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,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 40333C432BE for ; Tue, 31 Aug 2021 17:52:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 21E8360FE8 for ; Tue, 31 Aug 2021 17:52:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240684AbhHaRxI (ORCPT ); Tue, 31 Aug 2021 13:53:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240648AbhHaRxE (ORCPT ); Tue, 31 Aug 2021 13:53:04 -0400 Received: from mail-pl1-x633.google.com (mail-pl1-x633.google.com [IPv6:2607:f8b0:4864:20::633]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B6A0C061575 for ; Tue, 31 Aug 2021 10:52:09 -0700 (PDT) Received: by mail-pl1-x633.google.com with SMTP id bg1so5820349plb.13 for ; Tue, 31 Aug 2021 10:52:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=1oP3U2JdXU+Z0EH54sEwuWhZOymozEo9q+P44Deggqg=; b=aIQOhoKeoVIf3ymiT1Jp8ldQtjWpjSCSN3x+fDuHDz8p/6AthANUCkqe+Fkhj++QVw g6b6paonBc/BVxc8K4lQd/LzxtG8EePpVX6u2TFtBqtLAZo32FT1zTW8Kf7QxH1xTgHf Mz9rdF8GlIO+trmp7JT5maiTgeF9PFaRXUekYFa70vQZ3gJtb4NQn72A9FHgI3e+cTJ4 LaNI0xAeqJ4LiXLKYic/is7ZYfBL4FT/61c3Z2dSEFPQeUHNTP1JTdY5DZq4y/Q0rjke zimiU51IhG8sK37p8KiEMLFMqPtBfX48KBv3T47irqo3jm27ELPTBiVFHc31IL1dGTOf MzpA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=1oP3U2JdXU+Z0EH54sEwuWhZOymozEo9q+P44Deggqg=; b=uJJ15kZ2mvl9jgpDUt0tZr8Kl/Ey5qa0tT3FJuSsJC4spyHUy0JWCGfDiWguASnAkQ FHNddVwvDFb6kjobJJXkWld+ZaMTU1UTkza1z92KthMbr9AmJNNZH132iKmDc61st8MR rfwcXYjRsKj+jNeFNlxB7e+6kh7tzQcHg8Qma9Iv2WH6FyIWKSIgLnoRqLkrFoZx66XV 0dCW5Z4UYCcf72bfc65Cg8d8evaZYk1ebrhNIclg+80/PMzIfO6IMzOsQkl1vIRZ/sQ0 5qJuj+EaV1HAoTRIcJ4I0zVolble4D5I8BituCs4+QHMw06bFkhKlim/7Y4pmwx1vS4l 5F8Q== X-Gm-Message-State: AOAM531IMWKA2ts5XQfcBjCN26PM6ZIPxPwAQIkpIvRJiU8ZRCWRZg9I lnDzZpynAxfm59PQd4RSJ+5dySrFVoE= X-Google-Smtp-Source: ABdhPJyYO1J/K/ZmmZn1T7o2rRmHBMeJtKZsqLIgZS4DfP1PnjGBmSmjLcm0lc2YZvJhtwnQPpKecw== X-Received: by 2002:a17:90a:64c1:: with SMTP id i1mr6635234pjm.111.1630432328797; Tue, 31 Aug 2021 10:52:08 -0700 (PDT) Received: from localhost ([47.251.3.230]) by smtp.gmail.com with ESMTPSA id 138sm18830174pfz.187.2021.08.31.10.52.07 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 31 Aug 2021 10:52:08 -0700 (PDT) From: Lai Jiangshan To: linux-kernel@vger.kernel.org Cc: Lai Jiangshan , Andy Lutomirski , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" Subject: [PATCH 16/24] x86/entry: Use skip_rdi instead of save_ret for PUSH_AND_CLEAR_REGS Date: Wed, 1 Sep 2021 01:50:17 +0800 Message-Id: <20210831175025.27570-17-jiangshanlai@gmail.com> X-Mailer: git-send-email 2.19.1.6.gb485710b In-Reply-To: <20210831175025.27570-1-jiangshanlai@gmail.com> References: <20210831175025.27570-1-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 It allows the user of PUSH_AND_CLEAR_REGS to use its own ways to handle the return addr. For example, error_entry() can save it to r12 