From owner-svn-src-stable@freebsd.org Mon Sep 16 13:45:32 2019 Return-Path: Delivered-To: svn-src-stable@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 66AFB122399; Mon, 16 Sep 2019 13:45:32 +0000 (UTC) (envelope-from andrew@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) server-signature RSA-PSS (4096 bits) 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 46X6vJ28Cjz4gHw; Mon, 16 Sep 2019 13:45:32 +0000 (UTC) (envelope-from andrew@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 2E17F21203; Mon, 16 Sep 2019 13:45:32 +0000 (UTC) (envelope-from andrew@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x8GDjWaJ096729; Mon, 16 Sep 2019 13:45:32 GMT (envelope-from andrew@FreeBSD.org) Received: (from andrew@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x8GDjW4E096728; Mon, 16 Sep 2019 13:45:32 GMT (envelope-from andrew@FreeBSD.org) Message-Id: <201909161345.x8GDjW4E096728@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: andrew set sender to andrew@FreeBSD.org using -f From: Andrew Turner Date: Mon, 16 Sep 2019 13:45:32 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r352395 - stable/12/sys/arm64/arm64 X-SVN-Group: stable-12 X-SVN-Commit-Author: andrew X-SVN-Commit-Paths: stable/12/sys/arm64/arm64 X-SVN-Commit-Revision: 352395 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-stable@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for all the -stable branches of the src tree List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 16 Sep 2019 13:45:32 -0000 Author: andrew Date: Mon Sep 16 13:45:31 2019 New Revision: 352395 URL: https://svnweb.freebsd.org/changeset/base/352395 Log: MFC r346996: Restore x18 in efi_arch_leave. Some UEFI implementations trash this register and, as we use it as a platform register, the kernel doesn't save it before calling into the UEFI runtime services. As we have a copy in tpidr_el1 restore from there when exiting the EFI environment. PR: 237234, 237055 Reviewed by: manu Tested On: Ampere eMAG Sponsored by: DARPA, AFRL Sponsored by: Ampere Computing (hardware) Differential Revision: https://reviews.freebsd.org/D20127 Modified: stable/12/sys/arm64/arm64/efirt_machdep.c Directory Properties: stable/12/ (props changed) Modified: stable/12/sys/arm64/arm64/efirt_machdep.c ============================================================================== --- stable/12/sys/arm64/arm64/efirt_machdep.c Mon Sep 16 13:41:24 2019 (r352394) +++ stable/12/sys/arm64/arm64/efirt_machdep.c Mon Sep 16 13:45:31 2019 (r352395) @@ -260,6 +260,16 @@ efi_arch_leave(void) { struct thread *td; + /* + * Restore the pcpu pointer. Some UEFI implementations trash it and + * we don't store it before calling into them. To fix this we need + * to restore it after returning to the kernel context. As reading + * curthread will access x18 we need to restore it before loading + * the thread pointer. + */ + __asm __volatile( + "mrs x18, tpidr_el1 \n" + ); td = curthread; __asm __volatile( "msr ttbr0_el1, %0 \n"