From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-183.mta1.migadu.com (out-183.mta1.migadu.com [95.215.58.183]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6CBBD2367CC for ; Tue, 12 Aug 2025 01:22:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.183 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754961762; cv=none; b=jcpMPlUBsBYzlJ/X/HzF8gK3J+DcNOCzrzkbOSKOVbORcPGgOOf9fo0TgJyQ8elMG0RVolUcYGUQovvHMwjg9+ykZq1HJ+pUuryqy0o91DzVQ5+nN0U+jzSybc8soalSRKlwC5dJ5JCObyTPaVdIwEGcnxPPalP+3uE/i8O9SbY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754961762; c=relaxed/simple; bh=G8gxWvMovGeu0q+QZwOqtNcTfZkerkosarL8CBusYJ0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ODI4EG/BwUspq9pRYProWPrlrH3mdYdUMsXFrLYiG3yI7krL6bw6jJrmG+GC1wPaKX7z9VsurIsmF4bo0vy4/LvuaqemsZPWXTsTrIkyy6FXdq++H52JtzGEjukwTVz2gkyKATZih8D95IESYK2mqmX4EKDE2MWw91eHIX9tjFw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=lY4Akxb5; arc=none smtp.client-ip=95.215.58.183 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="lY4Akxb5" Message-ID: <9760e574-3eb0-46b2-bccd-916f73b9c39e@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1754961757; 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=akQgPLt0rU1NO/ECRY4EbvXlLiEYaE9L1zWyh6GJbjk=; b=lY4Akxb58vBAMONc1Hbrr3rh6wP5QmNCGXr0on3dGeUvXypsSmYM8GirF6e9U2Z0FADh7O XjOYnjiQkhNu9Nxr24ONAIYy1b5DzZ5Rwg33N+gtu1VAoan9cmwUKta3RX7ugUxkdQ57wN RyV1DZxd/hnt/W/Xjr7QT8BYo3XXN5A= Date: Tue, 12 Aug 2025 09:21:25 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH 2/6] LoongArch: Add kexec_file support To: Huacai Chen Cc: WANG Xuerui , Baoquan He , kexec@lists.infradead.org, loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, Youling Tang References: <20250811092659.14903-1-youling.tang@linux.dev> <20250811092659.14903-3-youling.tang@linux.dev> Content-Language: en-US X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Youling Tang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT Hi, Huacai On 2025/8/11 22:07, Huacai Chen wrote: > Hi, Youling, > > On Mon, Aug 11, 2025 at 5:28 PM Youling Tang wrote: >> From: Youling Tang >> >> This patch adds support for kexec_file on LoongArch. >> >> The image_load() as two parts: >> - the first part loads the kernel image (vmlinuz.efi or vmlinux.efi) >> - the second part loads other segments (eg: initrd, cmdline) >> >> Currently, pez(vmlinuz.efi) and pei(vmlinux.efi) format images are supported, >> but ELF format is not supported. >> >> Signed-off-by: Youling Tang >> --- >> arch/loongarch/Kconfig | 8 ++ >> arch/loongarch/include/asm/image.h | 18 ++++ >> arch/loongarch/include/asm/kexec.h | 12 +++ >> arch/loongarch/kernel/Makefile | 1 + >> arch/loongarch/kernel/kexec_image.c | 112 +++++++++++++++++++++ >> arch/loongarch/kernel/machine_kexec.c | 33 ++++-- >> arch/loongarch/kernel/machine_kexec_file.c | 46 +++++++++ >> 7 files changed, 219 insertions(+), 11 deletions(-) >> create mode 100644 arch/loongarch/kernel/kexec_image.c >> create mode 100644 arch/loongarch/kernel/machine_kexec_file.c >> >> diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig >> index f0abc38c40ac..fd50c83f7827 100644 >> --- a/arch/loongarch/Kconfig >> +++ b/arch/loongarch/Kconfig >> @@ -625,6 +625,14 @@ config CPU_HAS_PREFETCH >> config ARCH_SUPPORTS_KEXEC >> def_bool y >> >> +config ARCH_SUPPORTS_KEXEC_FILE >> + def_bool 64BIT >> + >> +config ARCH_SELECTS_KEXEC_FILE >> + def_bool y >> + depends on KEXEC_FILE >> + select HAVE_IMA_KEXEC if IMA >> + >> config ARCH_SUPPORTS_CRASH_DUMP >> def_bool y >> >> diff --git a/arch/loongarch/include/asm/image.h b/arch/loongarch/include/asm/image.h >> index 1f090736e71d..829e1ecb1f5d 100644 >> --- a/arch/loongarch/include/asm/image.h >> +++ b/arch/loongarch/include/asm/image.h >> @@ -36,5 +36,23 @@ struct loongarch_image_header { >> uint32_t pe_header; >> }; >> >> +static const uint8_t loongarch_image_pe_sig[2] = {'M', 'Z'}; >> +static const uint8_t loongarch_pe_machtype[6] = {'P', 'E', 0x0, 0x0, 0x64, 0x62}; >> + >> +/** >> + * loongarch_header_check_pe_sig - Helper to check the loongarch image header. >> + * >> + * Returns non-zero if 'MZ' signature is found. >> + */ >> + >> +static inline int loongarch_header_check_pe_sig(const struct loongarch_image_header *h) >> +{ >> + if (!h) >> + return 0; >> + >> + return (h->pe_sig[0] == loongarch_image_pe_sig[0] >> + && h->pe_sig[1] == loongarch_image_pe_sig[1]); >> +} >> + >> #endif /* __ASSEMBLY__ */ >> #endif /* __ASM_IMAGE_H */ >> diff --git a/arch/loongarch/include/asm/kexec.h b/arch/loongarch/include/asm/kexec.h >> index cf95cd3eb2de..3ef8517a3670 100644 >> --- a/arch/loongarch/include/asm/kexec.h >> +++ b/arch/loongarch/include/asm/kexec.h >> @@ -41,6 +41,18 @@ struct kimage_arch { >> unsigned long systable_ptr; >> }; >> >> +#ifdef CONFIG_KEXEC_FILE >> +extern const struct kexec_file_ops kexec_image_ops; >> + >> +int arch_kimage_file_post_load_cleanup(struct kimage *image); >> +#define arch_kimage_file_post_load_cleanup arch_kimage_file_post_load_cleanup >> + >> +extern int load_other_segments(struct kimage *image, >> + unsigned long kernel_load_addr, unsigned long kernel_size, >> + char *initrd, unsigned long initrd_len, >> + char *cmdline, unsigned long cmdline_len); > I think the RISC-V naming "load_extra_segments" is better. This name is also fine, but I prefer it to be consistent with that in kexec-tools. > >> +#endif >> + >> typedef void (*do_kexec_t)(unsigned long efi_boot, >> unsigned long cmdline_ptr, >> unsigned long systable_ptr, >> diff --git a/arch/loongarch/kernel/Makefile b/arch/loongarch/kernel/Makefile >> index 6f5a4574a911..bd9405ee3888 100644 >> --- a/arch/loongarch/kernel/Makefile >> +++ b/arch/loongarch/kernel/Makefile >> @@ -62,6 +62,7 @@ obj-$(CONFIG_MAGIC_SYSRQ) += sysrq.o >> obj-$(CONFIG_RELOCATABLE) += relocate.o >> >> obj-$(CONFIG_KEXEC_CORE) += machine_kexec.o relocate_kernel.o >> +obj-$(CONFIG_KEXEC_FILE) += machine_kexec_file.o kexec_image.o > We only support the efi format, so we don't need to split a > kexec_image.c like RISC-V, just put everything into > machine_kexec_file.c is OK. I hope it is separated and consistent with other architectures. For instance, arm64 only supports one type. Youling. > > Huacai > >> obj-$(CONFIG_CRASH_DUMP) += crash_dump.o >> >> obj-$(CONFIG_UNWINDER_GUESS) += unwind_guess.o >> diff --git a/arch/loongarch/kernel/kexec_image.c b/arch/loongarch/kernel/kexec_image.c >> new file mode 100644 >> index 000000000000..fdd1845b4e2e >> --- /dev/null >> +++ b/arch/loongarch/kernel/kexec_image.c >> @@ -0,0 +1,112 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * Kexec