Commit Graph

63013 Commits

Author SHA1 Message Date
Ingo Molnar
636f0c70f2 Merge branch 'tip/perf/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core 2012-01-08 12:31:24 +01:00
Ingo Molnar
03f70388c3 Merge branch 'tip/x86/core-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace into perf/core 2012-01-07 13:25:49 +01:00
Linus Torvalds
06867fbb8a Merge branch 'fixes' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm
* 'fixes' of http://ftp.arm.linux.org.uk/pub/linux/arm/kernel/git-cur/linux-2.6-arm:
  ARM: 7237/1: PL330: Fix driver freeze
  ARM: 7197/1: errata: Remove SMP dependency for erratum 751472
  ARM: 7196/1: errata: Remove SMP dependency for erratum 720789
  ARM: 7220/1: mmc: mmci: Fixup error handling for dma
  ARM: 7214/1: mmc: mmci: Fixup handling of MCI_STARTBITERR
2011-12-30 13:45:34 -08:00
Linus Torvalds
604a16b74c Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: plat-orion: make gpiochip label unique
  enable uncompress log on cpuimx35sd
  cpuimx35: fix touchscreen support
  cpuimx35sd: fix Kconfig
  clock-imx35: fix reboot in internal boot mode
  dma: MX3_IPU fix depends
  imx_v4_v5_defconfig: update default configuration
  cpuimx25sd: fix Kconfig
  arm/imx: fix cpufreq section mismatch
  ARM:imx:fix pwm period value
  ARM: OMAP: hwmod data: fix iva and mailbox hwmods for OMAP 3
2011-12-30 13:43:45 -08:00
Linus Torvalds
e95bf44fba Merge branch 'v3.2-samsung-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung
* 'v3.2-samsung-fixes-4' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
  ARM: EXYNOS: Remove duplicated SROMC static memory mapping
  ARM: SAMSUNG: Fix build error when selecting CPU_FREQ_S3C24XX_DEBUGFS on S3C2440
2011-12-30 13:34:00 -08:00
Linus Torvalds
7578ed02e4 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86: Fix raw_spin_unlock_irqrestore() usage
  oprofile, arm/sh: Fix oprofile_arch_exit() linkage issue
2011-12-29 17:09:16 -08:00
Andreas Schwab
34845636a1 procfs: do not confuse jiffies with cputime64_t
Commit 2a95ea6c0d ("procfs: do not overflow get_{idle,iowait}_time
for nohz") did not take into account that one some architectures jiffies
and cputime use different units.

This causes get_idle_time() to return numbers in the wrong units, making
the idle time fields in /proc/stat wrong.

Instead of converting the usec value returned by
get_cpu_{idle,iowait}_time_us to units of jiffies, use the new function
usecs_to_cputime64 to convert it to the correct unit of cputime64_t.

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "Artem S. Tashkinov" <t.artem@mailcity.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-12-29 16:31:57 -08:00
Thomas Abraham
9edf52621d ARM: EXYNOS: Remove duplicated SROMC static memory mapping
SROMC static memory mapping is included in the common s5p initialization
code. Hence, remove the duplicated SROMC static memory mapping for EXYNOS.

Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Cc: stable@kernel.org
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
2011-12-28 15:10:30 +09:00
Denis Kuzmenko
baaf939db4 ARM: SAMSUNG: Fix build error when selecting CPU_FREQ_S3C24XX_DEBUGFS on S3C2440
Following is happened when CONFIG_CPU_FREQ_S3C24XX_DEBUGFS
is selected without building of s3c2410-iotiming.c file:

arch/arm/mach-s3c2440/built-in.o:(.data+0x38c): undefined reference to `s3c2410_iotiming_debugfs

Basically, the CONFIG_S3C2410_IOTIMING is not selected for
MACH_MINI2440. Because the s3c2410-iotiming.c is not ever
compiled and enabling CONFIG_CPU_FREQ_S3C24XX_DEBUGFS option
caused undefined reference to s3c2410_iotiming_debugfs()
defined in that file.  The s3c2410_iotiming_debugfs defined
as NULL for this case.

