From patchwork Fri Dec 6 22:13:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 180938 Delivered-To: patch@linaro.org Received: by 2002:a92:3001:0:0:0:0:0 with SMTP id x1csp1377621ile; Fri, 6 Dec 2019 14:14:08 -0800 (PST) X-Google-Smtp-Source: APXvYqweeX+Wvp1u64ydCj/J+kxkXAlzO8eDFEGtuWH6dtvZCn+COjCAunNRyXcO7gJ9of1ZinLl X-Received: by 2002:a9d:27c4:: with SMTP id c62mr13285811otb.292.1575670448212; Fri, 06 Dec 2019 14:14:08 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1575670448; cv=none; d=google.com; s=arc-20160816; b=NoDGtvlX5/RDBKK64KQ/hg0JkzXm1HV1RwJG70SQF4QHSR5LdGjQMmKvOfPmcuu8mY tj9eTZEGeJs9oMzxMLfjRj7p5oNhtqsT5oMa+nGtL3pWnIsCki1sAx75pK4SIw1YThGS DQ+FxTIcEVbwa07NbubJxwaxoaVGvIdkgMss3e8ZkR4XO3WFI5RV+vCsVjza4a2+T0Vb eiHrgSyaVitGA6XDFRmGRclN3sIdYpx6Mc6jl9GFrNujgbaV7uhyzS5g4Q6ZZCLqALca aAGhf9WL7pyaFDmicGGr4dWkdwn3FTFOoSwy12Ovpd4HF5HZb6KeACmtSmtkUcNFG+i5 GUSg== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:cc:to:from:subject:references :mime-version:message-id:in-reply-to:date:dkim-signature; bh=8cEo3bnB2JOErtud3GvPd9W0QqVJKhLYL3PxcgBL0pc=; b=OOwIIOLEcCLr2Xx2gwTXrfmXYM3QtKfBJ95vuIb0B31zsU2YlKEd5B93zKjHsTbfns LxwU7/AzLt9j4L2abA6na3PK7axRrkSCbDq2emfsBobi8iveuG24EHZBnAZbYVWSy2XF l5h/z4cD3rP8fjKxJ4pHevTa/FsyIkyr+VWU0w9BzimYBzc3rzdaMJIS3t/OxHzqRUIl cpdg1zampjO9WPSiblnn8y+JAX3l8YKdXyH6T8ziy3lmLSxpynJTBpynfjcZgzk1slmC f1oXCVNYJdlg0VKtrH8KYN/U0igxaRqxkH/uAS9ZqX3WMsAMM4ojKhck9+bALP75NNeN b3kw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=CPqQmv4W; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id u16si7965239otq.92.2019.12.06.14.14.07; Fri, 06 Dec 2019 14:14:08 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=CPqQmv4W; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726513AbfLFWOD (ORCPT + 27 others); Fri, 6 Dec 2019 17:14:03 -0500 Received: from mail-pg1-f202.google.com ([209.85.215.202]:48377 "EHLO mail-pg1-f202.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726374AbfLFWOB (ORCPT ); Fri, 6 Dec 2019 17:14:01 -0500 Received: by mail-pg1-f202.google.com with SMTP id p188so4542171pgp.15 for ; Fri, 06 Dec 2019 14:14:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=8cEo3bnB2JOErtud3GvPd9W0QqVJKhLYL3PxcgBL0pc=; b=CPqQmv4WqCQBFArArM8RhJECBGvYc1DYgdPm0u6MVe0Oqz9fNy0AzMgv/8cEGG/BAU aAtkoPugaKUj5l+B6gmWuX+5yxOs+N3ZWs/7Q39Wy7REQEzECblVDxd+is2N3naPmb+Z AqE5JEDUA8ZArMaJifiVfToRBNBcxgJbfiPhEMzN4QT7addM2NEiDmiH+MHpEUOrpMuY 5mCBPj6zphQUPpZkvQxiKNqQZVXSG5ZKCqPY/yDTZAouky3k/+Eg/at4qlCky/F1/OE5 FKwHQSFj6kwEepxRANrOWOQ7iDHcCUd0e0fNHAJuNQWb5uPQ20sY1xVXRPXlBPWsO0w5 mmMA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=8cEo3bnB2JOErtud3GvPd9W0QqVJKhLYL3PxcgBL0pc=; b=NKosL1b35FzYQHAZqEjTBpaMWC0mpL1+tAAnLRYQU4M2LTmuf/854kUxmDnDE2znAj Ma3qdMeZvQ8dLvrUWDe7zdm2PBOL7sLph1GSPdObhFtWZnDMI3bUutpMwq2tWL7rJuyK