From nobody Mon Feb 9 04:44:32 2026 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 A3023C77B7A for ; Thu, 18 May 2023 11:09:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231179AbjERLJ2 (ORCPT ); Thu, 18 May 2023 07:09:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231165AbjERLJS (ORCPT ); Thu, 18 May 2023 07:09:18 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D3FE8213B; Thu, 18 May 2023 04:08:36 -0700 (PDT) Date: Thu, 18 May 2023 11:08:03 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1684408083; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5ejN/mH3LR4t0/RUCezt3x65qUEpqLMlgQXY4nbjFu8=; b=XC6eLNNsAdHp2b1+A3c+pnQghTjEL3wVKhHYIY5YjHmAUd88GYRm6AG5WTglqeoArFVR2h UxivzU+HIJyIjwZvNlHpo06Bq2aw6vGRhtAzUPUtQjF7QB+iqVLR9RJRTPJyfbNhnUliFu hDqUlFpq+tT+xIZmZov+y1iKmkvpSSG9/bmWQGqzqPfFEkmhhKgcZuz3Cix7IW1nyXHQ+W gYinMFk1gCFu+z2f9th7ZoIvMcrHuQ10fopwSBPfMxQ3f81NTWZtwPnMC6RCWcCG3wlJCY zGgt9aQJaSedQdj8hMKaNa8OnehslekxEapqvhf32gRHvMWQu7RUxD50R6qYjg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1684408083; h=from:from:sender:sender:reply-to:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5ejN/mH3LR4t0/RUCezt3x65qUEpqLMlgQXY4nbjFu8=; b=51/M3jrukm/XcJMmtDuSZIBW9GG7Y57/BG1pVdiWYWKLgYj54RmbGam1WV0cPwlL7YbrgJ 4wLJdsY5DeCsEJBw== From: "tip-bot2 for Josh Poimboeuf" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: objtool/core] x86/unwind/orc: Add 'unwind_debug' cmdline option Cc: Miroslav Benes , Josh Poimboeuf , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <6afb9e48a05fd2046bfad47e69b061b43dfd0e0e.1681331449.git.jpoimboe@kernel.org> References: <6afb9e48a05fd2046bfad47e69b061b43dfd0e0e.1681331449.git.jpoimboe@kernel.org> MIME-Version: 1.0 Message-ID: <168440808334.404.13534074205868319070.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following commit has been merged into the objtool/core branch of tip: Commit-ID: 89da5a69a831f20df6463fd524e1578e12a8f46f Gitweb: https://git.kernel.org/tip/89da5a69a831f20df6463fd524e1578e1= 2a8f46f Author: Josh Poimboeuf AuthorDate: Wed, 12 Apr 2023 13:31:05 -07:00 Committer: Josh Poimboeuf CommitterDate: Tue, 16 May 2023 06:31:50 -07:00 x86/unwind/orc: Add 'unwind_debug' cmdline option Sometimes the one-line ORC unwinder warnings aren't very helpful. Add a new 'unwind_debug' cmdline option which will dump the full stack contents of the current task when an error condition is encountered. Reviewed-by: Miroslav Benes Link: https://lore.kernel.org/r/6afb9e48a05fd2046bfad47e69b061b43dfd0e0e.16= 81331449.git.jpoimboe@kernel.org Signed-off-by: Josh Poimboeuf --- Documentation/admin-guide/kernel-parameters.txt | 6 ++- arch/x86/kernel/unwind_orc.c | 49 +++++++++++++++- 2 files changed, 54 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentatio= n/admin-guide/kernel-parameters.txt index 9e5bab2..f922eea 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -6563,6 +6563,12 @@ unknown_nmi_panic [X86] Cause panic on unknown NMI. =20 + unwind_debug [X86-64] + Enable unwinder debug output. This can be + useful for debugging certain unwinder error + conditions, including corrupt stacks and + bad/missing unwinder metadata. + usbcore.authorized_default=3D [USB] Default USB device authorization: (default -1 =3D authorized except for wireless USB, diff --git a/arch/x86/kernel/unwind_orc.c b/arch/x86/kernel/unwind_orc.c index 5fbcb22..7891727 100644 --- a/arch/x86/kernel/unwind_orc.c +++ b/arch/x86/kernel/unwind_orc.c @@ -13,8 +13,14 @@ =20 #define orc_warn_current(args...) \ ({ \ - if (state->task =3D=3D current && !state->error) \ + static bool dumped_before; \ + if (state->task =3D=3D current && !state->error) { \ orc_warn(args); \ + if (unwind_debug && !dumped_before) { \ + dumped_before =3D true; \ + unwind_dump(state); \ + } \ + } \ }) =20 extern int __start_orc_unwind_ip[]; @@ -23,8 +29,49 @@ extern struct orc_entry __start_orc_unwind[]; extern struct orc_entry __stop_orc_unwind[]; =20 static bool orc_init __ro_after_init; +static bool unwind_debug __ro_after_init; static unsigned int lookup_num_blocks __ro_after_init; =20 +static int __init unwind_debug_cmdline(char *str) +{ + unwind_debug =3D true; + + return 0; +} +early_param("unwind_debug", unwind_debug_cmdline); + +static void unwind_dump(struct unwind_state *state) +{ + static bool dumped_before; + unsigned long word, *sp; + struct stack_info stack_info =3D {0}; + unsigned long visit_mask =3D 0; + + if (dumped_before) + return; + + dumped_before =3D true; + + printk_deferred("unwind stack type:%d next_sp:%p mask:0x%lx graph_idx:%d\= n", + state->stack_info.type, state->stack_info.next_sp, + state->stack_mask, state->graph_idx); + + for (sp =3D __builtin_frame_address(0); sp; + sp =3D PTR_ALIGN(stack_info.next_sp, sizeof(long))) { + if (get_stack_info(sp, state->task, &stack_info, &visit_mask)) + break; + + for (; sp < stack_info.end; sp++) { + + word =3D READ_ONCE_NOCHECK(*sp); + + printk_deferred("%0*lx: %0*lx (%pB)\n", BITS_PER_LONG/4, + (unsigned long)sp, BITS_PER_LONG/4, + word, (void *)word); + } + } +} + static inline unsigned long orc_ip(const int *ip) { return (unsigned long)ip + *ip;