From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <4F3A5564.1080607@hitachi.com> Date: Tue, 14 Feb 2012 21:36:52 +0900 From: Masami Hiramatsu MIME-Version: 1.0 To: Prashanth Nageshappa Cc: linux-kernel@vger.kernel.org, ananth@in.ibm.com, akpm@linux-foundation.org, jbaron@redhat.com, rostedt@goodmis.org, srikar@linux.vnet.ibm.com, stable@vger.kernel.org Subject: Re: [PATCH] Return proper error code from register_kprobe() References: <4F3A3D30.5010506@linux.vnet.ibm.com> In-Reply-To: <4F3A3D30.5010506@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: (2012/02/14 19:53), Prashanth Nageshappa wrote: > register_kprobe() aborts if the address of the new request falls in a prohibited > area (such as ftrace pouch, __kprobes annotated functions, non-kernel text > addresses, jump label text). We however don't return the right error on this > abort, resulting in incorrect adding/reporting of kprobes (Ex: 'perf probe > do_fork+18' or 'perf probe mcount') OK, I see. > > This patch fixes it by returning -EINVAL upon failure. > > Signed-off-by: Ananth N Mavinakayanahalli > Signed-off-by: Prashanth K Nageshappa However, I can't agree with this change :(, because this ignores possibilities of -ENOENT error code in other error paths. What I'm expecting is, setup an error code where the error occurs, as below; jump_label_lock(); preempt_disable(); if (!kernel_text_address((unsigned long) p->addr) || in_kprobes_functions((unsigned long) p->addr) || ftrace_text_reserved(p->addr, p->addr) || - jump_label_text_reserved(p->addr, p->addr)) + jump_label_text_reserved(p->addr, p->addr)) { + ret = -EINVAL; goto fail_with_jump_label; + } IMHO, we should change the label name too... Thank you, -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com