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Commit Graph

33 Commits

Author SHA1 Message Date
Linus Torvalds
b0b7065b64 Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (24 commits)
  tracing/urgent: warn in case of ftrace_start_up inbalance
  tracing/urgent: fix unbalanced ftrace_start_up
  function-graph: add stack frame test
  function-graph: disable when both x86_32 and optimize for size are configured
  ring-buffer: have benchmark test print to trace buffer
  ring-buffer: do not grab locks in nmi
  ring-buffer: add locks around rb_per_cpu_empty
  ring-buffer: check for less than two in size allocation
  ring-buffer: remove useless compile check for buffer_page size
  ring-buffer: remove useless warn on check
  ring-buffer: use BUF_PAGE_HDR_SIZE in calculating index
  tracing: update sample event documentation
  tracing/filters: fix race between filter setting and module unload
  tracing/filters: free filter_string in destroy_preds()
  ring-buffer: use commit counters for commit pointer accounting
  ring-buffer: remove unused variable
  ring-buffer: have benchmark test handle discarded events
  ring-buffer: prevent adding write in discarded area
  tracing/filters: strloc should be unsigned short
  tracing/filters: operand can be negative
  ...

Fix up kmemcheck-induced conflict in kernel/trace/ring_buffer.c manually
2009-06-20 10:56:46 -07:00
Steven Rostedt
71e308a239 function-graph: add stack frame test
In case gcc does something funny with the stack frames, or the return
from function code, we would like to detect that.

An arch may implement passing of a variable that is unique to the
function and can be saved on entering a function and can be tested
when exiting the function. Usually the frame pointer can be used for
this purpose.

This patch also implements this for x86. Where it passes in the stack
frame of the parent function, and will test that frame on exit.

There was a case in x86_32 with optimize for size (-Os) where, for a
few functions, gcc would align the stack frame and place a copy of the
return address into it. The function graph tracer modified the copy and
not the actual return address. On return from the funtion, it did not go
to the tracer hook, but returned to the parent. This broke the function
graph tracer, because the return of the parent (where gcc did not do
this funky manipulation) returned to the location that the child function
was suppose to. This caused strange kernel crashes.

This test detected the problem and pointed out where the issue was.

This modifies the parameters of one of the functions that the arch
specific code calls, so it includes changes to arch code to accommodate
the new prototype.

Note, I notice that the parsic arch implements its own push_return_trace.
This is now a generic function and the ftrace_push_return_trace should be
used instead. This patch does not touch that code.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2009-06-18 18:40:18 -04:00
Michael Ellerman
92e02a5125 powerpc/ftrace: Use PPC_INST_NOP directly
There's no need to wrap PPC_INST_NOP in a static inline.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-06-02 10:36:53 +10:00
Michael Ellerman
898b160fe9 powerpc/ftrace: Remove unused macros
These macros were used in the original port, but since commit
e4486fe316 (ftrace, use probe_kernel API to modify code) they
are unused.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-06-02 10:36:46 +10:00
Michael Ellerman
4a9e3f8e94 powerpc/ftrace: Use ppc_function_entry() instead of GET_ADDR
Use ppc_function_entry() from code-patching.h.

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-06-02 10:36:32 +10:00
Steven Rostedt
c3cf8667ed powerpc/ftrace: Fix constraint to be early clobber
After upgrading my distcc boxes from gcc 4.2.2 to 4.4.0, the function
graph tracer broke. This was discovered on my x86 boxes.

The issue is that gcc used the same register for an output as it did for
an input in an asm statement. I first thought this was a bug in gcc and
reported it. I was notified that gcc was correct and that the output had
to be flagged as an "early clobber".

I noticed that powerpc had the same issue and this patch fixes it.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-05-18 15:19:05 +10:00
Michael Ellerman
021376a3b6 powerpc/ftrace: Use pr_devel() in ftrace.c
pr_debug() can now result in code being generated even when #DEBUG
is not defined. That's not really desirable in the ftrace code
which we want to be snappy.

