2009-03-19 21:12:09

by Masami Hiramatsu

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Subject: [RFC][PATCH -tip 9/9] tracing: kprobe-tracer plugin supports module_probe

Use register/unregister_module_*probe functions for tracing
module .init/.exit functions.

Signed-off-by: Masami Hiramatsu <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Ananth N Mavinakayanahalli <[email protected]>
Cc: Ingo Molnar <[email protected]>
---
kernel/trace/trace_kprobe.c | 15 ++++++++++-----
1 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index e801e8c..7b7ab53 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -226,6 +226,11 @@ static void free_trace_probe(struct trace_probe *tp)
kfree(tp);
}

+static int activate_handler(void *offset, struct module *mod)
+{
+ return ((unsigned long)offset == 0) ? 1 : 0;
+}
+
static int register_trace_probe(struct trace_probe *tp)
{
int ret;
@@ -234,9 +239,10 @@ static int register_trace_probe(struct trace_probe *tp)
list_add_tail(&tp->list, &probe_list);

if (probe_is_return(tp))
- ret = register_kretprobe(&tp->rp);
+ ret = register_module_kretprobe(&tp->rp, activate_handler, 0);
else
- ret = register_kprobe(&tp->kp);
+ ret = register_module_kprobe(&tp->kp, activate_handler,
+ (void *)(tp->kp.offset));

if (ret) {
pr_warning("Probe registering error: %d\n", ret);
@@ -249,9 +255,9 @@ static int register_trace_probe(struct trace_probe *tp)
static void unregister_trace_probe(struct trace_probe *tp)
{
if (probe_is_return(tp))
- unregister_kretprobe(&tp->rp);
+ unregister_module_kretprobe(&tp->rp);
else
- unregister_kprobe(&tp->kp);
+ unregister_module_kprobe(&tp->kp);
list_del(&tp->list);
}

@@ -301,7 +307,6 @@ static int create_trace_probe(int argc, char **argv)
} else {
/* a symbol specified */
symbol = argv[1];
- /* TODO: support .init module functions */
tmp = strchr(symbol, '+');
if (!tmp)
tmp = strchr(symbol, '-');
--
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division

e-mail: [email protected]


2009-03-20 00:08:44

by Steven Rostedt

[permalink] [raw]
Subject: Re: [RFC][PATCH -tip 9/9] tracing: kprobe-tracer plugin supports module_probe


On Thu, 19 Mar 2009, Masami Hiramatsu wrote:

> Use register/unregister_module_*probe functions for tracing
> module .init/.exit functions.
>
> Signed-off-by: Masami Hiramatsu <[email protected]>
> Cc: Steven Rostedt <[email protected]>
> Cc: Ananth N Mavinakayanahalli <[email protected]>
> Cc: Ingo Molnar <[email protected]>
> ---
> kernel/trace/trace_kprobe.c | 15 ++++++++++-----
> 1 files changed, 10 insertions(+), 5 deletions(-)
>
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index e801e8c..7b7ab53 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -226,6 +226,11 @@ static void free_trace_probe(struct trace_probe *tp)
> kfree(tp);
> }
>
> +static int activate_handler(void *offset, struct module *mod)
> +{
> + return ((unsigned long)offset == 0) ? 1 : 0;

This is a strange way to implement:

return !offset;

-- Steve

> +}
> +
> static int register_trace_probe(struct trace_probe *tp)
> {
> int ret;
> @@ -234,9 +239,10 @@ static int register_trace_probe(struct trace_probe *tp)
> list_add_tail(&tp->list, &probe_list);
>
> if (probe_is_return(tp))
> - ret = register_kretprobe(&tp->rp);
> + ret = register_module_kretprobe(&tp->rp, activate_handler, 0);
> else
> - ret = register_kprobe(&tp->kp);
> + ret = register_module_kprobe(&tp->kp, activate_handler,
> + (void *)(tp->kp.offset));
>
> if (ret) {
> pr_warning("Probe registering error: %d\n", ret);
> @@ -249,9 +255,9 @@ static int register_trace_probe(struct trace_probe *tp)
> static void unregister_trace_probe(struct trace_probe *tp)
> {
> if (probe_is_return(tp))
> - unregister_kretprobe(&tp->rp);
> + unregister_module_kretprobe(&tp->rp);
> else
> - unregister_kprobe(&tp->kp);
> + unregister_module_kprobe(&tp->kp);
> list_del(&tp->list);
> }
>
> @@ -301,7 +307,6 @@ static int create_trace_probe(int argc, char **argv)
> } else {
> /* a symbol specified */
> symbol = argv[1];
> - /* TODO: support .init module functions */
> tmp = strchr(symbol, '+');
> if (!tmp)
> tmp = strchr(symbol, '-');
> --
> Masami Hiramatsu
>
> Software Engineer
> Hitachi Computer Products (America) Inc.
> Software Solutions Division
>
> e-mail: [email protected]
>
>
>

