Impact: clean up

Itroduce MCOUNT_SAVE/RESTORE_FRAME which allow us to
save a number of lines on source level.

Also fix a comment in ftrace.h.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: change the reporting of empty BTS records

Correctly report a cleared BTS record as invalid. Used to be reported
as branch from 0 to 0.
Signed-off-by: NMarkus Metzger <markus.t.metzger@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

Optimistically allocate a DS context. It is extremely unlikely that
one already existed. This simplifies the code a lot.
Signed-off-by: NMarkus Metzger <markus.t.metzger@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

VMI initialiation can relocate the fixmap, causing early_ioremap to
malfunction if it is initialized before the relocation.  To fix this,
VMI activation is split into two phases; the detection, which must
happen before setting up ioremap, and the activation, which must happen
after parsing early boot parameters.

This fixes a crash on boot when VMI is enabled under VMware.
Signed-off-by: NZachary Amsden <zach@vmware.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Impact: build fix

32-bit x86 needs this section too.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: move most important x86 irq entry-points to a separate subsection

Annotate do_IRQ and smp_apic_timer_interrupt to put them into the .irqentry.text
subsection. These function will so be recognized as hardirq entrypoints for the
function-graph-tracer. We could also annotate other irq entries but the others
are far less important but they can be added on request.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: let the function-graph-tracer be aware of the irq entrypoints

Add a new .irqentry.text section to store the irq entrypoints functions
inside the same section. This way, the tracer will be able to signal
an interrupts triggering on output by recognizing these entrypoints.

Also, make this section recordable for dynamic tracing.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: build fix

 arch/x86/kernel/ds.c: In function 'ds_request':
 arch/x86/kernel/ds.c:236: sorry, unimplemented: inlining failed in call to 'ds_get_context': recursive inlining

but the recursion here is scary ...
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: cleanup

Move the BTS bits from ptrace.c into ds.c.
Signed-off-by: NMarkus Metzger <markus.t.metzger@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: make the ds code more debuggable

Turn BUG_ON's into WARN_ON_ONCE.
Signed-off-by: NMarkus Metzger <markus.t.metzger@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

these warnings:

  arch/x86/kernel/paravirt-spinlocks.c: In function ‘default_spin_lock_flags’:
  arch/x86/kernel/paravirt-spinlocks.c:12: warning: passing argument 1 of ‘__raw_spin_lock’ from incompatible pointer type
  arch/x86/kernel/paravirt-spinlocks.c: At top level:
  arch/x86/kernel/paravirt-spinlocks.c:11: warning: ‘default_spin_lock_flags’ defined but not used

showed that the prototype of default_spin_lock_flags() was confused about
what type spinlocks have.

the proper type on UP is raw_spinlock_t.
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: Provide a way to pause the function graph tracer

As suggested by Steven Rostedt, the previous patch that prevented from
spinlock function tracing shouldn't use the raw_spinlock to fix it.
It's much better to follow lockdep with normal spinlock, so this patch
adds a new flag for each task to make the function graph tracer able
to be paused. We also can send an ftrace_printk whithout worrying of
the irrelevant traced spinlock during insertion.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: trace more functions

When the function graph tracer is configured, three more files are not
traced to prevent only four functions to be traced. And this impacts the
normal function tracer too.

arch/x86/kernel/process_64/32.c:

I had crashes when I let this file traced. After some debugging, I saw
that the "current" task point was changed inside__swtich_to(), ie:
"write_pda(pcurrent, next_p);" inside process_64.c Since the tracer store
the original return address of the function inside current, we had
crashes. Only __switch_to() has to be excluded from tracing.

kernel/module.c and kernel/extable.c:

Because of a function used internally by the function graph tracer:
__kernel_text_address()

To let the other functions inside these files to be traced, this patch
introduces the __notrace_funcgraph function prefix which is __notrace if
function graph tracer is configured and nothing if not.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: minor fix
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Impact: minor fix
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Impact: cleanup
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Impact: bugfix
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Impact: bugfix in iommu_map_page function
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Impact: fix boot crash with numcpus=0 on certain systems

Fix early exception in __get_smp_config with nosmp.

