[PATCH 0/4] Do some changes about kprobe

[PATCH 0/4] Do some changes about kprobe

[Tiezhu Yang]

This patchset is based on kprobes kernel tree:
https://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git/ for-next

Tiezhu Yang (4):
  samples/kretprobes: Fix return value if register_kretprobe() failed
  docs, kprobes: Remove invalid URL and add new reference
  test_kprobes: Move it from kernel/ to lib/
  MAINTAINERS: Add git tree and missing files for KPROBES

 Documentation/trace/kprobes.rst     | 2 +-
 MAINTAINERS                         | 3 +++
 kernel/Makefile                     | 1 -
 lib/Makefile                        | 1 +
 {kernel => lib}/test_kprobes.c      | 0
 samples/kprobes/kretprobe_example.c | 2 +-
 6 files changed, 6 insertions(+), 3 deletions(-)
 rename {kernel => lib}/test_kprobes.c (100%)

-- 
2.1.0

[PATCH 1/4] samples/kretprobes: Fix return value if register_kretprobe() failed

[Tiezhu Yang]

Use the actual return value instead of always -1 if register_kretprobe()
failed.

E.g. without this patch:

 # insmod samples/kprobes/kretprobe_example.ko func=no_such_func
 insmod: ERROR: could not insert module samples/kprobes/kretprobe_example.ko: Operation not permitted

With this patch:

 # insmod samples/kprobes/kretprobe_example.ko func=no_such_func
 insmod: ERROR: could not insert module samples/kprobes/kretprobe_example.ko: Unknown symbol in module

Fixes: 804defea1c02 ("Kprobes: move kprobe examples to samples/")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
 samples/kprobes/kretprobe_example.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/samples/kprobes/kretprobe_example.c b/samples/kprobes/kretprobe_example.c
index 5dc1bf3..228321e 100644
--- a/samples/kprobes/kretprobe_example.c
+++ b/samples/kprobes/kretprobe_example.c
@@ -86,7 +86,7 @@ static int __init kretprobe_init(void)
 	ret = register_kretprobe(&my_kretprobe);
 	if (ret < 0) {
 		pr_err("register_kretprobe failed, returned %d\n", ret);
-		return -1;
+		return ret;
 	}
 	pr_info("Planted return probe at %s: %p\n",
 			my_kretprobe.kp.symbol_name, my_kretprobe.kp.addr);
-- 
2.1.0

[PATCH 2/4] docs, kprobes: Remove invalid URL and add new reference

[Tiezhu Yang]

The following reference is invalid, remove it.
https://www.ibm.com/developerworks/library/l-kprobes/index.html

Add the following new reference "An introduction to KProbes":
https://lwn.net/Articles/132196/

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
 Documentation/trace/kprobes.rst | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Documentation/trace/kprobes.rst b/Documentation/trace/kprobes.rst
index 998149c..f318bce 100644
--- a/Documentation/trace/kprobes.rst
+++ b/Documentation/trace/kprobes.rst
@@ -784,6 +784,6 @@ References
 
 For additional information on Kprobes, refer to the following URLs:
 
-- https://www.ibm.com/developerworks/library/l-kprobes/index.html
+- https://lwn.net/Articles/132196/
 - https://www.kernel.org/doc/ols/2006/ols2006v2-pages-109-124.pdf
 
-- 
2.1.0

[PATCH 3/4] test_kprobes: Move it from kernel/ to lib/

[Tiezhu Yang]

Since config KPROBES_SANITY_TEST is in lib/Kconfig.debug, it is better to
let test_kprobes.c in lib/, just like other similar tests found in lib/.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
 kernel/Makefile                | 1 -
 lib/Makefile                   | 1 +
 {kernel => lib}/test_kprobes.c | 0
 3 files changed, 1 insertion(+), 1 deletion(-)
 rename {kernel => lib}/test_kprobes.c (100%)

diff --git a/kernel/Makefile b/kernel/Makefile
index 4df609b..9e4d33d 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -85,7 +85,6 @@ obj-$(CONFIG_PID_NS) += pid_namespace.o
 obj-$(CONFIG_IKCONFIG) += configs.o
 obj-$(CONFIG_IKHEADERS) += kheaders.o
 obj-$(CONFIG_SMP) += stop_machine.o
-obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
 obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
 obj-$(CONFIG_AUDITSYSCALL) += auditsc.o audit_watch.o audit_fsnotify.o audit_tree.o
 obj-$(CONFIG_GCOV_KERNEL) += gcov/
diff --git a/lib/Makefile b/lib/Makefile
index 2cfd339..2c70452 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -100,6 +100,7 @@ obj-$(CONFIG_TEST_MEMINIT) += test_meminit.o
 obj-$(CONFIG_TEST_LOCKUP) += test_lockup.o
 obj-$(CONFIG_TEST_HMM) += test_hmm.o
 obj-$(CONFIG_TEST_FREE_PAGES) += test_free_pages.o
+obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
 
