linux-kernel - [tip: x86/cleanups] x86/asm: Use RDPKRU and WRPKRU mnemonics in <asm/special

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Message-ID: <175588255895.1420.13540168684035053080.tip-bot2@tip-bot2>
Date: Fri, 22 Aug 2025 17:09:18 -0000
From: "tip-bot2 for Uros Bizjak" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Uros Bizjak <ubizjak@...il.com>, "Borislav Petkov (AMD)" <bp@...en8.de>,
 "Peter Zijlstra (Intel)" <peterz@...radead.org>, x86@...nel.org,
 linux-kernel@...r.kernel.org
Subject: [tip: x86/cleanups] x86/asm: Use RDPKRU and WRPKRU mnemonics in
 <asm/special_insns.h>

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

Commit-ID:     966f504977e3a04fcadbaf199e3302e95e8958b7
Gitweb:        https://git.kernel.org/tip/966f504977e3a04fcadbaf199e3302e95e8958b7
Author:        Uros Bizjak <ubizjak@...il.com>
AuthorDate:    Mon, 16 Jun 2025 10:35:57 +02:00
Committer:     Borislav Petkov (AMD) <bp@...en8.de>
CommitterDate: Fri, 22 Aug 2025 18:54:07 +02:00

x86/asm: Use RDPKRU and WRPKRU mnemonics in <asm/special_insns.h>

Current minimum required version of binutils is 2.30, which supports RDPKRU and
WRPKRU instruction mnemonics.

Replace the byte-wise specification of RDPKRU and WRPKRU with these proper
mnemonics.

No functional change intended.

Signed-off-by: Uros Bizjak <ubizjak@...il.com>
Signed-off-by: Borislav Petkov (AMD) <bp@...en8.de>
Acked-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Link: https://lore.kernel.org/20250616083611.157740-1-ubizjak@gmail.com
---
 arch/x86/include/asm/special_insns.h | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/arch/x86/include/asm/special_insns.h b/arch/x86/include/asm/special_insns.h
index fde2bd7..c999145 100644
--- a/arch/x86/include/asm/special_insns.h
+++ b/arch/x86/include/asm/special_insns.h
@@ -75,9 +75,7 @@ static inline u32 rdpkru(void)
 	 * "rdpkru" instruction.  Places PKRU contents in to EAX,
 	 * clears EDX and requires that ecx=0.
 	 */
-	asm volatile(".byte 0x0f,0x01,0xee\n\t"
-		     : "=a" (pkru), "=d" (edx)
-		     : "c" (ecx));
+	asm volatile("rdpkru" : "=a" (pkru), "=d" (edx) : "c" (ecx));
 	return pkru;
 }
 
@@ -89,8 +87,7 @@ static inline void wrpkru(u32 pkru)
 	 * "wrpkru" instruction.  Loads contents in EAX to PKRU,
 	 * requires that ecx = edx = 0.
 	 */
-	asm volatile(".byte 0x0f,0x01,0xef\n\t"
-		     : : "a" (pkru), "c"(ecx), "d"(edx));
+	asm volatile("wrpkru" : : "a" (pkru), "c"(ecx), "d"(edx));
 }
 
 #else