From patchwork Tue Nov 15 23:09:27 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kyle Huey X-Patchwork-Id: 13044274 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 11A0CC43219 for ; Tue, 15 Nov 2022 23:12:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231421AbiKOXMA (ORCPT ); Tue, 15 Nov 2022 18:12:00 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57098 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232157AbiKOXLe (ORCPT ); Tue, 15 Nov 2022 18:11:34 -0500 Received: from mail-pj1-x1029.google.com (mail-pj1-x1029.google.com [IPv6:2607:f8b0:4864:20::1029]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4DA0A2E6A6 for ; Tue, 15 Nov 2022 15:11:33 -0800 (PST) Received: by mail-pj1-x1029.google.com with SMTP id r61-20020a17090a43c300b00212f4e9cccdso533517pjg.5 for ; Tue, 15 Nov 2022 15:11:33 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kylehuey.com; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=qhCq8AfDMkagyPimKyHUX7gwQAIYuE0429CZlbx4GKo=; b=GimrCofVDchBbipFskt1iUCOXnsWmIdeeUhJXRau6K5YrKcWWLcbm4F6m/Rt+KUJAw +WRhPd+7BzDfOsxy0qrFpcfJzeV+BcJpYPqUUHzjI40fCqFnDZ/60Sn/OqkCFCwvJ1Pa 8fbLcULMD5kLsZxJQx+HNteTzYyOKSAqUvU6rdjNsW8sgOgMMV75IDivsBzAHyMGZTSN 1LCWAgm2a9FTx2BX9r0sq0SdTky6C/z5V1IyDlILeX5grbmZ82gCRccKNehMA4xWGVLe jDkvaMW/D3aT8UGl4tk5nqXwC7c4CNpe93sbiL70+q70UZ6IwOrMNi/O9mCpoQygC8oy X3Rg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=qhCq8AfDMkagyPimKyHUX7gwQAIYuE0429CZlbx4GKo=; b=1MbGKlJhIGh1OoSl72QjS37c5qo5UCQa5Je5sTz083Vq9rAmB8OA5Tf12oCQKY5jzh b8wOLapTQBJBUbzi83pkzQcQm9zrK6VJJlW24RxCM8l3CTknbrmAuTz82qKiVdFD9xty PPDJhfnaUjY7J5zER9wqA6K9ud+RcYBMNYDFJnRQ//O0pdj6t8Tg+mnN/mJcLvQDqxsH YcpP0j82IhACbdMLcg8EcCBSNe1hDbsG7G4XKz6+QsH/OwwugJqf5eOIhIp000bU68qs u3iMwW2qZqsHE47yuBtpgv/56ubT1+Y96dgB4c9fQNQWuBWQjn0F5w22BZo9oRbR4n6x I/Mg== X-Gm-Message-State: ANoB5pmdYsub1z8a8BGNh0RFDaq+/8vN5wwNlyyHS8MS2d3rnWNhL8G9 CpOEJ3qkYUXfIbuCpETOTE+qow== X-Google-Smtp-Source: AA0mqf50b32MPLpexUP0a4tDcIJCk5x0ZodYS2aCyV4pcpz0b8K3PiqlqkiYrSo+RAIM5LHM0r8f/w== X-Received: by 2002:a17:902:e483:b0:188:b44b:598 with SMTP id i3-20020a170902e48300b00188b44b0598mr6272266ple.54.1668553892785; Tue, 15 Nov 2022 15:11:32 -0800 (PST) Received: from minbar.home.kylehuey.com (c-71-198-251-229.hsd1.ca.comcast.net. [71.198.251.229]) by smtp.gmail.com with ESMTPSA id f15-20020a62380f000000b0056c360af4e3sm9308372pfa.9.2022.11.15.15.11.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Nov 2022 15:11:32 -0800 (PST) From: Kyle Huey X-Google-Original-From: Kyle Huey To: Dave Hansen Cc: Linus Torvalds , Thomas Gleixner , Borislav Petkov , Ingo Molnar , x86@kernel.org, "H. Peter Anvin" , Paolo Bonzini , Andy Lutomirski , Peter Zijlstra , Sean Christopherson , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Robert O'Callahan , David Manouchehri , Kyle Huey Subject: [PATCH v7 1/6] x86/fpu: Take task_struct* in copy_sigframe_from_user_to_xstate() Date: Tue, 15 Nov 2022 15:09:27 -0800 Message-Id: <20221115230932.7126-2-khuey@kylehuey.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221115230932.7126-1-khuey@kylehuey.com> References: <20221115230932.7126-1-khuey@kylehuey.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org This will allow copy_sigframe_from_user_to_xstate() to grab the address of thread_struct's pkru value in a later patch. Signed-off-by: Kyle Huey --- arch/x86/kernel/fpu/signal.c | 2 +- arch/x86/kernel/fpu/xstate.c | 4 ++-- arch/x86/kernel/fpu/xstate.h | 2 +- 3 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c index 91d4b6de58ab..558076dbde5b 100644 --- a/arch/x86/kernel/fpu/signal.c +++ b/arch/x86/kernel/fpu/signal.c @@ -396,7 +396,7 @@ static bool __fpu_restore_sig(void __user *buf, void __user *buf_fx, fpregs = &fpu->fpstate->regs; if (use_xsave() && !fx_only) { - if (copy_sigframe_from_user_to_xstate(fpu->fpstate, buf_fx)) + if (copy_sigframe_from_user_to_xstate(tsk, buf_fx)) return false; } else { if (__copy_from_user(&fpregs->fxsave, buf_fx, diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 59e543b95a3c..32ba5d95628d 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1278,10 +1278,10 @@ int copy_uabi_from_kernel_to_xstate(struct fpstate *fpstate, const void *kbuf) * XSAVE[S] format and copy to the target thread. This is called from the * sigreturn() and rt_sigreturn() system calls. */ -int copy_sigframe_from_user_to_xstate(struct fpstate *fpstate, +int copy_sigframe_from_user_to_xstate(struct task_struct *tsk, const void __user *ubuf) { - return copy_uabi_to_xstate(fpstate, NULL, ubuf); + return copy_uabi_to_xstate(tsk->thread.fpu.fpstate, NULL, ubuf); } static bool validate_independent_components(u64 mask) diff --git a/arch/x86/kernel/fpu/xstate.h b/arch/x86/kernel/fpu/xstate.h index 5ad47031383b..f08ee2722e74 100644 --- a/arch/x86/kernel/fpu/xstate.h +++ b/arch/x86/kernel/fpu/xstate.h @@ -47,7 +47,7 @@ extern void __copy_xstate_to_uabi_buf(struct membuf to, struct fpstate *fpstate, extern void copy_xstate_to_uabi_buf(struct membuf to, struct task_struct *tsk, enum xstate_copy_mode mode); extern int copy_uabi_from_kernel_to_xstate(struct fpstate *fpstate, const void *kbuf); -extern int copy_sigframe_from_user_to_xstate(struct fpstate *fpstate, const void __user *ubuf); +extern int copy_sigframe_from_user_to_xstate(struct task_struct *tsk, const void __user *ubuf); extern void fpu__init_cpu_xstate(void); From patchwork Tue Nov 15 23:09:28 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kyle Huey X-Patchwork-Id: 13044277 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 33F35C43217 for ; Tue, 15 Nov 2022 23:12:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231821AbiKOXMD (ORCPT ); Tue, 15 Nov 2022 18:12:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57054 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231262AbiKOXLf (ORCPT ); Tue, 15 Nov 2022 18:11:35 -0500 Received: from mail-pj1-x102e.google.com (mail-pj1-x102e.google.com [IPv6:2607:f8b0:4864:20::102e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E93232E680 for ; Tue, 15 Nov 2022 15:11:34 -0800 (PST) Received: by mail-pj1-x102e.google.com with SMTP id e7-20020a17090a77c700b00216928a3917so542238pjs.4 for ; Tue, 15 Nov 2022 15:11:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kylehuey.com; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=VkXZyYO2hGQH+BId88DD3kMOt/JKYNASeU3kq3/BxNg=; b=PJSFalW97JocjRPsweyy+GvKZWv53ItjFSUoPx5y9DdQ6EZ/fzc+SZpCngVuSd9ea1 LlVOTnFpygwuMc3lztlKy+xmDdb+Jp/+xaSiCp9boUPxnjP7mObm84gEd526bQlKMdKW tIgzIfdG2ycjjmG23/XuePNtsMRIGoQMQNfwDlCWtaSjDiGY1UowCVM8bqRYoONG2bbc I+d6SnAqmdBy6cFZWgDfGsC9zzqcv8d4iGLP/cJX/FPyfHJrLqafXYRt827bXtjHLxHW lHyI34dIT86OTlpWY2FinxvlEhvZLL0UIdSVo1hAKM3l1YPJV1d/rsASSEGIkcIKAwnZ RwBg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=VkXZyYO2hGQH+BId88DD3kMOt/JKYNASeU3kq3/BxNg=; b=lg56whyyMzJpkGjmLnTriy4Hhr9/51B3XZ9rsiT8zEjDLZZByq2skbgrsT5K46rZzO bxPISmvMpdCLLaPlcqPr3mPIb65JviNcUib8M6orTKvPaAa7mS87rkD6B0wLPTJd16t6 2wbmont8GwMlMJAsXuWK4lV12NTaQVK9YV2U/QyNw97GliYL2bf3SFgGtT+RQEJuz+qy mnsoatEwW1G7QOKG56eo48KEfCti+iJUQts5gOy8yopvEeFO8JQ1kPYwrhkWVs+omaEI WzYH91uZ5TolwXjBNWXzR176SwmbKKVfgW/4qRasU1FCTcDrzYMc6AhMMc2YVKSJbnDe CmfQ== X-Gm-Message-State: ANoB5pnhLYeLEi39xERzn5XXmgjZoygx7lc3vl8XHn9HzFZAVCq9Bnpt Uigsop2cE71dfGbeByB2znJOGQ== X-Google-Smtp-Source: AA0mqf75xxW4N9M95sb0sBsucwu2KWj9VrPDShkwX51uZY6Fbc5+qkz1jqYor6l+Fxz5aXrzC9V3Gw== X-Received: by 2002:a17:903:228e:b0:177:faf5:58c5 with SMTP id b14-20020a170903228e00b00177faf558c5mr6230654plh.166.1668553894421; Tue, 15 Nov 2022 15:11:34 -0800 (PST) Received: from minbar.home.kylehuey.com (c-71-198-251-229.hsd1.ca.comcast.net. [71.198.251.229]) by smtp.gmail.com with ESMTPSA id f15-20020a62380f000000b0056c360af4e3sm9308372pfa.9.2022.11.15.15.11.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Nov 2022 15:11:34 -0800 (PST) From: Kyle Huey X-Google-Original-From: Kyle Huey To: Dave Hansen Cc: Linus Torvalds , Thomas Gleixner , Borislav Petkov , Ingo Molnar , x86@kernel.org, "H. Peter Anvin" , Paolo Bonzini , Andy Lutomirski , Peter Zijlstra , Sean Christopherson , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Robert O'Callahan , David Manouchehri , Kyle Huey Subject: [PATCH v7 2/6] x86/fpu: Add a pkru argument to copy_uabi_from_kernel_to_xstate(). Date: Tue, 15 Nov 2022 15:09:28 -0800 Message-Id: <20221115230932.7126-3-khuey@kylehuey.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221115230932.7126-1-khuey@kylehuey.com> References: <20221115230932.7126-1-khuey@kylehuey.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Both KVM (through KVM_SET_XSTATE) and ptrace (through PTRACE_SETREGSET with NT_X86_XSTATE) ultimately call copy_uabi_from_kernel_to_xstate(), but the canonical locations for the current PKRU value for KVM guests and processes in a ptrace stop are different (in the kvm_vcpu_arch and the thread_state structs respectively). In preparation for eventually handling PKRU in copy_uabi_to_xstate, pass in a pointer to the PKRU location. Signed-off-by: Kyle Huey --- arch/x86/kernel/fpu/core.c | 2 +- arch/x86/kernel/fpu/regset.c | 2 +- arch/x86/kernel/fpu/xstate.c | 2 +- arch/x86/kernel/fpu/xstate.h | 2 +- 4 files changed, 4 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 3b28c5b25e12..550157686323 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -406,7 +406,7 @@ int fpu_copy_uabi_to_guest_fpstate(struct fpu_guest *gfpu, const void *buf, if (ustate->xsave.header.xfeatures & ~xcr0) return -EINVAL; - ret = copy_uabi_from_kernel_to_xstate(kstate, ustate); + ret = copy_uabi_from_kernel_to_xstate(kstate, ustate, vpkru); if (ret) return ret; diff --git a/arch/x86/kernel/fpu/regset.c