 #
 # CFLAGS for compiling floating point code inside the kernel. x86/Makefile turns
diff --git a/kernel/test_kprobes.c b/lib/test_kprobes.c
similarity index 100%
rename from kernel/test_kprobes.c
rename to lib/test_kprobes.c
-- 
2.1.0

[PATCH 4/4] MAINTAINERS: Add git tree and missing files for KPROBES

[Tiezhu Yang]

There is no git tree for KPROBES in MAINTAINERS, it is not convinent to
rebase, lib/test_kprobes.c and samples/kprobes belong to kprobe, add them.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
---
 MAINTAINERS | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 4372473..0e9bc60 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -10506,10 +10506,13 @@ M:	Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
 M:	"David S. Miller" <davem@davemloft.net>
 M:	Masami Hiramatsu <mhiramat@kernel.org>
 S:	Maintained
+T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git
 F:	Documentation/trace/kprobes.rst
 F:	include/asm-generic/kprobes.h
 F:	include/linux/kprobes.h
 F:	kernel/kprobes.c
+F:	lib/test_kprobes.c
+F:	samples/kprobes
 
 KS0108 LCD CONTROLLER DRIVER
 M:	Miguel Ojeda <ojeda@kernel.org>
-- 
2.1.0

Re: [PATCH 0/4] Do some changes about kprobe

[Masami Hiramatsu]

Hi Tiezhu,

On Mon, 25 Oct 2021 11:30:56 +0800
Tiezhu Yang <yangtiezhu@loongson.cn> wrote:

> This patchset is based on kprobes kernel tree:
> https://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git/ for-next

Sorry for confusion, that is not the kernel branch for kprobes. Currently
the kprobes is maintained under the Steve's tracing tree.

Anyway, some of your patch should be merged. Let me pick it.

Thank you,

> 
> Tiezhu Yang (4):
>   samples/kretprobes: Fix return value if register_kretprobe() failed
>   docs, kprobes: Remove invalid URL and add new reference
>   test_kprobes: Move it from kernel/ to lib/
>   MAINTAINERS: Add git tree and missing files for KPROBES
> 
>  Documentation/trace/kprobes.rst     | 2 +-
>  MAINTAINERS                         | 3 +++
>  kernel/Makefile                     | 1 -
>  lib/Makefile                        | 1 +
>  {kernel => lib}/test_kprobes.c      | 0
>  samples/kprobes/kretprobe_example.c | 2 +-
>  6 files changed, 6 insertions(+), 3 deletions(-)
>  rename {kernel => lib}/test_kprobes.c (100%)
> 
> -- 
> 2.1.0
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>

Re: [PATCH 1/4] samples/kretprobes: Fix return value if register_kretprobe() failed

[Masami Hiramatsu]

On Mon, 25 Oct 2021 11:30:57 +0800
Tiezhu Yang <yangtiezhu@loongson.cn> wrote:

> Use the actual return value instead of always -1 if register_kretprobe()
> failed.
> 
> E.g. without this patch:
> 
>  # insmod samples/kprobes/kretprobe_example.ko func=no_such_func
>  insmod: ERROR: could not insert module samples/kprobes/kretprobe_example.ko: Operation not permitted
> 
> With this patch:
> 
>  # insmod samples/kprobes/kretprobe_example.ko func=no_such_func
>  insmod: ERROR: could not insert module samples/kprobes/kretprobe_example.ko: Unknown symbol in module
> 
> Fixes: 804defea1c02 ("Kprobes: move kprobe examples to samples/")
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>

This looks good to me.

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>

Thanks!

