ftrace: Synchronize the initialization of ftrace_opsgrafted

There's some internal state that ftrace_ops needs to have set, but since
it can be declared outside of the ftrace.c code, it calls
ftrace_ops_init() on the ops in every global function. The issue is that
if two tasks call it on the same ops at the same time it is possible to
have the initialization of one corrupt the initialization of the other
call.

Create a ops_mutex to use to synchronize every initialization of the
ftrace_ops. The mutex is taken within checking the ftrace_ops flag that
states it was initializied but the flag is checked again after the mutex
has been taken. Checking first outside the mutex allows it to shortcut
having to take the mutex. But then the check needs to be done again after
the mute is taken in case of races.

Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home
Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock")
Reported-by: sashiko-bot@kernel.org
Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 274 insertions, 0 deletions

diff --git a/tools/usb/hcd-tests.sh b/tools/usb/hcd-tests.sh
new file mode 100644
index 000000000..73f914d13
--- /dev/null
+++ b/tools/usb/hcd-tests.sh
@@ -0,0 +1,274 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+#
+# test types can be passed on the command line:
+#
+# - control: any device can do this
+# - out, in:  out needs 'bulk sink' firmware, in needs 'bulk src'
+# - iso-out, iso-in:  out needs 'iso sink' firmware, in needs 'iso src'
+# - halt: needs bulk sink+src, tests halt set/clear from host
+# - unlink: needs bulk sink and/or src, test HCD unlink processing
+# - loop: needs firmware that will buffer N transfers
+#
+# run it for hours, days, weeks.
+#
+
+#
+# this default provides a steady test load for a bulk device
+#
+TYPES='control out in'
+#TYPES='control out in halt'
+
+#
+# to test HCD code
+#
+#  - include unlink tests
+#  - add some ${RANDOM}ness
+#  - connect several devices concurrently (same HC)
+#  - keep HC's IRQ lines busy with unrelated traffic (IDE, net, ...)
+#  - add other concurrent system loads
+#
+
+declare -i COUNT BUFLEN
+
+COUNT=50000
+BUFLEN=2048
+
+# NOTE:  the 'in' and 'out' cases are usually bulk, but can be
+# set up to use interrupt transfers by 'usbtest' module options
+
+
+if [ "$DEVICE" = "" ]; then
+	echo "testing ALL recognized usbtest devices"
+	echo ""
+	TEST_ARGS="-a"
+else
+	TEST_ARGS=""
+fi
+
+do_test ()
+{
+    if ! ./testusb $TEST_ARGS -s $BUFLEN -c $COUNT $* 2>/dev/null
+    then
+	echo "FAIL"
+	exit 1
+    fi
+}
+
+ARGS="$*"
+
+if [ "$ARGS" = "" ];
+then
+    ARGS="$TYPES"
+fi
+
+# FIXME use /sys/bus/usb/device/$THIS/bConfigurationValue to
+# check and change configs
+
+CONFIG=''
+
+check_config ()
+{
+    if [ "$CONFIG" = "" ]; then
+	CONFIG=$1
+	echo "assuming $CONFIG configuration"
+	return
+    fi
+    if [ "$CONFIG" = $1 ]; then
+	return
+    fi
+
+    echo "** device must be in $1 config, but it's $CONFIG instead"
+    exit 1
+}
+
+
+echo "TESTING:  $ARGS"
+
+while : true
+do
+    echo $(date)
+
+    for TYPE in $ARGS
+    do
+	# restore defaults
+	COUNT=5000
+	BUFLEN=2048
+
+	# FIXME automatically multiply COUNT by 10 when
+	# /sys/bus/usb/device/$THIS/speed == "480"
+
+#	COUNT=50000
+
+	case $TYPE in
+	control)
+	    # any device, in any configuration, can use this.
+	    echo '** Control test cases:'
+
+	    echo "test 9: ch9 postconfig"
+	    do_test -t 9 -c 5000
+	    echo "test 10: control queueing"
+	    do_test -t 10 -c 5000
+
+	    # this relies on some vendor-specific commands
+	    echo "test 14: control writes"
+	    do_test -t 14 -c 15000 -s 256 -v 1
+
+	    echo "test 21: control writes, unaligned"
+	    do_test -t 21 -c 100 -s 256 -v 1
+
+	    ;;
+
+	out)
+	    check_config sink-src
+	    echo '** Host Write (OUT) test cases:'
+
+	    echo "test 1: $COUNT transfers, same size"