b/arch/x86/kernel/fpu/regset.c index 75ffaef8c299..6d056b68f4ed 100644 --- a/arch/x86/kernel/fpu/regset.c +++ b/arch/x86/kernel/fpu/regset.c @@ -167,7 +167,7 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, } fpu_force_restore(fpu); - ret = copy_uabi_from_kernel_to_xstate(fpu->fpstate, kbuf ?: tmpbuf); + ret = copy_uabi_from_kernel_to_xstate(fpu->fpstate, kbuf ?: tmpbuf, &target->thread.pkru); out: vfree(tmpbuf); diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 32ba5d95628d..a4d24ae66796 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1268,7 +1268,7 @@ static int copy_uabi_to_xstate(struct fpstate *fpstate, const void *kbuf, * Convert from a ptrace standard-format kernel buffer to kernel XSAVE[S] * format and copy to the target thread. Used by ptrace and KVM. */ -int copy_uabi_from_kernel_to_xstate(struct fpstate *fpstate, const void *kbuf) +int copy_uabi_from_kernel_to_xstate(struct fpstate *fpstate, const void *kbuf, u32 *pkru) { return copy_uabi_to_xstate(fpstate, kbuf, NULL); } diff --git a/arch/x86/kernel/fpu/xstate.h b/arch/x86/kernel/fpu/xstate.h index f08ee2722e74..a4ecb04d8d64 100644 --- a/arch/x86/kernel/fpu/xstate.h +++ b/arch/x86/kernel/fpu/xstate.h @@ -46,7 +46,7 @@ extern void __copy_xstate_to_uabi_buf(struct membuf to, struct fpstate *fpstate, u32 pkru_val, enum xstate_copy_mode copy_mode); extern void copy_xstate_to_uabi_buf(struct membuf to, struct task_struct *tsk, enum xstate_copy_mode mode); -extern int copy_uabi_from_kernel_to_xstate(struct fpstate *fpstate, const void *kbuf); +extern int copy_uabi_from_kernel_to_xstate(struct fpstate *fpstate, const void *kbuf, u32 *pkru); extern int copy_sigframe_from_user_to_xstate(struct task_struct *tsk, const void __user *ubuf); From patchwork Tue Nov 15 23:09:29 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kyle Huey X-Patchwork-Id: 13044275 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5AB04C433FE for ; Tue, 15 Nov 2022 23:12:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229923AbiKOXMB (ORCPT ); Tue, 15 Nov 2022 18:12:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57240 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238483AbiKOXLh (ORCPT ); Tue, 15 Nov 2022 18:11:37 -0500 Received: from mail-pj1-x1034.google.com (mail-pj1-x1034.google.com [IPv6:2607:f8b0:4864:20::1034]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 92C362E688 for ; Tue, 15 Nov 2022 15:11:36 -0800 (PST) Received: by mail-pj1-x1034.google.com with SMTP id m6-20020a17090a5a4600b00212f8dffec9so681222pji.0 for ; Tue, 15 Nov 2022 15:11:36 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kylehuey.com; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=IkcqOwsa0mNg6ehrFGqMru8FrDdXrPVN26VUHl2O8Uk=; b=COkajg1xfIWppQNgvV1yPMUIBGJNDsN7XOZhgcmUBNkuQT5h7POGLw7aCrSgOJf1TM fi7NPk3zvATxjZv2bNJcrHavWcRc2UgJAIP6OCemRQn3b/U6IWlcE7pn+5h1em+rNTul dzS9rv2/1ApGIHuka4h6ZnT7Kkg/TNMxfv+hcGk4Brs4h4vfyIqc/JprwgljCNFZg+/x 3nAyLM4Y+r/cslbUQ7jeW+L9I4aGcWyK0cnm1r5cbcnQtlYkw/v6LwqzmcrfBRb9dOQH Vos5+xpdw5OowrlXFlUM6umMxnMY9+Y3UBnE2eqKNCAOLOgVeg0qKEGNs0Bv4+m4ydV6 QivA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=IkcqOwsa0mNg6ehrFGqMru8FrDdXrPVN26VUHl2O8Uk=; b=yUdpm75dvAdAaqApputDnUUETBYy67mONgQ3Do+PXg6Y9BcSBEVf2se2FHYj/UYukP Ul1EaZKW4/0ebV9Nl7ZfsLfH2uJEbjOo18kECsCW84hL7jM8X1TYSgCT29k24Lb3/aFn 9Swe0N2cAM+GcDdvSInKgsFtE7milRRGxhd7TRj49zwG4Io/0tFd10ws2aEN7DgeXvwd IE66Fn7x4RWpkLhxELOhWzNorUOlTDi/W6/khL8bI91pe03zvs5TMln7xadZvm5qt8ty 8nDAOCNArNhfuAN3AQq3cYNGVLt+qun1uWVhScUkqLBR3f/JeDQn8pAWRLFn2hlUSfoX elDw== X-Gm-Message-State: ANoB5pn/YwUFdPIHDiXE4j/9IQIlfa3dJ4QNO7t47HFkIei/82t5Yfmf b9nqbiS9B97spV3Yvx13rTNvzg== X-Google-Smtp-Source: AA0mqf4dptDJmAPgoQ4OkUe9nMGJp9rh79WYxrBrUwxXp0R9JuF4HjY7fHwca8S1czlJLhZS8jHY5g== X-Received: by 2002:a17:902:8c8d:b0:17f:73d6:4375 with SMTP id t13-20020a1709028c8d00b0017f73d64375mr6208515plo.24.1668553896035; Tue, 15 Nov 2022 15:11:36 -0800 (PST) Received: from minbar.home.kylehuey.com (c-71-198-251-229.hsd1.ca.comcast.net. [71.198.251.229]) by smtp.gmail.com with ESMTPSA id f15-20020a62380f000000b0056c360af4e3sm9308372pfa.9.2022.11.15.15.11.34 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Nov 2022 15:11:35 -0800 (PST) From: Kyle Huey X-Google-Original-From: Kyle Huey To: Dave Hansen Cc: Linus Torvalds , Thomas Gleixner , Borislav Petkov , Ingo Molnar , x86@kernel.org, "H. Peter Anvin" , Paolo Bonzini , Andy Lutomirski , Peter Zijlstra , Sean Christopherson , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Robert O'Callahan , David Manouchehri , Kyle Huey Subject: [PATCH v7 3/6] x86/fpu: Add a pkru argument to copy_uabi_to_xstate() Date: Tue, 15 Nov 2022 15:09:29 -0800 Message-Id: <20221115230932.7126-4-khuey@kylehuey.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221115230932.7126-1-khuey@kylehuey.com> References: <20221115230932.7126-1-khuey@kylehuey.