Signed-off-by: Denis Kuzmenko <linux@solonet.org.ua>
Cc: stable@kernel.org
[kgene.kim@samsung.com: removed useless changes]
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
2011-12-28 15:08:28 +09:00
Scott Wood
fae9dbb4b4 KVM: PPC: e500: include linux/export.h
This is required for THIS_MODULE.  We recently stopped acquiring
it via some other header.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
2011-12-26 13:28:03 +02:00
Michael Neuling
251da03897 KVM: PPC: fix kvmppc_start_thread() for CONFIG_SMP=N
Currently kvmppc_start_thread() tries to wake other SMT threads via
xics_wake_cpu().  Unfortunately xics_wake_cpu only exists when
CONFIG_SMP=Y so when compiling with CONFIG_SMP=N we get:

  arch/powerpc/kvm/built-in.o: In function `.kvmppc_start_thread':
  book3s_hv.c:(.text+0xa1e0): undefined reference to `.xics_wake_cpu'

The following should be fine since kvmppc_start_thread() shouldn't
called to start non-zero threads when SMP=N since threads_per_core=1.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2011-12-26 13:28:02 +02:00
Andreas Schwab
96f38d7286 KVM: PPC: protect use of kvmppc_h_pr
kvmppc_h_pr is only available if CONFIG_KVM_BOOK3S_64_PR.

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2011-12-26 13:28:01 +02:00
Andreas Schwab
36cc66d638 KVM: PPC: move compute_tlbie_rb to book3s_64 common header
compute_tlbie_rb is only used on ppc64 and cannot be compiled on ppc32.

Signed-off-by: Andreas Schwab <schwab@linux-m68k.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
2011-12-26 13:28:00 +02:00
Jan Kiszka
4d25a066b6 KVM: Don't automatically expose the TSC deadline timer in cpuid
Unlike all of the other cpuid bits, the TSC deadline timer bit is set
unconditionally, regardless of what userspace wants.

This is broken in several ways:
 - if userspace doesn't use KVM_CREATE_IRQCHIP, and doesn't emulate the TSC
   deadline timer feature, a guest that uses the feature will break
 - live migration to older host kernels that don't support the TSC deadline
   timer will cause the feature to be pulled from under the guest's feet;
   breaking it
 - guests that are broken wrt the feature will fail.

Fix by not enabling the feature automatically; instead report it to userspace.
Because the feature depends on KVM_CREATE_IRQCHIP, which we cannot guarantee
will be called, we expose it via a KVM_CAP_TSC_DEADLINE_TIMER and not
KVM_GET_SUPPORTED_CPUID.

Fixes the Illumos guest kernel, which uses the TSC deadline timer feature.

[avi: add the KVM_CAP + documentation]

Reported-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Tested-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2011-12-26 13:27:44 +02:00
Jan Kiszka
0924ab2cfa KVM: x86: Prevent starting PIT timers in the absence of irqchip support
User space may create the PIT and forgets about setting up the irqchips.
In that case, firing PIT IRQs will crash the host:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000128
IP: [<ffffffffa10f6280>] kvm_set_irq+0x30/0x170 [kvm]
...
Call Trace:
 [<ffffffffa11228c1>] pit_do_work+0x51/0xd0 [kvm]
 [<ffffffff81071431>] process_one_work+0x111/0x4d0
 [<ffffffff81071bb2>] worker_thread+0x152/0x340
 [<ffffffff81075c8e>] kthread+0x7e/0x90
 [<ffffffff815a4474>] kernel_thread_helper+0x4/0x10

Prevent this by checking the irqchip mode before starting a timer. We
can't deny creating the PIT if the irqchips aren't set up yet as
current user land expects this order to work.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2011-12-25 17:13:18 +02:00
Javi Merino
abb959f8a3 ARM: 7237/1: PL330: Fix driver freeze
Add a req_running field to the pl330_thread to track which request (if
any) has been submitted to the DMA.  This mechanism replaces the old
one in which we tried to guess the same by looking at the PC of the
DMA, which could prevent the driver from sending more requests if it
didn't guess correctly.

