Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757982Ab3CTDSu (ORCPT ); Tue, 19 Mar 2013 23:18:50 -0400 Received: from mail-pb0-f51.google.com ([209.85.160.51]:49983 "EHLO mail-pb0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757967Ab3CTDSk (ORCPT ); Tue, 19 Mar 2013 23:18:40 -0400 From: kpark3469@gmail.com To: rostedt@goodmis.org Cc: keun-o.park@windriver.com, linux-kernel@vger.kernel.org, kpark3469@gmail.com Subject: [PATCH] tracepoints: prevents null probe from being added Date: Wed, 20 Mar 2013 12:18:17 +0900 Message-Id: <1363749497-12176-1-git-send-email-kpark3469@gmail.com> X-Mailer: git-send-email 1.7.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2424 Lines: 74 From: Sahara Somehow tracepoint_entry_add/remove_probe functions allow a null probe function. Especially on getting a null probe in remove function, it seems to be used to remove all probe functions in the entry. But, the code is not handled as expected. Since the tracepoint_entry maintains funcs array's last func as NULL in order to mark it as the end of the array. Also NULL func is used in for-loop to check out the end of the loop. So if there's NULL func in the entry's funcs, the for-loop will be abruptly ended in the middle of operation. Also checking out if probe is null in for-loop is not efficient. Signed-off-by: Sahara --- kernel/tracepoint.c | 18 ++++++++++++------ 1 files changed, 12 insertions(+), 6 deletions(-) diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 0c05a45..30f427e 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -112,7 +112,10 @@ tracepoint_entry_add_probe(struct tracepoint_entry *entry, int nr_probes = 0; struct tracepoint_func *old, *new; - WARN_ON(!probe); + if (unlikely(!probe)) { + WARN_ON(!probe); + return ERR_PTR(-EINVAL); + } debug_print_probes(entry); old = entry->funcs; @@ -147,15 +150,19 @@ tracepoint_entry_remove_probe(struct tracepoint_entry *entry, old = entry->funcs; + if (unlikely(!probe)) { + WARN_ON(!probe); + return ERR_PTR(-EINVAL); + } + if (!old) return ERR_PTR(-ENOENT); debug_print_probes(entry); /* (N -> M), (N > 1, M >= 0) probes */ for (nr_probes = 0; old[nr_probes].func; nr_probes++) { - if (!probe || - (old[nr_probes].func == probe && - old[nr_probes].data == data)) + if (old[nr_probes].func == probe && + old[nr_probes].data == data) nr_del++; } @@ -173,8 +180,7 @@ tracepoint_entry_remove_probe(struct tracepoint_entry *entry, if (new == NULL) return ERR_PTR(-ENOMEM); for (i = 0; old[i].func; i++) - if (probe && - (old[i].func != probe || old[i].data != data)) + if (old[i].func != probe || old[i].data != data) new[j++] = old[i]; new[nr_probes - nr_del].func = NULL; entry->refcount = nr_probes - nr_del; -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/