From nobody Sat Aug 1 21:31:43 2026 Received: from sender4-op-o15.zoho.com (sender4-op-o15.zoho.com [136.143.188.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4EDB326056C; Sat, 1 Aug 2026 18:30:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.15 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785609032; cv=pass; b=YMY50aWbpUFV2eKAOcSUKELv0tBMDjhtHgOUCR5IxC44xBrrtv3ZFOfcBulxhUUiqPADkYGvGSqnbFthLqLuyWt7rQpcioJDkIHtWjBjFhWU34fr3eNnMHakFV3PFHtMIXcVtvAZips7qNGZjfI/F1ioUipF+PTCAc3n2YoeYN0= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785609032; c=relaxed/simple; bh=LsLocPztgc0MIEvQ+cd2LUVytDQYlNNR5kx3yB2tALY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=BtKaObSLaq/XE4eNAHT/Sx6vA9QW1no6wovU4IwdhufsIefWGJbZp0hYKBIbk3f9GxZ37wMl4FRbIhZ+ufljx3HOPn7Stmc7ceb++Ag4Vljz2e3fZxm/mHWjxLAlQiemD2EpLuhrEVOJpEDeSUmplZLokKu5CmpVux0h3R9tX2s= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ziyao.cc; spf=pass smtp.mailfrom=ziyao.cc; dkim=pass (1024-bit key) header.d=ziyao.cc header.i=me@ziyao.cc header.b=I0bfAgbR; arc=pass smtp.client-ip=136.143.188.15 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=ziyao.cc Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=ziyao.cc Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=ziyao.cc header.i=me@ziyao.cc header.b="I0bfAgbR" ARC-Seal: i=1; a=rsa-sha256; t=1785609003; cv=none; d=zohomail.com; s=zohoarc; b=IutjnJ0eKwPlwye5dSJLG6343UF/Xh3tOHQ9KGAu+/1JwDVpO7zdEuTfRc4A/+rzxI0WXSrsVxUVleUyo+wOnFUZ9W1YnIKHpUNxzw28WP0q83VpccXYZC1Yj/SNNPG8CepVHoI7btZxZIxQlUiAd75K7agLmsfw++WGDzYSbUA= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1785609003; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:MIME-Version:Message-ID:Subject:Subject:To:To:Message-Id:Reply-To; bh=mCppxZrojOm46wdBTGTzBj3o6Vvdx98OHQ45neCAuH0=; b=GV5t60dLo0FARDPQQHcNQlkTVlwoyB+JHtBx+PCkK6tiYpvY+gnUOKuYnPsiuFKaotrHxoAicPG2FO1bxKzVGur4F1xILJN1We0KO7vB9RoKZ9SdQ7HDXztEvSzIKfxiKu11QelYGXHIem8VyJ2z471yTozD9LF6s/Zo0jiiiFE= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=ziyao.cc; spf=pass smtp.mailfrom=me@ziyao.cc; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1785609003; s=zmail; d=ziyao.cc; i=me@ziyao.cc; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:MIME-Version:Content-Transfer-Encoding:Message-Id:Reply-To; bh=mCppxZrojOm46wdBTGTzBj3o6Vvdx98OHQ45neCAuH0=; b=I0bfAgbReKZq8ieSkMwQI5NUqzRGW2zB5frfowg3WdCZsTEFUaqaM9ON/lelvCf4 vcN0H1oSQr/okAwtyZDfMD0BR188HuibJssUH1zHKyA2Ghb5FGDqkiWDVNEGUKpy1J+ In5+u9CR3K/Bj50NhHR8K70dq8JMpxCNT6QCHjCE= Received: by mx.zohomail.com with SMTPS id 1785609001608693.425839747884; Sat, 1 Aug 2026 11:30:01 -0700 (PDT) From: Yao Zi To: Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Randy Dunlap , "Peter Zijlstra (Intel)" Cc: x86@kernel.org, linux-kernel@vger.kernel.org, Yao Zi , stable@vger.kernel.org Subject: [PATCH] x86/locking: Use sfence for wmb() if SSE is available Date: Sat, 1 Aug 2026 18:29:53 +0000 Message-ID: <20260801182953.15069-1-me@ziyao.cc> X-Mailer: git-send-email 2.54.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMailClient: External Content-Type: text/plain; charset="utf-8" When adding cc clobber to wmb()'s definition, the alternative() condition to use sfence was incorrectly raised from X86_FEATURE_XMM to X86_FEATURE_XMM2. Restore the correct constraint for potential better performance on machines without SSE2. Fixes: bd922477d935 ("locking/x86: Add cc clobber for ADDL") Signed-off-by: Yao Zi Cc: stable@vger.kernel.org --- arch/x86/include/asm/barrier.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h index b0096b5645a9..e0e59da15748 100644 --- a/arch/x86/include/asm/barrier.h +++ b/arch/x86/include/asm/barrier.h @@ -17,7 +17,7 @@ #define rmb() asm volatile(ALTERNATIVE("lock addl $0,-4(%%esp)", "lfence",= \ X86_FEATURE_XMM2) ::: "memory", "cc") #define wmb() asm volatile(ALTERNATIVE("lock addl $0,-4(%%esp)", "sfence",= \ - X86_FEATURE_XMM2) ::: "memory", "cc") + X86_FEATURE_XMM) ::: "memory", "cc") #else #define __mb() asm volatile("mfence":::"memory") #define __rmb() asm volatile("lfence":::"memory") --=20 2.54.0