linux-kernel - [PATCH v2] x86/vmware: use unsigned integer for shifting

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Message-Id: <20220520140954.597725-1-sshedi@vmware.com>
Date:   Fri, 20 May 2022 19:39:54 +0530
From:   Shreenidhi Shedi <yesshedi@...il.com>
To:     srivatsa@...il.mit.edu, amakhalov@...are.com, tglx@...utronix.de,
        mingo@...hat.com, bp@...en8.de, dave.hansen@...ux.intel.com,
        hpa@...or.com
Cc:     virtualization@...ts.linux-foundation.org, pv-drivers@...are.com,
        x86@...nel.org, linux-kernel@...r.kernel.org, yesshedi@...il.com,
        Shreenidhi Shedi <sshedi@...are.com>
Subject: [PATCH v2] x86/vmware: use unsigned integer for shifting

From: Shreenidhi Shedi <yesshedi@...il.com>

From: Shreenidhi Shedi <sshedi@...are.com>

Shifting signed 32-bit value by 31 bits is implementation-defined
behaviour. Using unsigned is better option for this.

Fixes: 4cca6ea04d31 ("x86/apic: Allow x2apic without IR on VMware platform")

Signed-off-by: Shreenidhi Shedi <sshedi@...are.com>
---
 arch/x86/kernel/cpu/vmware.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index c04b933f48d3..cd809c5b17f0 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -28,6 +28,7 @@
 #include <linux/cpu.h>
 #include <linux/reboot.h>
 #include <linux/static_call.h>
+#include <linux/bits.h>
 #include <asm/div64.h>
 #include <asm/x86_init.h>
 #include <asm/hypervisor.h>
@@ -476,8 +477,8 @@ static bool __init vmware_legacy_x2apic_available(void)
 {
 	uint32_t eax, ebx, ecx, edx;
 	VMWARE_CMD(GETVCPU_INFO, eax, ebx, ecx, edx);
-	return (eax & (1 << VMWARE_CMD_VCPU_RESERVED)) == 0 &&
-	       (eax & (1 << VMWARE_CMD_LEGACY_X2APIC)) != 0;
+	return !(eax & BIT(VMWARE_CMD_VCPU_RESERVED)) &&
+		(eax & BIT(VMWARE_CMD_LEGACY_X2APIC))
 }
 
 #ifdef CONFIG_AMD_MEM_ENCRYPT
-- 
2.36.1