> ---
>  samples/kprobes/kretprobe_example.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/samples/kprobes/kretprobe_example.c b/samples/kprobes/kretprobe_example.c
> index 5dc1bf3..228321e 100644
> --- a/samples/kprobes/kretprobe_example.c
> +++ b/samples/kprobes/kretprobe_example.c
> @@ -86,7 +86,7 @@ static int __init kretprobe_init(void)
>  	ret = register_kretprobe(&my_kretprobe);
>  	if (ret < 0) {
>  		pr_err("register_kretprobe failed, returned %d\n", ret);
> -		return -1;
> +		return ret;
>  	}
>  	pr_info("Planted return probe at %s: %p\n",
>  			my_kretprobe.kp.symbol_name, my_kretprobe.kp.addr);
> -- 
> 2.1.0
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>

Re: [PATCH 2/4] docs, kprobes: Remove invalid URL and add new reference

[Masami Hiramatsu]

On Mon, 25 Oct 2021 11:30:58 +0800
Tiezhu Yang <yangtiezhu@loongson.cn> wrote:

> The following reference is invalid, remove it.
> https://www.ibm.com/developerworks/library/l-kprobes/index.html
> 
> Add the following new reference "An introduction to KProbes":
> https://lwn.net/Articles/132196/

Looks good to me.

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>

Thanks!

> 
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> ---
>  Documentation/trace/kprobes.rst | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/Documentation/trace/kprobes.rst b/Documentation/trace/kprobes.rst
> index 998149c..f318bce 100644
> --- a/Documentation/trace/kprobes.rst
> +++ b/Documentation/trace/kprobes.rst
> @@ -784,6 +784,6 @@ References
>  
>  For additional information on Kprobes, refer to the following URLs:
>  
> -- https://www.ibm.com/developerworks/library/l-kprobes/index.html
> +- https://lwn.net/Articles/132196/
>  - https://www.kernel.org/doc/ols/2006/ols2006v2-pages-109-124.pdf
>  
> -- 
> 2.1.0
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>

Re: [PATCH 3/4] test_kprobes: Move it from kernel/ to lib/

[Masami Hiramatsu]

On Mon, 25 Oct 2021 11:30:59 +0800
Tiezhu Yang <yangtiezhu@loongson.cn> wrote:

> Since config KPROBES_SANITY_TEST is in lib/Kconfig.debug, it is better to
> let test_kprobes.c in lib/, just like other similar tests found in lib/.

This is also good to me. It may be a good timing to move this under the
lib/ because there is KUnit too.

Acked-by: Masami Hiramatsu <mhiramat@kernel.org>

Thank you,

> 
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> ---
>  kernel/Makefile                | 1 -
>  lib/Makefile                   | 1 +
>  {kernel => lib}/test_kprobes.c | 0
>  3 files changed, 1 insertion(+), 1 deletion(-)
>  rename {kernel => lib}/test_kprobes.c (100%)
> 
> diff --git a/kernel/Makefile b/kernel/Makefile
> index 4df609b..9e4d33d 100644
> --- a/kernel/Makefile
> +++ b/kernel/Makefile
> @@ -85,7 +85,6 @@ obj-$(CONFIG_PID_NS) += pid_namespace.o
>  obj-$(CONFIG_IKCONFIG) += configs.o
>  obj-$(CONFIG_IKHEADERS) += kheaders.o
>  obj-$(CONFIG_SMP) += stop_machine.o
> -obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
>  obj-$(CONFIG_AUDIT) += audit.o auditfilter.o
>  obj-$(CONFIG_AUDITSYSCALL) += auditsc.o audit_watch.o audit_fsnotify.o audit_tree.o
>  obj-$(CONFIG_GCOV_KERNEL) += gcov/
> diff --git a/lib/Makefile b/lib/Makefile
> index 2cfd339..2c70452 100644
> --- a/lib/Makefile
> +++ b/lib/Makefile
> @@ -100,6 +100,7 @@ obj-$(CONFIG_TEST_MEMINIT) += test_meminit.o
>  obj-$(CONFIG_TEST_LOCKUP) += test_lockup.o
>  obj-$(CONFIG_TEST_HMM) += test_hmm.o
>  obj-$(CONFIG_TEST_FREE_PAGES) += test_free_pages.o
> +obj-$(CONFIG_KPROBES_SANITY_TEST) += test_kprobes.o
>  
>  #
>  # CFLAGS for compiling floating point code inside the kernel. x86/Makefile turns
> diff --git a/kernel/test_kprobes.c b/lib/test_kprobes.c
> similarity index 100%
> rename from kernel/test_kprobes.c
> rename to lib/test_kprobes.c
> -- 
> 2.1.0
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>

