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 47B11C07548 for ; Wed, 15 Nov 2023 12:51:51 +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:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=byVq/X99w0r+NrpuEoe2kOM7CWgJ2u8W9fjcjI1oeOM=; b=tV6LbnUIEfCUSd zt6qbGJVpVDcVqEd+R1B2fC4T5IoeFPDTbdAPwA5lLDnrVQCBWQw4U7dp0lg6uBenNSfMjICd0ByJ 5LKRQFjNtm2DBF14Csl+ZgzO6VBXM6aciCdIK5GanVsVWwbr5i0v3MKp5vxzz9yCV58BrCS7YB5V2 VOh2a5bPab46gMJ3WXyfAQ3huQndPvAuDhk9n95VeRkuCFNKM3HES0FDf273irXmuEx1cFQRRbZVz IGFmggZ0Tif3+Xp1wHM2G70gze2iaWstcbbSXt9/GC3Dlge6iCCk2m6YXcwWlKoCBM1iVDT0+xhpF Lt7QHR/uS/Kz+fSU9G2g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1r3FMc-000nmh-1V; Wed, 15 Nov 2023 12:51:26 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1r3FMY-000nkd-2f for linux-arm-kernel@lists.infradead.org; Wed, 15 Nov 2023 12:51:24 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1700052676; 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: in-reply-to:in-reply-to:references:references; bh=ehFjwhsPPcv7nimSjR09jzg4Dqe1DEZTTTAxghtYd8o=; b=Li7vBIckN0jSl6O+UzRlH9meV8DXaKk6AOfSd9pUv3OswdDkbpkiWEgxanobhQSe4FgEZs sCCrze/WLh/b17DRe2/pRXK9RX8eDYuWLV7+nyNiBz+RUYIZbZYQ8w8Vrw18IEjA04l9AH qUkhU7COLHorZdp7vCsZXey9OhdUKuY= 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-378-LR_rUWiCNDKtUhiOdXXDbA-1; Wed, 15 Nov 2023 07:51:13 -0500 X-MC-Unique: LR_rUWiCNDKtUhiOdXXDbA-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (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 9AB1C1C068CA; Wed, 15 Nov 2023 12:51:10 +0000 (UTC) Received: from localhost (unknown [10.72.112.9]) by smtp.corp.redhat.com (Postfix) with ESMTPS id E5CD41121307; Wed, 15 Nov 2023 12:51:09 +0000 (UTC) Date: Wed, 15 Nov 2023 20:51:06 +0800 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 Subject: Re: [PATCH v2 1/7] kexec_file: add kexec_file flag to control debug printing Message-ID: References: <20231114153253.241262-1-bhe@redhat.com> <20231114153253.241262-2-bhe@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20231114153253.241262-2-bhe@redhat.com> X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.3 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231115_045122_952862_96E0D21D X-CRM114-Status: GOOD ( 18.84 ) 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 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 at KERN_INFO level. If '-d' is not specified, it regresses to print message at KERN_DEBUG level. Signed-off-by: Baoquan He --- v1->v2: - Rewrite the kexec_dprintk() macro as Joe suggested to reduce kernel text size. include/linux/kexec.h | 10 +++++++++- include/uapi/linux/kexec.h | 1 + kernel/kexec_file.c | 5 +++++ 3 files changed, 15 insertions(+), 1 deletion(-) diff --git a/include/linux/kexec.h b/include/linux/kexec.h index 8227455192b7..66997efe36f1 100644 --- a/include/linux/kexec.h +++ b/include/linux/kexec.h @@ -264,6 +264,14 @@ arch_kexec_apply_relocations(struct purgatory_info *pi, Elf_Shdr *section, return -ENOEXEC; } #endif + +extern bool kexec_file_dbg_print; + +#define kexec_dprintk(fmt, ...) \ + printk("%s" fmt, \ + kexec_file_dbg_print ? KERN_INFO : KERN_DEBUG, \ + ##__VA_ARGS__) + #endif /* CONFIG_KEXEC_FILE */ #ifdef CONFIG_KEXEC_ELF @@ -403,7 +411,7 @@ bool kexec_load_permitted(int kexec_image_type); /* 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) /* flag to track if kexec reboot is in progress */ extern bool kexec_in_progress; 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 /* 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_file.c b/kernel/kexec_file.c index f9a419cd22d4..4c35500ae40a 100644 --- a/kernel/kexec_file.c +++ b/kernel/kexec_file.c @@ -38,6 +38,8 @@ void set_kexec_sig_enforced(void) } #endif +bool kexec_file_dbg_print; + static int kexec_calculate_store_digests(struct kimage *image); /* Maximum size in bytes for kernel/initrd files. */ @@ -123,6 +125,8 @@ void kimage_file_post_load_cleanup(struct kimage *image) */ kfree(image->image_loader_data); image->image_loader_data = NULL; + + kexec_file_dbg_print = false; } #ifdef CONFIG_KEXEC_SIG @@ -278,6 +282,7 @@ kimage_file_alloc_init(struct kimage **rimage, int kernel_fd, if (!image) return -ENOMEM; + kexec_file_dbg_print = !!(flags & KEXEC_FILE_DEBUG); image->file_mode = 1; if (kexec_on_panic) { -- 2.41.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel