From nobody Tue Dec 16 23:57:28 2025 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 92DF5C4332F for ; Wed, 13 Dec 2023 05:58:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378537AbjLMF6F (ORCPT ); Wed, 13 Dec 2023 00:58:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229476AbjLMF6C (ORCPT ); Wed, 13 Dec 2023 00:58:02 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E06CEE3 for ; Tue, 12 Dec 2023 21:58:08 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702447088; h=from:from: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=mO1KBSR/aHS3/goavwyErIvJSA5uOL+z59IlmO49PfM=; b=iTVFlhfBf9C+R72SRLf91LR9TMs4PjXdolzPPehWT8ZDnxfT3jkNfiFjoB6VtQB4Z2eZXM bRbEHjUxw6GvpIGztmOttj9LCwsyF/Eg/GL23KSpDIQghHRGE7e1Ft5UzzwjVDscnU3Sji 3ewl7PQ0BPLi+mZiZUmmbb/G63dYPkU= Received: from mimecast-mx02.redhat.com (mx-ext.redhat.com [66.187.233.73]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-620-h16RJlpCNyOpEy5PoUnaNw-1; Wed, 13 Dec 2023 00:58:02 -0500 X-MC-Unique: h16RJlpCNyOpEy5PoUnaNw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.rdu2.redhat.com [10.11.54.7]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 7D1273C40B56; Wed, 13 Dec 2023 05:58:01 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (unknown [10.72.116.83]) by smtp.corp.redhat.com (Postfix) with ESMTP id D608A1C060AF; Wed, 13 Dec 2023 05:57:56 +0000 (UTC) From: Baoquan He To: linux-kernel@vger.kernel.org Cc: kexec@lists.infradead.org, x86@kernel.org, linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, linuxppc-dev@lists.ozlabs.org, linux-parisc@vger.kernel.org, akpm@linux-foundation.org, joe@perches.com, nathan@kernel.org, conor@kernel.org, Baoquan He Subject: [PATCH v4 1/7] kexec_file: add kexec_file flag to control debug printing Date: Wed, 13 Dec 2023 13:57:41 +0800 Message-ID: <20231213055747.61826-2-bhe@redhat.com> In-Reply-To: <20231213055747.61826-1-bhe@redhat.com> References: <20231213055747.61826-1-bhe@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.7 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" When specifying 'kexec -c -d', kexec_load interface will print loading information, e.g the regions where kernel/initrd/purgatory/cmdline are put, the memmap passed to 2nd kernel taken as system RAM ranges, and printing all contents of struct kexec_segment, etc. These are very helpful for analyzing or positioning what's happening when kexec/kdump itself failed. The debugging printing for kexec_load interface is made in user space utility kexec-tools. Whereas, with kexec_file_load interface, 'kexec -s -d' print nothing. Because kexec_file code is mostly implemented in kernel space, and the debugging printing functionality is missed. It's not convenient when debugging kexec/kdump loading and jumping with kexec_file_load interface. Now add KEXEC_FILE_DEBUG to kexec_file flag to control the debugging message printing. And add global variable kexec_file_dbg_print and macro kexec_dprintk() to facilitate the printing. This is a preparation, later kexec_dprintk() will be used to replace the existing pr_debug(). Once 'kexec -s -d' is specified, it will print out kexec/kdump loading information. If '-d' is not specified, it regresses to pr_debug(). Signed-off-by: Baoquan He --- include/linux/kexec.h | 9 ++++++++- include/uapi/linux/kexec.h | 1 + kernel/kexec_core.c | 2 ++ kernel/kexec_file.c | 3 +++ 4 files changed, 14 insertions(+), 1 deletion(-) diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 8227455192b7..400cb6c02176 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -403,7 +403,7 @@ bool kexec_load_permitted(int kexec_image_type); =20 /* List of defined/legal kexec file flags */ #define KEXEC_FILE_FLAGS (KEXEC_FILE_UNLOAD | KEXEC_FILE_ON_CRASH | \ - KEXEC_FILE_NO_INITRAMFS) + KEXEC_FILE_NO_INITRAMFS | KEXEC_FILE_DEBUG) =20 /* flag to track if kexec reboot is in progress */ extern bool kexec_in_progress; @@ -500,6 +500,13 @@ static inline int crash_hotplug_memory_support(void) {= return 0; } static inline unsigned int crash_get_elfcorehdr_size(void) { return 0; } #endif =20 +extern bool kexec_file_dbg_print; + +#define kexec_dprintk(fmt, ...) \ + printk("%s" fmt, \ + kexec_file_dbg_print ? KERN_INFO : KERN_DEBUG, \ + ##__VA_ARGS__) + #else /* !CONFIG_KEXEC_CORE */ struct pt_regs; struct task_struct; diff --git a/include/uapi/linux/kexec.h b/include/uapi/linux/kexec.h index 01766dd839b0..c17bb096ea68 100644 --- a/include/uapi/linux/kexec.h +++ b/include/uapi/linux/kexec.h @@ -25,6 +25,7 @@ #define KEXEC_FILE_UNLOAD 0x00000001 #define KEXEC_FILE_ON_CRASH 0x00000002 #define KEXEC_FILE_NO_INITRAMFS 0x00000004 +#define KEXEC_FILE_DEBUG 0x00000008 =20 /* These values match the ELF architecture values. * Unless there is a good reason that should continue to be the case. diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c index be5642a4ec49..f70bf3a7885c 100644 --- a/kernel/kexec_core.c +++ b/kernel/kexec_core.c @@ -52,6 +52,8 @@ atomic_t __kexec_lock =3D ATOMIC_INIT(0); /* Flag to indicate we are going to kexec a new kernel */ bool kexec_in_progress =3D false; =20 +bool kexec_file_dbg_print; + int kexec_should_crash(struct task_struct *p) { /* diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c index f9a419cd22d4..aca5dac74044 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -123,6 +123,8 @@ void kimage_file_post_load_cleanup(struct kimage *image) */ kfree(image->image_loader_data); image->image_loader_data =3D NULL; + + kexec_file_dbg_print =3D false; } =20 #ifdef CONFIG_KEXEC_SIG @@ -278,6 +280,7 @@ kimage_file_alloc_init(struct kimage **rimage, int kern= el_fd, if (!image) return -ENOMEM; =20 + kexec_file_dbg_print =3D !!(flags & KEXEC_FILE_DEBUG); image->file_mode =3D 1; =20 if (kexec_on_panic) { --=20 2.41.0