Re: [PATCH v2] Return proper error code from register_kprobe()

[Andrew Morton <akpm@linux-foundation.org>]

On Wed, 15 Feb 2012 12:46:03 +0530
Prashanth Nageshappa <prashanth@linux.vnet.ibm.com> wrote:

> register_kprobe() aborts if the address of the new request falls in a
> prohibited area (such as ftrace pouch, __kprobes annotated functions,

I'm sitting here wondering what you meant to type when you typed
"ftrace pouch".  I'm stumped!  But you're not allowed to tell us - that
would take all the fun out of it.

> non-kernel text addresses, jump label text). We however don't return the
> right error on this abort, resulting in a silent failure - incorrect 
> adding/reporting of kprobes ('perf probe do_fork+18' or
> 'perf probe mcount' for instance).
> 
> In V2 we are incorporating Masami Hiramatsu's  feedback.
> 
> This patch fixes it by returning -EINVAL upon failure.
> 
> While we are here, rename the label used for exit to be more appropriate.
> 
> Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
> Signed-off-by: Prashanth K Nageshappa <prashanth@linux.vnet.ibm.com>
> Cc: stable@vger.kernel.org

So we want this for 3.3 with a -stable backport.