[PATCH] x86/resctrl: Fix a silly -Wunused-but-set-variable warning

Borislav Petkov
2023-01-24T18:13:20Z

From: "Borislav Petkov (AMD)" <bp@alien8.de>

clang correctly complains

arch/x86/kernel/cpu/resctrl/rdtgroup.c:1456:6: warning: variable \
'h' set but not used [-Wunused-but-set-variable]
u32 h;
^

but it can't know whether this use is innocuous or really a problem.
There's a reason why those warning switches are behind a W=1 and not
enabled by default - yes, one needs to do:

make W=1 CC=clang HOSTCC=clang arch/x86/kernel/cpu/resctrl/

with clang 14 in order to trigger it.

I would normally not take a silly fix like that but this one is simple
and doesn't make the code uglier so...

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/202301242015.kbzkVteJ-lkp@intel.com
---
arch/x86/kernel/cpu/resctrl/rdtgroup.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 5990589f8a21..e2c1599d1b37 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -1453,17 +1453,17 @@ static void mon_event_config_read(void *info)
{
struct mon_config_info *mon_info = info;
unsigned int index;
- u32 h;
+ u64 msrval;

index = mon_event_config_index_get(mon_info->evtid);
if (index == INVALID_CONFIG_INDEX) {
pr_warn_once("Invalid event id %d\n", mon_info->evtid);
return;
}
- rdmsr(MSR_IA32_EVT_CFG_BASE + index, mon_info->mon_config, h);
+ rdmsrl(MSR_IA32_EVT_CFG_BASE + index, msrval);

/* Report only the valid event configuration bits */
- mon_info->mon_config &= MAX_EVT_CONFIG_BITS;
+ mon_info->mon_config = msrval & MAX_EVT_CONFIG_BITS;
}

static void mondata_config_read(struct rdt_domain *d, struct mon_config_info *mon_info)
--
2.35.1

--
Regards/Gruss,
Boris.