[PATCH v3 2/2] cpupower: Fix amd cpu (family >= 0x17) active state issue

From: 徐福海
Date: Sat Apr 17 2021 - 23:31:42 EST


From: xufuhai <xufuhai@xxxxxxxxxxxx>

If the read_msr function is executed by a non-root user, the function returns
-1, which means that there is no permission to access /dev/cpu/%d/msr, but
cpufreq_has_boost_support should also return -1 immediately, and should not
follow the original logic to return 0, which will cause amd The cpupower tool
returns the boost active state as 0.

Reproduce procedure:
cpupower frequency-info

Reported-by: yangrui <yangrui@xxxxxxxxxxxx>
Signed-off-by: xufuhai <xufuhai@xxxxxxxxxxxx>
Signed-off-by: chenguanqiao <chenguanqiao@xxxxxxxxxxxx>
Signed-off-by: lishujin <lishujin@xxxxxxxxxxxx>
Reviewed-by: Thomas Renninger <trenn@xxxxxxxx>
---
tools/power/cpupower/utils/helpers/misc.c | 13 ++++++++-----
1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/tools/power/cpupower/utils/helpers/misc.c b/tools/power/cpupower/utils/helpers/misc.c
index fc6e34511721..565f8c414396 100644
--- a/tools/power/cpupower/utils/helpers/misc.c
+++ b/tools/power/cpupower/utils/helpers/misc.c
@@ -16,7 +16,7 @@
int cpufreq_has_boost_support(unsigned int cpu, int *support, int *active,
int *states)
{
- int ret;
+ int ret = 0;
unsigned long long val;

*support = *active = *states = 0;
@@ -30,18 +30,21 @@ int cpufreq_has_boost_support(unsigned int cpu, int *support, int *active,
*/

if (cpupower_cpu_info.caps & CPUPOWER_CAP_AMD_CPB_MSR) {
- if (!read_msr(cpu, MSR_AMD_HWCR, &val)) {
+ /*
+ * no permission to access /dev/cpu/%d/msr, return -1 immediately,
+ * and should not follow the original logic to return 0
+ */
+ ret = read_msr(cpu, MSR_AMD_HWCR, &val);
+ if (!ret) {
if (!(val & CPUPOWER_AMD_CPBDIS))
*active = 1;
}
} else {
ret = amd_pci_get_num_boost_states(active, states);
- if (ret)
- return ret;
}
} else if (cpupower_cpu_info.caps & CPUPOWER_CAP_INTEL_IDA)
*support = *active = 1;
- return 0;
+ return ret;
}

int cpupower_intel_get_perf_bias(unsigned int cpu)
--
2.24.3 (Apple Git-128)