[TRIVIAL PATCH 0/2] kprobes: a couple of trivial changes

[TRIVIAL PATCH 0/2] kprobes: a couple of trivial changes

[Naveen N. Rao]

Two trivial fixes for kprobes:
- one, to document NOKPROBE_SYMBOL() in kprobe tracer doc
- two, change __kprobes to NOKPROBE_SYMBOL() for
  kprobe_exceptions_notify()

I noticed the latter while making this change for arch/powerpc.

- Naveen

Naveen N. Rao (2):
  doc: trace/kprobes: add information about NOKPROBE_SYMBOL
  kprobes: Convert kprobe_exceptions_notify to use NOKPROBE_SYMBOL

 Documentation/trace/kprobetrace.txt | 5 +++--
 kernel/kprobes.c                    | 5 +++--
 2 files changed, 6 insertions(+), 4 deletions(-)

-- 
2.11.1

[TRIVIAL PATCH 1/2] doc: trace/kprobes: add information about NOKPROBE_SYMBOL

[Naveen N. Rao]

Update kprobe tracer documentation to also mention that
NOKPROBE_SYMBOL() and nokprobe_inline add symbols to the kprobes
blacklist.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
 Documentation/trace/kprobetrace.txt | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt
index 41ef9d8efe95..5ea85059db3b 100644
--- a/Documentation/trace/kprobetrace.txt
+++ b/Documentation/trace/kprobetrace.txt
@@ -8,8 +8,9 @@ Overview
 --------
 These events are similar to tracepoint based events. Instead of Tracepoint,
 this is based on kprobes (kprobe and kretprobe). So it can probe wherever
-kprobes can probe (this means, all functions body except for __kprobes
-functions). Unlike the Tracepoint based event, this can be added and removed
+kprobes can probe (this means, all functions except those with
+__kprobes/nokprobe_inline annotation and those marked NOKPROBE_SYMBOL).
+Unlike the Tracepoint based event, this can be added and removed
 dynamically, on the fly.
 
 To enable this feature, build your kernel with CONFIG_KPROBE_EVENTS=y.
-- 
2.11.1

[TRIVIAL PATCH 2/2] kprobes: Convert kprobe_exceptions_notify to use NOKPROBE_SYMBOL

[Naveen N. Rao]

commit fc62d0207ae0 ("kprobes: Introduce weak variant of
kprobe_exceptions_notify()") used the __kprobes annotation to exclude
kprobe_exceptions_notify from being probed. Since NOKPROBE_SYMBOL() is a
better way to do this enabling the symbol to be discovered as being
blacklisted, change over to using NOKPROBE_SYMBOL().

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
---
 kernel/kprobes.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 699c5bc51a92..b52d952d6d41 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1740,11 +1740,12 @@ void unregister_kprobes(struct kprobe **kps, int num)
 }
 EXPORT_SYMBOL_GPL(unregister_kprobes);
 
-int __weak __kprobes kprobe_exceptions_notify(struct notifier_block *self,
-					      unsigned long val, void *data)
+int __weak kprobe_exceptions_notify(struct notifier_block *self,
+					unsigned long val, void *data)
 {
 	return NOTIFY_DONE;
 }
+NOKPROBE_SYMBOL(kprobe_exceptions_notify);
 
 static struct notifier_block kprobe_exceptions_nb = {
 	.notifier_call = kprobe_exceptions_notify,
-- 
2.11.1

Re: [TRIVIAL PATCH 2/2] kprobes: Convert kprobe_exceptions_notify to use NOKPROBE_SYMBOL

[Masami Hiramatsu]

On Wed,  8 Mar 2017 22:34:15 +0530
"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> wrote:

> commit fc62d0207ae0 ("kprobes: Introduce weak variant of
> kprobe_exceptions_notify()") used the __kprobes annotation to exclude
> kprobe_exceptions_notify from being probed. Since NOKPROBE_SYMBOL() is a
> better way to do this enabling the symbol to be discovered as being
> blacklisted, change over to using NOKPROBE_SYMBOL().
> 

Oops, yes it should be.

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

Thanks,

> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
> ---
>  kernel/kprobes.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index 699c5bc51a92..b52d952d6d41 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -1740,11 +1740,12 @@ void unregister_kprobes(struct kprobe **kps, int num)
>  }
>  EXPORT_SYMBOL_GPL(unregister_kprobes);
>  
> -int __weak __kprobes kprobe_exceptions_notify(struct notifier_block *self,
> -					      unsigned long val, void *data)
> +int __weak kprobe_exceptions_notify(struct notifier_block *self,
> +					unsigned long val, void *data)
>  {
>  	return NOTIFY_DONE;
>  }
> +NOKPROBE_SYMBOL(kprobe_exceptions_notify);
>  
>  static struct notifier_block kprobe_exceptions_nb = {
>  	.notifier_call = kprobe_exceptions_notify,
> -- 
> 2.11.1
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>

Re: [TRIVIAL PATCH 1/2] doc: trace/kprobes: add information about NOKPROBE_SYMBOL

[Masami Hiramatsu]

On Wed,  8 Mar 2017 22:34:14 +0530
"Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> wrote:

> Update kprobe tracer documentation to also mention that
> NOKPROBE_SYMBOL() and nokprobe_inline add symbols to the kprobes
> blacklist.

