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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C6AD3C433EF for ; Tue, 3 May 2022 03:21:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230347AbiECDYc (ORCPT ); Mon, 2 May 2022 23:24:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60866 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230337AbiECDYX (ORCPT ); Mon, 2 May 2022 23:24:23 -0400 Received: from mail-pf1-x42f.google.com (mail-pf1-x42f.google.com [IPv6:2607:f8b0:4864:20::42f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B2E533E0A for ; Mon, 2 May 2022 20:20:52 -0700 (PDT) Received: by mail-pf1-x42f.google.com with SMTP id h1so13739739pfv.12 for ; Mon, 02 May 2022 20:20:52 -0700 (PDT) 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=x61TjLKwnlPP/1Q/z1UHB85PFlxeFJXks6RYgmVkwuc=; b=iXYClFs+HWZ4g95as2fyx9dN6umKDVfdPfMOgeeXq1YD+Crki+bpt7fhpQ4rcCe/VX mADF6JsQl3FLiqepNL/BA7AB0vXrUxTtOGj9Z/sSEqtKqbyMifwxk47RG0ZTnWxSzHJe bZ4XgjrHfcNMlq/Y+Ao2ao8wNz1pb8PWjdFtbDbnYxwKRdHn6u6BbZ4cqr7XOSh4Jj1B KpxrPqAnTsSP2aUHBAlewzK2SwgqHEItUjSD3FT4vjsHkU1DZOWb3sGomgCatb76wBrn Bh4YC2ryd9RNUBhjXRJXelmWBk8ct2Mhbc3Llxzmhb4s4RN+8gIDRpZXXXxyb3nNNUBw Ex6A== 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=x61TjLKwnlPP/1Q/z1UHB85PFlxeFJXks6RYgmVkwuc=; b=aSHhkWdovUVGoW4t5qQFH3BqfmRLfDOXbtSk6R78ZQvAkMF4MHVRCX/2ZRgpQYiWyX jiaXREEuBCxS6dsjJsSSoHhIacId9f2j3MyhPCBt2susRPB13ZacqOG4TYZUCD2s6Ael P4NRHsfvlJlJx8S1mP0xiPfSEptT6SgxBJskJ4Co8RC+0SxgoU8VxxEAEaJoZ0ZYy7QG Taikgtr1r9t18fJXf6w9zS1fdECAOCu77pRYk2FWlZlnVWn0K4zy9eQCdi8rb5IlRiaZ zWe2ID8PEZ9aqIxwmiAjmL/ZojpkerfBPdIE8VIeI7UFApbpgwTapGx1gPe5FvRwbgcK uxPQ== X-Gm-Message-State: AOAM5313kMKI/vOK5dqGxPSxF9M+/DiTqkCTku4X3mvQNLIqDZ5wMEad VnfA+8SCIt+HWQ3ccNSKoT3x4hTVfkw= X-Google-Smtp-Source: ABdhPJwIJaYiXyDx8XCMWi6AiESvXSZzHhrbf5VnJ2C4/dkUn4HNJwq/+9PI8RUCXpaA6TSn/z+jPw== X-Received: by 2002:a05:6a00:1352:b0:50d:ecff:f06c with SMTP id k18-20020a056a00135200b0050decfff06cmr7592097pfu.6.1651548051873; Mon, 02 May 2022 20:20:51 -0700 (PDT) Received: from localhost ([47.251.4.198]) by smtp.gmail.com with ESMTPSA id z21-20020aa791d5000000b0050dc76281ddsm5395704pfa.183.2022.05.02.20.20.50 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Mon, 02 May 2022 20:20:51 -0700 (PDT) From: Lai Jiangshan To: linux-kernel@vger.kernel.org Cc: Borislav Petkov , Peter Zijlstra , Josh Poimboeuf , Andy Lutomirski , Thomas Gleixner , Juergen Gross , x86@kernel.org, Lai Jiangshan , Ingo Molnar , Dave Hansen , "H. Peter Anvin" Subject: [PATCH V7 3/6] x86/entry: Move PUSH_AND_CLEAR_REGS out of error_entry() Date: Tue, 3 May 2022 11:21:04 +0800 Message-Id: <20220503032107.680190-4-jiangshanlai@gmail.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: <20220503032107.680190-1-jiangshanlai@gmail.com> References: <20220503032107.680190-1-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 macro idtentry calls error_entry() unconditionally even on XENPV. But the code XENPV needs in error_entry() is PUSH_AND_CLEAR_REGS only. And PUSH_AND_CLEAR_REGS in error_entry() makes the stack not return to its original place when the function returns, which means it is not possible to convert it to a C function. Move PUSH_AND_CLEAR_REGS out of error_entry(), add a function to wrap PUSH_AND_CLEAR_REGS and call it before error_entry(). It will allow for error_entry() to be not called on XENPV and for error_entry() to be converted to C code. Cc: Juergen Gross Signed-off-by: Lai Jiangshan --- arch/x86/entry/entry_64.S | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-) diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index ca3e99e08a44..b1cef3b0a7ab 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -318,6 +318,14 @@ SYM_CODE_END(ret_from_fork) #endif .endm +/* Save all registers in pt_regs */ +SYM_CODE_START_LOCAL(push_and_clear_regs) + UNWIND_HINT_FUNC + PUSH_AND_CLEAR_REGS save_ret=1 + ENCODE_FRAME_POINTER 8 + RET +SYM_CODE_END(push_and_clear_regs) + /** * idtentry_body - Macro to emit code calling the C function * @cfunc: C function to be called @@ -325,6 +333,9 @@ SYM_CODE_END(ret_from_fork) */ .macro idtentry_body cfunc has_error_code:req + call push_and_clear_regs + UNWIND_HINT_REGS + call error_entry movq %rax, %rsp /* switch to the task stack if from userspace */ ENCODE_FRAME_POINTER @@ -985,13 +996,11 @@ SYM_CODE_START_LOCAL(paranoid_exit) SYM_CODE_END(paranoid_exit) /* - * Save all registers in pt_regs, and switch GS if needed. + * Switch GS and CR3 if needed. */ SYM_CODE_START_LOCAL(error_entry) UNWIND_HINT_FUNC cld - PUSH_AND_CLEAR_REGS save_ret=1 - ENCODE_FRAME_POINTER 8 testb $3, CS+8(%rsp) jz .Lerror_kernelspace -- 2.19.1.6.gb485710b