From nobody Sat Oct 4 06:34:56 2025 Received: from out-188.mta1.migadu.com (out-188.mta1.migadu.com [95.215.58.188]) (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 940112BE63F for ; Wed, 20 Aug 2025 05:57:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.188 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755669456; cv=none; b=BClCNDACFXe2FBfuEXxMhiBLA2t5WjXfPDVzLKJxyb8H8PyrwlM2lIYtt/FpVmd8qxqocg+rUL0rjOMUsV7yHpDBMLGLxGH7Q4zKCbgXtgCVVrZRuLYSUK5Tl/+flhAsy45JJcVzu6tpH5pdVH+Od8f2t97fJugXAzoy6aRki6Q= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755669456; c=relaxed/simple; bh=xjRkJ0XsAaJaI/+Znc10zqDKckIajqUHCCu8arY2r4E=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=T5NWCAl+5rGfjbsbwGsMGk3JbfZ2xwG9nhb1ufzDGDJbkyYJvzs4pvAQJr4iG8N+MsZoZkRdKWWsQ7Nj+5C3GS9FAhfYbNjevG5oqZMMHMJx5zX+/YZnRfgH+1+oyQTa5Cngew3WftvGHnyS4Q/JDgrxavJ6IhDDvnMXL3rG1RM= 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=qRZf+3mV; arc=none smtp.client-ip=95.215.58.188 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="qRZf+3mV" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1755669452; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=GBzbvApVwC+zuz1F6RmfDj67Mme+a/DUkrAhV+yXG4k=; b=qRZf+3mVn8Dt8h+ljDOPv/LrFxVG7+kxLW/U68gtPkcBXZGWNCikFtQ6zhSrWNYqCBMq2b t+9IedNCK+FuYLUWV8dILkup1Pw/cQepSU+oetS1JWNu3ylDDPWxLDO4HyL2iyvV9GabKf wB6Ui7fyOShYbh5EFMCVpMaFYkJhWgw= From: Youling Tang To: Huacai Chen Cc: WANG Xuerui , Baoquan He , Yao Zi , kexec@lists.infradead.org, loongarch@lists.linux.dev, linux-kernel@vger.kernel.org, youling.tang@linux.dev, Youling Tang Subject: [PATCH v2 2/5] LoongArch: Add kexec_file support Date: Wed, 20 Aug 2025 13:56:57 +0800 Message-Id: <20250820055700.24344-3-youling.tang@linux.dev> In-Reply-To: <20250820055700.24344-1-youling.tang@linux.dev> References: <20250820055700.24344-1-youling.tang@linux.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Migadu-Flow: FLOW_OUT Content-Type: text/plain; charset="utf-8" From: Youling Tang This patch adds support for kexec_file on LoongArch. The efi_kexec_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) This initrd will be passed to the second kernel via the command line 'initrd=3Dstart,size'. Currently, pez(vmlinuz.efi) and pei(vmlinux.efi) format images are supporte= d, but ELF format is not supported. Signed-off-by: Youling Tang --- arch/loongarch/Kconfig | 9 ++ arch/loongarch/include/asm/image.h | 17 +++ arch/loongarch/include/asm/kexec.h | 12 +++ arch/loongarch/kernel/Makefile | 1 + arch/loongarch/kernel/kexec_efi.c | 111 +++++++++++++++++++ arch/loongarch/kernel/machine_kexec.c | 33 ++++-- arch/loongarch/kernel/machine_kexec_file.c | 117 +++++++++++++++++++++ 7 files changed, 289 insertions(+), 11 deletions(-) create mode 100644 arch/loongarch/kernel/kexec_efi.c create mode 100644 arch/loongarch/kernel/machine_kexec_file.c diff --git a/arch/loongarch/Kconfig b/arch/loongarch/Kconfig index f0abc38c40ac..490dc6eed749 100644 --- a/arch/loongarch/Kconfig +++ b/arch/loongarch/Kconfig @@ -625,6 +625,15 @@ config CPU_HAS_PREFETCH config ARCH_SUPPORTS_KEXEC def_bool y =20 +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 + select RELOCATABLE + config ARCH_SUPPORTS_CRASH_DUMP def_bool y =20 diff --git a/arch/loongarch/include/asm/image.h b/arch/loongarch/include/as= m/image.h index 1f090736e71d..655d5836c4e8 100644 --- a/arch/loongarch/include/asm/image.h +++ b/arch/loongarch/include/asm/image.h @@ -36,5 +36,22 @@ struct loongarch_image_header { uint32_t pe_header; }; =20 +static const uint8_t loongarch_image_pe_sig[2] =3D {'M', 'Z'}; + +/** + * loongarch_header_check_pe_sig - Helper to check the loongarch image hea= der. + * + * Returns non-zero if 'MZ' signature is found. + */ + +static inline int loongarch_header_check_pe_sig(const struct loongarch_ima= ge_header *h) +{ + if (!h) + return 0; + + return (h->pe_sig[0] =3D=3D loongarch_image_pe_sig[0] + && h->pe_sig[1] =3D=3D loongarch_image_pe_sig[1]); +} + #endif /* __ASSEMBLY__ */ #endif /* __ASM_IMAGE_H */ diff --git a/arch/loongarch/include/asm/kexec.h b/arch/loongarch/include/as= m/kexec.h