[LTP] [PATCH v3 2/9] tracing/ftrace: add new case for ftrace userstacktrace

[Chunyu Hu]

From: Li Wang <liwang@redhat.com>

This case is the reproducer of ftrace userstacktrace bug.

BUG: unable to handle kernel paging request at 00000000417683c0
     IP: [<ffffffff8105c834>] update_curr+0x124/0x1e0
     PGD 41a796067 PUD 0
     Thread overran stack, or stack corrupted
     Oops: 0000 [#1] SMP
     last sysfs file: /sys/devices/system/cpu/cpu15/cache/index2/shared_cpu_map

The bug was fixed by:
     1dbd195 (tracing: Fix preempt count leak)

Signed-off-by: Li Wang <liwang@redhat.com>
---
 runtest/tracing                                    |  1 +
 .../tracing/ftrace_test/ftrace_regression01.sh     | 86 ++++++++++++++++++++++
 2 files changed, 87 insertions(+)
 create mode 100755 testcases/kernel/tracing/ftrace_test/ftrace_regression01.sh

diff --git a/runtest/tracing b/runtest/tracing
index ef3a048..fb82515 100644
--- a/runtest/tracing
+++ b/runtest/tracing
@@ -1,2 +1,3 @@
 #DESCRIPTION:Tracing testing
+ftrace_regression01	ftrace_regression01.sh
 ftrace-stress-test	ftrace_stress_test.sh 90
diff --git a/testcases/kernel/tracing/ftrace_test/ftrace_regression01.sh b/testcases/kernel/tracing/ftrace_test/ftrace_regression01.sh
new file mode 100755
index 0000000..b25111a
--- /dev/null
+++ b/testcases/kernel/tracing/ftrace_test/ftrace_regression01.sh
@@ -0,0 +1,86 @@
+#! /bin/sh
+
+###########################################################################
+##                                                                       ##
+## Copyright (c) 2015, Red Hat Inc.                                      ##
+##                                                                       ##
+## This program is free software: you can redistribute it and/or modify  ##
+## it under the terms of the GNU General Public License as published by  ##
+## the Free Software Foundation, either version 3 of the License, or     ##
+## (at your option) any later version.                                   ##
+##                                                                       ##
+## This program is distributed in the hope that it will be useful,       ##
+## but WITHOUT ANY WARRANTY; without even the implied warranty of        ##
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the          ##
+## GNU General Public License for more details.                          ##
+##                                                                       ##
+## You should have received a copy of the GNU General Public License     ##
+## along with this program. If not, see <http://www.gnu.org/licenses/>.  ##
+##                                                                       ##
+## Author: Li Wang <liwang@redhat.com>                                   ##
+##                                                                       ##
+###########################################################################
+##                                                                       ##
+## Summary:  panic while using userstacktrace                            ##
+##                                                                       ##
+## BUG: unable to handle kernel paging request at 00000000417683c0       ##
+##      IP: [<ffffffff8105c834>] update_curr+0x124/0x1e0                 ##
+##      PGD 41a796067 PUD 0                                              ##
+##      Thread overran stack, or stack corrupted                         ##
+##      Oops: 0000 [#1] SMP                                              ##
+##      last sysfs file: ../system/cpu/cpu15/cache/index2/shared_cpu_map ##
+##                                                                       ##
+## The bug was fixed by:                                                 ##
+##      1dbd195 (tracing: Fix preempt count leak)                        ##
+##                                                                       ##
+###########################################################################
+
+export TCID="ftrace_regression01"
+export TST_TOTAL=1
+
+. ftrace_lib.sh
+
+LOOP=10
+
+TSTACK_TRACE_PATH="/proc/sys/kernel/stack_tracer_enabled"
+EXC_PAGE_FAULT_ENABLE="$TRACING_PATH/events/exceptions/page_fault_kernel/enable"
+MM_PAGE_FAULT_ENABLE="$TRACING_PATH/events/kmem/mm_kernel_pagefault/enable"
+
+ftrace_userstacktrace_test()
+{
+	if [ ! -e "$TSTACK_TRACE_PATH" ]; then
+		tst_brkm TCONF "Stack Tracer is not cofigured in This kernel"
+	fi
+
+	for i in $(seq $LOOP); do
+		echo 1 >  $TSTACK_TRACE_PATH
+		echo userstacktrace > $TRACING_PATH/trace_options
+		grep -q "^userstacktrace"  $TRACING_PATH/trace_options
+		if [ $? -ne 0 ]; then
+			tst_brkm TBROK "Failed to set userstacktrace"
+		fi
+
+		if [ -f "$EXC_PAGE_FAULT_ENABLE" ]; then
+			exc_page_fault_enable=`cat $EXC_PAGE_FAULT_ENABLE`
+			echo 1 > $EXC_PAGE_FAULT_ENABLE
+		else
+			mm_page_fault_enable=`cat MM_PAGE_FAULT_ENABLE`
+			echo 1 > $MM_PAGE_FAULT_ENABLE
+		fi
+	done
+
+	if [ -f "$EXC_PAGE_FAULT_ENABLE" ]; then
+		echo "$exc_page_fault_enable" > $EXC_PAGE_FAULT_ENABLE
+	else
+		echo "$mm_page_fault_enable" > $MM_PAGE_FAULT_ENABLE
+	fi
+
+	tst_resm TPASS "Finished running the test"
+}
+
+#--------Test Start--------------
+save_old_setting
+
+ftrace_userstacktrace_test
+
+clean_up
-- 
1.8.3.1