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org In preparation for moving PKRU handling code out of fpu_copy_uabi_to_guest_fpstate() and into copy_uabi_to_xstate(), add an argument that copy_uabi_from_kernel_to_xstate() can use to pass the canonical location of the PKRU value. For copy_sigframe_from_user_to_xstate() the kernel will actually restore the PKRU value from the fpstate, but pass in the thread_struct's pkru location anyways for consistency. Signed-off-by: Kyle Huey --- arch/x86/kernel/fpu/xstate.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index a4d24ae66796..3a6ced76e932 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1200,8 +1200,18 @@ static int copy_from_buffer(void *dst, unsigned int offset, unsigned int size, } +/** + * copy_uabi_to_xstate - Copy a UABI format buffer to the kernel xstate + * @fpstate: The fpstate buffer to copy to + * @kbuf: The UABI format buffer, if it comes from the kernel + * @ubuf: The UABI format buffer, if it comes from userspace + * @pkru: unused + * + * Converts from the UABI format into the kernel internal hardware + * dependent format. + */ static int copy_uabi_to_xstate(struct fpstate *fpstate, const void *kbuf, - const void __user *ubuf) + const void __user *ubuf, u32 *pkru) { struct xregs_state *xsave = &fpstate->regs.xsave; unsigned int offset, size; @@ -1270,7 +1280,7 @@ static int copy_uabi_to_xstate(struct fpstate *fpstate, const void *kbuf, */ int copy_uabi_from_kernel_to_xstate(struct fpstate *fpstate, const void *kbuf, u32 *pkru) { - return copy_uabi_to_xstate(fpstate, kbuf, NULL); + return copy_uabi_to_xstate(fpstate, kbuf, NULL, pkru); } /* @@ -1281,7 +1291,7 @@ int copy_uabi_from_kernel_to_xstate(struct fpstate *fpstate, const void *kbuf, u int copy_sigframe_from_user_to_xstate(struct task_struct *tsk, const void __user *ubuf) { - return copy_uabi_to_xstate(tsk->thread.fpu.fpstate, NULL, ubuf); + return copy_uabi_to_xstate(tsk->thread.fpu.fpstate, NULL, ubuf, &tsk->thread.pkru); } static bool validate_independent_components(u64 mask) From patchwork Tue Nov 15 23:09:30 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kyle Huey X-Patchwork-Id: 13044276 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 12353C4167B for ; Tue, 15 Nov 2022 23:12:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231216AbiKOXMC (ORCPT ); Tue, 15 Nov 2022 18:12:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57336 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232555AbiKOXLj (ORCPT ); Tue, 15 Nov 2022 18:11:39 -0500 Received: from mail-pg1-x530.google.com (mail-pg1-x530.google.com [IPv6:2607:f8b0:4864:20::530]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5E4A62E68F for ; Tue, 15 Nov 2022 15:11:38 -0800 (PST) Received: by mail-pg1-x530.google.com with SMTP id b62so15015518pgc.0 for ; Tue, 15 Nov 2022 15:11:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kylehuey.com; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=JUnl5mVywhHwsFoEEbFn7p+05kDcFKVp21uUWgQ1eAI=; b=DsjDjVjE5eNrFy11hX+hSy394Ka7KCuWodECy1nbg4uc4FpRLFMxTr7G36Ovt+sQHk PJv0QI4UTeM0xRiJvJWeBsIm5Q1VBiC189XuLKUxCFH5vPD5+GxmyGT8AR8kM22M8GrL DCvOCfX0BrGFAKtgXxQL6ZUikSpBFMguHt956oDc3b6N7lspDsJfAG/p6bg6xbm3QlBH hoPVV1PE6f8ffwIlgLBK/5a56Bivs/clznujDp0ZxHLWrtfEJFItl/cOgwoynuqc00pq 3JeGMobmsgjOK8KhTh9+nH4EvwzFFsQiXb8Q/k0aI/lQC0M0h4gRgm9f8mFiOt5R1YBv ukLg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=JUnl5mVywhHwsFoEEbFn7p+05kDcFKVp21uUWgQ1eAI=; b=5QIcCOrQZdLy+Q5PmrAmRd+stdNDHprgZaWHOuwKWRSuo8jXMoIU00GMM79m1+oGP1 b2+UeHf/f0t1fUDZj5TcfIBSvRxOY23SOJ0iimF6E/ycZ/30nR6B76go874Uh6z7aGb9 4TLkr4ALJq2knn4id4938dKKzZQVYytRGNvYi2z3jAJQlyoyRRLV+TMMjdjzgAACY15p KeO9usG/LPslbECaGDvYbcOJLgCz1Jmfhk/JgG9GJAvihaOxnjQj7gmF8yoT3uIxjcRl TM4NZmT/yMV3su6MhA/ag1fPnjMgOXDCJEUGDF3dGJLkacBf5z/Aaa2rOW0GNaz1kgrs l9hQ== X-Gm-Message-State: ANoB5plPVZSYlYeI2xpv2vzE6CoQXPkOe88smwpzttmKTA9TSbEt+mir uyU2sOyZ4sOd1w3sW72K+usmxw== X-Google-Smtp-Source: AA0mqf5Vevz7nIR3nzoyndXemt0pvmtLDIs7P8cK+Uk6E7iQU9QVJZ+4D4aKm5gpTaDsqkycsqUNwA== X-Received: by 2002:a63:1a24:0:b0:470:60a5:2f70 with SMTP id a36-20020a631a24000000b0047060a52f70mr18313359pga.99.1668553897780; Tue, 15 Nov 2022 15:11:37 -0800 (PST) Received: from minbar.home.kylehuey.com (c-71-198-251-229.hsd1.ca.comcast.net. [71.198.251.229]) by smtp.gmail.com with ESMTPSA id f15-20020a62380f000000b0056c360af4e3sm9308372pfa.9.2022.11.15.15.11.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Nov 2022 15:11:37 -0800 (PST) From: Kyle Huey X-Google-Original-From: Kyle Huey To: Dave Hansen Cc: Linus Torvalds , Thomas Gleixner , Borislav Petkov , Ingo Molnar , x86@kernel.org, "H. Peter Anvin" , Paolo Bonzini , Andy Lutomirski , Peter Zijlstra , Sean Christopherson , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Robert O'Callahan , David Manouchehri , Kyle Huey , Borislav Petkov , stable@vger.kernel.org Subject: [PATCH v7 4/6] x86/fpu: Allow PKRU to be (once again) written by ptrace. Date: Tue, 15 Nov 2022 15:09:30 -0800 Message-Id: <20221115230932.7126-5-khuey@kylehuey.