2009-03-20 03:57:12

by Masami Hiramatsu

[permalink] [raw]
Subject: Re: [RFC][PATCH -tip 9/9] tracing: kprobe-tracer plugin supports module_probe

Steven Rostedt wrote:
> On Thu, 19 Mar 2009, Masami Hiramatsu wrote:
>
>> Use register/unregister_module_*probe functions for tracing
>> module .init/.exit functions.
>>
>> Signed-off-by: Masami Hiramatsu <[email protected]>
>> Cc: Steven Rostedt <[email protected]>
>> Cc: Ananth N Mavinakayanahalli <[email protected]>
>> Cc: Ingo Molnar <[email protected]>
>> ---
>> kernel/trace/trace_kprobe.c | 15 ++++++++++-----
>> 1 files changed, 10 insertions(+), 5 deletions(-)
>>
>> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
>> index e801e8c..7b7ab53 100644
>> --- a/kernel/trace/trace_kprobe.c
>> +++ b/kernel/trace/trace_kprobe.c
>> @@ -226,6 +226,11 @@ static void free_trace_probe(struct trace_probe *tp)
>> kfree(tp);
>> }
>>
>> +static int activate_handler(void *offset, struct module *mod)
>> +{
>> + return ((unsigned long)offset == 0) ? 1 : 0;
>
> This is a strange way to implement:
>
> return !offset;

Yes. Thanks!

>
> -- Steve
>
>> +}
>> +
>> static int register_trace_probe(struct trace_probe *tp)
>> {
>> int ret;
>> @@ -234,9 +239,10 @@ static int register_trace_probe(struct trace_probe *tp)
>> list_add_tail(&tp->list, &probe_list);
>>
>> if (probe_is_return(tp))
>> - ret = register_kretprobe(&tp->rp);
>> + ret = register_module_kretprobe(&tp->rp, activate_handler, 0);
>> else
>> - ret = register_kprobe(&tp->kp);
>> + ret = register_module_kprobe(&tp->kp, activate_handler,
>> + (void *)(tp->kp.offset));
>>
>> if (ret) {
>> pr_warning("Probe registering error: %d\n", ret);
>> @@ -249,9 +255,9 @@ static int register_trace_probe(struct trace_probe *tp)
>> static void unregister_trace_probe(struct trace_probe *tp)
>> {
>> if (probe_is_return(tp))
>> - unregister_kretprobe(&tp->rp);
>> + unregister_module_kretprobe(&tp->rp);
>> else
>> - unregister_kprobe(&tp->kp);
>> + unregister_module_kprobe(&tp->kp);
>> list_del(&tp->list);
>> }
>>
>> @@ -301,7 +307,6 @@ static int create_trace_probe(int argc, char **argv)
>> } else {
>> /* a symbol specified */
>> symbol = argv[1];
>> - /* TODO: support .init module functions */
>> tmp = strchr(symbol, '+');
>> if (!tmp)
>> tmp = strchr(symbol, '-');
>> --
>> Masami Hiramatsu
>>
>> Software Engineer
>> Hitachi Computer Products (America) Inc.
>> Software Solutions Division
>>
>> e-mail: [email protected]
>>
>>
>>

--
Masami Hiramatsu

Software Engineer
Hitachi Computer Products (America) Inc.
Software Solutions Division

e-mail: [email protected]