On Sun, Apr 08, 2007 at 11:22:31AM +0100, Christoph Hellwig wrote:
> On Wed, Apr 04, 2007 at 05:43:49PM +0530, Ananth N Mavinakayanahalli wrote:
> > This patch provides a debugfs knob to turn kprobes on/off
> >
> > o A new file /debug/kprobes/enabled indicates if kprobes is enabled or
> > not (default enabled)
> > o Echoing 0 to this file will disarm all installed probes
> > o Any new probe registration when disabled will register the probe but
> > not arm it. A message will be printed out in such a case.
> > o When a value 1 is echoed to the file, all probes (including ones
> > registered in the intervening period) will be enabled
> > o Unregistration will happen irrespective of whether probes are globally
> > enabled or not.
> > o Update Documentation/kprobes.txt to reflect these changes. While there
> > also update the doc to make it current.
>
> Looks good.
>
> When I suggested a user interface to enable/disable probes was nice to
> have I was more thinking about a interface to enable/disable individual
> probes. Any chance you could try to implement that aswell as see if
> any code can be shared with this feature?
Thats on the TODO list - any preferences on what the debugfs control
should look like? One file per kprobe seems simplest, but it'd be
unwieldly if there are hundreds of active probes.
> > - arch_arm_kprobe(p);
> > + arch_arm_kprobe(p);
> > + } else
> > + printk("Kprobes are globally disabled. This kprobe [@ %p] "
> > + "will be enabled with all other probes\n", p->addr);
>
> This printk seems far too verbose. Just remove it and make sure
> the debugfs interface has an indicator of whether probes are en- or
> disabled.
Agreed... and "enabled" file is the indicator.
Andrew, please include this incremental patch against 2.6.21-rc6-mm1
that removes the verbose printk.
o Remove verbose printk during registration with kprobes globally
disabled
o Print out a message when kprobes are enabled/disabled globally
Signed-off-by: Ananth N Mavinakyanahalli <[EMAIL PROTECTED]>
---
kernel/kprobes.c | 7 +++----
1 files changed, 3 insertions(+), 4 deletions(-)
Index: linux-2.6.21-rc6/kernel/kprobes.c
===================================================================
--- linux-2.6.21-rc6.orig/kernel/kprobes.c
+++ linux-2.6.21-rc6/kernel/kprobes.c
@@ -574,10 +574,7 @@ static int __kprobes __register_kprobe(s
register_page_fault_notifier(&kprobe_page_fault_nb);
arch_arm_kprobe(p);
- } else
- printk("Kprobes are globally disabled. This kprobe [@ %p] "
- "will be enabled with all other probes\n", p->addr);
-
+ }
out:
mutex_unlock(&kprobe_mutex);
@@ -928,6 +925,7 @@ static void __kprobes enable_all_kprobes
}
kprobe_enabled = true;
+ printk("Kprobes globally enabled\n");
already_enabled:
mutex_unlock(&kprobe_mutex);
@@ -948,6 +946,7 @@ static void __kprobes disable_all_kprobe
goto already_disabled;
kprobe_enabled = false;
+ printk("Kprobes globally disabled\n");
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = &kprobe_table[i];
hlist_for_each_entry_rcu(p, node, head, hlist) {
-
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