for the consistent mappings, and a driver tries to access
such a mapping, we are in the same situation as described above,
except this time in a kernel thread rather than a user thread
executing inside the kernel.

See bugzilla: 15425, 15836, 15862, 16106, 16793

Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Merge branch 'sh/st-integration' into sh/urgent
x86, intel_cacheinfo: Fix error return code in amd_set_l3_disable_slot()

If the L3 disable slot is already in use, return -EEXIST instead of
-EINVAL. The caller, store_cache_disable(), checks this return value to
print an appropriate warning.

Also, we want to signal with -EEXIST that the current index we're
disabling has actually been already disabled on the node:

$ echo 12 > /sys/devices/system/cpu/cpu3/cache/index3/cache_disable_0
$ echo 12 > /sys/devices/system/cpu/cpu3/cache/index3/cache_disable_0
-bash: echo: write error: File exists
$ echo 12 > /sys/devices/system/cpu/cpu3/cache/index3/cache_disable_1
-bash: echo: write error: File exists
$ echo 12 > /sys/devices/system/cpu/cpu5/cache/index3/cache_disable_1
-bash: echo: write error: File exists

The old code would say

-bash: echo: write error: Invalid argument

for disable slot 1 when playing the example above with no output in
dmesg, which is clearly misleading.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20120419070053.GB16645@elgon.mountain
[Boris: add testing for the other index too]
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
tracing: Fix stacktrace of latency tracers (irqsoff and friends)

While debugging a latency with someone on IRC (mirage335) on #linux-rt (OFTC),
we discovered that the stacktrace output of the latency tracers
(preemptirqsoff) was empty.

This bug was caused by the creation of the dynamic length stack trace
again (like commit 12b5da3 "tracing: Fix ent_size in trace output" was).

This bug is caused by the latency tracers requiring the next event
to determine the time between the current event and the next. But by
grabbing the next event, the iter->ent_size is set to the next event
instead of the current one. As the stacktrace event is the last event,
this makes the ent_size zero and causes nothing to be printed for
the stack trace. The dynamic stacktrace uses the ent_size to determine
how much of the stack can be printed. The ent_size of zero means
no stack.

The simple fix is to save the iter->ent_size before finding the next event.

Note, mirage335 asked to remain anonymous from LKML and git, so I will
not add the Reported-by and Tested-by tags, even though he did report
the issue and tested the fix.

Cc: stable@vger.kernel.org # 3.1+
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
perf symbols: Read plt symbols from proper symtab_type binary

When loading symbols from DSO we check multiple paths of DSO binary
until we succeed to load symbols ('.symtab' section). Once symbols are
read we try to load also plt symbols.

During the reading of plt symbols, the dso file is reopened from
location given by dso->long_name. This could be wrong in case we want
process buildid binaries.

The change is to make the plt symbols being read from the DSO path, that
normal symbols were read from.

Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1334756818-6631-1-git-send-email-jolsa@redhat.com
[ committer note: moved dso to be the first parameter of that function ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
drm/i915: fixup load-detect on enabled, but not active pipe

Somehow we have a fast-path that tries to avoid going through
the load-detect code when the encode already has a crtc associated.
But this fails horribly when the crtc is off. The load detect pipe
itself manages this case well (and also does not forget to restore the
dpms state), so just rip out this special case.

The issue seems to go back all the way to the commit that originally
introduced load-detection on the vga output:

commit e4a5d54f924ea5ce2913d9d0687d034004816465
Author: Ma Ling <ling.ma@intel.com>
Date:   Tue May 26 11:31:00 2009 +0800

    drm/i915: Add support for VGA load detection (pre-945).

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=43020
Reported-by: Jean Delvare <khali@linux-fr.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-Off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
hwmon: (ad7314) Fix build warning

The following build warning is seen in some configurations.

drivers/hwmon/ad7314.c: In function 'ad7314_show_temperature':
drivers/hwmon/ad7314.c:70: warning: 'data' may be used uninitialized in this function

Fix by overloading the return value from ad7314_spi_read with both data and
error code (the returned data is really u16 and needs to be converted into a
signed value anyway).

Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Cameron <jic23@cam.ac.uk>
Acked-by: Jean Delvare <khali@linux-fr.org>
drm/exynos: fixed duplicatd memory allocation bug.

the gem was already allocated at gem allocation time but is allocated
at page fault handler so this patch fixes the problem that gem was
allocated one more time.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
drm/exynos: fixed exynos_drm_gem_map_pages bug.

this patch fixes the problem that the physical memory region to be mapped
to user space could be exceeded. if page fault address was placed at between
buffer start and end then memory region to be mapped would be exceeded.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
drm/exynos: added missed vm area region mapping type.

with this patch, if the memory region is physically non-continuous
then VM_MIXEDMAP is set to vm->vm_flags otherwise VM_PFNMAP.
we had missed this flag setting.

Signed-off-by: Inki Dae <inki.dae@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
xtensa: fix build failure in xtensa/kernel/signal.c

Caused by commit 3785006ac3c8941feb63097c416de92114a6bc39

    "xtensa: don't mask signals if we fail to setup signal stack"

It assigns a return value to "ret", but there is no such variable
anywhere in scope.  Create one.

Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: Matt Fleming <matt.fleming@intel.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
xtensa: fix build error in xtensa/include/asm/io.h

Caused by commit 6c03438edeb5c359af35f060ea016ca65671c269

    kernel.h: doesn't explicitly use bug.h, so don't include it.

This header uses bug.h so explicitly include it now that the
implicit presence was removed by 6c03438ed.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>