Commit b67a9170 authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

torture: Add gdb support 



This commit adds a "--gdb" parameter to kvm.sh, which causes
"CONFIG_DEBUG_INFO=y" to be added to the Kconfig options, "nokaslr"
to be added to the boot parameters, and "-s -S" to be added to the qemu
arguments.  Furthermore, the scripting prints messages telling the user
how to start up gdb for the run in question.

Because of the interactive nature of gdb sessions, only one "--configs"
scenario is permitted when "--gdb" is specified.  For most torture types,
this means that a "--configs" argument is required, and that argument
must specify the single scenario of interest.

The usual cautions about breakpoints and timing apply, for example,
staring at your gdb prompt for too long will likely get you many
complaints, including RCU CPU stall warnings.  Omar Sandoval further
suggests using gdb's "hbreak" command instead of the "break" command on
systems supporting hardware breakpoints, and further using the "commands"
option because the resulting non-interactive breakpoints are less likely
to get you RCU CPU stall warnings.

Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent d6855142

tools/testing/selftests/rcutorture/bin/kvm-test-1-run.sh

+25 −8
Original line number Diff line number Diff line
@@ -66,6 +66,7 @@ config_override_param () { 
echo > $T/KcList

config_override_param "$config_dir/CFcommon" KcList "`cat $config_dir/CFcommon 2> /dev/null`"

config_override_param "$config_template" KcList "`cat $config_template 2> /dev/null`"

config_override_param "--gdb options" KcList "$TORTURE_KCONFIG_GDB_ARG"

config_override_param "--kasan options" KcList "$TORTURE_KCONFIG_KASAN_ARG"

config_override_param "--kcsan options" KcList "$TORTURE_KCONFIG_KCSAN_ARG"

config_override_param "--kconfig argument" KcList "$TORTURE_KCONFIG_ARG"
@@ -152,7 +153,11 @@ qemu_append="`identify_qemu_append "$QEMU"`" 
boot_args="`configfrag_boot_params "$boot_args" "$config_template"`"

# Generate kernel-version-specific boot parameters

boot_args="`per_version_boot_params "$boot_args" $resdir/.config $seconds`"

echo $QEMU $qemu_args -m $TORTURE_QEMU_MEM -kernel $KERNEL -append \"$qemu_append $boot_args\" > $resdir/qemu-cmd

if test -n "$TORTURE_BOOT_GDB_ARG"

then

	boot_args="$boot_args $TORTURE_BOOT_GDB_ARG"

fi

echo $QEMU $qemu_args -m $TORTURE_QEMU_MEM -kernel $KERNEL -append \"$qemu_append $boot_args\" $TORTURE_QEMU_GDB_ARG > $resdir/qemu-cmd



if test -n "$TORTURE_BUILDONLY"

then
@@ -171,6 +176,8 @@ echo "NOTE: $QEMU either did not run or was interactive" > $resdir/console.log 
# Attempt to run qemu

( . $T/qemu-cmd; wait `cat  $resdir/qemu_pid`; echo $? > $resdir/qemu-retval ) &

commandcompleted=0

if test -z "$TORTURE_KCONFIG_GDB_ARG"

then

	sleep 10 # Give qemu's pid a chance to reach the file

	if test -s "$resdir/qemu_pid"

	then
@@ -180,6 +187,16 @@ else 
		qemu_pid=""

		echo Monitoring qemu job at yet-as-unknown pid

	fi

fi

if test -n "$TORTURE_KCONFIG_GDB_ARG"

then

	echo Waiting for you to attach a debug session, for example: > /dev/tty

	echo "    gdb $base_resdir/vmlinux" > /dev/tty

	echo 'After symbols load and the "(gdb)" prompt appears:' > /dev/tty

	echo "    target remote :1234" > /dev/tty

	echo "    continue" > /dev/tty

	kstarttime=`gawk 'BEGIN { print systime() }' < /dev/null`

fi

while :

do

	if test -z "$qemu_pid" -a -s "$resdir/qemu_pid"

tools/testing/selftests/rcutorture/bin/kvm.sh

+21 −0
Original line number Diff line number Diff line
@@ -31,6 +31,9 @@ TORTURE_DEFCONFIG=defconfig 
TORTURE_BOOT_IMAGE=""

TORTURE_INITRD="$KVM/initrd"; export TORTURE_INITRD

TORTURE_KCONFIG_ARG=""

TORTURE_KCONFIG_GDB_ARG=""

TORTURE_BOOT_GDB_ARG=""

TORTURE_QEMU_GDB_ARG=""

TORTURE_KCONFIG_KASAN_ARG=""

TORTURE_KCONFIG_KCSAN_ARG=""

TORTURE_KMAKE_ARG=""
@@ -56,6 +59,7 @@ usage () { 
	echo "       --defconfig string"

	echo "       --dryrun sched|script"

	echo "       --duration minutes"

	echo "       --gdb"

	echo "       --help"

	echo "       --interactive"

	echo "       --jitter N [ maxsleep (us) [ maxspin (us) ] ]"
@@ -128,6 +132,11 @@ do 
		dur=$(($2*60))

		shift

		;;

	--gdb)

		TORTURE_KCONFIG_GDB_ARG="CONFIG_DEBUG_INFO=y"; export TORTURE_KCONFIG_GDB_ARG

		TORTURE_BOOT_GDB_ARG="nokaslr"; export TORTURE_BOOT_GDB_ARG

		TORTURE_QEMU_GDB_ARG="-s -S"; export TORTURE_QEMU_GDB_ARG

		;;

	--help|-h)

		usage

		;;
@@ -253,6 +262,15 @@ do 
done

touch $T/cfgcpu

configs_derep="`echo $configs_derep | sed -e "s/\<CFLIST\>/$defaultconfigs/g"`"

if test -n "$TORTURE_KCONFIG_GDB_ARG"

then

	if test "`echo $configs_derep | wc -w`" -gt 1

	then

		echo "The --config list is: $configs_derep."

		echo "Only one --config permitted with --gdb, terminating."

		exit 1

	fi

fi

for CF1 in $configs_derep

do

	if test -f "$CONFIGFRAG/$CF1"
@@ -328,6 +346,9 @@ TORTURE_BUILDONLY="$TORTURE_BUILDONLY"; export TORTURE_BUILDONLY 
TORTURE_DEFCONFIG="$TORTURE_DEFCONFIG"; export TORTURE_DEFCONFIG

TORTURE_INITRD="$TORTURE_INITRD"; export TORTURE_INITRD

TORTURE_KCONFIG_ARG="$TORTURE_KCONFIG_ARG"; export TORTURE_KCONFIG_ARG

TORTURE_KCONFIG_GDB_ARG="$TORTURE_KCONFIG_GDB_ARG"; export TORTURE_KCONFIG_GDB_ARG

TORTURE_BOOT_GDB_ARG="$TORTURE_BOOT_GDB_ARG"; export TORTURE_BOOT_GDB_ARG

TORTURE_QEMU_GDB_ARG="$TORTURE_QEMU_GDB_ARG"; export TORTURE_QEMU_GDB_ARG

TORTURE_KCONFIG_KASAN_ARG="$TORTURE_KCONFIG_KASAN_ARG"; export TORTURE_KCONFIG_KASAN_ARG

TORTURE_KCONFIG_KCSAN_ARG="$TORTURE_KCONFIG_KCSAN_ARG"; export TORTURE_KCONFIG_KCSAN_ARG

TORTURE_KMAKE_ARG="$TORTURE_KMAKE_ARG"; export TORTURE_KMAKE_ARG

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