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 A0F80C54EF1 for ; Wed, 4 Jan 2023 16:13:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235343AbjADQNU (ORCPT ); Wed, 4 Jan 2023 11:13:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33900 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239593AbjADQMV (ORCPT ); Wed, 4 Jan 2023 11:12:21 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58DE6615A for ; Wed, 4 Jan 2023 08:12:10 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id EA74A6179F for ; Wed, 4 Jan 2023 16:12:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E3F98C433F0; Wed, 4 Jan 2023 16:12:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1672848729; bh=OtasWp51uoh1GKZJjeCWnmyPy+gugPGzgdtqTOPndOg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XESwv+ctWCpgLBQ92arju+aFpgjJwe7bWRk1kmpZttFje2b+wOslhlTHy+GUolOMY 2Ll33zxaCMXAUEDGlaOZdsYFg6zNQkJVynW6X/1hFOdqtTr1N2dCP/32YxGACY7Wa7 RnnTPlRr5wD4X2WUQlG0TG+iWE3qvmNKbYeCDhCQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Masami Hiramatsu (Google)" , Mark Rutland , Will Deacon Subject: [PATCH 6.0 005/177] arm64: Prohibit instrumentation on arch_stack_walk() Date: Wed, 4 Jan 2023 17:04:56 +0100 Message-Id: <20230104160507.819828707@linuxfoundation.org> X-Mailer: git-send-email 2.39.0 In-Reply-To: <20230104160507.635888536@linuxfoundation.org> References: <20230104160507.635888536@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Masami Hiramatsu (Google) commit 0fbcd8abf3375052cc7627cc53aba6f2eb189fbb upstream. Mark arch_stack_walk() as noinstr instead of notrace and inline functions called from arch_stack_walk() as __always_inline so that user does not put any instrumentations on it, because this function can be used from return_address() which is used by lockdep. Without this, if the kernel built with CONFIG_LOCKDEP=y, just probing arch_stack_walk() via /kprobe_events will crash the kernel on arm64. # echo p arch_stack_walk >> ${TRACEFS}/kprobe_events # echo 1 > ${TRACEFS}/events/kprobes/enable kprobes: Failed to recover from reentered kprobes. kprobes: Dump kprobe: .symbol_name = arch_stack_walk, .offset = 0, .addr = arch_stack_walk+0x0/0x1c0 ------------[ cut here ]------------ kernel BUG at arch/arm64/kernel/probes/kprobes.c:241! kprobes: Failed to recover from reentered kprobes. kprobes: Dump kprobe: .symbol_name = arch_stack_walk, .offset = 0, .addr = arch_stack_walk+0x0/0x1c0 ------------[ cut here ]------------ kernel BUG at arch/arm64/kernel/probes/kprobes.c:241! PREEMPT SMP Modules linked in: CPU: 0 PID: 17 Comm: migration/0 Tainted: G N 6.1.0-rc5+ #6 Hardware name: linux,dummy-virt (DT) Stopper: 0x0 <- 0x0 pstate: 600003c5 (nZCv DAIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : kprobe_breakpoint_handler+0x178/0x17c lr : kprobe_breakpoint_handler+0x178/0x17c sp : ffff8000080d3090 x29: ffff8000080d3090 x28: ffff0df5845798c0 x27: ffffc4f59057a774 x26: ffff0df5ffbba770 x25: ffff0df58f420f18 x24: ffff49006f641000 x23: ffffc4f590579768 x22: ffff0df58f420f18 x21: ffff8000080d31c0 x20: ffffc4f590579768 x19: ffffc4f590579770 x18: 0000000000000006 x17: 5f6b636174735f68 x16: 637261203d207264 x15: 64612e202c30203d x14: 2074657366666f2e x13: 30633178302f3078 x12: 302b6b6c61775f6b x11: 636174735f686372 x10: ffffc4f590dc5bd8 x9 : ffffc4f58eb31958 x8 : 00000000ffffefff x7 : ffffc4f590dc5bd8 x6 : 80000000fffff000 x5 : 000000000000bff4 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 0000000000000000 x1 : ffff0df5845798c0 x0 : 0000000000000064 Call trace: kprobes: Failed to recover from reentered kprobes. kprobes: Dump kprobe: .symbol_name = arch_stack_walk, .offset = 0, .addr = arch_stack_walk+0x0/0x1c0 ------------[ cut here ]------------ kernel BUG at arch/arm64/kernel/probes/kprobes.c:241! Fixes: 39ef362d2d45 ("arm64: Make return_address() use arch_stack_walk()") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) Acked-by: Mark Rutland Link: https://lore.kernel.org/r/166994751368.439920.3236636557520824664.stgit@devnote3 Signed-off-by: Will Deacon Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/stacktrace.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/arch/arm64/kernel/stacktrace.c +++ b/arch/arm64/kernel/stacktrace.c @@ -23,8 +23,8 @@ * * The regs must be on a stack currently owned by the calling task. */ -static inline void unwind_init_from_regs(struct unwind_state *state, - struct pt_regs *regs) +static __always_inline void unwind_init_from_regs(struct unwind_state *state, + struct pt_regs *regs) { unwind_init_common(state, current); @@ -58,8 +58,8 @@ static __always_inline void unwind_init_ * duration of the unwind, or the unwind will be bogus. It is never valid to * call this for the current task. */ -static inline void unwind_init_from_task(struct unwind_state *state, - struct task_struct *task) +static __always_inline void unwind_init_from_task(struct unwind_state *state, + struct task_struct *task) { unwind_init_common(state, task); @@ -190,7 +190,7 @@ void show_stack(struct task_struct *tsk, barrier(); } -noinline notrace void arch_stack_walk(stack_trace_consume_fn consume_entry, +noinline noinstr void arch_stack_walk(stack_trace_consume_fn consume_entry, void *cookie, struct task_struct *task, struct pt_regs *regs) {