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221115230932.7126-1-khuey@kylehuey.com> References: <20221115230932.7126-1-khuey@kylehuey.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org Move KVM's PKRU handling code in fpu_copy_uabi_to_guest_fpstate() to copy_uabi_to_xstate() so that it is shared with other APIs that write the XSTATE such as PTRACE_SETREGSET with NT_X86_XSTATE. This restores the pre-5.14 behavior of ptrace. The regression can be seen by running gdb and executing `p $pkru`, `set $pkru = 42`, and `p $pkru`. On affected kernels (5.14+) the write to the PKRU register (which gdb performs through ptrace) is ignored. Fixes: e84ba47e313d ("x86/fpu: Hook up PKRU into ptrace()") Signed-off-by: Kyle Huey Cc: Dave Hansen Cc: Thomas Gleixner Cc: Borislav Petkov Cc: stable@vger.kernel.org # 5.14+ --- arch/x86/kernel/fpu/core.c | 13 +------------ arch/x86/kernel/fpu/xstate.c | 21 ++++++++++++++++++++- 2 files changed, 21 insertions(+), 13 deletions(-) diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 550157686323..46b935bc87c8 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -391,8 +391,6 @@ int fpu_copy_uabi_to_guest_fpstate(struct fpu_guest *gfpu, const void *buf, { struct fpstate *kstate = gfpu->fpstate; const union fpregs_state *ustate = buf; - struct pkru_state *xpkru; - int ret; if (!cpu_feature_enabled(X86_FEATURE_XSAVE)) { if (ustate->xsave.header.xfeatures & ~XFEATURE_MASK_FPSSE) @@ -406,16 +404,7 @@ int fpu_copy_uabi_to_guest_fpstate(struct fpu_guest *gfpu, const void *buf, if (ustate->xsave.header.xfeatures & ~xcr0) return -EINVAL; - ret = copy_uabi_from_kernel_to_xstate(kstate, ustate, vpkru); - if (ret) - return ret; - - /* Retrieve PKRU if not in init state */ - if (kstate->regs.xsave.header.xfeatures & XFEATURE_MASK_PKRU) { - xpkru = get_xsave_addr(&kstate->regs.xsave, XFEATURE_PKRU); - *vpkru = xpkru->pkru; - } - return 0; + return copy_uabi_from_kernel_to_xstate(kstate, ustate, vpkru); } EXPORT_SYMBOL_GPL(fpu_copy_uabi_to_guest_fpstate); #endif /* CONFIG_KVM */ diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index 3a6ced76e932..bebc30c29ed3 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1205,10 +1205,22 @@ static int copy_from_buffer(void *dst, unsigned int offset, unsigned int size, * @fpstate: The fpstate buffer to copy to * @kbuf: The UABI format buffer, if it comes from the kernel * @ubuf: The UABI format buffer, if it comes from userspace - * @pkru: unused + * @pkru: The location to write the PKRU value to * * Converts from the UABI format into the kernel internal hardware * dependent format. + * + * This function ultimately has three different callers with distinct PKRU + * behavior. + * 1. When called from sigreturn the PKRU register will be restored from + * @fpstate via an XRSTOR. Correctly copying the UABI format buffer to + * @fpstate is sufficient to cover this case, but the caller will also + * pass a pointer to the thread_struct's pkru field in @pkru and updating + * it is harmless. + * 2. When called from ptrace the PKRU register will be restored from the + * thread_struct's pkru field. A pointer to that is passed in @pkru. + * 3. When called from KVM the PKRU register will be restored from the vcpu's + * pkru field. A pointer to that is passed in @pkru. */ static int copy_uabi_to_xstate(struct fpstate *fpstate, const void *kbuf, const void __user *ubuf, u32 *pkru) @@ -1260,6 +1272,13 @@ static int copy_uabi_to_xstate(struct fpstate *fpstate, const void *kbuf, } } + if (hdr.xfeatures & XFEATURE_MASK_PKRU) { + struct pkru_state *xpkru; + + xpkru = __raw_xsave_addr(xsave, XFEATURE_PKRU); + *pkru = xpkru->pkru; + } + /* * The state that came in from userspace was user-state only. * Mask all the user states out of 'xfeatures': From patchwork Tue Nov 15 23:09:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kyle Huey X-Patchwork-Id: 13044278 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8B814C4332F for ; Tue, 15 Nov 2022 23:12:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231262AbiKOXME (ORCPT ); Tue, 15 Nov 2022 18:12:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238606AbiKOXLl (ORCPT ); Tue, 15 Nov 2022 18:11:41 -0500 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 267832E9C8 for ; Tue, 15 Nov 2022 15:11:40 -0800 (PST) Received: by mail-pl1-x62f.google.com with SMTP id l2so14766904pld.13 for ; Tue, 15 Nov 2022 15:11:40 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kylehuey.com; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=1qpXWSCDrMjTrrN7DSUZrVNnGlngy6qbcHa+BWaBxfw=; b=by3OpFNkQCvqiF7Z+Ei1ZUihu4ifOPLgyDRqCGJ9mDwSmsppwq5B3L7OSbVs6FSzZq