With CONFIG_DYNAMIC_DEBUG=y:

size before:
   text	   data	    bss	    dec	    hex	filename
   3334	    672	      4	   4010	    faa	arch/powerpc/kernel/ftrace.o

size after:
   text	   data	    bss	    dec	    hex	filename
   2616	    360	      4	   2980	    ba4	arch/powerpc/kernel/ftrace.o

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-05-18 15:19:04 +10:00
Michael Ellerman
7ddb7ad11f powerpc/ftrace: Fix printf format warning
'tramp' is an unsigned long, so print it with %lx.

Fixes the following build warning:
arch/powerpc/kernel/ftrace.c:291: error: format ‘%x’ expects type ‘unsigned int’, but argument 2 has type ‘long unsigned int’

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-04-07 15:19:00 +10:00
Michael Ellerman
f4952f6cbe powerpc/ftrace: Fix #if that should be #ifdef
Commit bb7253403f ("powerpc64,
ftrace: save toc only on modules for function graph"), added an
#if CONFIG_PPC64.  This changes it to #ifdef.

Fixes the following warning on 32-bit builds:
 arch/powerpc/kernel/ftrace.c:562:5: error: "CONFIG_PPC64" is not defined

Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-04-07 15:19:00 +10:00
Stephen Rothwell
a095bdbb13 tracing, powerpc: fix powerpc tree and tracing tree interaction
Today's linux-next build (powerpc allyesconfig) failed like this:

arch/powerpc/kernel/ftrace.c: In function 'prepare_ftrace_return':
arch/powerpc/kernel/ftrace.c:612: warning: passing argument 3 of 'ftrace_push_return_trace' makes pointer from integer without a cast
arch/powerpc/kernel/ftrace.c:612: error: too many arguments to function 'ftrace_push_return_trace'

Caused by commit 5d1a03dc54
("function-graph: moved the timestamp from arch to generic code") from
the tracing tree which (removed an argument from
ftrace_push_return_trace()) interacting with commit
6794c78243 ("powerpc64: port of the
function graph tracer") from the powerpc tree.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: <linuxppc-dev@ozlabs.org>
LKML-Reference: <20090327230834.93d0221d.sfr@canb.auug.org.au>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-04-02 00:50:24 +02:00
Kumar Gala
16c57b3620 powerpc: Unify opcode definitions and support
Create a new header that becomes a single location for defining PowerPC
opcodes used by code that is either generationg instructions
at runtime (fixups, debug, etc.), emulating instructions, or just
compiling instructions old assemblers don't know about.

We currently don't handle the floating point emulation or alignment decode
as both are better handled by the specific decode support they already
have.

Added support for the new dcbzl, dcbal, msgsnd, tlbilx, & wait instructions
since older assemblers don't know about them.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23 10:48:56 +11:00
Steven Rostedt
bb9b903527 powerpc, ftrace: use create_branch lib function
Impact: clean up, remove duplicate code

When ftrace was first ported to PowerPC, there existed a
create_function_call that would create the instruction to make a call
to a given address. Unfortunately, this call expected to write to
the address it was given, and since it used the address to calculate
the offset, it could not be faked.

ftrace needed a way to create the instruction without actually writing
that instruction to the text section. So ftrace had to implement its
own code.

Now we have create_branch in the code patching library, which does
exactly what ftrace needs. This patch replaces ftrace's implementation
with the library function.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23 10:48:56 +11:00
Steven Rostedt
b54dcfe108 powerpc, ftrace: use unsigned int for instruction manipulation
The original port of ftrace to PowerPC kept a lot of the code used
by x86. Some of this code was to handle x86's 5 byte instruction.
This was handled by using character arrays to manipulate the
code.

PowerPC has a consistent 4 byte instruction. Using unsigned ints
makes the code more efficient as well as more readable.
By converting to use unsigned ints to represent instructions,
I was able to remove the side effects that were needed for
manipulating character strings.

  i.e. memcpy and memcmp

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23 10:48:55 +11:00
Steven Rostedt
fad4f47cc8 powerpc32, ftrace: port function graph tracer to ppc32, static only
This patch ports the function graph tracer for PowerPC, but only
for static function tracing.

Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23 10:48:55 +11:00
Steven Rostedt
bb7253403f powerpc64, ftrace: save toc only on modules for function graph
The TOCS used by modules are different than the one used by
the core kernel code. The function graph tracer must save and
restore the TOC whenever it traces a module call. But this
is an added overhead to burden the majority of core kernel
code being traced.

Benjamin Herrenschmidt suggested in testing the entry of
the call to tell if it is a core kernel function or a module.
He recommended using the REGION_ID() macro to perform this test.

This patch implements Benjamin's idea, and uses a different
return_to_handler routine dependent on if the entry is a core
kernel function or not. The module version saves the TOC, where as
the core kernel version does not.

Geoff Lavand tested on PS3.

Tested-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23 10:48:54 +11:00
Steven Rostedt
4654288847 powerpc64, tracing: add function graph tracer with dynamic tracing
This is the port of the function graph tracer to PowerPC with
dynamic tracing.

Geoff Lavand tested on PS3.

Tested-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23 10:48:54 +11:00
Steven Rostedt
6794c78243 powerpc64: port of the function graph tracer
This is a port of the function graph tracer that was written by
Frederic Weisbecker for the x86.

This only works for PPC64 at the moment and only for static tracing.
PPC32 and dynamic function graph tracing support will come later.

The trace produces a visual calling of functions:

 # tracer: function_graph
 #
 # CPU  DURATION                  FUNCTION CALLS
 # |     |   |                     |   |   |   |
  0)   2.224 us    |                        }
  0) ! 271.024 us  |                      }
  0) ! 320.080 us  |                    }
  0) ! 324.656 us  |                  }
  0) ! 329.136 us  |                }
  0)               |                .put_prev_task_fair() {
  0)               |                  .update_curr() {
  0)   2.240 us    |                    .update_min_vruntime();
  0)   6.512 us    |                  }
  0)   2.528 us    |                  .__enqueue_entity();
  0) + 15.536 us   |                }
  0)               |                .pick_next_task_fair() {
  0)   2.032 us    |                  .__pick_next_entity();
  0)   2.064 us    |                  .__clear_buddies();
  0)               |                  .set_next_entity() {
  0)   2.672 us    |                    .__dequeue_entity();
  0)   6.864 us    |                  }

Geoff Lavand tested on PS3.

Tested-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23 10:48:53 +11:00
Steven Rostedt
17be5b3ddf powerpc, ftrace: fix compile error when modules not configured
Michael Neuling reported a compile bug when dynamic ftrace was
configured in and modules were not. This was due to the ftrace
code referencing module specific structures.

Reported-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23 10:48:53 +11:00
Steven Rostedt
44e1d064b9 ftrace, powerpc: replace debug macro with proper pr_deug
Impact: cleanup

The PowerPC ftrace code uses a hacked up DEBUGP macro for prints.
This patch converts it to the standard pr_debug.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23 10:48:52 +11:00
Steven Rostedt
f25f9074c2 powerpc/ftrace: Fix math to calculate offset in TOC
Impact: fix dynamic ftrace with large modules in PPC64

The math to calculate the offset into the TOC that is taken from reading
the trampoline is incorrect. The bottom half of the offset is a signed
extended short. The current code was using an OR to create the offset
when it should have been using an addition.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Acked-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-10 14:39:08 +11:00
Steven Rostedt
0029ff8752 powerpc: ftrace, use create_branch
Impact: clean up

Paul Mackerras pointed out that the code to determine if the branch
can reach the destination is incorrect. Michael Ellerman suggested
to pull out the code from create_branch and use that.

Simply using create_branch is probably the best.

Reported-by: Michael Ellerman <michael@ellerman.id.au>
Reported-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-28 14:08:01 +01:00
Steven Rostedt
ec682cef2d powerpc: ftrace, added missing icache flush
Impact: fix to PowerPC code modification

After modifying code it is essential to flush the icache. This patch
adds the missing flush.