+	    do_test -t 1
+	    echo "test 3: $COUNT transfers, variable/short size"
+	    do_test -t 3 -v 421
+
+	    COUNT=100
+	    echo "test 17: $COUNT transfers, unaligned DMA map by core"
+	    do_test -t 17
+
+	    echo "test 19: $COUNT transfers, unaligned DMA map by usb_alloc_coherent"
+	    do_test -t 19
+
+	    COUNT=2000
+	    echo "test 5: $COUNT scatterlists, same size entries"
+	    do_test -t 5
+
+	    # try to trigger short OUT processing bugs
+	    echo "test 7a: $COUNT scatterlists, variable size/short entries"
+	    do_test -t 7 -v 579
+	    BUFLEN=4096
+	    echo "test 7b: $COUNT scatterlists, variable size/bigger entries"
+	    do_test -t 7 -v 41
+	    BUFLEN=64
+	    echo "test 7c: $COUNT scatterlists, variable size/micro entries"
+	    do_test -t 7 -v 63
+	    ;;
+
+	iso-out)
+	    check_config sink-src
+	    echo '** Host ISOCHRONOUS Write (OUT) test cases:'
+
+	    # at peak iso transfer rates:
+	    # - usb 2.0 high bandwidth, this is one frame.
+	    # - usb 1.1, it's twenty-four frames.
+	    BUFLEN=24500
+
+	    COUNT=1000
+
+# COUNT=10000
+
+	    echo "test 15: $COUNT transfers, same size"
+	    # do_test -t 15 -g 3 -v 0
+	    BUFLEN=32768
+	    do_test -t 15 -g 8 -v 0
+
+	    # FIXME it'd make sense to have an iso OUT test issuing
+	    # short writes on more packets than the last one
+
+	    COUNT=100
+	    echo "test 22: $COUNT transfers, non aligned"
+	    do_test -t 22 -g 8 -v 0
+
+	    ;;
+
+	in)
+	    check_config sink-src
+	    echo '** Host Read (IN) test cases:'
+
+	    # NOTE:  these "variable size" reads are just multiples
+	    # of 512 bytes, no EOVERFLOW testing is done yet
+
+	    echo "test 2: $COUNT transfers, same size"
+	    do_test -t 2
+	    echo "test 4: $COUNT transfers, variable size"
+	    do_test -t 4
+
+	    COUNT=100
+	    echo "test 18: $COUNT transfers, unaligned DMA map by core"
+	    do_test -t 18
+
+	    echo "test 20: $COUNT transfers, unaligned DMA map by usb_alloc_coherent"
+	    do_test -t 20
+
+	    COUNT=2000
+	    echo "test 6: $COUNT scatterlists, same size entries"
+	    do_test -t 6
+	    echo "test 8: $COUNT scatterlists, variable size entries"
+	    do_test -t 8
+	    ;;
+
+	iso-in)
+	    check_config sink-src
+	    echo '** Host ISOCHRONOUS Read (IN) test cases:'
+
+	    # at peak iso transfer rates:
+	    # - usb 2.0 high bandwidth, this is one frame.
+	    # - usb 1.1, it's twenty-four frames.
+	    BUFLEN=24500
+
+	    COUNT=1000
+
+# COUNT=10000
+
+	    echo "test 16: $COUNT transfers, same size"
+	    # do_test -t 16 -g 3 -v 0
+	    BUFLEN=32768
+	    do_test -t 16 -g 8 -v 0
+
+	    # FIXME since iso expects faults, it'd make sense
+	    # to have an iso IN test issuing short reads ...
+
+	    COUNT=100
+	    echo "test 23: $COUNT transfers, unaligned"
+	    do_test -t 23 -g 8 -v 0
+
+	    ;;
+
+	halt)
+	    # NOTE:  sometimes hardware doesn't cooperate well with halting
+	    # endpoints from the host side.  so long as mass-storage class
+	    # firmware can halt them from the device, don't worry much if
+	    # you can't make this test work on your device.
+	    COUNT=2000
+	    echo "test 13: $COUNT halt set/clear"
+	    do_test -t 13
+	    ;;
+
+	unlink)
+	    COUNT=2000
+	    echo "test 11: $COUNT read unlinks"
+	    do_test -t 11
+
+	    echo "test 12: $COUNT write unlinks"
+	    do_test -t 12
+	    ;;
+
+	loop)
+	    # defaults need too much buffering for ez-usb devices
+	    BUFLEN=2048
+	    COUNT=32
+
+	    # modprobe g_zero qlen=$COUNT buflen=$BUFLEN loopdefault
+	    check_config loopback
+
+	    # FIXME someone needs to write and merge a version of this
+
+	    echo "write $COUNT buffers of $BUFLEN bytes, read them back"
+
+	    echo "write $COUNT variable size buffers, read them back"
+
+	    ;;
+
+	*)
+	    echo "Don't understand test type $TYPE"
+	    exit 1;
+	esac
+	echo ''
+    done
+done