From owner-svn-src-head@freebsd.org Sun Jul 19 17:47:56 2020 Return-Path: Delivered-To: svn-src-head@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 954433649AA; Sun, 19 Jul 2020 17:47:56 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4B8slJ3MHbz3ZY8; Sun, 19 Jul 2020 17:47:56 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 572571F5AC; Sun, 19 Jul 2020 17:47:56 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 06JHluZb049505; Sun, 19 Jul 2020 17:47:56 GMT (envelope-from kib@FreeBSD.org) Received: (from kib@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 06JHluPi049504; Sun, 19 Jul 2020 17:47:56 GMT (envelope-from kib@FreeBSD.org) Message-Id: <202007191747.06JHluPi049504@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: kib set sender to kib@FreeBSD.org using -f From: Konstantin Belousov Date: Sun, 19 Jul 2020 17:47:56 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r363329 - head/sys/amd64/amd64 X-SVN-Group: head X-SVN-Commit-Author: kib X-SVN-Commit-Paths: head/sys/amd64/amd64 X-SVN-Commit-Revision: 363329 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.33 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sun, 19 Jul 2020 17:47:56 -0000 Author: kib Date: Sun Jul 19 17:47:55 2020 New Revision: 363329 URL: https://svnweb.freebsd.org/changeset/base/363329 Log: Simplify non-pti syscall entry on amd64. Limit manipulations to use %rax as scratch to the pti portion of the syscall entry code. Submitted by: alc Reviewed by: markj MFC after: 1 week Differential revision: https://reviews.freebsd.org/D25722 Modified: head/sys/amd64/amd64/exception.S Modified: head/sys/amd64/amd64/exception.S ============================================================================== --- head/sys/amd64/amd64/exception.S Sun Jul 19 17:27:48 2020 (r363328) +++ head/sys/amd64/amd64/exception.S Sun Jul 19 17:47:55 2020 (r363329) @@ -526,17 +526,17 @@ prot_addrf: IDTVEC(fast_syscall_pti) swapgs lfence - movq %rax,PCPU(SCRATCH_RAX) cmpq $~0,PCPU(UCR3) je fast_syscall_common + movq %rax,PCPU(SCRATCH_RAX) movq PCPU(KCR3),%rax movq %rax,%cr3 + movq PCPU(SCRATCH_RAX),%rax jmp fast_syscall_common SUPERALIGN_TEXT IDTVEC(fast_syscall) swapgs lfence - movq %rax,PCPU(SCRATCH_RAX) fast_syscall_common: movq %rsp,PCPU(SCRATCH_RSP) movq PCPU(RSP0),%rsp @@ -547,7 +547,6 @@ fast_syscall_common: movq %rcx,TF_RIP(%rsp) /* %rcx original value is in %r10 */ movq PCPU(SCRATCH_RSP),%r11 /* %r11 already saved */ movq %r11,TF_RSP(%rsp) /* user stack pointer */ - movq PCPU(SCRATCH_RAX),%rax /* * Save a few arg registers early to free them for use in * handle_ibrs_entry(). %r10 is especially tricky. It is not an