directly instead of moving it around and reduce two instructions. And in later patch, it allows us to move the return addr lower and add a little more space between pt_regs and the return addr which consists a new type ist_regs for IST interrupts. No functional change intended. Signed-off-by: Lai Jiangshan --- arch/x86/entry/calling.h | 18 +++++------------- arch/x86/entry/entry_64.S | 12 ++++++++---- 2 files changed, 13 insertions(+), 17 deletions(-) diff --git a/arch/x86/entry/calling.h b/arch/x86/entry/calling.h index 996b041e92d2..aeee1575332f 100644 --- a/arch/x86/entry/calling.h +++ b/arch/x86/entry/calling.h @@ -63,15 +63,11 @@ For 32-bit we have the following conventions - kernel is built with * for assembly code: */ -.macro PUSH_REGS rdx=%rdx rax=%rax save_ret=0 - .if \save_ret - pushq %rsi /* pt_regs->si */ - movq 8(%rsp), %rsi /* temporarily store the return address in %rsi */ - movq %rdi, 8(%rsp) /* pt_regs->di (overwriting original return address) */ - .else +.macro PUSH_REGS rdx=%rdx rax=%rax skip_rdi=0 + .if \skip_rdi == 0 pushq %rdi /* pt_regs->di */ - pushq %rsi /* pt_regs->si */ .endif + pushq %rsi /* pt_regs->si */ pushq \rdx /* pt_regs->dx */ pushq %rcx /* pt_regs->cx */ pushq \rax /* pt_regs->ax */ @@ -86,10 +82,6 @@ For 32-bit we have the following conventions - kernel is built with pushq %r14 /* pt_regs->r14 */ pushq %r15 /* pt_regs->r15 */ UNWIND_HINT_REGS - - .if \save_ret - pushq %rsi /* return address on top of stack */ - .endif .endm .macro CLEAR_REGS @@ -114,8 +106,8 @@ For 32-bit we have the following conventions - kernel is built with .endm -.macro PUSH_AND_CLEAR_REGS rdx=%rdx rax=%rax save_ret=0 - PUSH_REGS rdx=\rdx, rax=\rax, save_ret=\save_ret +.macro PUSH_AND_CLEAR_REGS rdx=%rdx rax=%rax skip_rdi=0 + PUSH_REGS rdx=\rdx, rax=\rax, skip_rdi=\skip_rdi CLEAR_REGS .endm diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S index ac67a1109c9c..e968074046c3 100644 --- a/arch/x86/entry/entry_64.S +++ b/arch/x86/entry/entry_64.S @@ -849,7 +849,10 @@ SYM_CODE_END(xen_failsafe_callback) SYM_CODE_START_LOCAL(paranoid_entry) UNWIND_HINT_FUNC cld - PUSH_AND_CLEAR_REGS save_ret=1 + PUSH_AND_CLEAR_REGS skip_rdi=1 + movq RDI(%rsp), %rsi /* temporarily store the return address in %rsi */ + movq %rdi, RDI(%rsp) /* put %rdi onto pt_regs */ + pushq %rsi /* put the return address onto the stack */ ENCODE_FRAME_POINTER 8 /* @@ -973,10 +976,11 @@ SYM_CODE_END(paranoid_exit) SYM_CODE_START_LOCAL(error_entry) UNWIND_HINT_FUNC cld - PUSH_AND_CLEAR_REGS save_ret=1 - ENCODE_FRAME_POINTER 8 + PUSH_AND_CLEAR_REGS skip_rdi=1 + movq RDI(%rsp), %r12 /* save return addr in %12 */ + movq %rdi, RDI(%rsp) /* put %rdi onto pt_regs */ + ENCODE_FRAME_POINTER - popq %r12 /* save return addr in %12 */ movq %rsp, %rdi /* arg0 = pt_regs pointer */ call do_error_entry movq %rax, %rsp /* switch stack */ -- 2.19.1.6.gb485710b