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 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 485E2C4332F for ; Wed, 19 Oct 2022 15:03:46 +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=FXmSTOZnrINQNUSpCR/tUfllXsSDaOQvSKN9Ue+ioCM=; b=tpf9EOBfS6fdSp dfeXc8W5/tvTE3XPD2cn837vjbFZsfKdzw0CCXFlKcNKwp9JAIZVGx5fdX9XzFusR2kwgyf1g9RrX IWCGBMxCwBavgdq7JYhPFvo+jcYclYxcYfS0G/niO1aTPE2zNPYXY5cf6h/J6uhr44wrc6G78KQHJ KipBaLEeku3VZKo94v9ieWkqUp5JE7Vu3iG5CFfIzGlYcd1x07vMeRdTpLRqDbSKI0r2FpXtHNaD0 QfWIN+qNhu97vI8aqKu4XwRNOywW8KZRBQUDCdsYtblJCdYTKblAiafwTX7x96gRolRoHVBGkP9/Y 26HFpdotJsN9L26R5pYg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1olAaL-002ztq-Pn; Wed, 19 Oct 2022 15:02:22 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1olAGK-002qVt-3Z for linux-arm-kernel@lists.infradead.org; Wed, 19 Oct 2022 14:41:44 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 3E2A5176A; Wed, 19 Oct 2022 07:41:44 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 0BED43F7D8; Wed, 19 Oct 2022 07:41:36 -0700 (PDT) From: Mark Rutland To: linux-arm-kernel@lists.infradead.org Cc: catalin.marinas@arm.com, james.morse@arm.com, joey.gouly@arm.com, mark.rutland@arm.com, peterz@infradead.org, will@kernel.org Subject: [PATCH v2 4/9] arm64: factor insn read out of call_undef_hook() Date: Wed, 19 Oct 2022 15:41:18 +0100 Message-Id: <20221019144123.612388-5-mark.rutland@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20221019144123.612388-1-mark.rutland@arm.com> References: <20221019144123.612388-1-mark.rutland@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20221019_074140_321936_C28D46A0 X-CRM114-Status: GOOD ( 15.20 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Subsequent patches will rework EL0 UNDEF handling, removing the need for struct undef_hook and call_undef_hook. In preparation for those changes, this patch factors the logic for reading user instructions out of call_undef_hook() and into a new user_insn_read() helper, matching the style of the existing aarch64_insn_read() helper used for reading kernel instructions. There should be no functional change as a result of this patch. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: James Morse Cc: Joey Gouly Cc: Peter Zijlstra Cc: Will Deacon --- arch/arm64/kernel/traps.c | 31 ++++++++++++++++++++++--------- 1 file changed, 22 insertions(+), 9 deletions(-) diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index ccd7d773e5cd..4d51afd010e1 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -394,25 +394,22 @@ void unregister_undef_hook(struct undef_hook *hook) raw_spin_unlock_irqrestore(&undef_lock, flags); } -static int call_undef_hook(struct pt_regs *regs) +static int user_insn_read(struct pt_regs *regs, u32 *insnp) { - struct undef_hook *hook; - unsigned long flags; u32 instr; - int (*fn)(struct pt_regs *regs, u32 instr) = NULL; unsigned long pc = instruction_pointer(regs); if (compat_thumb_mode(regs)) { /* 16-bit Thumb instruction */ __le16 instr_le; if (get_user(instr_le, (__le16 __user *)pc)) - goto exit; + return -EFAULT; instr = le16_to_cpu(instr_le); if (aarch32_insn_is_wide(instr)) { u32 instr2; if (get_user(instr_le, (__le16 __user *)(pc + 2))) - goto exit; + return -EFAULT; instr2 = le16_to_cpu(instr_le); instr = (instr << 16) | instr2; } @@ -420,10 +417,20 @@ static int call_undef_hook(struct pt_regs *regs) /* 32-bit ARM instruction */ __le32 instr_le; if (get_user(instr_le, (__le32 __user *)pc)) - goto exit; + return -EFAULT; instr = le32_to_cpu(instr_le); } + *insnp = instr; + return 0; +} + +static int call_undef_hook(struct pt_regs *regs, u32 instr) +{ + struct undef_hook *hook; + unsigned long flags; + int (*fn)(struct pt_regs *regs, u32 instr) = NULL; + raw_spin_lock_irqsave(&undef_lock, flags); list_for_each_entry(hook, &undef_hook, node) if ((instr & hook->instr_mask) == hook->instr_val && @@ -431,7 +438,7 @@ static int call_undef_hook(struct pt_regs *regs) fn = hook->fn; raw_spin_unlock_irqrestore(&undef_lock, flags); -exit: + return fn ? fn(regs, instr) : 1; } @@ -483,13 +490,19 @@ void arm64_notify_segfault(unsigned long addr) void do_el0_undef(struct pt_regs *regs, unsigned long esr) { + u32 insn; + /* check for AArch32 breakpoint instructions */ if (!aarch32_break_handler(regs)) return; - if (call_undef_hook(regs) == 0) + if (user_insn_read(regs, &insn)) + goto out_err; + + if (call_undef_hook(regs, insn) == 0) return; +out_err: force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0); } -- 2.30.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel