From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 80E10C48BE0 for ; Fri, 11 Jun 2021 16:46:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BCEF613FA for ; Fri, 11 Jun 2021 16:46:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231962AbhFKQsI (ORCPT ); Fri, 11 Jun 2021 12:48:08 -0400 Received: from Galois.linutronix.de ([193.142.43.55]:41386 "EHLO galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231320AbhFKQqm (ORCPT ); Fri, 11 Jun 2021 12:46:42 -0400 Message-Id: <20210611163115.112228696@linutronix.de> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1623429883; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=wQr0r7P5VaAUM0wiyKLjFNgm5bK6vlsmxesP/+ZiFzE=; b=Rg34eeoO5K4z4ZN0VGw1PA2T6nV5CvJWE2aI2ileCh3zD+ijstrlne8uOyQ5yrYlh24j0m VS2ZVpl1XMCOqfvZoghjPfExu+I4Pm8vkNi/w+pvx2ZUjHLbq4UobLZzIbjvwfJ2Apn65d adaQS720JQxlE0jQuKEeB688uvqf7UD0bbavMaB0u7BOSMVtwCJTXgVLVnPWhVzJcEfrdm RsCBC03IEJd+GjbMfXzfBXFqoT2eeVab2u17L+6wCTYODS1lqb14f4gqIKNsOBPSNj82/z aPjfGe2mmVNFdFcUvwg9nNqBrd92whjXwK2TTlibPI5c4q3YCHxS9QTfIbjBvA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1623429883; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: references:references; bh=wQr0r7P5VaAUM0wiyKLjFNgm5bK6vlsmxesP/+ZiFzE=; b=e5nAc0iI315D6tpXJSZ81eU2SNDNPfmzZxgpD4n10Lk+niWmkX4eiZPfINP26cKFa+I14D 7Hz0bEXPhm/EM4AQ== Date: Fri, 11 Jun 2021 18:16:01 +0200 From: Thomas Gleixner To: LKML Cc: Andy Lutomirski , Dave Hansen , Fenghua Yu , Tony Luck , Yu-cheng Yu , Sebastian Andrzej Siewior , Borislav Petkov , Peter Zijlstra , Kan Liang Subject: [patch 38/41] x86/fpu: Mask PKRU from kernel XRSTOR[S] operations References: <20210611161523.508908024@linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-transfer-encoding: 8-bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As the PKRU state is managed seperately restoring it from the xstate buffer would be counterproductive as it might either restore a stale value or reinit the PKRU state to 0. Signed-off-by: Thomas Gleixner --- V4: New patch --- arch/x86/include/asm/fpu/internal.h | 4 ++-- arch/x86/include/asm/fpu/xstate.h | 10 ++++++++++ arch/x86/kernel/fpu/xstate.c | 1 + arch/x86/mm/extable.c | 2 +- 4 files changed, 14 insertions(+), 3 deletions(-) --- a/arch/x86/include/asm/fpu/internal.h +++ b/arch/x86/include/asm/fpu/internal.h @@ -281,7 +281,7 @@ static inline void xsave_to_kernel_booti */ static inline void xrstor_from_kernel_booting(struct xregs_state *xstate) { - u64 mask = -1; + u64 mask = xfeatures_mask_fpstate(); u32 lmask = mask; u32 hmask = mask >> 32; int err; @@ -408,7 +408,7 @@ extern void __restore_fpregs_from_fpstat static inline void restore_fpregs_from_fpstate(union fpregs_state *fpstate) { - __restore_fpregs_from_fpstate(fpstate, -1); + __restore_fpregs_from_fpstate(fpstate, xfeatures_mask_fpstate()); } extern int copy_fpstate_to_sigframe(void __user *buf, void __user *fp, int size); --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -111,6 +111,16 @@ static inline u64 xfeatures_mask_restore return xfeatures_mask_all & XFEATURE_MASK_USER_RESTORE; } +/* + * Like xfeatures_mask_restore_user() but additionally restors the + * supported supervisor states. + */ +static inline u64 xfeatures_mask_fpstate(void) +{ + return xfeatures_mask_all & \ + (XFEATURE_MASK_USER_RESTORE | XFEATURE_MASK_SUPERVISOR_SUPPORTED); +} + static inline u64 xfeatures_mask_independent(void) { if (!boot_cpu_has(X86_FEATURE_ARCH_LBR)) --- a/arch/x86/kernel/fpu/xstate.c +++ b/arch/x86/kernel/fpu/xstate.c @@ -60,6 +60,7 @@ static short xsave_cpuid_features[] __in * XSAVE buffer, both supervisor and user xstates. */ u64 xfeatures_mask_all __ro_after_init; +EXPORT_SYMBOL_GPL(xfeatures_mask_all); static unsigned int xstate_offsets[XFEATURE_MAX] __ro_after_init = { [ 0 ... XFEATURE_MAX - 1] = -1}; --- a/arch/x86/mm/extable.c +++ b/arch/x86/mm/extable.c @@ -65,7 +65,7 @@ EXPORT_SYMBOL_GPL(ex_handler_fault); WARN_ONCE(1, "Bad FPU state detected at %pB, reinitializing FPU registers.", (void *)instruction_pointer(regs)); - __restore_fpregs_from_fpstate(&init_fpstate, -1); + __restore_fpregs_from_fpstate(&init_fpstate, xfeatures_mask_fpstate()); return true; } EXPORT_SYMBOL_GPL(ex_handler_fprestore);