GxvU12+Lbn96WIlNhrVekufY3ta9AnnHgc48Y3mBhD6aefLceIS9I4Ew1VbdOu2VTiKL jiD/FXWK+s1EY0t3CsCBxXd8sLtC5iGKr8NuXzOXATXlQ+OzIoKLUpwEd90e/Pidy+O1 kUzG785bDjksdmp87lFcyvRWpTmnDYyrjHnZRy8JZoSTjnoAbOzY+7UxlF+E27MxAgUo ZGzQ== X-Gm-Message-State: APjAAAWFU8ataknMMTbzEO6jftSwZKB1Kuop0CX0akcx60Sjt6REE0Bs 33Qaxf6PG2sXDZJ0siTDaVDbpKOMwPgFcHvS3lE= X-Received: by 2002:a63:184d:: with SMTP id 13mr6053846pgy.132.1575670440912; Fri, 06 Dec 2019 14:14:00 -0800 (PST) Date: Fri, 6 Dec 2019 14:13:38 -0800 In-Reply-To: <20191206221351.38241-1-samitolvanen@google.com> Message-Id: <20191206221351.38241-3-samitolvanen@google.com> Mime-Version: 1.0 References: <20191018161033.261971-1-samitolvanen@google.com> <20191206221351.38241-1-samitolvanen@google.com> X-Mailer: git-send-email 2.24.0.393.g34dc348eaf-goog Subject: [PATCH v6 02/15] arm64/lib: copy_page: avoid x18 register in assembler code From: Sami Tolvanen To: Will Deacon , Catalin Marinas , Steven Rostedt , Masami Hiramatsu , Ard Biesheuvel , Mark Rutland Cc: Dave Martin , Kees Cook , Laura Abbott , Marc Zyngier , Nick Desaulniers , Jann Horn , Miguel Ojeda , Masahiro Yamada , clang-built-linux@googlegroups.com, kernel-hardening@lists.openwall.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Sami Tolvanen Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ard Biesheuvel Register x18 will no longer be used as a caller save register in the future, so stop using it in the copy_page() code. Link: https://patchwork.kernel.org/patch/9836869/ Signed-off-by: Ard Biesheuvel [Sami: changed the offset and bias to be explicit] Signed-off-by: Sami Tolvanen Reviewed-by: Mark Rutland --- arch/arm64/lib/copy_page.S | 38 +++++++++++++++++++------------------- 1 file changed, 19 insertions(+), 19 deletions(-) -- 2.24.0.393.g34dc348eaf-goog diff --git a/arch/arm64/lib/copy_page.S b/arch/arm64/lib/copy_page.S index bbb8562396af..290dd3c5266c 100644 --- a/arch/arm64/lib/copy_page.S +++ b/arch/arm64/lib/copy_page.S @@ -34,45 +34,45 @@ alternative_else_nop_endif ldp x14, x15, [x1, #96] ldp x16, x17, [x1, #112] - mov x18, #(PAGE_SIZE - 128) + add x0, x0, #256 add x1, x1, #128 1: - subs x18, x18, #128 + tst x0, #(PAGE_SIZE - 1) alternative_if ARM64_HAS_NO_HW_PREFETCH prfm pldl1strm, [x1, #384] alternative_else_nop_endif - stnp x2, x3, [x0] + stnp x2, x3, [x0, #-256] ldp x2, x3, [x1] - stnp x4, x5, [x0, #16] + stnp x4, x5, [x0, #16 - 256] ldp x4, x5, [x1, #16] - stnp x6, x7, [x0, #32] + stnp x6, x7, [x0, #32 - 256] ldp x6, x7, [x1, #32] - stnp x8, x9, [x0, #48] + stnp x8, x9, [x0, #48 - 256] ldp x8, x9, [x1, #48] - stnp x10, x11, [x0, #64] + stnp x10, x11, [x0, #64 - 256] ldp x10, x11, [x1, #64] - stnp x12, x13, [x0, #80] + stnp x12, x13, [x0, #80 - 256] ldp x12, x13, [x1, #80] - stnp x14, x15, [x0, #96] + stnp x14, x15, [x0, #96 - 