linux-kernel - [PATCH v3] x86/vmware: use unsigned integer for shifting

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 27 May 2022 23:27:37 +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,
        stable@...r.kernel.org, Shreenidhi Shedi <sshedi@...are.com>
Subject: [PATCH v3] x86/vmware: use unsigned integer for shifting

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")
Cc: stable@...r.kernel.org
Signed-off-by: Shreenidhi Shedi <sshedi@...are.com>
---
 arch/x86/kernel/cpu/vmware.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/vmware.c b/arch/x86/kernel/cpu/vmware.c
index c04b933f4..02039ec35 100644
--- a/arch/x86/kernel/cpu/vmware.c
+++ b/arch/x86/kernel/cpu/vmware.c
@@ -476,8 +476,8 @@ 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