From patchwork Tue Jun 25 04:04:59 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jisheng Zhang X-Patchwork-Id: 13710582 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8C0EBC3064D for ; Tue, 25 Jun 2024 04:19:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-ID:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=EAEpT7XPO2fo5+rcGH9ja8LyUSEEGVesHQHKG8DgZMM=; b=e4zIkUpj8Rvdfs EVZCXAsm1nS7EiJmWA3re19KPwVVXOaGEDpKWFmebtc8bFbMqu4AqLC/gM4hRgjitXkYNkMwxJ4Jh bQgQT8j8K4Gu0JhSZwGaqs/lm9A1VR5A+Y4+ntHvwkNUVF/k51tJytDlv8fyVRm6z2WiOi7L1cFX2 EPq2Rvl/IpyS8csBC3AZKx++3MokF9thzBTG9beeHpSttzVhsPY8TKEKNU/0ZmQVuhiKdFRv8oUdk tIZ/Sl+LefeMoUF2xM5/9cyg3T7BTbbM/Rk/4T+91mxqssRMR/rsGbhL7gWYaCic+Eq1bwlpNkGSt pT11bp/4yZXglJjMbgEw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sLxeE-00000001XPw-1OwZ; Tue, 25 Jun 2024 04:19:14 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sLxeA-00000001XNr-023y for linux-riscv@lists.infradead.org; Tue, 25 Jun 2024 04:19:11 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 6EB1261195; Tue, 25 Jun 2024 04:19:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2927FC32782; Tue, 25 Jun 2024 04:19:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719289149; bh=ZzlEc7s3uYpxeTkZStcoK6OMbfxXl2VXk7KZNHt3OpE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AhGk98Mv6hs+xLaijlXJ/I4OLbsJW/jkS3axHL7EefamGHEOtW1ZtoJvCEg85A6XL ItftEQ4YK4kTtKWFpCYEXezDscYbWPD3IzrXXzr5tKOecVnYIBSK/ojBHSr+B2y7C4 NfeS1uaz7Ayl1voJExBvwc+qq9qNvjMpiTJ8oDytePSBOTK4a5EFOuwdrvWoZqqZhN JAkk4oz1BgQGcHR9zrfBIfqdrdAxPG8hJFdKN6nV42e8vOOKfEXjCIIlcUYIIpsK45 DGqRJScKzZV08XVnqphuA+74tE+WeSgl+r5K/FQmbw87cuDBK0FhEsifP3eKlUqCKL dpsr6/4206wgw== From: Jisheng Zhang To: Paul Walmsley , Palmer Dabbelt , Albert Ou Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 3/4] riscv: uaccess: use 'asm goto' for put_user() Date: Tue, 25 Jun 2024 12:04:59 +0800 Message-ID: <20240625040500.1788-4-jszhang@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240625040500.1788-1-jszhang@kernel.org> References: <20240625040500.1788-1-jszhang@kernel.org> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240624_211910_225940_406D078A X-CRM114-Status: GOOD ( 11.31 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org 'asm goto' generates noticeably better code since we don't need to test the error etc, the exception just jumps to the error handling directly. Signed-off-by: Jisheng Zhang --- arch/riscv/include/asm/uaccess.h | 68 +++++++++++++++----------------- 1 file changed, 32 insertions(+), 36 deletions(-) diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h index 84b084e388a7..d8c44705b61d 100644 --- a/arch/riscv/include/asm/uaccess.h +++ b/arch/riscv/include/asm/uaccess.h @@ -181,61 +181,66 @@ do { \ ((x) = (__force __typeof__(x))0, -EFAULT); \ }) -#define __put_user_asm(insn, x, ptr, err) \ +#define __put_user_asm(insn, x, ptr, label) \ do { \ __typeof__(*(ptr)) __x = x; \ - __asm__ __volatile__ ( \ + asm goto( \ "1:\n" \ - " " insn " %z1, %2\n" \ - "2:\n" \ - _ASM_EXTABLE_UACCESS_ERR(1b, 2b, %0) \ - : "+r" (err) \ - : "rJ" (__x), "m"(*(ptr))); \ + " " insn " %z0, %1\n" \ + _ASM_EXTABLE(1b, %l2) \ + : : "rJ" (__x), "m"(*(ptr)) : : label); \ } while (0) #ifdef CONFIG_64BIT -#define __put_user_8(x, ptr, err) \ - __put_user_asm("sd", x, ptr, err) +#define __put_user_8(x, ptr, label) \ + __put_user_asm("sd", x, ptr, label) #else /* !CONFIG_64BIT */ -#define __put_user_8(x, ptr, err) \ +#define __put_user_8(x, ptr, label) \ do { \ u32 __user *__ptr = (u32 __user *)(ptr); \ u64 __x = (__typeof__((x)-(x)))(x); \ __asm__ __volatile__ ( \ "1:\n" \ - " sw %z1, %3\n" \ + " sw %z0, %2\n" \ "2:\n" \ - " sw %z2, %4\n" \ - "3:\n" \ - _ASM_EXTABLE_UACCESS_ERR(1b, 3b, %0) \ - _ASM_EXTABLE_UACCESS_ERR(2b, 3b, %0) \ - : "+r" (err) \ - : "rJ" (__x), "rJ" (__x >> 32), \ + " sw %z1, %3\n" \ + _ASM_EXTABLE(1b, %l4) \ + _ASM_EXTABLE(2b, %l4) \ + : : "rJ" (__x), "rJ" (__x >> 32), \ "m" (__ptr[__LSW]), \ - "m" (__ptr[__MSW])); \ + "m" (__ptr[__MSW]) : : label); \ } while (0) #endif /* CONFIG_64BIT */ -#define __put_user_nocheck(x, __gu_ptr, __pu_err) \ +#define __put_user_nocheck(x, __gu_ptr, label) \ do { \ switch (sizeof(*__gu_ptr)) { \ case 1: \ - __put_user_asm("sb", (x), __gu_ptr, __pu_err); \ + __put_user_asm("sb", (x), __gu_ptr, label); \ break; \ case 2: \ - __put_user_asm("sh", (x), __gu_ptr, __pu_err); \ + __put_user_asm("sh", (x), __gu_ptr, label); \ break; \ case 4: \ - __put_user_asm("sw", (x), __gu_ptr, __pu_err); \ + __put_user_asm("sw", (x), __gu_ptr, label); \ break; \ case 8: \ - __put_user_8((x), __gu_ptr, __pu_err); \ + __put_user_8((x), __gu_ptr, label); \ break; \ default: \ BUILD_BUG(); \ } \ } while (0) +#define __put_user_error(x, ptr, err) \ +do { \ + __label__ err_label; \ + __put_user_nocheck(x, ptr, err_label); \ + break; \ +err_label: \ + (err) = -EFAULT; \ +} while (0) + /** * __put_user: - Write a simple value into user space, with less checking. * @x: Value to copy to user space. @@ -266,7 +271,7 @@ do { \ __chk_user_ptr(__gu_ptr); \ \ __enable_user_access(); \ - __put_user_nocheck(__val, __gu_ptr, __pu_err); \ + __put_user_error(__val, __gu_ptr, __pu_err); \ __disable_user_access(); \ \ __pu_err; \ @@ -340,13 +345,7 @@ do { \ } while (0) #define __put_kernel_nofault(dst, src, type, err_label) \ -do { \ - long __kr_err = 0; \ - \ - __put_user_nocheck(*((type *)(src)), (type *)(dst), __kr_err); \ - if (unlikely(__kr_err)) \ - goto err_label; \ -} while (0) + __put_user_nocheck(*((type *)(src)), (type *)(dst), err_label); static __must_check __always_inline bool user_access_begin(const void __user *ptr, size_t len) { @@ -361,11 +360,8 @@ static __must_check __always_inline bool user_access_begin(const void __user *pt static inline unsigned long user_access_save(void) { return 0UL; } static inline void user_access_restore(unsigned long enabled) { } -#define unsafe_put_user(x, ptr, label) do { \ - long __kr_err = 0; \ - __put_user_nocheck(x, (ptr), __kr_err); \ - if (__kr_err) goto label; \ -} while (0) +#define unsafe_put_user(x, ptr, label) \ + __put_user_nocheck(x, (ptr), label); #define unsafe_get_user(x, ptr, label) do { \ long __kr_err = 0; \