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 E5387C433EF for ; Mon, 13 Dec 2021 15:03:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239878AbhLMPDn (ORCPT ); Mon, 13 Dec 2021 10:03:43 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48772 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230320AbhLMPDm (ORCPT ); Mon, 13 Dec 2021 10:03:42 -0500 Received: from mail-pl1-x636.google.com (mail-pl1-x636.google.com [IPv6:2607:f8b0:4864:20::636]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9ECEBC061574 for ; Mon, 13 Dec 2021 07:03:42 -0800 (PST) Received: by mail-pl1-x636.google.com with SMTP id u11so11362427plf.3 for ; Mon, 13 Dec 2021 07:03:42 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=hJwijpzMhoemmdJvFmudMWTP4Nq09IHw0RlJ2NYTKQg=; b=m2aQ0wzohjpaPwlk/4/TI5NJL6Lx7UhjeG4Zai2SEpGab/FNLp9XabPLjj2UdD5eK5 rLOR2cqrjSYknAWnEBh0MtSC3zI9XrKk1Ckwyfak/ceHCnKKXuhB94OiiGjZjxUJCqQF gtR15Z9IdgaeFYOlnzramri+90L8o00EefpR7/ZJxmKcOv/m4XXPvUSz6eiNAaCkf2J0 DW8Pz//GO7J2gsksWiWPjuG8TigOv0jpD5Z3au7xRlDk2niss3JLUlHflQ4IdKijizRm xBjlZxOWsfqhZGCJb4euThUaqkNJZZnmDi0IrIH31k4Ur98XSrOaDmmXGnfxnSqvfPBO 8PwQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=hJwijpzMhoemmdJvFmudMWTP4Nq09IHw0RlJ2NYTKQg=; b=3NJF8JaHDHTBOgxLUKZIbgMQ/gWg0M/WVSPLk4NArWAiQLAi67pem7GhUnD40jPFde KI5ucFVAXjtB9GS55ljCGQ+2rKNcGF0qJveDEuyX0lTB5hEBQCKb0L5sdDR9pf7+N2dG iFiCS9c80psTjbnArJz00WNTtXsI4neczWHUwNhXOmL1v2YMqTlJeWuXSNMOCQfqEvMO /GgT0HKv09ULMe01CDOMibB0nMK/XIJVd9FQpGgxZ6zL4lESIn+pGGwf2zjPQKFr+Tr8 8IJfhSP6oyC/BEioKLHwEQl/VraW6IpIefS5Rd+aic/WTn8sEkeN4kdawqOG31wjNTXY mAdw== X-Gm-Message-State: AOAM533TGjqr/XpB9x2qe/Wnl9ePypariePezHSsBbWd7dHbesSarVf7 +fBMny6oV9Ud3jGmIyUWf1tHOQKZq1vAmQ== X-Google-Smtp-Source: ABdhPJxXu0A5a8i0U7P1Xp1pTWPaWZRx7VeHb/8o793TBGJdQUk8tYJkUM2Jo4OpryjdU9GuA7nwcA== X-Received: by 2002:a17:90b:1d83:: with SMTP id pf3mr44985333pjb.5.1639407822005; Mon, 13 Dec 2021 07:03:42 -0800 (PST) Received: from localhost ([47.88.60.64]) by smtp.gmail.com with ESMTPSA id l186sm10536763pga.24.2021.12.13.07.03.40 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 13 Dec 2021 07:03:41 -0800 (PST) From: Lai Jiangshan To: linux-kernel@vger.kernel.org Cc: x86@kernel.org, Lai Jiangshan , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" Subject: [PATCH 2/4] x86/entry: Call paranoid_exit() in asm_exc_nmi() Date: Mon, 13 Dec 2021 23:03:38 +0800 Message-Id: <20211213150340.9419-3-jiangshanlai@gmail.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: <20211213150340.9419-1-jiangshanlai@gmail.com> References: <20211213150340.9419-1-jiangshanlai@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lai Jiangshan The code between "call exc_nmi" and nmi_restore is as the same as paranoid_exit(), so we can just use paranoid_exit() instead of the open duplicated code. No functional change intended. Signed-off-by: Lai Jiangshan --- arch/x86/entry/entry_64.S | 34 +++++----------------------------- 1 file changed, 5 insertions(+), 29 deletions(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index 3dc3cec03425..47ff4abd87b5 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -920,8 +920,7 @@ SYM_CODE_END(paranoid_entry) /* * "Paranoid" exit path from exception stack. This is invoked - * only on return from non-NMI IST interrupts that came - * from kernel space. + * only on return from IST interrupts that came from kernel space. * * We may be returning to very strange contexts (e.g. very early * in syscall entry), so checking for preemption here would @@ -1354,11 +1353,7 @@ end_repeat_nmi: pushq $-1 /* ORIG_RAX: no syscall to restart */ /* - * Use paranoid_entry to handle SWAPGS, but no need to use paranoid_exit - * as we should not be calling schedule in NMI context. - * Even with normal interrupts enabled. An NMI should not be - * setting NEED_RESCHED or anything that normal interrupts and - * exceptions might do. + * Use paranoid_entry to handle SWAPGS and CR3. */ call paranoid_entry UNWIND_HINT_REGS @@ -1367,31 +1362,12 @@ end_repeat_nmi: movq $-1, %rsi call exc_nmi - /* Always restore stashed CR3 value (see paranoid_entry) */ - RESTORE_CR3 scratch_reg=%r15 save_reg=%r14 - /* - * The above invocation of paranoid_entry stored the GSBASE - * related information in R/EBX depending on the availability - * of FSGSBASE. - * - * If FSGSBASE is enabled, restore the saved GSBASE value - * unconditionally, otherwise take the conditional SWAPGS path. + * Use paranoid_exit to handle SWAPGS and CR3, but no need to use + * restore_regs_and_return_to_kernel as we must handle nested NMI. */ - ALTERNATIVE "jmp nmi_no_fsgsbase", "", X86_FEATURE_FSGSBASE - - wrgsbase %rbx - jmp nmi_restore - -nmi_no_fsgsbase: - /* EBX == 0 -> invoke SWAPGS */ - testl %ebx, %ebx - jnz nmi_restore - -nmi_swapgs: - swapgs + call paranoid_exit -nmi_restore: POP_REGS /* -- 2.19.1.6.gb485710b