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Merge branch 'for-6.15/ftrace-test' into for-linus
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Petr Mladek committed Mar 27, 2025
2 parents 59481b8 + 474eecc commit d11f0d1
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49 changes: 49 additions & 0 deletions tools/testing/selftests/livepatch/functions.sh
Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,7 @@ SYSFS_KERNEL_DIR="/sys/kernel"
SYSFS_KLP_DIR="$SYSFS_KERNEL_DIR/livepatch"
SYSFS_DEBUG_DIR="$SYSFS_KERNEL_DIR/debug"
SYSFS_KPROBES_DIR="$SYSFS_DEBUG_DIR/kprobes"
SYSFS_TRACING_DIR="$SYSFS_DEBUG_DIR/tracing"

# Kselftest framework requirement - SKIP code is 4
ksft_skip=4
Expand Down Expand Up @@ -62,6 +63,9 @@ function push_config() {
awk -F'[: ]' '{print "file " $1 " line " $2 " " $4}')
FTRACE_ENABLED=$(sysctl --values kernel.ftrace_enabled)
KPROBE_ENABLED=$(cat "$SYSFS_KPROBES_DIR/enabled")
TRACING_ON=$(cat "$SYSFS_TRACING_DIR/tracing_on")
CURRENT_TRACER=$(cat "$SYSFS_TRACING_DIR/current_tracer")
FTRACE_FILTER=$(cat "$SYSFS_TRACING_DIR/set_ftrace_filter")
}

function pop_config() {
Expand All @@ -74,6 +78,17 @@ function pop_config() {
if [[ -n "$KPROBE_ENABLED" ]]; then
echo "$KPROBE_ENABLED" > "$SYSFS_KPROBES_DIR/enabled"
fi
if [[ -n "$TRACING_ON" ]]; then
echo "$TRACING_ON" > "$SYSFS_TRACING_DIR/tracing_on"
fi
if [[ -n "$CURRENT_TRACER" ]]; then
echo "$CURRENT_TRACER" > "$SYSFS_TRACING_DIR/current_tracer"
fi
if [[ -n "$FTRACE_FILTER" ]]; then
echo "$FTRACE_FILTER" \
| sed -e "/#### all functions enabled ####/d" \
> "$SYSFS_TRACING_DIR/set_ftrace_filter"
fi
}

function set_dynamic_debug() {
Expand Down Expand Up @@ -351,3 +366,37 @@ function check_sysfs_value() {
die "Unexpected value in $path: $expected_value vs. $value"
fi
}

# cleanup_tracing() - stop and clean up function tracing
function cleanup_tracing() {
echo 0 > "$SYSFS_TRACING_DIR/tracing_on"
echo "" > "$SYSFS_TRACING_DIR/set_ftrace_filter"
echo "nop" > "$SYSFS_TRACING_DIR/current_tracer"
echo "" > "$SYSFS_TRACING_DIR/trace"
}

# trace_function(function) - start tracing of a function
# function - to be traced function
function trace_function() {
local function="$1"; shift

cleanup_tracing

echo "function" > "$SYSFS_TRACING_DIR/current_tracer"
echo "$function" > "$SYSFS_TRACING_DIR/set_ftrace_filter"
echo 1 > "$SYSFS_TRACING_DIR/tracing_on"
}

# check_traced_functions(functions...) - check whether each function appeared in the trace log
# functions - list of functions to be checked
function check_traced_functions() {
local function

for function in "$@"; do
if ! grep -Fwq "$function" "$SYSFS_TRACING_DIR/trace" ; then
die "Function ($function) did not appear in the trace"
fi
done

cleanup_tracing
}
34 changes: 34 additions & 0 deletions tools/testing/selftests/livepatch/test-ftrace.sh
Original file line number Diff line number Diff line change
Expand Up @@ -61,4 +61,38 @@ livepatch: '$MOD_LIVEPATCH': unpatching complete
% rmmod $MOD_LIVEPATCH"


# - verify livepatch can load
# - check if traces have a patched function
# - reset trace and unload livepatch

start_test "trace livepatched function and check that the live patch remains in effect"

FUNCTION_NAME="livepatch_cmdline_proc_show"

load_lp $MOD_LIVEPATCH
trace_function "$FUNCTION_NAME"

if [[ "$(cat /proc/cmdline)" == "$MOD_LIVEPATCH: this has been live patched" ]] ; then
log "livepatch: ok"
fi

check_traced_functions "$FUNCTION_NAME"

disable_lp $MOD_LIVEPATCH
unload_lp $MOD_LIVEPATCH

check_result "% insmod test_modules/$MOD_LIVEPATCH.ko
livepatch: enabling patch '$MOD_LIVEPATCH'
livepatch: '$MOD_LIVEPATCH': initializing patching transition
livepatch: '$MOD_LIVEPATCH': starting patching transition
livepatch: '$MOD_LIVEPATCH': completing patching transition
livepatch: '$MOD_LIVEPATCH': patching complete
livepatch: ok
% echo 0 > $SYSFS_KLP_DIR/$MOD_LIVEPATCH/enabled
livepatch: '$MOD_LIVEPATCH': initializing unpatching transition
livepatch: '$MOD_LIVEPATCH': starting unpatching transition
livepatch: '$MOD_LIVEPATCH': completing unpatching transition
livepatch: '$MOD_LIVEPATCH': unpatching complete
% rmmod $MOD_LIVEPATCH"

exit 0

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