From patchwork Thu Nov 18 11:25:14 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jisheng Zhang X-Patchwork-Id: 12626715 X-Patchwork-Delegate: kuba@kernel.org 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 65A49C433FE for ; Thu, 18 Nov 2021 11:36:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4BEC160F26 for ; Thu, 18 Nov 2021 11:36:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344131AbhKRLjx (ORCPT ); Thu, 18 Nov 2021 06:39:53 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60126 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344217AbhKRLjB (ORCPT ); Thu, 18 Nov 2021 06:39:01 -0500 Received: from ustc.edu.cn (email6.ustc.edu.cn [IPv6:2001:da8:d800::8]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 1C74AC061210; Thu, 18 Nov 2021 03:35:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mail.ustc.edu.cn; s=dkim; h=Received:Date:From:To:Cc:Subject: Message-ID:In-Reply-To:References:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=3i4Rp/q45W+TZIYLx/C3ZWYjrNyJFZoaEf azRHAUX/o=; b=R7L6Vq068WV7uimSlqXh2xRnhfbz3P3uUPJ43k2X8EZXRHEj4b Yq1efcLblCThAwNAEmRWo0kzIxW3/bi3pA763T/YIIQGCguwUso/Ck8LY1LG2dX2 1d+8Z8aLkb4Fw2StcKU7ylLXYT/3w9uzvCGFtcGkONca+cg8WoWW+DGAA= Received: from xhacker (unknown [101.86.18.22]) by newmailweb.ustc.edu.cn (Coremail) with SMTP id LkAmygAHD99XOpZhwZ1cAQ--.27562S7; Thu, 18 Nov 2021 19:34:56 +0800 (CST) Date: Thu, 18 Nov 2021 19:25:14 +0800 From: Jisheng Zhang To: Paul Walmsley , Palmer Dabbelt , Albert Ou , " =?utf-8?b?QmrDtnJuIFTDtnBlbA==?= " , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Masahiro Yamada , Michal Marek , Nick Desaulniers Cc: Kefeng Wang , Tong Tiangen , linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-kbuild@vger.kernel.org Subject: [PATCH 07/12] riscv: lib: uaccess: fold fixups into body Message-ID: <20211118192514.13d3e873@xhacker> In-Reply-To: <20211118192130.48b8f04c@xhacker> References: <20211118192130.48b8f04c@xhacker> MIME-Version: 1.0 X-CM-TRANSID: LkAmygAHD99XOpZhwZ1cAQ--.27562S7 X-Coremail-Antispam: 1UD129KBjvJXoW7KFy3ur13GF4DZFW3AFy7ZFb_yoW8Ww13pw 1xur9rKw45Wrn7uFZ2yry5XF1rWa1fXF1UArW7Kw15ZrnFvr1vyFnYq39rWryDJFWrAF4x WF9ayr4rGryYk37anT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUUBCb7Iv0xC_tr1lb4IE77IF4wAFF20E14v26rWj6s0DM7CY07I2 0VC2zVCF04k26cxKx2IYs7xG6rWj6s0DM7CIcVAFz4kK6r1j6r18M28IrcIa0xkI8VA2jI 8067AKxVWUAVCq3wA2048vs2IY020Ec7CjxVAFwI0_Xr0E3s1l8cAvFVAK0II2c7xJM28C jxkF64kEwVA0rcxSw2x7M28EF7xvwVC0I7IYx2IY67AKxVW7JVWDJwA2z4x0Y4vE2Ix0cI 8IcVCY1x0267AKxVW8Jr0_Cr1UM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E 87Iv6xkF7I0E14v26rxl6s0DM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI64 kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r106r15McIj6I8E87Iv67AKxVWUJVW8JwAm 72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IY64vIr41lFIxGxcIEc7CjxVA2Y2ka0xkIwI1l42 xK82IYc2Ij64vIr41l4I8I3I0E4IkC6x0Yz7v_Jr0_Gr1lx2IqxVAqx4xG67AKxVWUJVWU GwC20s026x8GjcxK67AKxVWUGVWUWwC2zVAF1VAY17CE14v26r4a6rW5MIIYrxkI7VAKI4 8JMIIF0xvE2Ix0cI8IcVAFwI0_Gr0_Xr1lIxAIcVC0I7IYx2IY6xkF7I0E14v26r4UJVWx Jr1lIxAIcVCF04k26cxKx2IYs7xG6r1j6r1xMIIF0xvEx4A2jsIE14v26r4j6F4UMIIF0x vEx4A2jsIEc7CjxVAFwI0_Gr1j6F4UJbIYCTnIWIevJa73UjIFyTuYvjxU775rUUUUU X-CM-SenderInfo: xmv2xttqjtqzxdloh3xvwfhvlgxou0/ Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Jisheng Zhang uaccess functions such __asm_copy_to_user(), __arch_copy_from_user() and __clear_user() place their exception fixups in the `.fixup` section without any clear association with themselves. If we backtrace the fixup code, it will be symbolized as an offset from the nearest prior symbol. Similar as arm64 does, we must move fixups into the body of the functions themselves, after the usual fast-path returns. Inline assembly will be dealt with in subsequent patches. Signed-off-by: Jisheng Zhang --- arch/riscv/lib/uaccess.S | 22 +++++++++++----------- 1 file changed, 11 insertions(+), 11 deletions(-) diff --git a/arch/riscv/lib/uaccess.S b/arch/riscv/lib/uaccess.S index 55f80f84e23f..047f517ac780 100644 --- a/arch/riscv/lib/uaccess.S +++ b/arch/riscv/lib/uaccess.S @@ -173,6 +173,13 @@ ENTRY(__asm_copy_from_user) csrc CSR_STATUS, t6 li a0, 0 ret + + /* Exception fixup code */ +10: + /* Disable access to user memory */ + csrs CSR_STATUS, t6 + mv a0, t5 + ret ENDPROC(__asm_copy_to_user) ENDPROC(__asm_copy_from_user) EXPORT_SYMBOL(__asm_copy_to_user) @@ -218,19 +225,12 @@ ENTRY(__clear_user) addi a0, a0, 1 bltu a0, a3, 5b j 3b -ENDPROC(__clear_user) -EXPORT_SYMBOL(__clear_user) - .section .fixup,"ax" - .balign 4 - /* Fixup code for __copy_user(10) and __clear_user(11) */ -10: - /* Disable access to user memory */ - csrs CSR_STATUS, t6 - mv a0, t5 - ret + /* Exception fixup code */ 11: + /* Disable access to user memory */ csrs CSR_STATUS, t6 mv a0, a1 ret - .previous +ENDPROC(__clear_user) +EXPORT_SYMBOL(__clear_user)