256] ldp x14, x15, [x1, #96] - stnp x16, x17, [x0, #112] + stnp x16, x17, [x0, #112 - 256] ldp x16, x17, [x1, #112] add x0, x0, #128 add x1, x1, #128 - b.gt 1b + b.ne 1b - stnp x2, x3, [x0] - stnp x4, x5, [x0, #16] - stnp x6, x7, [x0, #32] - stnp x8, x9, [x0, #48] - stnp x10, x11, [x0, #64] - stnp x12, x13, [x0, #80] - stnp x14, x15, [x0, #96] - stnp x16, x17, [x0, #112] + stnp x2, x3, [x0, #-256] + stnp x4, x5, [x0, #16 - 256] + stnp x6, x7, [x0, #32 - 256] + stnp x8, x9, [x0, #48 - 256] + stnp x10, x11, [x0, #64 - 256] + stnp x12, x13, [x0, #80 - 256] + stnp x14, x15, [x0, #96 - 256] + stnp x16, x17, [x0, #112 - 256] ret ENDPROC(copy_page) From patchwork Fri Dec 6 22:13:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 180940 Delivered-To: patch@linaro.org Received: by 2002:a92:3001:0:0:0:0:0 with SMTP id x1csp1378471ile; Fri, 6 Dec 2019 14:14:52 -0800 (PST) X-Google-Smtp-Source: APXvYqyK2AdBEY/27OjgO2MiYMHZsUyuDE/v3InYTxjiYtY4uczHl1b7PXB7gThGwq50rIVTY/zg X-Received: by 2002:aca:3b54:: with SMTP id i81mr4769938oia.155.1575670492284; Fri, 06 Dec 2019 14:14:52 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1575670492; cv=none; d=google.com; s=arc-20160816; b=U0pkZcDDkn4zwh4sOdympcQyFDIMOz/Vq9wF/VG0lkGTGPvuuVA7lwFNScTpDsT1PO 7uwFqXrRZJrVOifA2veCwA+qwAlr8NJ5oePW6fvIHG+bSu5rQhkdIZy7h2jtONDQhCF3 Xm+LE+l8hiZnaSZIHweDFU6IYIxKGoJkn8vR3cBy7tBPJ7c1wtCBP/ZKasQXn0PVNogo /69mKpWz1Az4lM2bDTari6eKeVKwzKN1ngsxUf8kD5qaWi4aAuNqVA2e1wvR6r3OZ+8G o2cnkbh5GSP+wLELnCDFdApHCp/2ipi0mEpxwzamwIx31aqBcBK4e5qCeScBY23nhnPX +oyQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:cc:to:from:subject:references :mime-version:message-id:in-reply-to:date:dkim-signature; bh=uHQktI1tJwpSEASWzTTpFz8grSSRR6XNFC+ZxIDfRWA=; b=EelDdFK9oW7HQhXsea/ci52HeKcrCoG0QlApQIEWw/VHQoO2HzY+t8GOvuivLuR5gU r8NhhzNVqiYpqZ3ujDMFnI1S5jvGW7gwQPnZAlOmCNEBqCFsKZhgrFVLK66DvpDo++5Q hHR7slvsFbOat8PWMG1NqXfRcbuOWApsCBK8ZP9iIiXCfkZZq75FOC7Q1QtoVMGPBPeC /+xEL02MrPFRDd1WUokF+/UwRvrL9ebwdt+qBSdvNw5mMPsCmMadc1oLJaqe/1RfFqzz xAMdhdlcC60QXkTaJtIreYUzndLR81KWBFeD0RQ/17zPaf2kHEl/TvHzKHFLKE4tB98r vzQw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=JVSCGAex; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id b133si3905140oif.244.2019.12.06.14.14.51; Fri, 06 Dec 2019 14:14:52 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b=JVSCGAex; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726566AbfLFWOH (ORCPT + 27 others); Fri, 6 Dec 2019 17:14:07 -0500 Received: from mail-pj1-f73.google.com ([209.85.216.73]:56990 "EHLO mail-pj1-f73.