linux-kernel - [tip: x86/cache] x86/resctrl: Fix a silly -Wunused-but-set-variable warning

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Message-ID: <167472926132.4906.9798540795502253502.tip-bot2@tip-bot2>
Date:   Thu, 26 Jan 2023 10:34:21 -0000
From:   "tip-bot2 for Borislav Petkov (AMD)" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     kernel test robot <lkp@...el.com>,
        "Borislav Petkov (AMD)" <bp@...en8.de>,
        Reinette Chatre <reinette.chatre@...el.com>,
        Babu Moger <babu.moger@....com>, x86@...nel.org,
        linux-kernel@...r.kernel.org
Subject: [tip: x86/cache] x86/resctrl: Fix a silly -Wunused-but-set-variable warning

The following commit has been merged into the x86/cache branch of tip:

Commit-ID:     793207bad71c5339c614d12ac21d627da7bf771d
Gitweb:        https://git.kernel.org/tip/793207bad71c5339c614d12ac21d627da7bf771d
Author:        Borislav Petkov (AMD) <bp@...en8.de>
AuthorDate:    Tue, 24 Jan 2023 19:01:05 +01:00
Committer:     Borislav Petkov (AMD) <bp@...en8.de>
CommitterDate: Thu, 26 Jan 2023 11:15:20 +01:00

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

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@...el.com>
Signed-off-by: Borislav Petkov (AMD) <bp@...en8.de>
Acked-by: Reinette Chatre <reinette.chatre@...el.com>
Tested-by: Babu Moger <babu.moger@....com>
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 5990589..e2c1599 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)