2020-08-05 07:35:07

by Alexey Budankov

Subject: [PATCH v1] perf: extend message to mention CAP_SYS_PTRACE and perf security doc link

Adjust limited access message to mention CAP_SYS_PTRACE capability
for processes of unprivileged users. Add link to perf security
document in the end of the section about capabilities.
The change has been inspired by this discussion:
https://lore.kernel.org/lkml/[email protected]/

Signed-off-by: Alexey Budankov <[email protected]>
---
tools/perf/util/evsel.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 9aa51a65593d..e241ee773ccb 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -2500,8 +2500,10 @@ int evsel__open_strerror(struct evsel *evsel, struct target *target,

return scnprintf(msg + printed, size - printed,
"Consider adjusting /proc/sys/kernel/perf_event_paranoid setting to open\n"
- "access to performance monitoring and observability operations for users\n"
- "without CAP_PERFMON or CAP_SYS_ADMIN Linux capability.\n"
+ "access to performance monitoring and observability operations for processes\n"
+ "without CAP_PERFMON, CAP_SYS_PTRACE or CAP_SYS_ADMIN Linux capability.\n"
+ "More information can be found at 'Perf events and tool security' document:\n"
+ "https://www.kernel.org/doc/html/latest/admin-guide/perf-security.html\n"
"perf_event_paranoid setting is %d:\n"
" -1: Allow use of (almost) all events by all users\n"
" Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK\n"
--
2.24.1

2020-08-06 17:33:27

by Arnaldo Carvalho de Melo

Subject: Re: [PATCH v1] perf: extend message to mention CAP_SYS_PTRACE and perf security doc link

Em Wed, Aug 05, 2020 at 10:31:20AM +0300, Alexey Budankov escreveu:
>
> Adjust limited access message to mention CAP_SYS_PTRACE capability
> for processes of unprivileged users. Add link to perf security
> document in the end of the section about capabilities.
> The change has been inspired by this discussion:
> https://lore.kernel.org/lkml/[email protected]/

Thanks, applied.

- Arnaldo

> Signed-off-by: Alexey Budankov <[email protected]>
> ---
> tools/perf/util/evsel.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
> index 9aa51a65593d..e241ee773ccb 100644
> --- a/tools/perf/util/evsel.c
> +++ b/tools/perf/util/evsel.c
> @@ -2500,8 +2500,10 @@ int evsel__open_strerror(struct evsel *evsel, struct target *target,
>
> return scnprintf(msg + printed, size - printed,
> "Consider adjusting /proc/sys/kernel/perf_event_paranoid setting to open\n"
> - "access to performance monitoring and observability operations for users\n"
> - "without CAP_PERFMON or CAP_SYS_ADMIN Linux capability.\n"
> + "access to performance monitoring and observability operations for processes\n"
> + "without CAP_PERFMON, CAP_SYS_PTRACE or CAP_SYS_ADMIN Linux capability.\n"
> + "More information can be found at 'Perf events and tool security' document:\n"
> + "https://www.kernel.org/doc/html/latest/admin-guide/perf-security.html\n"
> "perf_event_paranoid setting is %d:\n"
> " -1: Allow use of (almost) all events by all users\n"
> " Ignore mlock limit after perf_event_mlock_kb without CAP_IPC_LOCK\n"
> --
> 2.24.1

--

- Arnaldo