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726374AbfLFWOE (ORCPT ); Fri, 6 Dec 2019 17:14:04 -0500 Received: by mail-pj1-f73.google.com with SMTP id y11so4319794pjr.23 for ; Fri, 06 Dec 2019 14:14:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=uHQktI1tJwpSEASWzTTpFz8grSSRR6XNFC+ZxIDfRWA=; b=JVSCGAexBdlmEE06N3xdBo1mMgDCQUAzeCFTnY/Fb4PUF3CdyU+S+dJmoeOBcQpskt pQlHMRe4/NoGMN6dRiHhDHP+i8N5fTr0akNG7dMtVlPdnkUgBYg1bOqnIs57w9tpOppn h3P6tDLRd1yFYEckmEJJCQxo0n3g9pJcL6H74Uh/VtTUvo+6MeQgSW2zhKMH+sCUToFI o7GV9ZRZyjNs77Qgw277M/tmmzzGpVVT9AYDXnhrnJbeuQt5uYXmjyR4tDv50Ia46lse OEhmSLK0RFYITFtLphqOwtnwFPc0VNKCOUxoxB5FuaqN/pL+ZqeV8gr3z7A4mE8JaAQ2 ESHQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=uHQktI1tJwpSEASWzTTpFz8grSSRR6XNFC+ZxIDfRWA=; b=Qtl9ui0KA2U3hQ4WgdxKaaRfPJBQ4o6Ij1kEYpnzHxgwqqOzFIpxdSurJBItvfJmBB 6YVVWehjUVGKUUFgkI48ECG7BBphryuylpUAvb3K4FMEEfwRYiLiBNb8FZcyHyuPokt8 EgGiuKh9+TWwn0jIsbgWTO9x7yex9Z28j6JWIqcK2scy6LGeCWJ1jrb6XPn9nNr1E3lf ZPCLvW31x7/wfzNSHc2BgA/UhD3xDY5MwykOStAkIzaM7wFA3glnjSPlYqLkZgRgkqIM 5gsoL8OsNe6yd0ZWegWZrUzbmoUuJhqbgkMkXG80DyBJsPhrRIlJwZFkt1AO4wTNIAK3 dbVA== X-Gm-Message-State: APjAAAURwGHxN2zp04WzSmV9WMHeoSw88EYVqZaY5iA1TUVDQH9fn9N9 phb92uj0ucyiXNUG0SNu6GQ11SZbWxArIctytSk= X-Received: by 2002:a63:ed56:: with SMTP id m22mr5943958pgk.261.1575670443383; Fri, 06 Dec 2019 14:14:03 -0800 (PST) Date: Fri, 6 Dec 2019 14:13:39 -0800 In-Reply-To: <20191206221351.38241-1-samitolvanen@google.com> Message-Id: <20191206221351.38241-4-samitolvanen@google.com> Mime-Version: 1.0 References: <20191018161033.261971-1-samitolvanen@google.com> <20191206221351.38241-1-samitolvanen@google.com> X-Mailer: git-send-email 2.24.0.393.g34dc348eaf-goog Subject: [PATCH v6 03/15] arm64: kvm: stop treating register x18 as caller save From: Sami Tolvanen To: Will Deacon , Catalin Marinas , Steven Rostedt , Masami Hiramatsu , Ard Biesheuvel , Mark Rutland Cc: Dave Martin , Kees Cook , Laura Abbott , Marc Zyngier , Nick Desaulniers , Jann Horn , Miguel Ojeda , Masahiro Yamada , clang-built-linux@googlegroups.com, kernel-hardening@lists.openwall.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Sami Tolvanen Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ard Biesheuvel In preparation of reserving x18, stop treating it as caller save in the KVM guest entry/exit code. Currently, the code assumes there is no need to preserve it for the host, given that it would have been assumed clobbered anyway by the function call to __guest_enter(). Instead, preserve its value and restore it upon return. Link: https://patchwork.kernel.org/patch/9836891/ Signed-off-by: Ard Biesheuvel [Sami: updated commit message, switched from x18 to x29 for the guest context] Signed-off-by: Sami Tolvanen Reviewed-by: Kees Cook Reviewed-by: Marc Zyngier Reviewed-by: Mark Rutland --- arch/arm64/kvm/hyp/entry.S | 45 ++++++++++++++++++++------------------ 1 file changed, 24 insertions(+), 21 deletions(-) -- 2.24.0.393.g34dc348eaf-goog diff --git a/arch/arm64/kvm/hyp/entry.S b/arch/arm64/kvm/hyp/entry.S index e5cc8d66bf53..0c6832ec52b1 100644 --- a/arch/arm64/kvm/hyp/entry.S +++ b/arch/arm64/kvm/hyp/entry.S @@ -22,7 +22,12 @@ .text .pushsection .hyp.text, "ax" +/* + * We treat x18 as callee-saved as the host may use it as a platform + * register (e.g. for shadow call stack). + */ .macro save_callee_saved_regs ctxt + str x18, [\ctxt, #CPU_XREG_OFFSET(18)] stp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)] stp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)] stp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)] @@ -32,6 +37,8 @@ .endm .macro restore_callee_saved_regs ctxt + // We require \ctxt is not x18-x28 + ldr x18, [\ctxt, #CPU_XREG_OFFSET(18)] ldp x19, x20, [\ctxt, #CPU_XREG_OFFSET(19)] ldp x21, x22, [\ctxt, #CPU_XREG_OFFSET(21)] ldp x23, x24, [\ctxt, #CPU_XREG_OFFSET(23)] @@ -48,7 +55,7 @@ ENTRY(__guest_enter) // x0: vcpu // x1: host context // x2-x17: clobbered by macros - // x18: guest context + // x29: guest context // Store the host regs save_callee_saved_regs x1 @@ -67,31 +74,28 @@ alternative_else_nop_endif ret 1: - add x18, x0, #VCPU_CONTEXT + add x29, x0, #VCPU_CONTEXT // Macro ptrauth_switch_to_guest format: // ptrauth_switch_to_guest(guest cxt, tmp1, tmp2, tmp3) // The below macro to restore guest keys is not implemented in C code // as it may cause Pointer Authentication key signing mismatch errors // when this feature is enabled for kernel code. - ptrauth_switch_to_guest x18, x0, x1, x2 + ptrauth_switch_to_guest x29, x0, x1, x2 // Restore guest regs x0-x17 - ldp x0, x1, [x18, #CPU_XREG_OFFSET(0)] - ldp x2, x3, [x18, #CPU_XREG_OFFSET(2)] - ldp x4, x5, [x18, #CPU_XREG_OFFSET(4)] - ldp x6, x7, [x18, #CPU_XREG_OFFSET(6)] - ldp x8, x9, [x18, #CPU_XREG_OFFSET(8)] - ldp x10, x11, [x18, #CPU_XREG_OFFSET(10)] - ldp x12, x13, [x18, #CPU_XREG_OFFSET(12)] - ldp x14, x15, [x18, #CPU_XREG_OFFSET(14)] - ldp x16, x17, [x18, #CPU_XREG_OFFSET(16)] - - // Restore guest regs x19-x29, lr - restore_callee_saved_regs x18 - - // Restore guest reg x18 - ldr x18, [x18, #CPU_XREG_OFFSET(18)] + ldp x0, x1, [x29, #CPU_XREG_OFFSET(0)] + ldp x2, x3, [x29, #CPU_XREG_OFFSET(2)] + ldp x4, x5, [x29, #CPU_XREG_OFFSET(4)] + ldp x6, x7, [x29, #CPU_XREG_OFFSET(6)] + ldp x8, x9, [x29, #CPU_XREG_OFFSET(8)] + ldp x10, x11, [x29, #CPU_XREG_OFFSET(10)] + ldp x12, x13, [x29, #CPU_XREG_OFFSET(12)] + ldp x14, x15, [x29, #CPU_XREG_OFFSET(14)] + ldp x16, x17, [x29, #CPU_XREG_OFFSET(16)] + + // Restore guest regs x18-x29, lr + restore_callee_saved_regs x29 // Do not touch any register after this! eret @@ -114,7 +118,7 @@ ENTRY(__guest_exit) // Retrieve the guest regs x0-x1 from the stack ldp x2, x3, [sp], #16 // x0, x1 - // Store the guest regs x0-x1 and x4-x18 + // Store the guest regs x0-x1 and x4-x17 stp x2, x3, [x1, #CPU_XREG_OFFSET(0)] stp x4, x5, [x1, #CPU_XREG_OFFSET(4)] stp x6, x7, [x1, #CPU_XREG_OFFSET(6)] @@ -123,9 +127,8 @@ ENTRY(__guest_exit) stp x12, x13, [x1, #CPU_XREG_OFFSET(12)] stp x14, x15, [x1, #CPU_XREG_OFFSET(14)] stp x16, x17, [x1, #CPU_XREG_OFFSET(16)] - str x18, [x1, #CPU_XREG_OFFSET(18)] - // Store the guest regs x19-x29, lr + // Store the guest regs x18-x29, lr save_callee_saved_regs x1 get_host_ctxt x2, x3 From patchwork Fri Dec 6 22:13:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sami Tolvanen X-Patchwork-Id: 180939 Delivered-To: patch@linaro.org Received: by 2002:a92:3001:0:0:0:0:0 with SMTP id x1csp1378406ile; Fri, 6 Dec 2019 14:14:48 -0800 (PST) X-Google-Smtp-Source: APXvYqxGNFZpfvNiVukiRkaoFcashEWbsnQfi0OxgV+B8cf60TyVU9fud5oUEz/Mp+GV5q2bcSw0 X-Received: by 2002:a9d:7c97:: with SMTP id q23mr12768882otn.253.1575670488143; Fri, 06 Dec 2019 14:14:48 -0800 (PST) ARC-Seal: i=1; a=rsa-sha256; t=1575670488; cv=none; d=google.com; s=arc-20160816; b=UEeTCiGk3qk6nkqD8SrTJFobCYPkUDMmWEz4LQ+6f7asvvuoQBiWbmwatmXA0tICsL B3eIllGdUOQDVv0+3yNo0d3iIeaJDs3PR9DFBXN1gg1YLElelSTFb0vVJAEJ4h7Jw1Dv RoiFWBDZGBwvUDCDXOerRlIzO/R1UwG/KnoBka4cwe1RfwG5vvEwnIcR2rLmC0BPyOEz 9vCoFtqzl7UA5IGFMCcZsvSZ65bIkoohgKy7zA4Gxx7ziObFhYXAHzJ0umw6jXONWr3R AmN01IgQGOnRYrCANc0jXZIRumG7NmYRCjKpm4v7LFwvF6pA/CHxBTgCbcqgV2Qgq3Dh imDA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:cc:to:from:subject:references :mime-version:message-id:in-reply-to:date:dkim-signature; bh=XVGcsXtiiPVE9a9TFllXGgGHEKcXDxSx20NO6hJScDc=; b=sXH/oEumq9AiW9VFFCoOQN0rw5X3ocIlhg62dC+pE7xYptQNVJfsj+mxEBU4ep746j q8auM42WSpbK3/jO8WU0kpyvqd2NIsgpccoqBfSozvhh8ZL3nqkUN2tBRyF4noWcTqef 1zjKgYNRrfsbxNOuwkMMfuYZ9o3D3OtBrqtY4YBETVyf9JzozL+UDADp2OSTBWrMk3pa 7o08ENiIZShrKpXQSX2TwHIyr1lBM57B8ZlPuXJEW9+XjbveQGWhr1m9JmNV38RQERlw AfDKI1c2psrOcayyr3UoxjIPQQFJTTYngNqRIHegGy4eWT8VhyRTy65kgn0QzoGOHAix OSAw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b="JUnATL/q"; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id b133si3905140oif.244.2019.12.06.14.14.47; Fri, 06 Dec 2019 14:14:48 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@google.com header.s=20161025 header.b="JUnATL/q"; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=REJECT sp=REJECT dis=NONE) header.from=google.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726598AbfLFWOK (ORCPT + 27 others); Fri, 6 Dec 2019 17:14:10 -0500 Received: from mail-pg1-f201.google.com ([209.85.215.201]:38480 "EHLO mail-pg1-f201.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726552AbfLFWOH (ORCPT ); Fri, 6 Dec 2019 17:14:07 -0500 Received: by mail-pg1-f201.google.com with SMTP id l13so4558951pgt.5 for ; Fri, 06 Dec 2019 14:14:06 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:in-reply-to:message-id:mime-version:references:subject:from:to :cc; bh=XVGcsXtiiPVE9a9TFllXGgGHEKcXDxSx20NO6hJScDc=; b=JUnATL/qYc1oxv8iBdTskfQzu3dUUjyggOYJEMcIQnnUL/Y0NRoC+SEMllJtcFOWiS N/ulKnmZgrhoasRLRMaSLDH6091pEOUYgXXuTdPJyA/+/zT+NjML18Xbk0q7JQJZlyWp 6rTkEVNH+fLD7+o9KvYuKvTopFNc6WKI4uib8O/Vx3iw4Shp3SUt/TKbmahphI0HKiU4 BPRPCXf6h87GZeFyHIHYFqSn3p3Rv69hjOpYO3XFPBCkg3Q3z4MrJ2EA56qijI8w4jiX NQZtE0UhN3gJbyVa0+qGFUMyTZbRuK6Bc5RytwdbEZTnrQcmzPqvaU68OoqewWa4Q8Up 87AQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=XVGcsXtiiPVE9a9TFllXGgGHEKcXDxSx20NO6hJScDc=; b=T7qqYmA8vquPRJiAb8xbeIaqQaA1p/1Lw8OC4/Yj9CJunnuazlww/9kX9tytfknRzm KAZoZwQ/KQHs20awWTuyxZKRHbf/JN9Ov0I2hlmaW5NrdaNRCIrSl1H9S25KEo8pSK6D z/vnCI2UhxfNMPY5Xrq4abqKw2dfM+TX4OvwxZQpbcXixWYXnbycmQcdwEsfE0rSGLUM vZvbXGkw4BH5b1Szm3c3NdAayOXoIBo2+Et2xfKuvuPN9b0cvuM+xJ2frqxC8Z/voPpP 1SskbNfc8/WkJLaR+IX5BDd3htK9dX3PSGpYtBbI8a8Y17rorCYOkIu+lL6RDvxSyjmb Cy0A== X-Gm-Message-State: APjAAAWALJ9ALcZ94cyyiXx81o4jgRja+8w5bDRnIL1ktMHgho4B6XhI MzQnk/omO+Rc1QJL6vlDMsNxHAVa+R5+C/NekN0= X-Received: by 2002:a63:1c66:: with SMTP id c38mr5983922pgm.368.1575670446054; Fri, 06 Dec 2019 14:14:06 -0800 (PST) Date: Fri, 6 Dec 2019 14:13:40 -0800 In-Reply-To: <20191206221351.38241-1-samitolvanen@google.com> Message-Id: <20191206221351.38241-5-samitolvanen@google.com> Mime-Version: 1.0 References: <20191018161033.261971-1-samitolvanen@google.com> <20191206221351.38241-1-samitolvanen@google.com> X-Mailer: git-send-email 2.24.0.393.g34dc348eaf-goog Subject: [PATCH v6 04/15] arm64: kernel: avoid x18 in __cpu_soft_restart From: Sami Tolvanen To: Will Deacon , Catalin Marinas , Steven Rostedt , Masami Hiramatsu , Ard Biesheuvel , Mark Rutland Cc: Dave Martin , Kees Cook , Laura Abbott , Marc Zyngier , Nick Desaulniers , Jann Horn , Miguel Ojeda , Masahiro Yamada , clang-built-linux@googlegroups.com, kernel-hardening@lists.openwall.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Sami Tolvanen Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ard Biesheuvel The code in __cpu_soft_restart() uses x18 as an arbitrary temp register, which will shortly be disallowed. So use x8 instead. Link: https://patchwork.kernel.org/patch/9836877/ Signed-off-by: Ard Biesheuvel [Sami: updated commit message] Signed-off-by: Sami Tolvanen Reviewed-by: Mark Rutland Reviewed-by: Kees Cook --- arch/arm64/kernel/cpu-reset.S | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 2.24.0.393.g34dc348eaf-goog diff --git a/arch/arm64/kernel/cpu-reset.S b/arch/arm64/kernel/cpu-reset.S index 6ea337d464c4..32c7bf858dd9 100644 --- a/arch/arm64/kernel/cpu-reset.S +++ b/arch/arm64/kernel/cpu-reset.S @@ -42,11 +42,11 @@ ENTRY(__cpu_soft_restart) mov x0, #HVC_SOFT_RESTART hvc #0 // no return -1: mov x18, x1 // entry +1: mov x8, x1 // entry mov x0, x2 // arg0 mov x1, x3 // arg1 mov x2, x4 // arg2 - br x18 + br x8 ENDPROC(__cpu_soft_restart) .popsection