[PATCH AUTOSEL 6.6 05/29] tools/power turbostat: Fix warning upon failed /dev/cpu_dma_latency read

Sasha Levin
2024-04-22T23:56:18Z

From: Len Brown <len.brown@intel.com>

[ Upstream commit b6fe938317eed58e8c687bd5965a956e15fb5828 ]

Previously a failed read of /dev/cpu_dma_latency erroneously complained
turbostat: capget(CAP_SYS_ADMIN) failed, try "# setcap cap_sys_admin=ep ./turbostat

This went unnoticed because this file is typically visible to root,
and turbostat was typically run as root.

Going forward, when a non-root user can run turbostat...
Complain about failed read access to this file only if --debug is used.

Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
tools/power/x86/turbostat/turbostat.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/power/x86/turbostat/turbostat.c b/tools/power/x86/turbostat/turbostat.c
index 4dfeda4870f71..0561362301c53 100644
--- a/tools/power/x86/turbostat/turbostat.c
+++ b/tools/power/x86/turbostat/turbostat.c
@@ -5479,7 +5479,8 @@ void print_dev_latency(void)

fd = open(path, O_RDONLY);
if (fd < 0) {
- warnx("capget(CAP_SYS_ADMIN) failed, try \"# setcap cap_sys_admin=ep %s\"", progname);
+ if (debug)
+ warnx("Read %s failed", path);
return;
}

--
2.43.0