Reference: <1323631637-9610-1-git-send-email-javi.merino@arm.com>

Signed-off-by: Javi Merino <javi.merino@arm.com>
Acked-by: Jassi Brar <jaswinder.singh@linaro.org>
Tested-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-12-23 22:57:26 +00:00
Dave Martin
ba90c516ba ARM: 7197/1: errata: Remove SMP dependency for erratum 751472
Activation conditions for a workaround should not be encoded in the
workaround's direct dependencies if this makes otherwise reasonable
configuration choices impossible.

This patches uses the SMP/UP patching facilities instead to compile
out the workaround if the configuration means that it is definitely
not needed.

This means that configs for buggy silicon can simply select
ARM_ERRATA_751472, without preventing a UP kernel from being built
or duplicatiing knowledge about when to activate the workaround.
This seems the correct way to do things, because the erratum is a
property of the silicon, irrespective of what the kernel config
happens to be.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-12-23 22:34:48 +00:00
Dave Martin
e66dc7452a ARM: 7196/1: errata: Remove SMP dependency for erratum 720789
Activation conditions for a workaround should not be encoded in the
workaround's direct dependencies if this makes otherwise reasonable
configuration choices impossible.

The workaround for erratum 720789 only affects a code path which is
not active in UP kernels; hence it should be safe to turn on in UP
kernels, without penalty.

This patch simply removes the extra dependency on SMP from Kconfig.

This means that configs for buggy silicon can simply select
ARM_ERRATA_720789, without preventing a UP kernel from being built
or duplicatiing knowledge about when to activate the workaround.

Signed-off-by: Dave Martin <dave.martin@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
2011-12-23 22:34:47 +00:00
Robert Richter
2e64694de2 perf/x86: Fix raw_spin_unlock_irqrestore() usage
Use raw_spin_unlock_irqrestore() as equivalent to
raw_spin_lock_irqsave().

Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1324646665-13334-1-git-send-email-robert.richter@amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-23 17:57:01 +01:00
Vladimir Zapolskiy
55205c916e oprofile, arm/sh: Fix oprofile_arch_exit() linkage issue
This change fixes a linking problem, which happens if oprofile
is selected to be compiled as built-in:

  `oprofile_arch_exit' referenced in section `.init.text' of
  arch/arm/oprofile/built-in.o: defined in discarded section
  `.exit.text' of arch/arm/oprofile/built-in.o

The problem is appeared after commit 87121ca504, which
introduced oprofile_arch_exit() calls from __init function. Note
that the aforementioned commit has been backported to stable
branches, and the problem is known to be reproduced at least
with 3.0.13 and 3.1.5 kernels.

Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@nokia.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Cc: <stable@kernel.org>
Link: http://lkml.kernel.org/r/20111222151540.GB16765@erda.amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-23 11:58:34 +01:00
David S. Miller
7cc8583372 sparc64: Fix MSIQ HV call ordering in pci_sun4v_msiq_build_irq().
This silently was working for many years and stopped working on
Niagara-T3 machines.

We need to set the MSIQ to VALID before we can set it's state to IDLE.

On Niagara-T3, setting the state to IDLE first was causing HV_EINVAL
errors.  The hypervisor documentation says, rather ambiguously, that
the MSIQ must be "initialized" before one can set the state.

