tracing/perf: Use strndup_user() instead of buggy open-coded version

The first version of this method was missing the check for
`ret == PATH_MAX`; then such a check was added, but it didn't call kfree()
on error, so there was still a small memory leak in the error case.
Fix it by using strndup_user() instead of open-coding it.

Link: http://lkml.kernel.org/r/[email protected]

Cc: Ingo Molnar <[email protected]>
Cc: [email protected]
Fixes: 0eadcc7a7bc0 ("perf/core: Fix perf_uprobe_init()")
Reviewed-by: Masami Hiramatsu <[email protected]>
Acked-by: Song Liu <[email protected]>
Signed-off-by: Jann Horn <[email protected]>
Signed-off-by: Steven Rostedt (VMware) <[email protected]>

0 files changed, 0 insertions, 0 deletions