From nobody Sat Nov 23 22:36:23 2024 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (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 E4FA219CC22; Mon, 11 Nov 2024 12:54:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731329679; cv=none; b=EjezGO8zd7tGLkIZdalUHw0kyJuGTf6ObJiltdLJLYf3wagdvJR6DQAUQHMfkeOq9atOoG4WLY0Gj4ZGP2u6s7UhHCRG1IbpgRZwrSrBFJCSpq9fNQ+OGtUB7f+QpLx8mQHeHLBJ4L4/qnyVEAtFgLhX4wHR9l1y9Ue6fAYyqk4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731329679; c=relaxed/simple; bh=m4wNEd9VZkRxLFzfitrd/BccDMwMsl2i+sWH+ZJYUu8=; h=Message-Id:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=Z3PUyF+yTCxwd7QmRcFm9St+T6e/1e7nxSvxxOjhlDbDp04orY1oLoicpZBFFtpG0TTg8cKsrz9CB+ul5VU4dtsuHAz66Gjf6jiKSho2cUyjgfrAbMD8smqWOu5myGM5/bMNIcKqgS/QeIsqzwPEomn+Qv7QXSjTry0tNVDm1zo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=tKMoI+CP; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="tKMoI+CP" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Type:MIME-Version:References: Subject:Cc:To:From:Date:Message-Id:Sender:Reply-To:Content-Transfer-Encoding: Content-ID:Content-Description:In-Reply-To; bh=6BeHqEa2jz3IbAPf4WR7i0ahbBf1txiVvqLKV6vDwuM=; b=tKMoI+CP/PLxiqcur0M0UoG0pN xYxe/ni2cjlN/+mDic/H+036MOmGoS0rMmgC4CyxiRpz4slRc2GJj7BS7DqRU592VLyTselmcyqat bFGRHrM1uh5Gcxl0DmhUybDQI1cSQqTjF/MTcAclqKeOnK+mUgcyJ2KW2woK6AVqGOoWCn3wxrOuc OGdzlmA+09HDpJsmjzVBo3AIGrMI4leOt+TIX8n8TEodWuRol+vaNxTvjpjp2dKWFtcL5u3SK89Jk gsax5mCH5oTMS4vbH4qGZ/N3+cdb/TpROmlAl9ficPHXRevmGQHuT1pm0yz829b02yhaVyS7XfO0R AM46fd/Q==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1tATwA-0000000Coes-1zxz; Mon, 11 Nov 2024 12:54:34 +0000 Received: by noisy.programming.kicks-ass.net (Postfix, from userid 0) id E98873021E5; Mon, 11 Nov 2024 13:54:32 +0100 (CET) Message-Id: <20241111125219.140262800@infradead.org> User-Agent: quilt/0.65 Date: Mon, 11 Nov 2024 12:59:45 +0100 From: Peter Zijlstra To: seanjc@google.com, pbonzini@redhat.com, jpoimboe@redhat.com, tglx@linutronix.de Cc: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org, jthoughton@google.com, "Peter Zijlstra (Intel)" Subject: [PATCH v2 10/12] x86,nospec: Simplify {JMP,CALL}_NOSPEC (part 2) References: <20241111115935.796797988@infradead.org> 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 Content-Type: text/plain; charset="utf-8" Counterpart to 09d09531a51a ("x86,nospec: Simplify {JMP,CALL}_NOSPEC"), x86_64 will rewrite all this anyway, see apply_retpoline. Signed-off-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/nospec-branch.h | 29 +++++++++++------------------ 1 file changed, 11 insertions(+), 18 deletions(-) --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -429,31 +429,24 @@ static inline void call_depth_return_thu =20 #ifdef CONFIG_X86_64 =20 +#define __CS_PREFIX \ + ".irp rs,r8,r9,r10,r11,r12,r13,r14,r15\n" \ + ".ifc %V[thunk_target],\\rs\n" \ + ".byte 0x2e\n" \ + ".endif\n" \ + ".endr\n" + /* * Inline asm uses the %V modifier which is only in newer GCC * which is ensured when CONFIG_MITIGATION_RETPOLINE is defined. */ # define CALL_NOSPEC \ - ALTERNATIVE_2( \ - ANNOTATE_RETPOLINE_SAFE \ - "call *%[thunk_target]\n", \ - "call __x86_indirect_thunk_%V[thunk_target]\n", \ - X86_FEATURE_RETPOLINE, \ - "lfence;\n" \ - ANNOTATE_RETPOLINE_SAFE \ - "call *%[thunk_target]\n", \ - X86_FEATURE_RETPOLINE_LFENCE) + __CS_PREFIX \ + "call __x86_indirect_thunk_%V[thunk_target]\n" =20 # define JMP_NOSPEC \ - ALTERNATIVE_2( \ - ANNOTATE_RETPOLINE_SAFE \ - "jmp *%[thunk_target]\n", \ - "jmp __x86_indirect_thunk_%V[thunk_target]\n", \ - X86_FEATURE_RETPOLINE, \ - "lfence;\n" \ - ANNOTATE_RETPOLINE_SAFE \ - "jmp *%[thunk_target]\n", \ - X86_FEATURE_RETPOLINE_LFENCE) + __CS_PREFIX \ + "jmp __x86_indirect_thunk_%V[thunk_target]\n" =20 # define THUNK_TARGET(addr) [thunk_target] "r" (addr)