From patchwork Tue Jun 25 04:05:00 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jisheng Zhang X-Patchwork-Id: 13710581 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 377BEC3065B for ; Tue, 25 Jun 2024 04:19:21 +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=/cfvi6NU+33hE/fsb9H/otUc13wfGdnL1HywfMzmnzA=; b=iLqzCf4JEP9qBu RnHkXQZT+2hJxMBqiTy2rbUhdwrEBavucEeiyWgq8sHLrKsyQtgpNSjAbtIxjS3OFxn12e8mastDC JqmM3SmWtLW6J+50LQPloQ0B1qioEmzufcwMJuoj1Y8kzCzD3kF3FSSTWnhg42JKnvi0/BHt+G2xU NUd7g/kE41UfMgZW69494ou9HlJxng7p8m/fqt3LH8eL16TXthLxWLhE8TfyyLbpH3C4/4BmUy9cI WgSvGkr1DzRhxz6QxSjmcmMeZ9rLBLk2ySAplAOvUqrCi4C1dm3Z/M+rYOmtCT4y/olu0Vc6Rf/2d 5BJwPGIqk+WUU6Tvj5rQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sLxeI-00000001XRv-1W8J; Tue, 25 Jun 2024 04:19:18 +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 1sLxeB-00000001XOY-3z5P for linux-riscv@lists.infradead.org; Tue, 25 Jun 2024 04:19:13 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 42B8D611D3; Tue, 25 Jun 2024 04:19:11 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9F93CC4AF09; Tue, 25 Jun 2024 04:19:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1719289150; bh=DRenIR1h1uckRbamCPlOygD4TulcG8SHfUvGTveeorc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YpozG22IEVA2nBqJ8c0xsbZt6uPkG5mxT2ifhOUxfWWnac5+tPiACBAcWM39RmioP WAEp3VD2DsbwQ/h9ZTjWxVMH1tZ3Cf1o8lnm9vddSd8BJPc/EW5SxdOZb7p+JcGTfv FtQ2CzUQdlD73BebltlmD75xZ0Xr6cOCwDW5z578rwoZN/2mqabQeVQ2EcrbH4ukK/ Sp0FKEHrsCvORglBeIDtt3mX3/ke4g3/aq1MA+0Hkf8hLAgR1my5jQYWl4xrXOGeae wuCggyCvHUqWM6Vv7RI9FJddfZOIUT+7HCOX/iTXnN8b8STZcIKMfmLqYwEaCT+kyW IbkiXTEg1mXKA== From: Jisheng Zhang To: Paul Walmsley , Palmer Dabbelt , Albert Ou Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH 4/4] riscv: uaccess: use 'asm goto output' for get_user Date: Tue, 25 Jun 2024 12:05:00 +0800 Message-ID: <20240625040500.1788-5-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_211912_107609_641B1FA2 X-CRM114-Status: GOOD ( 12.89 ) 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 output' 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 | 88 +++++++++++++++++++++++--------- 1 file changed, 63 insertions(+), 25 deletions(-) diff --git a/arch/riscv/include/asm/uaccess.h b/arch/riscv/include/asm/uaccess.h index d8c44705b61d..d9c32b4f7d13 100644 --- a/arch/riscv/include/asm/uaccess.h +++ b/arch/riscv/include/asm/uaccess.h @@ -63,27 +63,54 @@ * call. */ -#define __get_user_asm(insn, x, ptr, err) \ +#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT +#define __get_user_asm(insn, x, ptr, label) \ + asm_goto_output( \ + "1:\n" \ + " " insn " %0, %1\n" \ + _ASM_EXTABLE_UACCESS_ERR(1b, %l2, %0) \ + : "=&r" (x) \ + : "m" (*(ptr)) : : label) +#else /* !CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ +#define __get_user_asm(insn, x, ptr, label) \ do { \ - __typeof__(x) __x; \ + long __gua_err = 0; \ __asm__ __volatile__ ( \ "1:\n" \ " " insn " %1, %2\n" \ "2:\n" \ _ASM_EXTABLE_UACCESS_ERR_ZERO(1b, 2b, %0, %1) \ - : "+r" (err), "=&r" (__x) \ + : "+r" (__gua_err), "=&r" (x) \ : "m" (*(ptr))); \ - (x) = __x; \ + if (__gua_err) \ + goto label; \ } while (0) +#endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ #ifdef CONFIG_64BIT -#define __get_user_8(x, ptr, err) \ - __get_user_asm("ld", x, ptr, err) +#define __get_user_8(x, ptr, label) \ + __get_user_asm("ld", x, ptr, label) #else /* !CONFIG_64BIT */ -#define __get_user_8(x, ptr, err) \ + +#ifdef CONFIG_CC_HAS_ASM_GOTO_OUTPUT +#define __get_user_8(x, ptr, label) \ + asm_goto_output( \ + "1:\n" \ + " lw %0, %2\n" \ + "2:\n" \ + " lw %1, %3\n" \ + _ASM_EXTABLE_UACCESS_ERR(1b, %l4, %0) \ + _ASM_EXTABLE_UACCESS_ERR(2b, %l4, %0) \ + : "=&r" (__lo), "=r" (__hi) \ + : "m" (__ptr[__LSW]), "m" (__ptr[__MSW]) \ + : : label) + +#else /* !CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ +#define __get_user_8(x, ptr, label) \ do { \ u32 __user *__ptr = (u32 __user *)(ptr); \ u32 __lo, __hi; \ + long __gu8_err = 0; \ __asm__ __volatile__ ( \ "1:\n" \ " lw %1, %3\n" \ @@ -92,35 +119,51 @@ do { \ "3:\n" \ _ASM_EXTABLE_UACCESS_ERR_ZERO(1b, 3b, %0, %1) \ _ASM_EXTABLE_UACCESS_ERR_ZERO(2b, 3b, %0, %1) \ - : "+r" (err), "=&r" (__lo), "=r" (__hi) \ + : "+r" (__gu8_err), "=&r" (__lo), "=r" (__hi) \ : "m" (__ptr[__LSW]), "m" (__ptr[__MSW])); \ - if (err) \ + if (__gu8_err) { \ __hi = 0; \ + goto label; \ + } \ (x) = (__typeof__(x))((__typeof__((x)-(x)))( \ (((u64)__hi << 32) | __lo))); \ } while (0) +#endif /* CONFIG_CC_HAS_ASM_GOTO_OUTPUT */ + #endif /* CONFIG_64BIT */ -#define __get_user_nocheck(x, __gu_ptr, __gu_err) \ +#define __get_user_nocheck(x, __gu_ptr, label) \ do { \ switch (sizeof(*__gu_ptr)) { \ case 1: \ - __get_user_asm("lb", (x), __gu_ptr, __gu_err); \ + __get_user_asm("lb", (x), __gu_ptr, label); \ break; \ case 2: \ - __get_user_asm("lh", (x), __gu_ptr, __gu_err); \ + __get_user_asm("lh", (x), __gu_ptr, label); \ break; \ case 4: \ - __get_user_asm("lw", (x), __gu_ptr, __gu_err); \ + __get_user_asm("lw", (x), __gu_ptr, label); \ break; \ case 8: \ - __get_user_8((x), __gu_ptr, __gu_err); \ + __get_user_8((x), __gu_ptr, label); \ break; \ default: \ BUILD_BUG(); \ } \ } while (0) +#define __get_user_error(x, ptr, err) \ +do { \ + __label__ __gu_failed; \ + \ + __get_user_nocheck(x, ptr, __gu_failed); \ + err = 0; \ + break; \ +__gu_failed: \ + x = 0; \ + err = -EFAULT; \ +} while (0) + /** * __get_user: - Get a simple variable from user space, with less checking. * @x: Variable to store result. @@ -145,13 +188,16 @@ do { \ ({ \ const __typeof__(*(ptr)) __user *__gu_ptr = (ptr); \ long __gu_err = 0; \ + __typeof__(x) __gu_val; \ \ __chk_user_ptr(__gu_ptr); \ \ __enable_user_access(); \ - __get_user_nocheck(x, __gu_ptr, __gu_err); \ + __get_user_error(__gu_val, __gu_ptr, __gu_err); \ __disable_user_access(); \ \ + (x) = __gu_val; \ + \ __gu_err; \ }) @@ -336,13 +382,7 @@ unsigned long __must_check clear_user(void __user *to, unsigned long n) } #define __get_kernel_nofault(dst, src, type, err_label) \ -do { \ - long __kr_err = 0; \ - \ - __get_user_nocheck(*((type *)(dst)), (type *)(src), __kr_err); \ - if (unlikely(__kr_err)) \ - goto err_label; \ -} while (0) + __get_user_nocheck(*((type *)(dst)), (type *)(src), err_label); #define __put_kernel_nofault(dst, src, type, err_label) \ __put_user_nocheck(*((type *)(src)), (type *)(dst), err_label); @@ -364,11 +404,9 @@ static inline void user_access_restore(unsigned long enabled) { } __put_user_nocheck(x, (ptr), label); #define unsafe_get_user(x, ptr, label) do { \ - long __kr_err = 0; \ __inttype(*(ptr)) __gu_val; \ - __get_user_nocheck(__gu_val, (ptr), __kr_err); \ + __get_user_nocheck(__gu_val, (ptr), label); \ (x) = (__force __typeof__(*(ptr)))__gu_val; \ - if (__kr_err) goto label; \ } while (0) /*