Re: [PATCH v2 3.5/5] trace/kprobes: Add back warning about offset in return probes

From: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
To: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org,
	Arnaldo Carvalho de Melo <acme@kernel.org>,
	Masami Hiramatsu <mhiramat@kernel.org>,
	linuxppc-dev@lists.ozlabs.org, Ingo Molnar <mingo@redhat.com>
Subject: Re: [PATCH v2 3.5/5] trace/kprobes: Add back warning about offset in return probes
Date: Wed, 1 Mar 2017 20:46:59 +0530	[thread overview]
Message-ID: <20170301151659.GO4212@naverao1-tp.localdomain> (raw)
In-Reply-To: <20170227115204.00f92846@gandalf.local.home>

On 2017/02/27 11:52AM, Steven Rostedt (VMware) wrote:
> Let's not remove the warning about offsets and return probes when the
> offset is invalid.

Good point!

Thanks, Steve!

> 
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Acked-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>

> ---
> diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
> index 3f4f788..f626235 100644
> --- a/kernel/trace/trace_kprobe.c
> +++ b/kernel/trace/trace_kprobe.c
> @@ -695,6 +695,11 @@ static int create_trace_kprobe(int argc, char **argv)
>  			pr_info("Failed to parse symbol.\n");
>  			return ret;
>  		}
> +		if (offset && is_return &&
> +		    !arch_function_offset_within_entry(offset)) {
> +			pr_info("Given offset is not valid for return probe.\n");
> +			return -EINVAL;
> +		}
>  	}
>  	argc -= 2; argv += 2;
> 
> 