From patchwork Sun Dec 1 10:27:58 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ben Dooks X-Patchwork-Id: 13889453 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 CD28FD49761 for ; Sun, 1 Dec 2024 10:28:34 +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=+IqgdooJS5CpVfu/nBKwlsEQXMDlLJXlaCPq1uIfTXM=; b=o4yKkx1a46zLJb q0rj+LGTy5LhtZdXWI+iAcOzxE3NfqoXZ9Xj0swWftTQx6yxTAgO/UI8d85DslrBbi4q+HXKxPYxy QGa7pz8vf7KPWyoDYb+hTH9ZUTThWcmvZzqoA/LTCp1gq7tI3FO471sGkZHmu94M2J28974vNxmP6 x0r4tPGoP4XffzlV41c8oZglFGmFnyGTbscUhNgvEIpk9wxXPCGOstElx5N4ZlF2u+Drdrx9guPp3 kmJbN8vj3Yind+C6xMF9/MRICCkYC+OVfg9ZcDyiVGJz10JKwaf1xojHuZDqV1juf+tRAU70M5ifz TsOpBtprEw4yZcBteYxA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tHhBV-00000003IO1-1CdG; Sun, 01 Dec 2024 10:28:13 +0000 Received: from imap4.hz.codethink.co.uk ([188.40.203.114]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tHhBQ-00000003IMU-3yAu for linux-riscv@lists.infradead.org; Sun, 01 Dec 2024 10:28:11 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=codethink.co.uk; s=imap4-20230908; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=rziJ/igp4rrah2Qo06FBEcCbvzrdQxCbCn2xe/IEfkc=; b=Ifn5RY8KywWfjv2DYpfT/Xte/K vlBSHKlM/5sjIYSZ3FC4lWKvwBdL2rJra09WlE43AR2iQsPscyELQXzzvJyKmM5FjdidYdctSQ5Kc p7Z82ZLmmk16R4LfFe9PjmKjE4SuqnvSBZ5vPBF8CfGCbGooUB2vaBCzHT1QbHWAAb38QcdsPYjno 77Rnm5oM2fxBHIuLUzMs9bgJD7y/pbXqWl9qm0x25UDBmsSwjTMECfQ6cE+rORxphBYpFaoPxoiMg czIizL5w60WJ+2z/ksP5Lr/16G3yCn4aAZrLB8PGxheLiKGA2Xx5kLdIEQnr29PK0n+J9xMAe70mT Hl/AjJnA==; Received: from [167.98.27.226] (helo=rainbowdash) by imap4.hz.codethink.co.uk with esmtpsa (Exim 4.94.2 #2 (Debian)) id 1tHhBJ-00DpKm-BM; Sun, 01 Dec 2024 10:28:03 +0000 Received: from ben by rainbowdash with local (Exim 4.98) (envelope-from ) id 1tHhBJ-00000000vYr-3Ctu; Sun, 01 Dec 2024 10:28:01 +0000 From: Ben Dooks To: linux-riscv@lists.infradead.org Cc: ajones@ventanamicro.com, palmer@dabbelt.com, Ben Dooks Subject: [PATCH v2 2/3] riscv: traps: make insn fetch common in unknown instruction Date: Sun, 1 Dec 2024 10:27:58 +0000 Message-Id: <20241201102759.221176-3-ben.dooks@codethink.co.uk> X-Mailer: git-send-email 2.37.2.352.g3c44437643 In-Reply-To: <20241201102759.221176-1-ben.dooks@codethink.co.uk> References: <20241201102759.221176-1-ben.dooks@codethink.co.uk> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20241201_022809_165604_3AE5C679 X-CRM114-Status: GOOD ( 13.30 ) 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 Add the trapped instruction (insn) as the second argument to riscv_v_first_use_handler() from the trap handler so when we add more handlers we can do the fetch of the instruction just once. Signed-off-by: Ben Dooks --- - fixed wording of patch from rfc v2: - fixed todo by going to illegal instruction error if get_user fails - added pointer print for failed read - fixed issues with rebasing onto main branch --- arch/riscv/include/asm/vector.h | 4 ++-- arch/riscv/kernel/traps.c | 14 +++++++++++++- arch/riscv/kernel/vector.c | 11 +---------- 3 files changed, 16 insertions(+), 13 deletions(-) diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h index c7c023afbacd..9ec2473c1b73 100644 --- a/arch/riscv/include/asm/vector.h +++ b/arch/riscv/include/asm/vector.h @@ -22,7 +22,7 @@ extern unsigned long riscv_v_vsize; int riscv_v_setup_vsize(void); bool insn_is_vector(u32 insn_buf); -bool riscv_v_first_use_handler(struct pt_regs *regs); +bool riscv_v_first_use_handler(struct pt_regs *regs, u32 insn); void kernel_vector_begin(void); void kernel_vector_end(void); void get_cpu_vector_context(void); @@ -270,7 +270,7 @@ struct pt_regs; static inline int riscv_v_setup_vsize(void) { return -EOPNOTSUPP; } static __always_inline bool has_vector(void) { return false; } static __always_inline bool insn_is_vector(u32 insn_buf) { return false; } -static inline bool riscv_v_first_use_handler(struct pt_regs *regs) { return false; } +static inline bool riscv_v_first_use_handler(struct pt_regs *regs, u32 insn) { return false; } static inline bool riscv_v_vstate_query(struct pt_regs *regs) { return false; } static inline bool riscv_v_vstate_ctrl_user_allowed(void) { return false; } #define riscv_v_vsize (0) diff --git a/arch/riscv/kernel/traps.c b/arch/riscv/kernel/traps.c index 51ebfd23e007..9662138ba45c 100644 --- a/arch/riscv/kernel/traps.c +++ b/arch/riscv/kernel/traps.c @@ -172,11 +172,23 @@ asmlinkage __visible __trap_section void do_trap_insn_illegal(struct pt_regs *re bool handled; if (user_mode(regs)) { + u32 __user *epc = (u32 __user *)regs->epc; + u32 insn = (u32)regs->badaddr; + irqentry_enter_from_user_mode(regs); local_irq_enable(); - handled = riscv_v_first_use_handler(regs); + if (!insn) { + if (__get_user(insn, epc)) { + printk_ratelimited(KERN_ERR "traps: failed to read instruction at user %px\n", epc); + handled = false; + insn = 0; + } + } + + if (insn) + handled = riscv_v_first_use_handler(regs, insn); local_irq_disable(); diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c index 821818886fab..08164a9121fe 100644 --- a/arch/riscv/kernel/vector.c +++ b/arch/riscv/kernel/vector.c @@ -168,11 +168,8 @@ bool riscv_v_vstate_ctrl_user_allowed(void) } EXPORT_SYMBOL_GPL(riscv_v_vstate_ctrl_user_allowed); -bool riscv_v_first_use_handler(struct pt_regs *regs) +bool riscv_v_first_use_handler(struct pt_regs *regs, u32 insn) { - u32 __user *epc = (u32 __user *)regs->epc; - u32 insn = (u32)regs->badaddr; - if (!has_vector()) return false; @@ -184,12 +181,6 @@ bool riscv_v_first_use_handler(struct pt_regs *regs) if (riscv_v_vstate_query(regs)) return false; - /* Get the instruction */ - if (!insn) { - if (__get_user(insn, epc)) - return false; - } - /* Filter out non-V instructions */ if (!insn_is_vector(insn)) return false;