From patchwork Fri Nov 24 03:36:36 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Baoquan He X-Patchwork-Id: 13466899 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="UyBoEja1" 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 39D41D6E for ; Thu, 23 Nov 2023 19:37:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1700797020; 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=mRhf6yjEl6SoYtlH901fGSdzPcu9Tm5iYJM9D+81Yic=; b=UyBoEja1JF5S0FZPo6yhrPUxyvLLw39Vk2g/JL29DpOg+QkY7kIXQyq3su8yUdWRqxN1oi Vkg4ROqDfk679w/VBsJ2i9onWnNdJ8Z3m4j654ePo84gMBjBb+535JM+ak51MT0OCQeSDP ByHfLJNvIuAue/2TxxTRo12Gb2EioiA= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-500-54TtSm-JM8ed2wqZkmazOg-1; Thu, 23 Nov 2023 22:36:55 -0500 X-MC-Unique: 54TtSm-JM8ed2wqZkmazOg-1 Received: from smtp.corp.redhat.com (int-mx09.intmail.prod.int.rdu2.redhat.com [10.11.54.9]) (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 BCD1B811E7D; Fri, 24 Nov 2023 03:36:54 +0000 (UTC) Received: from MiWiFi-R3L-srv.redhat.com (unknown [10.72.112.8]) by smtp.corp.redhat.com (Postfix) with ESMTP id 46FE5492BE7; Fri, 24 Nov 2023 03:36:49 +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, yujie.liu@intel.com, Baoquan He Subject: [PATCH v2 1/7] kexec_file: add kexec_file flag to control debug printing Date: Fri, 24 Nov 2023 11:36:36 +0800 Message-ID: <20231124033642.520686-2-bhe@redhat.com> In-Reply-To: <20231124033642.520686-1-bhe@redhat.com> References: <20231124033642.520686-1-bhe@redhat.com> Precedence: bulk X-Mailing-List: linux-parisc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-type: text/plain X-Scanned-By: MIMEDefang 3.4.1 on 10.11.54.9 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 | 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) {