Bail out early when there is no MP table.
Reported-by: NWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Tested-by: NWu Fengguang <fengguang.wu@intel.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Alan Jenkins wrote:
> This is on an EeePC 701, /proc/cpuinfo as attached.
>
> Is this expected?  Will the next release work?
>
> Thanks, Alan
>
> # opcontrol --setup --no-vmlinux
> cpu_type 'unset' is not valid
> you should upgrade oprofile or force the use of timer mode
>
> # opcontrol -v
> opcontrol: oprofile 0.9.4 compiled on Nov 29 2008 22:44:10
>
> # cat /dev/oprofile/cpu_type
> i386/p6
> # uname -r
> 2.6.28-rc6eeepc

Hi Alan,

Looking at the kernel driver code for oprofile it can return the "i386/p6" for
the cpu_type. However, looking at the user-space oprofile code there isn't the
matching entry in libop/op_cpu_type.c or the events/unit_mask files in
events/i386 directory.

The Intel AP-485 says this is a "Intel Pentium M processor model D". Seems like
the oprofile kernel driver should be identifying the processor as "i386/p6_mobile"

The driver identification code doesn't look quite right in nmi_init.c

http://git.kernel.org/?p=linux/kernel/git/sfr/linux-next.git;a=blob;f=arch/x86/oprofile/nmi_int.c;h=022cd41ea9b4106e5884277096e80e9088a7c7a9;hb=HEAD

has:

409         case 10 ... 13:
410                 *cpu_type = "i386/p6";
411                 break;

Referring to the Intel AP-485:
case 10 and 11 should produce "i386/piii"
case 13 should produce "i386/p6_mobile"

I didn't see anything for case 12.

Something like the attached patch. I don't have a celeron machine to verify that
changes in this area of the kernel fix thing.

-Will
Signed-off-by: NWilliam Cohen <wcohen@redhat.com>
Tested-by: NAlan Jenkins <alan-jenkins@tuffmail.co.uk>
Acked-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

If oprofile statically compiled in kernel, a cpu unplug triggers
a panic in ppro_stop(), because a NULL pointer is dereferenced.
Signed-off-by: NEric Dumazet <dada1@cosmosbay.com>
Signed-off-by: NRobert Richter <robert.richter@amd.com>

The access to the iommu->need_sync member needs to be protected by the
iommu->lock. Otherwise this is a possible race condition. Fix it with
this patch.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

In some rare cases a request can arrive an IOMMU with its originial
requestor id even it is aliased. Handle this by setting the device table
entry to the same protection domain for the original and the aliased
requestor id.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Remove 16 bytes of padding from struct amd_iommu on 64bit builds
reducing its size to 120 bytes, allowing it to span one fewer
cachelines.
Signed-off-by: NRichard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>

Impact: remove stale IOTLB entries

In the non-default nofullflush case the GART is only flushed when
next_bit wraps around. But it can happen that an unmap operation unmaps
memory which is behind the current next_bit location. If these addresses
are reused it may result in stale GART IO/TLB entries. Fix this by
setting the GART next_bit always behind an unmapped location.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Import: robustness checks

Add more checks in the function graph code to detect errors and
perhaps print out better information if a bug happens.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: feature, let entry function decide to trace or not

This patch lets the graph tracer entry function decide if the tracing
should be done at the end as well. This requires all function graph
entry functions return 1 if it should trace, or 0 if the return should
not be traced.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: better dumpstack output

I noticed in my crash dumps and even in the stack tracer that a
lot of functions listed in the stack trace are simply
return_to_handler which is ftrace graphs way to insert its own
call into the return of a function.

But we lose out where the actually function was called from.

This patch adds in hooks to the dumpstack mechanism that detects
this and finds the real function to print. Both are printed to
let the user know that a hook is still in place.