I previously understood this to mean merely that a successful setconf()
operation has been performed on the MSIQ, which we have done at this
point.  But it seems to also mean that it has been set VALID too.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-22 13:46:53 -08:00
Linus Torvalds
ecefc36b41 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  net: Add a flow_cache_flush_deferred function
  ipv4: reintroduce route cache garbage collector
  net: have ipconfig not wait if no dev is available
  sctp: Do not account for sizeof(struct sk_buff) in estimated rwnd
  asix: new device id
  davinci-cpdma: fix locking issue in cpdma_chan_stop
  sctp: fix incorrect overflow check on autoclose
  r8169: fix Config2 MSIEnable bit setting.
  llc: llc_cmsg_rcv was getting called after sk_eat_skb.
  net: bpf_jit: fix an off-one bug in x86_64 cond jump target
  iwlwifi: update SCD BC table for all SCD queues
  Revert "Bluetooth: Revert: Fix L2CAP connection establishment"
  Bluetooth: Clear RFCOMM session timer when disconnecting last channel
  Bluetooth: Prevent uninitialized data access in L2CAP configuration
  iwlwifi: allow to switch to HT40 if not associated
  iwlwifi: tx_sync only on PAN context
  mwifiex: avoid double list_del in command cancel path
  ath9k: fix max phy rate at rate control init
  nfc: signedness bug in __nci_request()
  iwlwifi: do not set the sequence control bit is not needed
2011-12-21 18:29:26 -08:00
Steven Rostedt
42181186ad x86: Add counter when debug stack is used with interrupts enabled
Mathieu Desnoyers pointed out a case that can cause issues with
NMIs running on the debug stack:

  int3 -> interrupt -> NMI -> int3

Because the interrupt changes the stack, the NMI will not see that
it preempted the debug stack. Looking deeper at this case,
interrupts only happen when the int3 is from userspace or in
an a location in the exception table (fixup).

  userspace -> int3 -> interurpt -> NMI -> int3

All other int3s that happen in the kernel should be processed
without ever enabling interrupts, as the do_trap() call will
panic the kernel if it is called to process any other location
within the kernel.

Adding a counter around the sections that enable interrupts while
using the debug stack allows the NMI to also check that case.
If the NMI sees that it either interrupted a task using the debug
stack or the debug counter is non-zero, then it will have to
change the IDT table to make the int3 not change stacks (which will
corrupt the stack if it does).

Note, I had to move the debug_usage functions out of processor.h
and into debugreg.h because of the static inlined functions to
inc and dec the debug_usage counter. __get_cpu_var() requires
smp.h which includes processor.h, and would fail to build.

Link: http://lkml.kernel.org/r/1323976535.23971.112.camel@gandalf.stny.rr.com

Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul Turner <pjt@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 15:38:56 -05:00
Steven Rostedt
ccd49c2391 x86: Allow NMIs to hit breakpoints in i386
With i386, NMIs and breakpoints use the current stack and they
do not reset the stack pointer to a fix point that might corrupt
a previous NMI or breakpoint (as it does in x86_64). But NMIs are
still not made to be re-entrant, and need to prevent the case that
an NMI hitting a breakpoint (which does an iret), doesn't allow
another NMI to run.

The fix is to let the NMI be in 3 different states:

1) not running
2) executing
3) latched

When no NMI is executing on a given CPU, the state is "not running".
When the first NMI comes in, the state is switched to "executing".
On exit of that NMI, a cmpxchg is performed to switch the state
back to "not running" and if that fails, the NMI is restarted.

If a breakpoint is hit and does an iret, which re-enables NMIs,
and another NMI comes in before the first NMI finished, it will
detect that the state is not in the "not running" state and the
current NMI is nested. In this case, the state is switched to "latched"
to let the interrupted NMI know to restart the NMI handler, and
the nested NMI exits without doing anything.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul Turner <pjt@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 15:38:55 -05:00
Steven Rostedt
228bdaa95f x86: Keep current stack in NMI breakpoints
We want to allow NMI handlers to have breakpoints to be able to
remove stop_machine from ftrace, kprobes and jump_labels. But if
an NMI interrupts a current breakpoint, and then it triggers a
breakpoint itself, it will switch to the breakpoint stack and
corrupt the data on it for the breakpoint processing that it
interrupted.

Instead, have the NMI check if it interrupted breakpoint processing
by checking if the stack that is currently used is a breakpoint
stack. If it is, then load a special IDT that changes the IST
for the debug exception to keep the same stack in kernel context.
When the NMI is done, it puts it back.

This way, if the NMI does trigger a breakpoint, it will keep
using the same stack and not stomp on the breakpoint data for
the breakpoint it interrupted.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 15:38:55 -05:00
Steven Rostedt
3f3c8b8c4b x86: Add workaround to NMI iret woes
In x86, when an NMI goes off, the CPU goes into an NMI context that
prevents other NMIs to trigger on that CPU. If an NMI is suppose to
trigger, it has to wait till the previous NMI leaves NMI context.
At that time, the next NMI can trigger (note, only one more NMI will
trigger, as only one can be latched at a time).

