From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:39989 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752271AbbFWD1F (ORCPT ); Mon, 22 Jun 2015 23:27:05 -0400 Subject: Patch "tracing: Have filter check for balanced ops" has been added to the 3.14-stable tree To: rostedt@goodmis.org Cc: , From: Date: Mon, 22 Jun 2015 20:22:01 -0700 Message-ID: <1435029721180139@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled tracing: Have filter check for balanced ops to the 3.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: tracing-have-filter-check-for-balanced-ops.patch and it can be found in the queue-3.14 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 2cf30dc180cea808077f003c5116388183e54f9e Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 15 Jun 2015 17:50:25 -0400 Subject: tracing: Have filter check for balanced ops From: Steven Rostedt commit 2cf30dc180cea808077f003c5116388183e54f9e upstream. When the following filter is used it causes a warning to trigger: # cd /sys/kernel/debug/tracing # echo "((dev==1)blocks==2)" > events/ext4/ext4_truncate_exit/filter -bash: echo: write error: Invalid argument # cat events/ext4/ext4_truncate_exit/filter ((dev==1)blocks==2) ^ parse_error: No error ------------[ cut here ]------------ WARNING: CPU: 2 PID: 1223 at kernel/trace/trace_events_filter.c:1640 replace_preds+0x3c5/0x990() Modules linked in: bnep lockd grace bluetooth ... CPU: 3 PID: 1223 Comm: bash Tainted: G W 4.1.0-rc3-test+ #450 Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v02.05 05/07/2012 0000000000000668 ffff8800c106bc98 ffffffff816ed4f9 ffff88011ead0cf0 0000000000000000 ffff8800c106bcd8 ffffffff8107fb07 ffffffff8136b46c ffff8800c7d81d48 ffff8800d4c2bc00 ffff8800d4d4f920 00000000ffffffea Call Trace: [] dump_stack+0x4c/0x6e [] warn_slowpath_common+0x97/0xe0 [] ? _kstrtoull+0x2c/0x80 [] warn_slowpath_null+0x1a/0x20 [] replace_preds+0x3c5/0x990 [] create_filter+0x82/0xb0 [] apply_event_filter+0xd4/0x180 [] event_filter_write+0x8f/0x120 [] __vfs_write+0x28/0xe0 [] ? __sb_start_write+0x53/0xf0 [] ? security_file_permission+0x30/0xc0 [] vfs_write+0xb8/0x1b0 [] SyS_write+0x4f/0xb0 [] system_call_fastpath+0x12/0x6a ---[ end trace e11028bd95818dcd ]--- Worse yet, reading the error message (the filter again) it says that there was no error, when there clearly was. The issue is that the code that checks the input does not check for balanced ops. That is, having an op between a closed parenthesis and the next token. This would only cause a warning, and fail out before doing any real harm, but it should still not caues a warning, and the error reported should work: # cd /sys/kernel/debug/tracing # echo "((dev==1)blocks==2)" > events/ext4/ext4_truncate_exit/filter -bash: echo: write error: Invalid argument # cat events/ext4/ext4_truncate_exit/filter ((dev==1)blocks==2) ^ parse_error: Meaningless filter expression And give no kernel warning. Link: http://lkml.kernel.org/r/20150615175025.7e809215@gandalf.local.home Cc: Peter Zijlstra Cc: Ingo Molnar Cc: Arnaldo Carvalho de Melo Reported-by: Vince Weaver Tested-by: Vince Weaver Signed-off-by: Steven Rostedt Signed-off-by: Greg Kroah-Hartman --- kernel/trace/trace_events_filter.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -1399,19 +1399,26 @@ static int check_preds(struct filter_par { int n_normal_preds = 0, n_logical_preds = 0; struct postfix_elt *elt; + int cnt = 0; list_for_each_entry(elt, &ps->postfix, list) { - if (elt->op == OP_NONE) + if (elt->op == OP_NONE) { + cnt++; continue; + } if (elt->op == OP_AND || elt->op == OP_OR) { n_logical_preds++; + cnt--; continue; } + if (elt->op != OP_NOT) + cnt--; n_normal_preds++; + WARN_ON_ONCE(cnt < 0); } - if (!n_normal_preds || n_logical_preds >= n_normal_preds) { + if (cnt != 1 || !n_normal_preds || n_logical_preds >= n_normal_preds) { parse_error(ps, FILT_ERR_INVALID_FILTER, 0); return -EINVAL; } Patches currently in stable-queue which might be from rostedt@goodmis.org are queue-3.14/tracing-have-filter-check-for-balanced-ops.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in