Reported-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-28 14:07:56 +01:00
Steven Rostedt
d9af12b72b powerpc: ftrace, fix cast aliasing and add code verification
Impact: clean up and robustness addition

This patch addresses the comments made by Paul Mackerras.
It removes the type casting between unsigned int and unsigned char
pointers, and replaces them with a use of all unsigned int.

Verification that the jump is indeed made to a trampoline has also
been added.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-11-28 14:07:50 +01:00
Steven Rostedt
7cc45e6432 powerpc/ppc32: ftrace, dynamic ftrace to handle modules
Impact: add ability to trace modules on 32 bit PowerPC

This patch performs the necessary trampoline calls to handle
modules with dynamic ftrace on 32 bit PowerPC.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2008-11-20 10:52:53 -08:00
Steven Rostedt
f48cb8b48b powerpc/ppc64: ftrace, handle module trampolines for dyn ftrace
Impact: Allow 64 bit PowerPC to trace modules with dynamic ftrace

This adds code to handle the PPC64 module trampolines, and allows for
PPC64 to use dynamic ftrace.

Thanks to Paul Mackerras for these updates:

  - fix the mod and rec->arch.mod NULL checks.
  - fix to is_bl_op compare.

Thanks to Milton Miller for:

  - finding the nasty race with using two nops, and recommending
    instead that I use a branch 8 forward.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2008-11-20 10:52:28 -08:00
Steven Rostedt
e4486fe316 powerpc: ftrace, use probe_kernel API to modify code
Impact: use cleaner probe_kernel API over assembly

Using probe_kernel_read/write interface is a much cleaner approach
than the current assembly version.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2008-11-20 10:52:04 -08:00
Steven Rostedt
8fd6e5a8c8 powerpc: ftrace, convert to new dynamic ftrace arch API
Impact: update to PowerPC ftrace arch API

This patch converts PowerPC to use the new dynamic ftrace arch API.

Thanks to Paul Mackennas for pointing out the mistakes of my original
test_24bit_addr function.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
2008-11-20 10:51:40 -08:00
Steven Rostedt
15adc04898 ftrace, powerpc, sparc64, x86: remove notrace from arch ftrace file
The entire file of ftrace.c in the arch code needs to be marked
as notrace. It is much cleaner to do this from the Makefile with
CFLAGS_REMOVE_ftrace.o.

[ powerpc already had this in its Makefile. ]

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-23 16:00:25 +02:00
Steven Rostedt
4d296c2432 ftrace: remove mcount set
The arch dependent function ftrace_mcount_set was only used by the daemon
start up code. This patch removes it.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-10-23 16:00:23 +02:00
Abhishek Sagar
395a59d0f8 ftrace: store mcount address in rec->ip
Record the address of the mcount call-site. Currently all archs except sparc64
record the address of the instruction following the mcount call-site. Some
general cleanups are entailed. Storing mcount addresses in rec->ip enables
looking them up in the kprobe hash table later on to check if they're kprobe'd.

Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
Cc: davem@davemloft.net
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-23 22:10:56 +02:00
Abhishek Sagar
1d74f2a0f6 ftrace: remove ftrace_ip_converted()
Remove the unneeded function ftrace_ip_converted().

Signed-off-by: Abhishek Sagar <sagar.abhishek@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-06-10 11:57:49 +02:00
Steven Rostedt
ccbfac2923 ftrace: powerpc clean ups
This patch cleans up the ftrace code in PowerPC based on the comments from
Michael Ellerman.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Cc: Michael Ellerman <michael@ellerman.id.au>
Cc: proski@gnu.org
Cc: a.p.zijlstra@chello.nl
Cc: Pekka Paalanen <pq@iki.fi>
Cc: Steven Rostedt <srostedt@redhat.com>
Cc: linuxppc-dev@ozlabs.org
Cc: Soeren Sandmann Pedersen <sandmann@redhat.com>
Cc: paulus@samba.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-26 22:51:57 +02:00
Steven Rostedt
4e491d14f2 ftrace: support for PowerPC
This patch adds full support for ftrace for PowerPC (both 64 and 32 bit).
This includes dynamic tracing and function filtering.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-05-23 22:43:11 +02:00