The way x86 gets out of NMI context is by calling iret. The problem
with this is that this causes problems if the NMI handle either
triggers an exception, or a breakpoint. Both the exception and the
breakpoint handlers will finish with an iret. If this happens while
in NMI context, the CPU will leave NMI context and a new NMI may come
in. As NMI handlers are not made to be re-entrant, this can cause
havoc with the system, not to mention, the nested NMI will write
all over the previous NMI's stack.

Linus Torvalds proposed the following workaround to this problem:

https://lkml.org/lkml/2010/7/14/264

"In fact, I wonder if we couldn't just do a software NMI disable
instead? Hav ea per-cpu variable (in the _core_ percpu areas that get
allocated statically) that points to the NMI stack frame, and just
make the NMI code itself do something like

 NMI entry:
 - load percpu NMI stack frame pointer
 - if non-zero we know we're nested, and should ignore this NMI:
    - we're returning to kernel mode, so return immediately by using
"popf/ret", which also keeps NMI's disabled in the hardware until the
"real" NMI iret happens.
    - before the popf/iret, use the NMI stack pointer to make the NMI
return stack be invalid and cause a fault
  - set the NMI stack pointer to the current stack pointer

 NMI exit (not the above "immediate exit because we nested"):
   clear the percpu NMI stack pointer
   Just do the iret.

Now, the thing is, now the "iret" is atomic. If we had a nested NMI,
we'll take a fault, and that re-does our "delayed" NMI - and NMI's
will stay masked.

And if we didn't have a nested NMI, that iret will now unmask NMI's,
and everything is happy."

I first tried to follow this advice but as I started implementing this
code, a few gotchas showed up.

One, is accessing per-cpu variables in the NMI handler.

The problem is that per-cpu variables use the %gs register to get the
variable for the given CPU. But as the NMI may happen in userspace,
we must first perform a SWAPGS to get to it. The NMI handler already
does this later in the code, but its too late as we have saved off
all the registers and we don't want to do that for a disabled NMI.

Peter Zijlstra suggested to keep all variables on the stack. This
simplifies things greatly and it has the added benefit of cache locality.

Two, faulting on the iret.

I really wanted to make this work, but it was becoming very hacky, and
I never got it to be stable. The iret already had a fault handler for
userspace faulting with bad segment registers, and getting NMI to trigger
a fault and detect it was very tricky. But for strange reasons, the system
would usually take a double fault and crash. I never figured out why
and decided to go with a simple "jmp" approach. The new approach I took
also simplified things.

Finally, the last problem with Linus's approach was to have the nested
NMI handler do a ret instead of an iret to give the first NMI NMI-context
again.

The problem is that ret is much more limited than an iret. I couldn't figure
out how to get the stack back where it belonged. I could have copied the
current stack, pushed the return onto it, but my fear here is that there
may be some place that writes data below the stack pointer. I know that
is not something code should depend on, but I don't want to chance it.
I may add this feature later, but for now, an NMI handler that loses NMI
context will not get it back.

Here's what is done:

When an NMI comes in, the HW pushes the interrupt stack frame onto the
per cpu NMI stack that is selected by the IST.

A special location on the NMI stack holds a variable that is set when
the first NMI handler runs. If this variable is set then we know that
this is a nested NMI and we process the nested NMI code.

There is still a race when this variable is cleared and an NMI comes
in just before the first NMI does the return. For this case, if the
variable is cleared, we also check if the interrupted stack is the
NMI stack. If it is, then we process the nested NMI code.

Why the two tests and not just test the interrupted stack?

If the first NMI hits a breakpoint and loses NMI context, and then it
hits another breakpoint and while processing that breakpoint we get a
nested NMI. When processing a breakpoint, the stack changes to the
breakpoint stack. If another NMI comes in here we can't rely on the
interrupted stack to be the NMI stack.

