Commit-ID: 73e5de70dca00344cb48e018131a4cadec0fabf0 Gitweb: https://git.kernel.org/tip/73e5de70dca00344cb48e018131a4cadec0fabf0 Author: Arnaldo Carvalho de Melo <[email protected]> AuthorDate: Mon, 12 Aug 2019 17:27:11 -0300 Committer: Arnaldo Carvalho de Melo <[email protected]> CommitDate: Wed, 14 Aug 2019 10:59:59 -0300
perf ftrace: Improve error message about capability to use ftrace If we link against libcap, then we can state that CAP_SYS_ADMIN is needed, if not, fallback to telling the user it needs to be root, as was before linking against libcap. Cc: Adrian Hunter <[email protected]> Cc: Alexander Shishkin <[email protected]> Cc: Alexey Budankov <[email protected]> Cc: Igor Lubashev <[email protected]> Cc: James Morris <[email protected]> Cc: Jiri Olsa <[email protected]> Cc: Mathieu Poirier <[email protected]> Cc: Namhyung Kim <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Suzuki Poulouse <[email protected]> Link: https://lkml.kernel.org/n/[email protected] Signed-off-by: Arnaldo Carvalho de Melo <[email protected]> --- tools/perf/builtin-ftrace.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 01a5bb58eb04..1367bb5046a7 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -284,7 +284,13 @@ static int __cmd_ftrace(struct perf_ftrace *ftrace, int argc, const char **argv) }; if (!perf_cap__capable(CAP_SYS_ADMIN)) { - pr_err("ftrace only works for root!\n"); + pr_err("ftrace only works for %s!\n", +#ifdef HAVE_LIBCAP_SUPPORT + "users with the SYS_ADMIN capability" +#else + "root" +#endif + ); return -1; }
