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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id DC8CBCDB465 for ; Mon, 16 Oct 2023 08:50:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232573AbjJPIuI (ORCPT ); Mon, 16 Oct 2023 04:50:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44174 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232785AbjJPIuH (ORCPT ); Mon, 16 Oct 2023 04:50:07 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D8709A1 for ; Mon, 16 Oct 2023 01:50:05 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE017C433CA; Mon, 16 Oct 2023 08:50:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1697446205; bh=uHyBMS5zh5G4W+lqUJLvP6lAXCseEB8EMQIcTllExqY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AAkaHs/1zeRoR2ATHQQKWYtNWMunQ2U2/ZhmAxev4Vud7NlIeVKD1d1tXbKiCjJ/h KHySh+97mhQ35K6lIoE4yxLXMc2LGYn4SajsA07kpOY81lEi4bFosVmlo1pWfOEjyZ /ovYY8ssXvskUqKmPyKKk93CO956/e0Ui0erWktM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, ruanjinjie@huawei.com, Mark Rutland , Catalin Marinas , James Morse , Joey Gouly , Peter Zijlstra , Will Deacon Subject: [PATCH 5.15 093/102] arm64: factor insn read out of call_undef_hook() Date: Mon, 16 Oct 2023 10:41:32 +0200 Message-ID: <20231016083956.176201252@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231016083953.689300946@linuxfoundation.org> References: <20231016083953.689300946@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mark Rutland commit dbfbd87efa79575491af0ba1a87bf567eaea6cae upstream. 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 Link: https://lore.kernel.org/r/20221019144123.612388-5-mark.rutland@arm.com Signed-off-by: Will Deacon Signed-off-by: Jinjie Ruan Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/traps.c | 31 ++++++++++++++++++++++--------- 1 file changed, 22 insertions(+), 9 deletions(-) --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -394,25 +394,22 @@ void unregister_undef_hook(struct undef_ 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; void __user *pc = (void __user *)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_reg /* 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_reg 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 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); }