If the variable is not set and the interrupted task's stack is not the
NMI stack, then we know this is the first NMI and we can process things
normally. But in order to do so, we need to do a few things first.

1) Set the stack variable that tells us that we are in an NMI handler

2) Make two copies of the interrupt stack frame.
   One copy is used to return on iret
   The other is used to restore the first one if we have a nested NMI.

This is what the stack will look like:

	  +-------------------------+
	  | original SS             |
	  | original Return RSP     |
	  | original RFLAGS         |
	  | original CS             |
	  | original RIP            |
	  +-------------------------+
	  | temp storage for rdx    |
	  +-------------------------+
	  | NMI executing variable  |
	  +-------------------------+
	  | Saved SS                |
	  | Saved Return RSP        |
	  | Saved RFLAGS            |
	  | Saved CS                |
	  | Saved RIP               |
	  +-------------------------+
	  | copied SS               |
	  | copied Return RSP       |
	  | copied RFLAGS           |
	  | copied CS               |
	  | copied RIP              |
	  +-------------------------+
	  | pt_regs                 |
	  +-------------------------+

The original stack frame contains what the HW put in when we entered
the NMI.

We store %rdx as a temp variable to use. Both the original HW stack
frame and this %rdx storage will be clobbered by nested NMIs so we
can not rely on them later in the first NMI handler.

The next item is the special stack variable that is set when we execute
the rest of the NMI handler.

Then we have two copies of the interrupt stack. The second copy is
modified by any nested NMIs to let the first NMI know that we triggered
a second NMI (latched) and that we should repeat the NMI handler.

If the first NMI hits an exception or breakpoint that takes it out of
NMI context, if a second NMI comes in before the first one finishes,
it will update the copied interrupt stack to point to a fix up location
to trigger another NMI.

When the first NMI calls iret, it will instead jump to the fix up
location. This fix up location will copy the saved interrupt stack back
to the copy and execute the nmi handler again.

Note, the nested NMI knows enough to check if it preempted a previous
NMI handler while it is in the fixup location. If it has, it will not
modify the copied interrupt stack and will just leave as if nothing
happened. As the NMI handle is about to execute again, there's no reason
to latch now.

To test all this, I forced the NMI handler to call iret and take itself
out of NMI context. I also added assemble code to write to the serial to
make sure that it hits the nested path as well as the fix up path.
Everything seems to be working fine.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: H. Peter Anvin <hpa@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul Turner <pjt@google.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 15:38:54 -05:00
Steven Rostedt
1fd466efc8 x86: Document the NMI handler about not using paranoid_exit
Linus cleaned up the NMI handler but it still needs some comments to
explain why it uses save_paranoid but not paranoid_exit. Just to keep
others from adding that in the future, document why it's not used.

Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 15:38:53 -05:00
Linus Torvalds
549c89b98c x86: Do not schedule while still in NMI context
The NMI handler uses the paranoid_exit routine that checks the
NEED_RESCHED flag, and if it is set and the return is for userspace,
then interrupts are enabled, the stack is swapped to the thread's stack,
and schedule is called. The problem with this is that we are still in an
NMI context until an iret is executed. This means that any new NMIs are
now starved until an interrupt or exception occurs and does the iret.

As NMIs can not be masked and can interrupt any location, they are
treated as a special case. NEED_RESCHED should not be set in an NMI
handler. The interruption by the NMI should not disturb the work flow
for scheduling. Any IPI sent to a processor after sending the
NEED_RESCHED would have to wait for the NMI anyway, and after the IPI
finishes the schedule would be called as required.

There is no reason to do anything special leaving an NMI. Remove the
call to paranoid_exit and do a simple return. This not only fixes the
bug of starved NMIs, but it also cleans up the code.

Link: http://lkml.kernel.org/r/CA+55aFzgM55hXTs4griX5e9=v_O+=ue+7Rj0PTD=M7hFYpyULQ@mail.gmail.com

Acked-by: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul Turner <pjt@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2011-12-21 15:38:52 -05:00
Stephane Eranian
9c1497ea59 perf events: Add Intel x86 mapping for PERF_COUNT_HW_REF_CPU_CYCLES
Add event maps for Intel x86 processors (with architected PMU v2 or later).

On AMD, there is frequency scaling but no Turbo. There is no core
cycle event not subject to frequency scaling, therefore we do not
provide a mapping.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323559734-3488-4-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:26:39 +01:00
Stephane Eranian
cd09c0c40a perf events: Enable raw event support for Intel unhalted_reference_cycles event
This patch adds the encoding and definitions necessary for the
unhalted_reference_cycles event avaialble since Intel Core 2 processors.

Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1323559734-3488-2-git-send-email-eranian@google.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-21 10:26:32 +01:00
Linus Torvalds
7f3a54b817 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86, dumpstack: Fix code bytes breakage due to missing KERN_CONT
2011-12-20 11:43:08 -08:00
Linus Torvalds
a205b08218 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  oprofile: Fix uninitialized memory access when writing to writing to oprofilefs
2011-12-20 11:41:17 -08:00
Linus Torvalds
26957f0e4b Merge branch 'sh-fixes-for-linus' of git://github.com/pmundt/linux-sh
* 'sh-fixes-for-linus' of git://github.com/pmundt/linux-sh:
  sh: fix build warning in board-sh7757lcr
2011-12-20 11:39:21 -08:00
Linus Torvalds
72784134ce Merge branch 'rmobile-fixes-for-linus' of git://github.com/pmundt/linux-sh
* 'rmobile-fixes-for-linus' of git://github.com/pmundt/linux-sh:
  ARM: mach-shmobile: SH73A0 external Ethernet fix
  ARM: mach-shmobile: AG5EVM GIC Sparse IRQ fix
  ARM: mach-shmobile: Kota2 TPU LED platform data
  ARM: mach-shmobile: Kota2 GIC Sparse IRQ fix
  ARM: mach-shmobile: Kota2 PINT fix
2011-12-20 11:32:18 -08:00
Ingo Molnar
d87f69a16e Merge commit 'v3.2-rc6' into perf/core
Merge reason: Update with the latest fixes.

Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-20 20:32:11 +01:00
Olof Johansson
00ca4e4c8f Merge branch 'fixes-hwmod-regression' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into fixes 2011-12-20 09:56:00 -08:00
Ingo Molnar
124ba94033 Merge branch 'for-tip' of git://git.kernel.org/pub/scm/linux/kernel/git/rric/oprofile into perf/core 2011-12-20 12:10:29 +01:00
Holger Brunck
0b35a45bde ARM: plat-orion: make gpiochip label unique
The former implementation adds a fix gpiochip label string
to the framework. This is confusing because orion_gpio_init
is called more than once and this ends up in different gpiochips
with the same label.

This patch adds the already present orion_gpio_chip_count to the
label string to make it unique in the system.

Signed-off-by: Holger Brunck <holger.brunck@keymile.com>
Cc: Lennert Buytenhek <kernel@wantstofly.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
2011-12-19 20:55:36 -08:00
Clemens Ladisch
13f541c10b x86, dumpstack: Fix code bytes breakage due to missing KERN_CONT
When printing the code bytes in show_registers(), the markers around the
byte at the fault address could make the printk() format string look
like a valid log level and facility code.  This would prevent this byte
from being printed and result in a spurious newline:

[ 7555.765589] Code: 8b 32 e9 94 00 00 00 81 7d 00 ff 00 00 00 0f 87 96 00 00 00 48 8b 83 c0 00 00 00 44 89 e2 44 89 e6 48 89 df 48 8b 80 d8 02 00 00
[ 7555.765683]  8b 48 28 48 89 d0 81 e2 ff 0f 00 00 48 c1 e8 0c 48 c1 e0 04

Add KERN_CONT where needed, and elsewhere in show_registers() for
consistency.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Link: http://lkml.kernel.org/r/4EEFA7AE.9020407@ladisch.de
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2011-12-19 13:09:56 -08:00
Markus Kötter
a03ffcf873 net: bpf_jit: fix an off-one bug in x86_64 cond jump target
x86 jump instruction size is 2 or 5 bytes (near/long jump), not 2 or 6
bytes.

In case a conditional jump is followed by a long jump, conditional jump
target is one byte past the start of target instruction.

Signed-off-by: Markus Kötter <nepenthesdev@gmail.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-19 15:47:29 -05:00
Robert Richter
913050b91e oprofile: Fix uninitialized memory access when writing to writing to oprofilefs
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 <mikew@google.com>
Signed-off-by: Robert Richter <robert.richter@amd.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <stable@vger.kernel.org>
Cc: oprofile-list <oprofile-list@lists.sourceforge.net>
Link: http://lkml.kernel.org/r/20111219153830.GH16765@erda.amd.com
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2011-12-19 17:18:43 +01:00
Eric Bénard
334fef05fd enable uncompress log on cpuimx35sd
Signed-off-by: Eric Bénard <eric@eukrea.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2011-12-19 12:26:09 +01:00
Eric Bénard
4d4b2562fc cpuimx35: fix touchscreen support
Signed-off-by: Eric Bénard <eric@eukrea.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2011-12-19 12:26:09 +01:00
Eric Bénard
a69aa72af3 cpuimx35sd: fix Kconfig
in 0d6cfa3a75 I fixed the mach-types
records. We also need to make the name consistent in Kconfig else
the machine_is_eukrea_cpuimx35sd macro fails, and thus audio codec
is not properly initalized.

Signed-off-by: Eric Bénard <eric@eukrea.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2011-12-19 12:26:08 +01:00
Eric Bénard
9cd39fba1b clock-imx35: fix reboot in internal boot mode
commit 8d75a26 "ARM: mx35: use generic function for displaying silicon revision"
disabled IIM clock after reading silicon revision which will prevent
reboot in internal boot mode.

Signed-off-by: Eric Bénard <eric@eukrea.com>
Cc: Jason Liu <jason.hui@linaro.org>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2011-12-19 12:26:08 +01:00
Eric Bénard
83f250625b imx_v4_v5_defconfig: update default configuration
- add new machine APF9328
- update CPUIMX25 -> CPUIMX25SD
- add drivers :
	- MXC nand driver
	- DM9000
	- SMSC Phy
	- SPIdev
	- Led GPIO

Signed-off-by: Eric Bénard <eric@eukrea.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2011-12-19 12:26:06 +01:00
Eric Bénard
01dd520a50 cpuimx25sd: fix Kconfig
in 0d6cfa3a75 I fixed the mach-types
records. We also need to make the name consistent in Kconfig else
the machine_is_eukrea_cpuimx25sd macro fails, and thus audio codec
is not properly initalized.

Signed-off-by: Eric Bénard <eric@eukrea.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2011-12-19 12:26:06 +01:00
Richard Zhao
e1bff3149a arm/imx: fix cpufreq section mismatch
WARNING: arch/arm/plat-mxc/built-in.o(.data+0x488): Section mismatch in reference from the variable mxc_driver to the function .init.text:mxc_cpufreq_init()
The variable mxc_driver references
the function __init mxc_cpufreq_init()
If the reference is valid then annotate the
variable with __init* or __refdata (see linux/init.h) or name the variable:
*_template, *_timer, *_sht, *_ops, *_probe, *_probe_one, *_console

Signed-off-by: Richard Zhao <richard.zhao@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
2011-12-19 12:26:05 +01:00
Jason Chen
5776ac2eb3 ARM:imx:fix pwm period value
According to imx pwm RM, the real period value should be
PERIOD value in PWMPR plus 2.

PWMO (Hz) = PCLK(Hz) / (period +2)

Signed-off-by: Jason Chen <jason.chen@linaro.org>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Cc: stable@kernel.org
2011-12-19 12:25:35 +01:00
Linus Torvalds
64b3dcc35e Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc32: Be less strict in matching %lo part of relocation.
  sbus: convert drivers/sbus/char/* to use module_platform_driver()
  bbc_i2c: Remove unneeded err variable
  sparc: Use kmemdup rather than duplicating its implementation
2011-12-16 12:26:26 -08:00