uhL+U8YozGaxewngILbOAgMLv44xfey9tO53DDpqYVyjzvahWzl8o30YKcgVXdT8kNm+ yVYA2KpHsHz+kaX5LE4vA2BwqI/ZXosIYX/iaFNgbaNHzVkjrTPfHjGOFLGbgOY2TEO8 UoZlZ+woOIAoxIsgvz0lPHGOU7pjF/pHTS8lE2M3ixMF41UBdWT/uVG4VyrikJK0hbZp ANMTkWGeITdPtIEs873AmNugHQc01OnW4Tepj+jV9QwKdUq+iq1VRDxQMMnKRRXkkUfl w74A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=1qpXWSCDrMjTrrN7DSUZrVNnGlngy6qbcHa+BWaBxfw=; b=WPKQn4xn2YjQ1zcPpX1JuUOKFjkED+y9gns19hFZiLGhKyNZhQzespzLnId3NENHFt YBLjrUzDGEjCzG22/JOBL9lV06hymEA7w9SvYfBRyjsQLg6xgOsU2Ru550a4vq5c9MR3 qNIg+Zjke1naQYDgu+qZRgZ5+z/jwqm5W5mypK+CZnpu0I7TfNEjJ0WuCgxFmv8zX7k2 L+sGaa+8v8NOMJJsEHfjUZz3LfUYTpZzEUsbVHEswrATIlpY61O4XtY5SzdbhiAoJ3j2 cM9eJv8FEi7373t8m40iCnOZCWwjj8ixoBtBacaExFjrxw5K0e5PcPgsXW7KRyR0jmpi TU6A== X-Gm-Message-State: ANoB5plNiLKHigKFJXvmGRCvVtZFOcJLZ02o3HNnX6xCgd5MwZJe9POF DwNNOeVPEg68lc31OTcA2Fme2w== X-Google-Smtp-Source: AA0mqf6g2OWKVo26BWZuPzVY1oFYsPcCmZrMrHsai4e2FYYAhJslj93GI6fE4NLB74yKH7+yJpSz+w== X-Received: by 2002:a17:902:8649:b0:187:3921:2b2d with SMTP id y9-20020a170902864900b0018739212b2dmr6440688plt.13.1668553899569; Tue, 15 Nov 2022 15:11:39 -0800 (PST) Received: from minbar.home.kylehuey.com (c-71-198-251-229.hsd1.ca.comcast.net. [71.198.251.229]) by smtp.gmail.com with ESMTPSA id f15-20020a62380f000000b0056c360af4e3sm9308372pfa.9.2022.11.15.15.11.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Nov 2022 15:11:39 -0800 (PST) From: Kyle Huey X-Google-Original-From: Kyle Huey To: Dave Hansen Cc: Linus Torvalds , Thomas Gleixner , Borislav Petkov , Ingo Molnar , x86@kernel.org, "H. Peter Anvin" , Paolo Bonzini , Andy Lutomirski , Peter Zijlstra , Sean Christopherson , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Robert O'Callahan , David Manouchehri , Kyle Huey , Borislav Petkov , stable@vger.kernel.org Subject: [PATCH v7 5/6] x86/fpu: Emulate XRSTOR's behavior if the xfeatures PKRU bit is not set Date: Tue, 15 Nov 2022 15:09:31 -0800 Message-Id: <20221115230932.7126-6-khuey@kylehuey.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221115230932.7126-1-khuey@kylehuey.com> References: <20221115230932.7126-1-khuey@kylehuey.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org The hardware XRSTOR instruction resets the PKRU register to its hardware init value (namely 0) if the PKRU bit is not set in the xfeatures mask. Emulating that here restores the pre-5.14 behavior for PTRACE_SET_REGSET with NT_X86_XSTATE, and makes sigreturn (which still uses XRSTOR) and ptrace behave identically. KVM has never used XRSTOR and never had this behavior, so KVM opts-out of this emulation by passing a NULL pkru pointer to copy_uabi_to_xstate(). Fixes: e84ba47e313d ("x86/fpu: Hook up PKRU into ptrace()") Signed-off-by: Kyle Huey Cc: Dave Hansen Cc: Thomas Gleixner Cc: Borislav Petkov Cc: stable@vger.kernel.org # 5.14+ --- arch/x86/kernel/fpu/core.c | 8 ++++++++ arch/x86/kernel/fpu/xstate.c | 15 ++++++++++++++- 2 files changed, 22 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/fpu/core.c b/arch/x86/kernel/fpu/core.c index 46b935bc87c8..8d0f6019c21d 100644 --- a/arch/x86/kernel/fpu/core.c +++ b/arch/x86/kernel/fpu/core.c @@ -404,6 +404,14 @@ int fpu_copy_uabi_to_guest_fpstate(struct fpu_guest *gfpu, const void *buf, if (ustate->xsave.header.xfeatures & ~xcr0) return -EINVAL; + /* + * Nullify @vpkru to preserve its current value if PKRU's bit isn't set + * in the header. KVM's odd ABI is to leave PKRU untouched in this + * case (all other components are eventually re-initialized). + */ + if (!(ustate->xsave.header.xfeatures & XFEATURE_MASK_PKRU)) + vpkru = NULL; + return copy_uabi_from_kernel_to_xstate(kstate, ustate, vpkru); } EXPORT_SYMBOL_GPL(fpu_copy_uabi_to_guest_fpstate); diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c index bebc30c29ed3..193c6e95daa8 100644 --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -1219,8 +1219,14 @@ static int copy_from_buffer(void *dst, unsigned int offset, unsigned int size, * it is harmless. * 2. When called from ptrace the PKRU register will be restored from the * thread_struct's pkru field. A pointer to that is passed in @pkru. + * The kernel will restore it manually, so the XRSTOR behavior that resets + * the PKRU register to the hardware init value (0) if the corresponding + * xfeatures bit is not set is emulated here. * 3. When called from KVM the PKRU register will be restored from the vcpu's - * pkru field. A pointer to that is passed in @pkru. + * pkru field. A pointer to that is passed in @pkru. KVM hasn't used + * XRSTOR and hasn't had the PKRU resetting behavior described above. To + * preserve that KVM behavior, it passes NULL for @pkru if the xfeatures + * bit is not set. */ static int copy_uabi_to_xstate(struct fpstate *fpstate, const