From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752419AbbKZCVL (ORCPT ); Wed, 25 Nov 2015 21:21:11 -0500 Received: from mail.kernel.org ([198.145.29.136]:57712 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751495AbbKZCUw (ORCPT ); Wed, 25 Nov 2015 21:20:52 -0500 Message-Id: <20151126022048.537232677@goodmis.org> User-Agent: quilt/0.61-1 Date: Wed, 25 Nov 2015 21:19:08 -0500 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Ingo Molnar , Andrew Morton Subject: [for-next][PATCH 5/5] ftrace: Show all tramps registered to a record on ftrace_bug() References: <20151126021903.416197072@goodmis.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Content-Disposition: inline; filename=0005-ftrace-Show-all-tramps-registered-to-a-record-on-ftr.patch Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Steven Rostedt (Red Hat)" When an anomaly is detected in the function call modification code, ftrace_bug() is called to disable function tracing as well as give any information that may help debug the problem. Currently, only the first found trampoline that is attached to the failed record is reported. Instead, show all trampolines that are hooked to it. Also, not only show the ops pointer but also report the function it calls. While at it, add this info to the enabled_functions debug file too. Signed-off-by: Steven Rostedt --- kernel/trace/ftrace.c | 46 +++++++++++++++++++++++++++++++++++++--------- 1 file changed, 37 insertions(+), 9 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 7870c03b4c4d..e371aed51fcf 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -1952,6 +1952,8 @@ static void print_ip_ins(const char *fmt, const unsigned char *p) static struct ftrace_ops * ftrace_find_tramp_ops_any(struct dyn_ftrace *rec); +static struct ftrace_ops * +ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, struct ftrace_ops *ops); enum ftrace_bug_type ftrace_bug_type; const void *ftrace_expected; @@ -2028,15 +2030,19 @@ void ftrace_bug(int failed, struct dyn_ftrace *rec) rec->flags & FTRACE_FL_REGS ? " R" : " "); if (rec->flags & FTRACE_FL_TRAMP_EN) { ops = ftrace_find_tramp_ops_any(rec); - if (ops) - pr_cont("\ttramp: %pS", - (void *)ops->trampoline); - else + if (ops) { + do { + pr_cont("\ttramp: %pS (%pS)", + (void *)ops->trampoline, + (void *)ops->func); + ops = ftrace_find_tramp_ops_next(rec, ops); + } while (ops); + } else pr_cont("\ttramp: ERROR!"); } ip = ftrace_get_addr_curr(rec); - pr_cont(" expected tramp: %lx\n", ip); + pr_cont("\n expected tramp: %lx\n", ip); } } @@ -2179,6 +2185,24 @@ ftrace_find_tramp_ops_any(struct dyn_ftrace *rec) } static struct ftrace_ops * +ftrace_find_tramp_ops_next(struct dyn_ftrace *rec, + struct ftrace_ops *op) +{ + unsigned long ip = rec->ip; + + while_for_each_ftrace_op(op) { + + if (!op->trampoline) + continue; + + if (hash_contains_ip(ip, op->func_hash)) + return op; + } + + return NULL; +} + +static struct ftrace_ops * ftrace_find_tramp_ops_curr(struct dyn_ftrace *rec) { struct ftrace_ops *op; @@ -3306,10 +3330,14 @@ static int t_show(struct seq_file *m, void *v) rec->flags & FTRACE_FL_IPMODIFY ? " I" : " "); if (rec->flags & FTRACE_FL_TRAMP_EN) { ops = ftrace_find_tramp_ops_any(rec); - if (ops) - seq_printf(m, "\ttramp: %pS", - (void *)ops->trampoline); - else + if (ops) { + do { + seq_printf(m, "\ttramp: %pS (%pS)", + (void *)ops->trampoline, + (void *)ops->func); + ops = ftrace_find_tramp_ops_next(rec, ops); + } while (ops); + } else seq_puts(m, "\ttramp: ERROR!"); } -- 2.6.1