Re: [PATCH 4/4] MAINTAINERS: Add git tree and missing files for KPROBES

[Masami Hiramatsu]

On Mon, 25 Oct 2021 11:31:00 +0800
Tiezhu Yang <yangtiezhu@loongson.cn> wrote:

> There is no git tree for KPROBES in MAINTAINERS, it is not convinent to
> rebase, lib/test_kprobes.c and samples/kprobes belong to kprobe, add them.
> 
> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> ---
>  MAINTAINERS | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 4372473..0e9bc60 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -10506,10 +10506,13 @@ M:	Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
>  M:	"David S. Miller" <davem@davemloft.net>
>  M:	Masami Hiramatsu <mhiramat@kernel.org>
>  S:	Maintained
> +T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git

NACK. As I said, this branch was prepared when I discussed with tip maintainer 
on kretprobe stackfix series but now it has been maintained on Steve's tracing
tree.

Steve, should we put your tree here?

Anyway, I will pick your [1/4]-[3/4].

Thank you,

>  F:	Documentation/trace/kprobes.rst
>  F:	include/asm-generic/kprobes.h
>  F:	include/linux/kprobes.h
>  F:	kernel/kprobes.c
> +F:	lib/test_kprobes.c
> +F:	samples/kprobes
>  
>  KS0108 LCD CONTROLLER DRIVER
>  M:	Miguel Ojeda <ojeda@kernel.org>
> -- 
> 2.1.0
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>

Re: [PATCH 4/4] MAINTAINERS: Add git tree and missing files for KPROBES

[Tiezhu Yang]

On 10/25/2021 02:38 PM, Masami Hiramatsu wrote:
> On Mon, 25 Oct 2021 11:31:00 +0800
> Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
>
>> There is no git tree for KPROBES in MAINTAINERS, it is not convinent to
>> rebase, lib/test_kprobes.c and samples/kprobes belong to kprobe, add them.
>>
>> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
>> ---
>>   MAINTAINERS | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/MAINTAINERS b/MAINTAINERS
>> index 4372473..0e9bc60 100644
>> --- a/MAINTAINERS
>> +++ b/MAINTAINERS
>> @@ -10506,10 +10506,13 @@ M:	Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
>>   M:	"David S. Miller" <davem@davemloft.net>
>>   M:	Masami Hiramatsu <mhiramat@kernel.org>
>>   S:	Maintained
>> +T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git
> NACK. As I said, this branch was prepared when I discussed with tip maintainer
> on kretprobe stackfix series but now it has been maintained on Steve's tracing
> tree.
>
> Steve, should we put your tree here?

If yes, should I update patch #4 and then send a v2 version of this 
patch set?

@@ -10505,11 +10505,16 @@ M:    Naveen N. Rao <naveen.n.rao@linux.ibm.com>
  M:     Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
  M:     "David S. Miller" <davem@davemloft.net>
  M:     Masami Hiramatsu <mhiramat@kernel.org>
+L:     linux-trace-devel@vger.kernel.org
  S:     Maintained
+Q:     https://patchwork.kernel.org/project/linux-trace-devel/list/
+T:     git 
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
  F:     Documentation/trace/kprobes.rst
  F:     include/asm-generic/kprobes.h
  F:     include/linux/kprobes.h
  F:     kernel/kprobes.c
+F:     lib/test_kprobes.c
+F:     samples/kprobes

By the way, it seems that we should also update the TRACING git tree [1]?
If yes, should I send the following change as a new patch #5 in the v2 
version
or do the following change in the above patch #4?

@@ -19065,8 +19070,10 @@ F:     drivers/char/tpm/
  TRACING
  M:     Steven Rostedt <rostedt@goodmis.org>
  M:     Ingo Molnar <mingo@redhat.com>
+L:     linux-trace-devel@vger.kernel.org
  S:     Maintained
-T:     git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 
perf/core
+Q:     https://patchwork.kernel.org/project/linux-trace-devel/list/
+T:     git 
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
  F:     Documentation/trace/ftrace.rst
  F:     arch/*/*/*/ftrace.h
  F:     arch/*/kernel/ftrace.c

