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SubjectHow can I check creator of probe point?

Hi,

I am trying to find a way to make statistics for memory allocation of my device driver.
I want to know how much memory it allocates and how many times it calls kmalloc().

So I am considering to use kprobe but I think it doesn't provide a way to identify who makes the probe point.
Can I distinguish kmalloc() calling only from my driver?

For example I think it could be like this:

diff --git a/samples/kprobes/kretprobe_example.c b/samples/kprobes/kretprobe_example.c
index 1041b67..5322e0a 100644
--- a/samples/kprobes/kretprobe_example.c
+++ b/samples/kprobes/kretprobe_example.c
@@ -32,6 +32,7 @@ MODULE_PARM_DESC(func, "Function to kretprobe; this module will report the"

/* per-instance private data */
struct my_data {
+ unsigned long signature;
ktime_t entry_stamp;
};

@@ -43,8 +44,10 @@ static int entry_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
if (!current->mm)
return 1; /* Skip kernel threads */

- data = (struct my_data *)ri->data;
- data->entry_stamp = ktime_get();
+ if (signature == 0xabcdabcd) {
+ data = (struct my_data *)ri->data;
+ data->entry_stamp = ktime_get();
+ }
return 0;
}

@@ -60,10 +63,12 @@ static int ret_handler(struct kretprobe_instance *ri, struct pt_regs *regs)
s64 delta;
ktime_t now;

- now = ktime_get();
- delta = ktime_to_ns(ktime_sub(now, data->entry_stamp));
- printk(KERN_INFO "%s returned %d and took %lld ns to execute\n",
- func_name, retval, (long long)delta);
+ if (signature == 0xabcdabcd) {
+ now = ktime_get();
+ delta = ktime_to_ns(ktime_sub(now, data->entry_stamp));
+ printk(KERN_INFO "%s returned %d and took %lld ns to execute\n",
+ func_name, retval, (long long)delta);
+ }
return 0;
}

--
Thanks,
Gioh Kim


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