diff options
| author | Ian Rogers <irogers@google.com> | 2024-08-07 00:06:14 +0200 |
|---|---|---|
| committer | Arnaldo Carvalho de Melo <acme@redhat.com> | 2024-08-20 22:53:12 +0200 |
| commit | e25ebda78e230283bf707ae3e9655270ff40a7f9 (patch) | |
| tree | 74d714be33a29f0e33bdfcc9f9030207d972318e /tools/perf/util/cap.h | |
| parent | perf annotate-data: Set bitfield member offset and size properly (diff) | |
| download | linux-e25ebda78e230283bf707ae3e9655270ff40a7f9.tar.xz linux-e25ebda78e230283bf707ae3e9655270ff40a7f9.zip | |
perf cap: Tidy up and improve capability testing
Remove dependence on libcap. libcap is only used to query whether a
capability is supported, which is just 1 capget system call.
If the capget system call fails, fall back on root permission
checking. Previously if libcap fails then the permission is assumed
not present which may be pessimistic/wrong.
Add a used_root out argument to perf_cap__capable to say whether the
fall back root check was used. This allows the correct error message,
"root" vs "users with the CAP_PERFMON or CAP_SYS_ADMIN capability", to
be selected.
Tidy uses of perf_cap__capable so that tests aren't repeated if capget
isn't supported.
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Changbin Du <changbin.du@huawei.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linux.dev>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Oliver Upton <oliver.upton@linux.dev>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20240806220614.831914-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Diffstat (limited to 'tools/perf/util/cap.h')
| -rw-r--r-- | tools/perf/util/cap.h | 23 |
1 files changed, 3 insertions, 20 deletions
diff --git a/tools/perf/util/cap.h b/tools/perf/util/cap.h index ae52878c0b2e..0c6a1ff55f07 100644 --- a/tools/perf/util/cap.h +++ b/tools/perf/util/cap.h @@ -3,26 +3,6 @@ #define __PERF_CAP_H #include <stdbool.h> -#include <linux/capability.h> -#include <linux/compiler.h> - -#ifdef HAVE_LIBCAP_SUPPORT - -#include <sys/capability.h> - -bool perf_cap__capable(cap_value_t cap); - -#else - -#include <unistd.h> -#include <sys/types.h> - -static inline bool perf_cap__capable(int cap __maybe_unused) -{ - return geteuid() == 0; -} - -#endif /* HAVE_LIBCAP_SUPPORT */ /* For older systems */ #ifndef CAP_SYSLOG @@ -33,4 +13,7 @@ static inline bool perf_cap__capable(int cap __maybe_unused) #define CAP_PERFMON 38 #endif +/* Query if a capability is supported, used_root is set if the fallback root check was used. */ +bool perf_cap__capable(int cap, bool *used_root); + #endif /* __PERF_CAP_H */ |