  [1] 
https://lore.kernel.org/lkml/20211019091344.65629198@gandalf.local.home/

  Thanks,
  Tiezhu

>
> Anyway, I will pick your [1/4]-[3/4].
>
> Thank you,
>
>>   F:	Documentation/trace/kprobes.rst
>>   F:	include/asm-generic/kprobes.h
>>   F:	include/linux/kprobes.h
>>   F:	kernel/kprobes.c
>> +F:	lib/test_kprobes.c
>> +F:	samples/kprobes
>>   
>>   KS0108 LCD CONTROLLER DRIVER
>>   M:	Miguel Ojeda <ojeda@kernel.org>
>> -- 
>> 2.1.0
>>
>

Re: [PATCH 4/4] MAINTAINERS: Add git tree and missing files for KPROBES

[Steven Rostedt]

On Mon, 25 Oct 2021 16:31:07 +0800
Tiezhu Yang <yangtiezhu@loongson.cn> wrote:

> On 10/25/2021 02:38 PM, Masami Hiramatsu wrote:
> > On Mon, 25 Oct 2021 11:31:00 +0800
> > Tiezhu Yang <yangtiezhu@loongson.cn> wrote:
> >  
> >> There is no git tree for KPROBES in MAINTAINERS, it is not convinent to
> >> rebase, lib/test_kprobes.c and samples/kprobes belong to kprobe, add them.
> >>
> >> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
> >> ---
> >>   MAINTAINERS | 3 +++
> >>   1 file changed, 3 insertions(+)
> >>
> >> diff --git a/MAINTAINERS b/MAINTAINERS
> >> index 4372473..0e9bc60 100644
> >> --- a/MAINTAINERS
> >> +++ b/MAINTAINERS
> >> @@ -10506,10 +10506,13 @@ M:	Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
> >>   M:	"David S. Miller" <davem@davemloft.net>
> >>   M:	Masami Hiramatsu <mhiramat@kernel.org>
> >>   S:	Maintained
> >> +T:	git git://git.kernel.org/pub/scm/linux/kernel/git/mhiramat/linux.git  
> > NACK. As I said, this branch was prepared when I discussed with tip maintainer
> > on kretprobe stackfix series but now it has been maintained on Steve's tracing
> > tree.
> >
> > Steve, should we put your tree here?  
> 

I'm fine if kprobes goes through my tree.

> If yes, should I update patch #4 and then send a v2 version of this 
> patch set?
> 
> @@ -10505,11 +10505,16 @@ M:    Naveen N. Rao <naveen.n.rao@linux.ibm.com>
>   M:     Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
>   M:     "David S. Miller" <davem@davemloft.net>
>   M:     Masami Hiramatsu <mhiramat@kernel.org>
> +L:     linux-trace-devel@vger.kernel.org

Please do not add the above mailing list. That's more for tracing tools
like trace-cmd, kernelshark and the libtracefs/libtraceevent libraries.
Only API changes (additions) should go to that list. Not internal updates.

>   S:     Maintained
> +Q:     https://patchwork.kernel.org/project/linux-trace-devel/list/

And this too is for the tracing tools, not the kernel. The patches status
on that patchwork do not get updated by changes to the kernel. Only changes
to the libraries and tool git trees will update those patches.

> +T:     git 
> git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
>   F:     Documentation/trace/kprobes.rst
>   F:     include/asm-generic/kprobes.h
>   F:     include/linux/kprobes.h
>   F:     kernel/kprobes.c
> +F:     lib/test_kprobes.c
> +F:     samples/kprobes
> 
> By the way, it seems that we should also update the TRACING git tree [1]?
> If yes, should I send the following change as a new patch #5 in the v2 
> version
> or do the following change in the above patch #4?
> 
> @@ -19065,8 +19070,10 @@ F:     drivers/char/tpm/
>   TRACING
>   M:     Steven Rostedt <rostedt@goodmis.org>
>   M:     Ingo Molnar <mingo@redhat.com>
> +L:     linux-trace-devel@vger.kernel.org

Again, don't add that list.

>   S:     Maintained
> -T:     git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 
> perf/core
> +Q:     https://patchwork.kernel.org/project/linux-trace-devel/list/

Nor the patchwork.

> +T:     git 
> git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace.git
>   F:     Documentation/trace/ftrace.rst
>   F:     arch/*/*/*/ftrace.h
>   F:     arch/*/kernel/ftrace.c
> 

-- Steve