void *kbuf, const void __user *ubuf, u32 *pkru) @@ -1277,6 +1283,13 @@ static int copy_uabi_to_xstate(struct fpstate *fpstate, const void *kbuf, xpkru = __raw_xsave_addr(xsave, XFEATURE_PKRU); *pkru = xpkru->pkru; + } else { + /* + * KVM may pass NULL here to indicate that it does not need + * PKRU updated. + */ + if (pkru) + *pkru = 0; } /* From patchwork Tue Nov 15 23:09:32 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kyle Huey X-Patchwork-Id: 13044279 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BCC0AC433FE for ; Tue, 15 Nov 2022 23:12:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231931AbiKOXMF (ORCPT ); Tue, 15 Nov 2022 18:12:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57096 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238613AbiKOXLm (ORCPT ); Tue, 15 Nov 2022 18:11:42 -0500 Received: from mail-pj1-x1035.google.com (mail-pj1-x1035.google.com [IPv6:2607:f8b0:4864:20::1035]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BBD962D768 for ; Tue, 15 Nov 2022 15:11:41 -0800 (PST) Received: by mail-pj1-x1035.google.com with SMTP id k5so14898965pjo.5 for ; Tue, 15 Nov 2022 15:11:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kylehuey.com; s=google; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=kKbS/wfCljHaJs+yu72j7uPbynmA+GaQ8f/h+/BgRKY=; b=bZ3HnJm24MjM7JcrDyTgpeH8OkI1L3C7EdNdqnF1eW9Y7D1gI4VdHaJilFToAT8KMx PYpoNinjDQG8SGBPelhz1UeCskoSCwsbt0tFlD/yoRnBth+9dyBRKMRsSQULkvkkpDVQ pX7DgPeMF9hc71wHUtcEalQqWSc7SnNPsmZS4gdwz/5+b1JyjE3pLhVNpv/gmXHdtGOt xq/WzMVrd1jJogO/U+dShKXlgHy9j5A4a+XApFdHgzjrFWJgTTP4eh3g2W/YvWRZloBa M1MM0PiCQANScP4JnyUkUGnyZVRYVkX048SeqFRoJXKdeLg0LWSipYpxRcFU83CJyK2I ME/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=kKbS/wfCljHaJs+yu72j7uPbynmA+GaQ8f/h+/BgRKY=; b=HZmE03jail9Bk2A1vdEBhL+ZiWE2kA6NErR3gOHW6oamPrDWFqriwgYyFNGR3vUEo+ +UvBosIvCEYwGRRgzn1m26OM7bnZOc7jEm+sdhKz6k5qREK3n8GzARL1O21MZQXsrt4d EvaS/vdOpkyGshQA/9RcUpXoLEEWbKHLg+adrAaJVTpGssc1MC0jqxHML/O5SOJaiixk +ADpSoUOHRTgVMmjlWdunILe77qMfaUlC1PnCxOZGDsR0rGbg9XKYiHHFOHaQ1vvxmOf UGY/7qkif5KjjuI2SyIXpAS36+asyIxU51ucnxhvLK1spQ9jjuTrtOwA9lJ+iwxJq5zJ lp5g== X-Gm-Message-State: ANoB5pk2fBXe2ULCerydKXrpegKsu70EaTyg5FzntI5iV8X2+W3ghWGz R486LiK8t32DMQFBHyEK5u+Qkw== X-Google-Smtp-Source: AA0mqf6WZlEzo3p4p6oxKeveZiFRMoW2Zvyd+gYPNEldkXHMPSklpt6HckKh/olUeWpCyzReLfidag== X-Received: by 2002:a17:902:b694:b0:17f:7d9a:4952 with SMTP id c20-20020a170902b69400b0017f7d9a4952mr6190603pls.117.1668553901195; Tue, 15 Nov 2022 15:11:41 -0800 (PST) Received: from minbar.home.kylehuey.com (c-71-198-251-229.hsd1.ca.comcast.net. [71.198.251.229]) by smtp.gmail.com with ESMTPSA id f15-20020a62380f000000b0056c360af4e3sm9308372pfa.9.2022.11.15.15.11.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 15 Nov 2022 15:11:40 -0800 (PST) From: Kyle Huey X-Google-Original-From: Kyle Huey To: Dave Hansen Cc: Linus Torvalds , Thomas Gleixner , Borislav Petkov , Ingo Molnar , x86@kernel.org, "H. Peter Anvin" , Paolo Bonzini , Andy Lutomirski , Peter Zijlstra , Sean Christopherson , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Robert O'Callahan , David Manouchehri , Kyle Huey Subject: [PATCH v7 6/6] selftests/vm/pkeys: Add a regression test for setting PKRU through ptrace Date: Tue, 15 Nov 2022 15:09:32 -0800 Message-Id: <20221115230932.7126-7-khuey@kylehuey.com> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221115230932.7126-1-khuey@kylehuey.com> References: <20221115230932.7126-1-khuey@kylehuey.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-kselftest@vger.kernel.org This tests PTRACE_SETREGSET with NT_X86_XSTATE modifying PKRU directly and removing the PKRU bit from XSTATE_BV. Signed-off-by: Kyle Huey --- tools/testing/selftests/vm/pkey-x86.h | 12 ++ tools/testing/selftests/vm/protection_keys.c | 131 ++++++++++++++++++- 2 files changed, 141 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/vm/pkey-x86.h b/tools/testing/selftests/vm/pkey-x86.h index b078ce9c6d2a..72c14cd3ddc7 100644 --- a/tools/testing/selftests/vm/pkey-x86.h +++ b/tools/testing/selftests/vm/pkey-x86.h @@ -104,6 +104,18 @@ static inline int cpu_has_pkeys(void) return 1; } +static inline int cpu_max_xsave_size(void) +{ + unsigned long XSTATE_CPUID = 0xd; + unsigned int eax; + unsigned int ebx; + unsigned int ecx; + unsigned int edx; + + __cpuid_count(XSTATE_CPUID, 0, eax, ebx, ecx, edx); + return ecx; +} + static inline u32 pkey_bit_position(int pkey) { return pkey * PKEY_BITS_PER_PKEY; diff --git a/tools/testing/selftests/vm/protection_keys.c b/tools/testing/selftests/vm/protection_keys.c index 291bc1e07842..95f403a0c46d 100644 --- a/tools/testing/selftests/vm/protection_keys.c +++ b/tools/testing/selftests/vm/protection_keys.c @@ -18,12 +18,13 @@ * do a plain mprotect() to a mprotect_pkey() area and make sure the pkey sticks * * Compile