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 2921CC433F5 for ; Tue, 12 Apr 2022 12:52:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1354425AbiDLMwa (ORCPT ); Tue, 12 Apr 2022 08:52:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39498 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355036AbiDLMsA (ORCPT ); Tue, 12 Apr 2022 08:48:00 -0400 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 5558BBE0F for ; Tue, 12 Apr 2022 05:14:54 -0700 (PDT) Received: by mail-pj1-x1035.google.com with SMTP id c12-20020a17090a020c00b001cba1ebb20cso2058546pjc.0 for ; Tue, 12 Apr 2022 05:14:54 -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:mime-version :content-transfer-encoding; bh=WlhLvKY3zT5Zwc6BjY2DR6KFEYpYVNQay5CCAj2cOs4=; b=BFpKjK/Z/j7bELQYt2NhSukAKBLKCs3yubgOqHCgYAHf3RJ0ZyQoGpcNF2bzkqPHxT u/GnYtHYti4wn2Xh6Z8LHH8qRHwsNttAT3XuXDUG0WL7cW/enRV4PL3h8aerBy0sCdVr BN+UNgyBiiomhnx6JJcKGH62tQMzn7iV5spUUhdix5wODL2qJPF92lzeqXtReGIyU+Kf r+qnLRYkTmkgKQn6PkXDo1PKZSSJcnXloYRfGez2iOV7dqNYxs7yuI7yZCRHjb7+xN+V SJTZbgPSRHgB9GbMGNvTymodgyzAhWqgWE5l7ZgZ6/UNkSjxPpW3E44iB2sFf0Zgs1mA eLxA== 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:mime-version :content-transfer-encoding; bh=WlhLvKY3zT5Zwc6BjY2DR6KFEYpYVNQay5CCAj2cOs4=; b=G3D3A19cADnU/vlFsltJSZpvdyClJyO3rKk14ujJdCu7BpBJqjkTuLGqNrgNFVaguE 7KXNcHBKfXoAoZB8u35mmESolHSNAqVxmdEs/6RYJaugcV2TjPLa84wqDYWb/wtDc0/e Ckmvg7V87PyPRGcSk0eW/c5k8ZMH2Y4azewmZxwX8SqxsmxNX89/2MGgmKYMoTB5OOC/ L+xCwwjLBayg/AxDY3tNVSeM6BfmT+ENiqPpdu2bLJmGM1knBwpo8FLlzblOcc+x/teE QP0yKs5XIYBKzRzLiwegTrPSXdouvcNpVm7R8uISk8qNSOjY9KqE3PtO4C1+a4WKNqk2 zdPA== X-Gm-Message-State: AOAM531QGPCvTxWsAvWygarKW8oEwhG3AbHxqIKFb9nBrn+YSb8SiOPY iPHCFclJzLRxhSfjrqqHaFSu9D903qg= X-Google-Smtp-Source: ABdhPJx2pR6VS4BxQjB8Dl4fdWoxC6QU+VQHL/7oBEeqbc24hcPLhKeunYV0tH5CkL27f7vVqY+rOA== X-Received: by 2002:a17:902:ce0f:b0:156:5a4:926c with SMTP id k15-20020a170902ce0f00b0015605a4926cmr36849036plg.3.1649765693665; Tue, 12 Apr 2022 05:14:53 -0700 (PDT) Received: from localhost ([47.251.4.198]) by smtp.gmail.com with ESMTPSA id z16-20020a056a00241000b004f3a647ae89sm40248445pfh.174.2022.04.12.05.14.52 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Tue, 12 Apr 2022 05:14:53 -0700 (PDT) From: Lai Jiangshan To: linux-kernel@vger.kernel.org Cc: Borislav Petkov , Peter Zijlstra , Josh Poimboeuf , Andy Lutomirski , Thomas Gleixner , x86@kernel.org, Lai Jiangshan Subject: [PATCH V5 0/7] x86/entry: Clean up entry code Date: Tue, 12 Apr 2022 20:15:34 +0800 Message-Id: <20220412121541.4595-1-jiangshanlai@gmail.com> X-Mailer: git-send-email 2.19.1.6.gb485710b MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Lai Jiangshan This patchset moves the stack-switch code to the place where error_entry() return, unravels error_entry() from XENpv and makes entry_INT80_compat() uses idtentry macro. This patchset is highly related to XENpv, because it does the extra cleanup to convert SWAPGS to swapgs after major cleanup is done. The patches are the 5th version to pick patches from the patchset https://lore.kernel.org/lkml/20211126101209.8613-1-jiangshanlai@gmail.com/ which converts ASM code to C code. These patches are prepared for that purpose. But this patchset has it own value: it simplifies the stack switch, avoids leaving the old stack inside a function call, and separates XENpv code with native code without adding new code. Peter said in V3: > So AFAICT these patches are indeed correct. > > I'd love for some of the other x86 people to also look at this, > but a tentative ACK on this. [V4]: https://lore.kernel.org/lkml/20220318143016.124387-1-jiangshanlai@gmail.com/ [V3]: https://lore.kernel.org/lkml/20220315073949.7541-1-jiangshanlai@gmail.com/ [V2]: https://lore.kernel.org/lkml/20220303035434.20471-1-jiangshanlai@gmail.com/ [V1]: https://lore.kernel.org/lkml/20211208110833.65366-1-jiangshanlai@gmail.com/ Changed from V4: Update changelog largely of patch 1 and patch 2 Update changelog slightly of other patches Unbreak the line of fixup_bad_iret() in patch1 Add Reviewed-by from Juergen Gross in patch 6 since he gave the Reviewed-by in one of the squashed patches. Changed from V3: Only reorder the int80 thing as the last patch to make patches ordering more natural. (Both orders are correct) Other interactions in V3: Peter raised several questions and I think I answered them and I don't think the code need to be updated unless I missed some points. (Except reordering the patches) Josh asked to remove UNWIND_HINT_REGS in patch5, but I think UNWIND_HINT_REGS is old code before this patchset and I don't want to do a cleanup that is not relate to preparing converting ASM code C code in this patchset. He also asked to remove ENCODE_FRAME_POINTER in xenpv case, and I think it just complicates the code for just optimizing out a single assignment to %rbp. I would not always stick to these reasons of mine, but I just keep the code unchanged since he hasn't emphasized it again nor other people has requested it. Changed from V2: Make the patch of folding int80 thing as the first patch Add more changelog in "Switch the stack after error_entry() returns" Changed from V1 Squash cleanup patches converting SWAPGS to swapgs into one patch Use my official email address (Ant Group). The work is backed by my company and I was incorrectly misunderstood that XXX@linux.alibaba.com is the only portal for opensource work in the corporate group. Lai Jiangshan (7): x86/traps: Move pt_regs only in fixup_bad_iret() x86/entry: Switch the stack after error_entry() returns x86/entry: Move PUSH_AND_CLEAR_REGS out of error_entry() x86/entry: Move cld to the start of idtentry macro x86/entry: Don't call error_entry() for XENPV x86/entry: Convert SWAPGS to swapgs and remove the definition of SWAPGS x86/entry: Use idtentry macro for entry_INT80_compat arch/x86/entry/entry_64.S | 61 +++++++++++++----- arch/x86/entry/entry_64_compat.S | 105 +------------------------------ arch/x86/include/asm/idtentry.h | 47 ++++++++++++++ arch/x86/include/asm/irqflags.h | 8 --- arch/x86/include/asm/proto.h | 4 -- arch/x86/include/asm/traps.h | 2 +- arch/x86/kernel/traps.c | 18 ++---- 7 files changed, 100 insertions(+), 145 deletions(-) -- 2.19.1.6.gb485710b