image loader for LoongArch >> + >> + * Author: Youling Tang >> + * Copyright (C) 2025 KylinSoft Corporation. >> + */ >> + >> +#define pr_fmt(fmt) "kexec_file(Image): " fmt >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +static int image_probe(const char *kernel_buf, unsigned long kernel_len) >> +{ >> + const struct loongarch_image_header *h = >> + (const struct loongarch_image_header *)(kernel_buf); >> + >> + if (!h || (kernel_len < sizeof(*h))) { >> + pr_err("No loongarch image header.\n"); >> + return -EINVAL; >> + } >> + >> + if (!loongarch_header_check_pe_sig(h)) { >> + pr_err("Bad loongarch PE image header.\n"); >> + return -EINVAL; >> + } >> + >> + return 0; >> +} >> + >> +static void *image_load(struct kimage *image, >> + char *kernel, unsigned long kernel_len, >> + char *initrd, unsigned long initrd_len, >> + char *cmdline, unsigned long cmdline_len) >> +{ >> + struct loongarch_image_header *h; >> + struct kexec_buf kbuf; >> + unsigned long text_offset, kernel_segment_number; >> + struct kexec_segment *kernel_segment; >> + int ret; >> + >> + h = (struct loongarch_image_header *)kernel; >> + if (!h->image_size) >> + return ERR_PTR(-EINVAL); >> + >> + /* Load the kernel */ >> + kbuf.image = image; >> + kbuf.buf_min = 0; >> + kbuf.buf_max = ULONG_MAX; >> + kbuf.top_down = false; >> + >> + kbuf.buffer = kernel; >> + kbuf.bufsz = kernel_len; >> + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; >> + kbuf.memsz = le64_to_cpu(h->image_size); >> + text_offset = le64_to_cpu(h->text_offset); >> + kbuf.buf_align = SZ_2M; >> + >> + kernel_segment_number = image->nr_segments; >> + >> + /* >> + * The location of the kernel segment may make it impossible to satisfy >> + * the other segment requirements, so we try repeatedly to find a >> + * location that will work. >> + */ >> + while ((ret = kexec_add_buffer(&kbuf)) == 0) { >> + /* Try to load additional data */ >> + kernel_segment = &image->segment[kernel_segment_number]; >> + ret = load_other_segments(image, kernel_segment->mem, >> + kernel_segment->memsz, initrd, >> + initrd_len, cmdline, cmdline_len); >> + if (!ret) >> + break; >> + >> + /* >> + * We couldn't find space for the other segments; erase the >> + * kernel segment and try the next available hole. >> + */ >> + image->nr_segments -= 1; >> + kbuf.buf_min = kernel_segment->mem + kernel_segment->memsz; >> + kbuf.mem = KEXEC_BUF_MEM_UNKNOWN; >> + } >> + >> + if (ret) { >> + pr_err("Could not find any suitable kernel location!"); >> + return ERR_PTR(ret); >> + } >> + >> + kernel_segment = &image->segment[kernel_segment_number]; >> + >> + /* Make sure the second kernel jumps to the correct "kernel_entry". */ >> + image->start = kernel_segment->mem + h->kernel_entry - text_offset; >> + >> + kexec_dprintk("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n", >> + kernel_segment->mem, kbuf.bufsz, >> + kernel_segment->memsz); >> + >> + return NULL; >> +} >> + >> +const struct kexec_file_ops kexec_image_ops = { >> + .probe = image_probe, >> + .load = image_load, >> +}; >> diff --git a/arch/loongarch/kernel/machine_kexec.c b/arch/loongarch/kernel/machine_kexec.c >> index f9381800e291..008f43e26120 100644 >> --- a/arch/loongarch/kernel/machine_kexec.c >> +++ b/arch/loongarch/kernel/machine_kexec.c >> @@ -70,18 +70,28 @@ int machine_kexec_prepare(struct kimage *kimage) >> kimage->arch.efi_boot = fw_arg0; >> kimage->arch.systable_ptr = fw_arg2; >> >> - /* Find the command line */ >> - for (i = 0; i < kimage->nr_segments; i++) { >> - if (!strncmp(bootloader, (char __user *)kimage->segment[i].buf, strlen(bootloader))) { >> - if (!copy_from_user(cmdline_ptr, kimage->segment[i].buf, COMMAND_LINE_SIZE)) >> - kimage->arch.cmdline_ptr = (unsigned long)cmdline_ptr; >> - break; >> + if (kimage->file_mode == 1) { >> + /* >> + * kimage->cmdline_buf will be released in kexec_file_load, so copy to >> + * the KEXEC_CMDLINE_ADDR safe area. >> + */ >> + memcpy((void *)KEXEC_CMDLINE_ADDR, (void *)kimage->arch.cmdline_ptr, >> + strlen((char *)kimage->arch.cmdline_ptr) + 1); >> + kimage->arch.cmdline_ptr = (unsigned long)KEXEC_CMDLINE_ADDR; >> + } else { >> + /* Find the command line */ >> + for (i = 0; i < kimage->nr_segments; i++) { >> + if (!strncmp(bootloader, (char __user *)kimage->segment[i].buf, strlen(bootloader))) { >> + if (!copy_from_user(cmdline_ptr, kimage->segment[i].buf, COMMAND_LINE_SIZE)) >> + kimage->arch.cmdline_ptr = (unsigned long)cmdline_ptr; >> + break; >> + } >> } >> - } >> >> - if (!kimage->arch.cmdline_ptr) { >> - pr_err("Command line not included in the provided image\n"); >> - return -EINVAL; >> + if (!kimage->arch.cmdline_ptr) { >> + pr_err("Command line not included in the provided image\n"); >> + return -EINVAL; >> + } >> } >> >> /* kexec/kdump need a safe page to save reboot_code_buffer */ >> @@ -288,7 +298,8 @@ void machine_kexec(struct kimage *image) >> local_irq_disable(); >> >> pr_notice("EFI boot flag 0x%lx\n", efi_boot); >> - pr_notice("Command line at 0x%lx\n", cmdline_ptr); >> + pr_notice("Command line addr at 0x%lx\n", cmdline_ptr); >> + pr_notice("Command line at %s\n", (char *)cmdline_ptr); >> pr_notice("System table at 0x%lx\n", systable_ptr); >> pr_notice("We will call new kernel at 0x%lx\n", start_addr); >> pr_notice("Bye ...\n"); >> diff --git a/arch/loongarch/kernel/machine_kexec_file.c b/arch/loongarch/kernel/machine_kexec_file.c >> new file mode 100644 >> index 000000000000..bc91ae0afa4c >> --- /dev/null >> +++ b/arch/loongarch/kernel/machine_kexec_file.c >> @@ -0,0 +1,46 @@ >> +// SPDX-License-Identifier: GPL-2.0 >> +/* >> + * kexec_file for LoongArch >> + * >> + * Author: Youling Tang >> + * Copyright (C) 2025 KylinSoft Corporation. >> + * >> + * Most code is derived from LoongArch port of kexec-tools >> + */ >> + >> +#define pr_fmt(fmt) "kexec_file: " fmt >> + >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> +#include >> + >> +const struct kexec_file_ops * const kexec_file_loaders[] = { >> + &kexec_image_ops, >> + NULL >> +}; >> + >> +int arch_kimage_file_post_load_cleanup(struct kimage *image) >> +{ >> + vfree(image->elf_headers); >> + image->elf_headers = NULL; >> + image->elf_headers_sz = 0; >> + >> + return kexec_image_post_load_cleanup_default(image); >> +} >> + >> +int load_other_segments(struct kimage *image, >> + unsigned long kernel_load_addr, >> + unsigned long kernel_size, >> + char *initrd, unsigned long initrd_len, >> + char *cmdline, unsigned long cmdline_len) >> +{ >> + image->arch.cmdline_ptr = (unsigned long)cmdline; >> + >> + return 0; >> +} >> -- >> 2.34.1 >>