This does give a funny side effect in the stack tracer output:

        Depth   Size      Location    (80 entries)
        -----   ----      --------
  0)     4144      48   save_stack_trace+0x2f/0x4d
  1)     4096     128   ftrace_call+0x5/0x2b
  2)     3968      16   mempool_alloc_slab+0x16/0x18
  3)     3952     384   return_to_handler+0x0/0x73
  4)     3568    -240   stack_trace_call+0x11d/0x209
  5)     3808     144   return_to_handler+0x0/0x73
  6)     3664    -128   mempool_alloc+0x4d/0xfe
  7)     3792     128   return_to_handler+0x0/0x73
  8)     3664     -32   scsi_sg_alloc+0x48/0x4a [scsi_mod]

As you can see, the real functions are now negative. This is due
to them not being found inside the stack.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: new ftrace_graph_stop function

While developing more features of function graph, I hit a bug that
caused the WARN_ON to trigger in the prepare_ftrace_return function.
Well, it was hard for me to find out that was happening because the
bug would not print, it would just cause a hard lockup or reboot.
The reason is that it is not safe to call printk from this function.

Looking further, I also found that it calls unregister_ftrace_graph,
which grabs a mutex and calls kstop machine. This would definitely
lock the box up if it were to trigger.

This patch adds a fast and safe ftrace_graph_stop() which will
stop the function tracer. Then it is safe to call the WARN ON.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: consistency change for function graph

This patch makes function graph record the mcount caller address
the same way the function tracer does.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: clean up

There exists macros for x86 asm to handle x86_64 and i386.
This patch updates function graph asm to use them.
Signed-off-by: NSteven Rostedt <srostedt@redhat.com>
Acked-by: NFrederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: extend and enable the function graph tracer to 64-bit x86

This patch implements the support for function graph tracer under x86-64.
Both static and dynamic tracing are supported.

This causes some small CPP conditional asm on arch/x86/kernel/ftrace.c I
wanted to use probe_kernel_read/write to make the return address
saving/patching code more generic but it causes tracing recursion.

That would be perhaps useful to implement a notrace version of these
function for other archs ports.

Note that arch/x86/process_64.c is not traced, as in X86-32. I first
thought __switch_to() was responsible of crashes during tracing because I
believed current task were changed inside but that's actually not the
case (actually yes, but not the "current" pointer).

So I will have to investigate to find the functions that harm here, to
enable tracing of the other functions inside (but there is no issue at
this time, while process_64.c stays out of -pg flags).

A little possible race condition is fixed inside this patch too. When the
tracer allocate a return stack dynamically, the current depth is not
initialized before but after. An interrupt could occur at this time and,
after seeing that the return stack is allocated, the tracer could try to
trace it with a random uninitialized depth. It's a prevention, even if I
hadn't problems with it.
Signed-off-by: NFrederic Weisbecker <fweisbec@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Tim Bird <tim.bird@am.sony.com>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: do not expose a control that has no effect

Fix to prevent sched_mc_power_saving from being exported through sysfs
on single-socket systems. (Say multicore single socket (Laptop))

CPU core map of the boot cpu should be equal to possible number
of cpus for single socket system.

This fix has been developed at FOSS.in kernel workout.
Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>
Acked-by: NPeter Zijlstra <peterz@infradead.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

All architectures now use the generic compat_sys_ptrace, as should every
new architecture that needs 32bit compat (if we'll ever get another).

Remove the now superflous __ARCH_WANT_COMPAT_SYS_PTRACE define, and also
kill a comment about __ARCH_SYS_PTRACE that was added after
__ARCH_SYS_PTRACE was already gone.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

... so get xen-ops.h in agreement with xen/smp.c
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

calls __init, called only from __init
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Devices like b44 ethernet can't dma from addresses above 1GB. The driver
handles this cases by falling back to GFP_DMA allocation. But for detecting
the problem it needs to get an indication from dma_mapping_error.
The bug is triggered by using a VMSPLIT option of 2G/2G.
Signed-off-by: NThomas Bogendoerfer <tsbogend@alpha.franken.de>
Acked-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Signed-off-by: NIngo Molnar <mingo@elte.hu>

Impact: fix boot crash on AMD IOMMU if CONFIG_GART_IOMMU is off

Currently these macros evaluate to a no-op except the kernel is compiled
with GART or Calgary support. But we also need these macros when we have
SWIOTLB, VT-d or AMD IOMMU in the kernel. Since we always compile at
least with SWIOTLB we can define these macros always.

This patch is also for stable backport for the same reason the SWIOTLB
default selection patch is.
Signed-off-by: NJoerg Roedel <joerg.roedel@amd.com>
Cc: <stable@kernel.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>