linux-kernel - [PATCH] x86: Use INVPCID mnemonic in invpcid.h

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]

Message-Id: <20200508092247.132147-1-ubizjak@gmail.com>
Date:   Fri,  8 May 2020 11:22:47 +0200
From:   Uros Bizjak <ubizjak@...il.com>
To:     x86@...nel.org, linux-kernel@...r.kernel.org
Cc:     Uros Bizjak <ubizjak@...il.com>, "H. Peter Anvin" <hpa@...or.com>,
        Ingo Molnar <mingo@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH] x86: Use INVPCID mnemonic in invpcid.h

Current minimum required version of binutils is 2.23,
which supports INVPCID instruction mnemonic.

Replace the byte-wise specification of INVPCID with
this proper mnemonic.

Signed-off-by: Uros Bizjak <ubizjak@...il.com>
CC: "H. Peter Anvin" <hpa@...or.com>
CC: Ingo Molnar <mingo@...hat.com>
CC: Thomas Gleixner <tglx@...utronix.de>
---
 arch/x86/include/asm/invpcid.h | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/invpcid.h b/arch/x86/include/asm/invpcid.h
index 989cfa86de85..23749bbca0ad 100644
--- a/arch/x86/include/asm/invpcid.h
+++ b/arch/x86/include/asm/invpcid.h
@@ -12,12 +12,9 @@ static inline void __invpcid(unsigned long pcid, unsigned long addr,
 	 * stale TLB entries and, especially if we're flushing global
 	 * mappings, we don't want the compiler to reorder any subsequent
 	 * memory accesses before the TLB flush.
-	 *
-	 * The hex opcode is invpcid (%ecx), %eax in 32-bit mode and
-	 * invpcid (%rcx), %rax in long mode.
 	 */
-	asm volatile (".byte 0x66, 0x0f, 0x38, 0x82, 0x01"
-		      : : "m" (desc), "a" (type), "c" (&desc) : "memory");
+	asm volatile ("invpcid %1, %0"
+		      : : "r" (type), "m" (desc) : "memory");
 }
 
 #define INVPCID_TYPE_INDIV_ADDR		0
-- 
2.25.4