linux-toradex.git/include/linux/ftrace.h, branch tegra-10.7.1

tracing: correct module boundaries for ftrace_release

2009-10-07T19:52:09+00:00

When the module is about the unload we release its call records.
The ftrace_release function was given wrong values representing
the module core boundaries, thus not releasing its call records.

Plus making ftrace_release function module specific.

Signed-off-by: Jiri Olsa 
LKML-Reference: <1254934835-363-3-git-send-email-jolsa@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Steven Rostedt

sysctl: remove "struct file *" argument of ->proc_handler

2009-09-24T14:21:04+00:00

It's unused.

It isn't needed -- read or write flag is already passed and sysctl
shouldn't care about the rest.

It _was_ used in two places at arch/frv for some reason.

Signed-off-by: Alexey Dobriyan 
Cc: David Howells 
Cc: "Eric W. Biederman" 
Cc: Al Viro 
Cc: Ralf Baechle 
Cc: Martin Schwidefsky 
Cc: Ingo Molnar 
Cc: "David S. Miller" 
Cc: James Morris 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

includecheck fix: include/linux, ftrace.h

2009-09-20T11:28:35+00:00

fix the following 'make includecheck' warning:

  include/linux/ftrace.h: linux/sched.h is included more than once.

Signed-off-by: Jaswinder Singh Rajput 
Cc: Steven Rostedt 
Cc: Ingo Molnar 
Cc: Sam Ravnborg 
LKML-Reference: <1247068321.4382.102.camel@ht.satnam>

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

tracing: add same level recursion detection

2009-04-17T20:21:32+00:00

The tracing infrastructure allows for recursion. That is, an interrupt
may interrupt the act of tracing an event, and that interrupt may very well
perform its own trace. This is a recursive trace, and is fine to do.

The problem arises when there is a bug, and the utility doing the trace
calls something that recurses back into the tracer. This recursion is not
caused by an external event like an interrupt, but by code that is not
expected to recurse. The result could be a lockup.

This patch adds a bitmask to the task structure that keeps track
of the trace recursion. To find the interrupt depth, the following
algorithm is used:

  level = hardirq_count() + softirq_count() + in_nmi;

Here, level will be the depth of interrutps and softirqs, and even handles
the nmi. Then the corresponding bit is set in the recursion bitmask.
If the bit was already set, we know we had a recursion at the same level
and we warn about it and fail the writing to the buffer.

After the data has been committed to the buffer, we clear the bit.
No atomics are needed. The only races are with interrupts and they reset
the bitmask before returning anywy.

[ Impact: detect same irq level trace recursion ]

Signed-off-by: Steven Rostedt

ftrace: use module notifier for function tracer

2009-04-17T14:59:15+00:00

The hooks in the module code for the function tracer must be called
before any of that module code runs. The function tracer hooks
modify the module (replacing calls to mcount to nops). If the code
is executed while the change occurs, then the CPU can take a GPF.

To handle the above with a bit of paranoia, I originally implemented
the hooks as calls directly from the module code.

After examining the notifier calls, it looks as though the start up
notify is called before any of the module's code is executed. This makes
the use of the notify safe with ftrace.

Only the startup notify is required to be "safe". The shutdown simply
removes the entries from the ftrace function list, and does not modify
any code.

This change has another benefit. It removes a issue with a reverse dependency
in the mutexes of ftrace_lock and module_mutex.

[ Impact: fix lock dependency bug, cleanup ]

Cc: Rusty Russell 
Signed-off-by: Steven Rostedt

Merge branch 'tracing/urgent' into tracing/core

2009-04-10T10:46:51+00:00

Merge reason: pick up both v2.6.30-rc1 [which includes tracing/urgent fixes]
              and pick up the current lineup of tracing/urgent fixes as well

Signed-off-by: Ingo Molnar

tracing/syscalls: use a dedicated file header

2009-04-09T03:43:32+00:00

Impact: fix build warnings and possibe compat misbehavior on IA64

Building a kernel on ia64 might trigger these ugly build warnings:

CC      arch/ia64/ia32/sys_ia32.o
In file included from arch/ia64/ia32/sys_ia32.c:55:
arch/ia64/ia32/ia32priv.h:290:1: warning: "elf_check_arch" redefined
In file included from include/linux/elf.h:7,
                 from include/linux/module.h:14,
                 from include/linux/ftrace.h:8,
                 from include/linux/syscalls.h:68,
                 from arch/ia64/ia32/sys_ia32.c:18:
arch/ia64/include/asm/elf.h:19:1: warning: this is the location of the previous definition
[...]

sys_ia32.c includes linux/syscalls.h which in turn includes linux/ftrace.h
to import the syscalls tracing prototypes.

But including ftrace.h can pull too much things for a low level file,
especially on ia64 where the ia32 private headers conflict with higher
level headers.

Now we isolate the syscall tracing headers in their own lightweight file.

Reported-by: Tony Luck 
Tested-by: Tony Luck 
Signed-off-by: Frederic Weisbecker 
Acked-by: Tony Luck 
Signed-off-by: Steven Rostedt 
Cc: Peter Zijlstra 
Cc: Jason Baron 
Cc: "Frank Ch. Eigler" 
Cc: Mathieu Desnoyers 
Cc: KOSAKI Motohiro 
Cc: Lai Jiangshan 
Cc: Jiaying Zhang 
Cc: Michael Rubin 
Cc: Martin Bligh 
Cc: Michael Davidson 
LKML-Reference: <20090408184058.GB6017@nowhere>
Signed-off-by: Ingo Molnar

tracing: append a comma to INIT_FTRACE_GRAPH

2009-04-08T08:25:25+00:00

Impact: dont break future extensions of INIT_TASK

While not a problem right now, due to lack of a comma, build fails if
elements are appended to INIT_TASK() macro in development code:

 arch/x86/kernel/init_task.c:33: error: request for member `XXXXXXXXXX' in something not a structure or union
 arch/x86/kernel/init_task.c:33: error: initializer element is not constant
 arch/x86/kernel/init_task.c:33: error: (near initialization for `init_task.ret_stack')
 make[1]: *** [arch/x86/kernel/init_task.o] Error 1
 make: *** [arch/x86/kernel] Error 2

Signed-off-by: Tetsuo Handa 
Cc: srostedt@redhat.com
LKML-Reference: <200904080505.n3855hcn017109@www262.sakura.ne.jp>
Signed-off-by: Ingo Molnar

Merge branch 'tracing/urgent' into tracing/ftrace

2009-04-07T12:41:17+00:00