like this: - * gcc -o protection_keys -O2 -g -std=gnu99 -pthread -Wall protection_keys.c -lrt -ldl -lm - * gcc -m32 -o protection_keys_32 -O2 -g -std=gnu99 -pthread -Wall protection_keys.c -lrt -ldl -lm + * gcc -mxsave -o protection_keys -O2 -g -std=gnu99 -pthread -Wall protection_keys.c -lrt -ldl -lm + * gcc -mxsave -m32 -o protection_keys_32 -O2 -g -std=gnu99 -pthread -Wall protection_keys.c -lrt -ldl -lm */ #define _GNU_SOURCE #define __SANE_USERSPACE_TYPES__ #include +#include #include #include #include @@ -1550,6 +1551,129 @@ void test_implicit_mprotect_exec_only_memory(int *ptr, u16 pkey) do_not_expect_pkey_fault("plain read on recently PROT_EXEC area"); } +#if defined(__i386__) || defined(__x86_64__) +void test_ptrace_modifies_pkru(int *ptr, u16 pkey) +{ + u32 new_pkru; + pid_t child; + int status, ret; + int pkey_offset = pkey_reg_xstate_offset(); + size_t xsave_size = cpu_max_xsave_size(); + void *xsave; + u32 *pkey_register; + u64 *xstate_bv; + struct iovec iov; + + new_pkru = ~read_pkey_reg(); + /* Don't make PROT_EXEC mappings inaccessible */ + new_pkru &= ~3; + + child = fork(); + pkey_assert(child >= 0); + dprintf3("[%d] fork() ret: %d\n", getpid(), child); + if (!child) { + ptrace(PTRACE_TRACEME, 0, 0, 0); + /* Stop and allow the tracer to modify PKRU directly */ + raise(SIGSTOP); + + /* + * need __read_pkey_reg() version so we do not do shadow_pkey_reg + * checking + */ + if (__read_pkey_reg() != new_pkru) + exit(1); + + /* Stop and allow the tracer to clear XSTATE_BV for PKRU */ + raise(SIGSTOP); + + if (__read_pkey_reg() != 0) + exit(1); + + /* Stop and allow the tracer to examine PKRU */ + raise(SIGSTOP); + + exit(0); + } + + pkey_assert(child == waitpid(child, &status, 0)); + dprintf3("[%d] waitpid(%d) status: %x\n", getpid(), child, status); + pkey_assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP); + + xsave = (void *)malloc(xsave_size); + pkey_assert(xsave > 0); + + /* Modify the PKRU register directly */ + iov.iov_base = xsave; + iov.iov_len = xsave_size; + ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov); + pkey_assert(ret == 0); + + pkey_register = (u32 *)(xsave + pkey_offset); + pkey_assert(*pkey_register == read_pkey_reg()); + + *pkey_register = new_pkru; + + ret = ptrace(PTRACE_SETREGSET, child, (void *)NT_X86_XSTATE, &iov); + pkey_assert(ret == 0); + + /* Test that the modification is visible in ptrace before any execution */ + memset(xsave, 0xCC, xsave_size); + ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov); + pkey_assert(ret == 0); + pkey_assert(*pkey_register == new_pkru); + + /* Execute the tracee */ + ret = ptrace(PTRACE_CONT, child, 0, 0); + pkey_assert(ret == 0); + + /* Test that the tracee saw the PKRU value change */ + pkey_assert(child == waitpid(child, &status, 0)); + dprintf3("[%d] waitpid(%d) status: %x\n", getpid(), child, status); + pkey_assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP); + + /* Test that the modification is visible in ptrace after execution */ + memset(xsave, 0xCC, xsave_size); + ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov); + pkey_assert(ret == 0); + pkey_assert(*pkey_register == new_pkru); + + /* Clear the PKRU bit from XSTATE_BV */ + xstate_bv = (u64 *)(xsave + 512); + *xstate_bv &= ~(1 << 9); + + ret = ptrace(PTRACE_SETREGSET, child, (void *)NT_X86_XSTATE, &iov); + pkey_assert(ret == 0); + + /* Test that the modification is visible in ptrace before any execution */ + memset(xsave, 0xCC, xsave_size); + ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov); + pkey_assert(ret == 0); + pkey_assert(*pkey_register == 0); + + ret = ptrace(PTRACE_CONT, child, 0, 0); + pkey_assert(ret == 0); + + /* Test that the tracee saw the PKRU value go to 0 */ + pkey_assert(child == waitpid(child, &status, 0)); + dprintf3("[%d] waitpid(%d) status: %x\n", getpid(), child, status); + pkey_assert(WIFSTOPPED(status) && WSTOPSIG(status) == SIGSTOP); + + /* Test that the modification is visible in ptrace after execution */ + memset(xsave, 0xCC, xsave_size); + ret = ptrace(PTRACE_GETREGSET, child, (void *)NT_X86_XSTATE, &iov); + pkey_assert(ret == 0); + pkey_assert(*pkey_register == 0); + + ret = ptrace(PTRACE_CONT, child, 0, 0); + pkey_assert(ret == 0); + pkey_assert(child == waitpid(child, &status, 0)); + dprintf3("[%d] waitpid(%d) status: %x\n", getpid(), child, status); + pkey_assert(WIFEXITED(status)); + pkey_assert(WEXITSTATUS(status) == 0); + free(xsave); +} +#endif + void test_mprotect_pkey_on_unsupported_cpu(int *ptr, u16 pkey) { int size = PAGE_SIZE; @@ -1585,6 +1709,9 @@ void (*pkey_tests[])(int *ptr, u16 pkey) = { test_pkey_syscalls_bad_args, test_pkey_alloc_exhaust, test_pkey_alloc_free_attach_pkey0, +#if defined(__i386__) || defined(__x86_64__) + test_ptrace_modifies_pkru, +#endif }; void run_tests_once(void)