linux-toradex.git/kernel/trace/Kconfig, branch tegra-10.9.9

trivial: Fix duplicated word "options" in comment

2009-09-21T13:14:58+00:00

this was introduced in

	5e0a093 (tracing: fix config options to not show when automatically selected)

Signed-off-by: Uwe Kleine-Koenig 
Cc: Steven Rostedt 
Cc: trivial@kernel.org
Signed-off-by: Jiri Kosina

ftrace: document function and function graph implementation

2009-09-15T01:43:15+00:00

While implementing function tracer and function tracer graph support,
I found the exact arch implementation details to be a bit lacking
(and my x86 foo ain't great).  So after pounding out support for
the Blackfin arch, start documenting the requirements/details.

Signed-off-by: Mike Frysinger 
LKML-Reference: <1252973415-21264-1-git-send-email-vapier@gentoo.org>
Acked-by: Frederic Weisbecker 
Signed-off-by: Steven Rostedt

tracing: make testing syscall events a separate configuration

2009-09-14T15:58:24+00:00

Parag noticed that the number of event tests has increased tremendously:

grep "Testing event" dmesg.31rc9 |wc -l
100

grep "Testing event" dmesg.31git |wc -l
1172

This is due to the testing of every syscall event when ftrace self
test is enabled. This adds a bit more time to kernel boot up and can
affect development by slowing down the time it takes between reboots.

This option makes the testing of the syscall events into a separate
config, to still be able to test most of ftrace internals at boot up
but not have to wait for all the syscall events to be tested.

The syscall event testing only tests the enabling and disabling of
the trace point, since the syscalls are not executed. What really needs
to be done is to somehow have a userspace tool test the syscall tracepoints
as well.

Reported-by: Parag Warudkar 
LKML-Reference: 
Signed-off-by: Steven Rostedt

ring-buffer: only enable ring_buffer_swap_cpu when needed

2009-09-04T23:42:22+00:00

Since the ability to swap the cpu buffers adds a small overhead to
the recording of a trace, we only want to add it when needed.

Only the irqsoff and preemptoff tracers use this feature, and both are
not recommended for production kernels. This patch disables its use
when neither irqsoff nor preemptoff is configured.

Signed-off-by: Steven Rostedt

tracing: remove legacy select of MARKERS by context switch tracing

2009-08-27T20:58:03+00:00

The context switch tracer was made before tracepoints were mature, and
the original version used markers. This is no longer true and this
patch removes the select.

Reported-by: Thomas Gleixner 
Signed-off-by: Steven Rostedt

tracing: Rename FTRACE_SYSCALLS for tracepoints

2009-08-25T22:17:35+00:00

s/HAVE_FTRACE_SYSCALLS/HAVE_SYSCALL_TRACEPOINTS/g
s/TIF_SYSCALL_FTRACE/TIF_SYSCALL_TRACEPOINT/g

The syscall enter/exit tracing is no longer specific to just ftrace, so
they now have names that reflect their tie to tracepoints instead.

Signed-off-by: Josh Stone 
Cc: Jason Baron 
Cc: Frederic Weisbecker 
Cc: Ingo Molnar 
Cc: Li Zefan 
Cc: Steven Rostedt 
Cc: Peter Zijlstra 
Cc: Mathieu Desnoyers 
Cc: Jiaying Zhang 
Cc: Martin Bligh 
Cc: Lai Jiangshan 
Cc: Paul Mundt 
Cc: Martin Schwidefsky 
Cc: Heiko Carstens 
LKML-Reference: <1251150194-1713-2-git-send-email-jistone@redhat.com>
Signed-off-by: Frederic Weisbecker

tracing/fastboot: Document the need of initcall_debug

2009-06-29T08:22:10+00:00

To use boot tracer, one should pass initcall_debug as well as
ftrace=initcall to the command line.

Signed-off-by: Li Zefan 
Cc: Frederic Weisbecker 
Cc: Steven Rostedt 
LKML-Reference: <4A48735E.9050002@cn.fujitsu.com>
Signed-off-by: Ingo Molnar

Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

2009-06-20T17:56:46+00:00

* '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

function-graph: add stack frame test

2009-06-18T22:40:18+00:00

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 
Cc: Paul Mackerras 
Cc: Heiko Carstens 
Cc: Martin Schwidefsky 
Cc: Frederic Weisbecker 
Cc: Helge Deller 
Cc: Kyle McMartin 
Signed-off-by: Steven Rostedt

function-graph: disable when both x86_32 and optimize for size are configured

2009-06-18T22:39:30+00:00

On x86_32, when optimize for size is set, gcc may align the frame pointer
and make a copy of the the return address inside the stack frame.
The return address that is located in the stack frame may not be
the one used to return to the calling function. This will break the
function graph tracer.

The function graph tracer replaces the return address with a jump to a hook
function that can trace the exit of the function. If it only replaces
a copy, then the hook will not be called when the function returns.
Worse yet, when the parent function returns, the function graph tracer
will return back to the location of the child function which will
easily crash the kernel with weird results.

To see the problem, when i386 is compiled with -Os we get:

c106be03:       57                      push   %edi
c106be04:       8d 7c 24 08             lea    0x8(%esp),%edi
c106be08:       83 e4 e0                and    $0xffffffe0,%esp
c106be0b:       ff 77 fc                pushl  0xfffffffc(%edi)
c106be0e:       55                      push   %ebp
c106be0f:       89 e5                   mov    %esp,%ebp
c106be11:       57                      push   %edi
c106be12:       56                      push   %esi
c106be13:       53                      push   %ebx
c106be14:       81 ec 8c 00 00 00       sub    $0x8c,%esp
c106be1a:       e8 f5 57 fb ff          call   c1021614 

When it is compiled with -O2 instead we get:

c10896f0:       55                      push   %ebp
c10896f1:       89 e5                   mov    %esp,%ebp
c10896f3:       83 ec 28                sub    $0x28,%esp
c10896f6:       89 5d f4                mov    %ebx,0xfffffff4(%ebp)
c10896f9:       89 75 f8                mov    %esi,0xfffffff8(%ebp)
c10896fc:       89 7d fc                mov    %edi,0xfffffffc(%ebp)
c10896ff:       e8 d0 08 fa ff          call   c1029fd4 

The compile with -Os will align the stack pointer then set up the
frame pointer (%ebp), and it copies the return address back into
the stack frame. The change to the return address in mcount is done
to the copy and not the real place holder of the return address.

Then compile with -O2 sets up the frame pointer first, this makes
the change to the return address by mcount affect where the function
will jump on exit.

Reported-by: Jake Edge 
Signed-off-by: Steven Rostedt