selftests: livepatch: use canonical ftrace path

[PATCH] selftests: livepatch: use canonical ftrace path

Posted by Fushuai Wang 2 months, 1 week ago

Since v4.1 kernel, a new interface for ftrace called "tracefs" was
introduced, which is usually mounted in /sys/kernel/tracing. Therefore,
tracing files can now be accessed via either the legacy path
/sys/kernel/debug/tracing or the newer path /sys/kernel/tracing.

Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>
---
 tools/testing/selftests/livepatch/functions.sh | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/livepatch/functions.sh b/tools/testing/selftests/livepatch/functions.sh
index 46991a029f7c..8ec0cb64ad94 100644
--- a/tools/testing/selftests/livepatch/functions.sh
+++ b/tools/testing/selftests/livepatch/functions.sh
@@ -10,7 +10,11 @@ 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"
+if [[ -e /sys/kernel/tracing/trace ]]; then
+	SYSFS_TRACING_DIR="$SYSFS_KERNEL_DIR/tracing"
+else
+	SYSFS_TRACING_DIR="$SYSFS_DEBUG_DIR/tracing"
+fi
 
 # Kselftest framework requirement - SKIP code is 4
 ksft_skip=4
-- 
2.36.1

Re: [PATCH] selftests: livepatch: use canonical ftrace path

Posted by Petr Mladek 2 months ago

On Fri 2025-10-10 20:07:27, Fushuai Wang wrote:
> Since v4.1 kernel, a new interface for ftrace called "tracefs" was
> introduced, which is usually mounted in /sys/kernel/tracing. Therefore,
> tracing files can now be accessed via either the legacy path
> /sys/kernel/debug/tracing or the newer path /sys/kernel/tracing.
> 
> Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>

JFYI, the patch has been comitted into livepatching.git,
branch for-6.19/trivial.

Best Regards,
Petr

Re: [PATCH] selftests: livepatch: use canonical ftrace path

Posted by Petr Mladek 2 months ago

On Fri 2025-10-10 20:07:27, Fushuai Wang wrote:
> Since v4.1 kernel, a new interface for ftrace called "tracefs" was
> introduced, which is usually mounted in /sys/kernel/tracing. Therefore,
> tracing files can now be accessed via either the legacy path
> /sys/kernel/debug/tracing or the newer path /sys/kernel/tracing.
> 
> Signed-off-by: Fushuai Wang <wangfushuai@baidu.com>

Looks good to me:

Reviewed-by: Petr Mladek <pmladek@suse.com>
Tested-by: Petr Mladek <pmladek@suse.com>

Best Regards,
Petr