Thanks for update!

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

> 
> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
> ---
>  Documentation/trace/kprobetrace.txt | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt
> index 41ef9d8efe95..5ea85059db3b 100644
> --- a/Documentation/trace/kprobetrace.txt
> +++ b/Documentation/trace/kprobetrace.txt
> @@ -8,8 +8,9 @@ Overview
>  --------
>  These events are similar to tracepoint based events. Instead of Tracepoint,
>  this is based on kprobes (kprobe and kretprobe). So it can probe wherever
> -kprobes can probe (this means, all functions body except for __kprobes
> -functions). Unlike the Tracepoint based event, this can be added and removed
> +kprobes can probe (this means, all functions except those with
> +__kprobes/nokprobe_inline annotation and those marked NOKPROBE_SYMBOL).
> +Unlike the Tracepoint based event, this can be added and removed
>  dynamically, on the fly.
>  
>  To enable this feature, build your kernel with CONFIG_KPROBE_EVENTS=y.
> -- 
> 2.11.1
> 


-- 
Masami Hiramatsu <mhiramat@kernel.org>

[tip:perf/core] doc: trace/kprobes: add information about NOKPROBE_SYMBOL

[tip-bot for Naveen N. Rao]

Commit-ID:  c1ac094d5061e757624a47217d2195ba24a75450
Gitweb:     http://git.kernel.org/tip/c1ac094d5061e757624a47217d2195ba24a75450
Author:     Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
AuthorDate: Wed, 8 Mar 2017 22:34:14 +0530
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 14 Mar 2017 15:17:40 -0300

doc: trace/kprobes: add information about NOKPROBE_SYMBOL

Update kprobe tracer documentation to also mention that
NOKPROBE_SYMBOL() and nokprobe_inline add symbols to the kprobes
blacklist.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/d924e20de099579ace4286e610304f054cd798db.1488991670.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 Documentation/trace/kprobetrace.txt | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/Documentation/trace/kprobetrace.txt b/Documentation/trace/kprobetrace.txt
index 41ef9d8..5ea8505 100644
--- a/Documentation/trace/kprobetrace.txt
+++ b/Documentation/trace/kprobetrace.txt
@@ -8,8 +8,9 @@ Overview
 --------
 These events are similar to tracepoint based events. Instead of Tracepoint,
 this is based on kprobes (kprobe and kretprobe). So it can probe wherever
-kprobes can probe (this means, all functions body except for __kprobes
-functions). Unlike the Tracepoint based event, this can be added and removed
+kprobes can probe (this means, all functions except those with
+__kprobes/nokprobe_inline annotation and those marked NOKPROBE_SYMBOL).
+Unlike the Tracepoint based event, this can be added and removed
 dynamically, on the fly.
 
 To enable this feature, build your kernel with CONFIG_KPROBE_EVENTS=y.

[tip:perf/core] kprobes: Convert kprobe_exceptions_notify to use NOKPROBE_SYMBOL

[tip-bot for Naveen N. Rao]

Commit-ID:  5f6bee34707973ea7879a7857fd63ddccc92fff3
Gitweb:     http://git.kernel.org/tip/5f6bee34707973ea7879a7857fd63ddccc92fff3
Author:     Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
AuthorDate: Wed, 8 Mar 2017 22:34:15 +0530
Committer:  Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Tue, 14 Mar 2017 15:17:40 -0300

kprobes: Convert kprobe_exceptions_notify to use NOKPROBE_SYMBOL

commit fc62d0207ae0 ("kprobes: Introduce weak variant of
kprobe_exceptions_notify()") used the __kprobes annotation to exclude
kprobe_exceptions_notify from being probed. Since NOKPROBE_SYMBOL() is a
better way to do this enabling the symbol to be discovered as being
blacklisted, change over to using NOKPROBE_SYMBOL().

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ananth N Mavinakayanahalli <ananth@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/3f25bf400da5c222cd9b10eec6ded2d6b58209f8.1488991670.git.naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
 kernel/kprobes.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index 448759d..4780ec23 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -1740,11 +1740,12 @@ void unregister_kprobes(struct kprobe **kps, int num)
 }
 EXPORT_SYMBOL_GPL(unregister_kprobes);
 
-int __weak __kprobes kprobe_exceptions_notify(struct notifier_block *self,
-					      unsigned long val, void *data)
+int __weak kprobe_exceptions_notify(struct notifier_block *self,
+					unsigned long val, void *data)
 {
 	return NOTIFY_DONE;
 }
+NOKPROBE_SYMBOL(kprobe_exceptions_notify);
 
 static struct notifier_block kprobe_exceptions_nb = {
 	.notifier_call = kprobe_exceptions_notify,