This patchset add ftrace helpers functions and add a new test makes sure that ftrace can trace a function that was introduced by a livepatch.
Signed-off-by: Filipe Xavier felipeaggger@gmail.com Suggested-by: Marcos Paulo de Souza mpdesouza@suse.com Reviewed-by: Marcos Paulo de Souza mpdesouza@suse.com Acked-by: Miroslav Benes mbenes@suse.cz --- Changes in v3: - functions.sh: fixed sed to remove warning from shellcheck and add grep -Fw params. - test-ftrace.sh: change constant to use common SYSFS_KLP_DIR. - Link to v2: https://lore.kernel.org/r/20250318-ftrace-sftest-livepatch-v2-0-60cb0aa95cca...
Changes in v2: - functions.sh: change check traced function to accept a list of functions. - Link to v1: https://lore.kernel.org/r/20250306-ftrace-sftest-livepatch-v1-0-a6f1dfc30e17...
--- Filipe Xavier (2): selftests: livepatch: add new ftrace helpers functions selftests: livepatch: test if ftrace can trace a livepatched function
tools/testing/selftests/livepatch/functions.sh | 49 ++++++++++++++++++++++++ tools/testing/selftests/livepatch/test-ftrace.sh | 34 ++++++++++++++++ 2 files changed, 83 insertions(+) --- base-commit: 848e076317446f9c663771ddec142d7c2eb4cb43 change-id: 20250306-ftrace-sftest-livepatch-60d9dc472235
Best regards,
Add new ftrace helpers functions cleanup_tracing, trace_function and check_traced_functions.
Signed-off-by: Filipe Xavier felipeaggger@gmail.com --- tools/testing/selftests/livepatch/functions.sh | 49 ++++++++++++++++++++++++++ 1 file changed, 49 insertions(+)
diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh index 15601402dee6567837c2c49ba342eb357e410d18..46991a029f7c64ace3945727b3540521ffe2e529 100644 --- a/tools/testing/selftests/livepatch/functions.sh +++ b/tools/testing/selftests/livepatch/functions.sh @@ -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 @@ -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() { @@ -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() { @@ -352,3 +367,37 @@ 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 ($function) did not appear in the trace" + fi + done + + cleanup_tracing +}
This new test makes sure that ftrace can trace a function that was introduced by a livepatch.
Signed-off-by: Filipe Xavier felipeaggger@gmail.com --- tools/testing/selftests/livepatch/test-ftrace.sh | 34 ++++++++++++++++++++++++ 1 file changed, 34 insertions(+)
diff --git a/tools/testing/selftests/livepatch/test-ftrace.sh b/tools/testing/selftests/livepatch/test-ftrace.sh index fe14f248913acbec46fb6c0fec38a2fc84209d39..094176f1a46aee8cf08667ae9e31ae8720bc1ae1 100755 --- a/tools/testing/selftests/livepatch/test-ftrace.sh +++ b/tools/testing/selftests/livepatch/test-ftrace.sh @@ -61,4 +61,38 @@ livepatch: '$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
On Mon, Mar 24, 2025 at 07:50:17PM -0300, Filipe Xavier wrote:
This patchset add ftrace helpers functions and add a new test makes sure that ftrace can trace a function that was introduced by a livepatch.
Signed-off-by: Filipe Xavier felipeaggger@gmail.com Suggested-by: Marcos Paulo de Souza mpdesouza@suse.com Reviewed-by: Marcos Paulo de Souza mpdesouza@suse.com Acked-by: Miroslav Benes mbenes@suse.cz
Changes in v3:
- functions.sh: fixed sed to remove warning from shellcheck and add grep -Fw params.
Oh, now I see what shellcheck was complaining about. I missed that there was no '' line continuation char at the end of the sed line. I thought it was complaining about starting the subsequent lines with the '|' and '>' redirection chars. Good eye on catching that :)
- test-ftrace.sh: change constant to use common SYSFS_KLP_DIR.
- Link to v2: https://lore.kernel.org/r/20250318-ftrace-sftest-livepatch-v2-0-60cb0aa95cca...
For both patches: Acked-by: Joe Lawrence joe.lawrence@redhat.com
Thanks, -- Joe
On Mon 2025-03-24 19:50:17, Filipe Xavier wrote:
This patchset add ftrace helpers functions and add a new test makes sure that ftrace can trace a function that was introduced by a livepatch.
Signed-off-by: Filipe Xavier felipeaggger@gmail.com Acked-by: Miroslav Benes mbenes@suse.cz
For both patches:
Reviewed-by: Petr Mladek pmladek@suse.com Tested-by: Petr Mladek pmladek@suse.com
Best Regards, Petr
On Mon 2025-03-24 19:50:17, Filipe Xavier wrote:
This patchset add ftrace helpers functions and add a new test makes sure that ftrace can trace a function that was introduced by a livepatch.
Signed-off-by: Filipe Xavier felipeaggger@gmail.com Acked-by: Miroslav Benes mbenes@suse.cz
JFYI, the patchset has been committed into livepatching.git, branch for-6.15/ftrace-test.
I had a dilemma whether to push it for 6.15 or postpone it. But it is a selftest and quite trivial. And it has been reviewed by several people. And it seems to work well so I think that we could push it for 6.15.
Best Regards, Petr
On 3/25/25 11:01 AM, Petr Mladek wrote:
On Mon 2025-03-24 19:50:17, Filipe Xavier wrote:
This patchset add ftrace helpers functions and add a new test makes sure that ftrace can trace a function that was introduced by a livepatch.
Signed-off-by: Filipe Xavier felipeaggger@gmail.com Acked-by: Miroslav Benes mbenes@suse.cz
JFYI, the patchset has been committed into livepatching.git, branch for-6.15/ftrace-test.
I had a dilemma whether to push it for 6.15 or postpone it. But it is a selftest and quite trivial. And it has been reviewed by several people. And it seems to work well so I think that we could push it for 6.15.
It sounds good to me, thank you all very much for the support.
Cheers,
Filipe
Best Regards, Petr
linux-kselftest-mirror@lists.linaro.org
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Filipe Xavier -
Joe Lawrence -
Petr Mladek