index cf95cd3eb2de..34799db933fb 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; }; =20 +#ifdef CONFIG_KEXEC_FILE +extern const struct kexec_file_ops kexec_efi_ops; + +int arch_kimage_file_post_load_cleanup(struct kimage *image); +#define arch_kimage_file_post_load_cleanup arch_kimage_file_post_load_clea= nup + +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); +#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..dd6183f353e6 100644 --- a/arch/loongarch/kernel/Makefile +++ b/arch/loongarch/kernel/Makefile @@ -62,6 +62,7 @@ obj-$(CONFIG_MAGIC_SYSRQ) +=3D sysrq.o obj-$(CONFIG_RELOCATABLE) +=3D relocate.o =20 obj-$(CONFIG_KEXEC_CORE) +=3D machine_kexec.o relocate_kernel.o +obj-$(CONFIG_KEXEC_FILE) +=3D machine_kexec_file.o kexec_efi.o obj-$(CONFIG_CRASH_DUMP) +=3D crash_dump.o =20 obj-$(CONFIG_UNWINDER_GUESS) +=3D unwind_guess.o diff --git a/arch/loongarch/kernel/kexec_efi.c b/arch/loongarch/kernel/kexe= c_efi.c new file mode 100644 index 000000000000..7741f1139a12 --- /dev/null +++ b/arch/loongarch/kernel/kexec_efi.c @@ -0,0 +1,111 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Load EFI vmlinux file for the kexec_file_load syscall. + * + * Author: Youling Tang + * Copyright (C) 2025 KylinSoft Corporation. + */ + +#define pr_fmt(fmt) "kexec_file(EFI): " fmt + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static int efi_kexec_probe(const char *kernel_buf, unsigned long kernel_le= n) +{ + const struct loongarch_image_header *h =3D (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_warn("No loongarch PE image header.\n"); + return -EINVAL; + } + + return 0; +} + +static void *efi_kexec_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 =3D (struct loongarch_image_header *)kernel; + if (!h->image_size) + return ERR_PTR(-EINVAL); + + /* Load the kernel */ + kbuf.image =3D image; + kbuf.buf_max =3D ULONG_MAX; + kbuf.top_down =3D false; + + kbuf.buffer =3D kernel; + kbuf.bufsz =3D kernel_len; + kbuf.mem =3D KEXEC_BUF_MEM_UNKNOWN; + kbuf.memsz =3D le64_to_cpu(h->image_size); + text_offset =3D le64_to_cpu(h->text_offset); + kbuf.buf_min =3D text_offset; + kbuf.buf_align =3D SZ_2M; + + kernel_segment_number =3D 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 =3D kexec_add_buffer(&kbuf)) =3D=3D 0) { + /* Try to load additional data */ + kernel_segment =3D &image->segment[kernel_segment_number]; + ret =3D 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 -=3D 1; + kbuf.buf_min =3D kernel_segment->mem + kernel_segment->memsz; + kbuf.mem =3D KEXEC_BUF_MEM_UNKNOWN; + } + + if (ret) { + pr_err("Could not find any suitable kernel location!"); + return ERR_PTR(ret); + } + + kernel_segment =3D &image->segment[kernel_segment_number]; + + /* Make sure the second kernel jumps to the correct "kernel_entry". */ + image->start =3D kernel_segment->mem + h->kernel_entry - text_offset; + + kexec_dprintk("Loaded kernel at 0x%lx bufsz=3D0x%lx memsz=3D0x%lx\n", + kernel_segment->mem, kbuf.bufsz, + kernel_segment->memsz); + + return NULL; +} + +const struct kexec_file_ops kexec_efi_ops =3D { + .probe =3D efi_kexec_probe, + .load =3D efi_kexec_load, +}; diff --git a/arch/loongarch/kernel/machine_kexec.c b/arch/loongarch/kernel/= machine_kexec.c index f9381800e291..ba8d64bc6549 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 =3D fw_arg0; kimage->arch.systable_ptr =3D fw_arg2; =20 - /* Find the command line */ - for (i =3D 0; i < kimage->nr_segments; i++) { - if (!strncmp(bootloader, (char __user *)kimage->segment[i].buf, strlen(b= ootloader))) { - if (!copy_from_user(cmdline_ptr, kimage->segment[i].buf, COMMAND_LINE_S= IZE)) - kimage->arch.cmdline_ptr =3D (unsigned long)cmdline_ptr; - break; + if (kimage->file_mode =3D=3D 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 =3D (unsigned long)KEXEC_CMDLINE_ADDR; + } else { + /* Find the command line */ + for (i =3D 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 =3D (unsigned long)cmdline_ptr; + break; + } } - } =20 - 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; + } } =20 /* kexec/kdump need a safe page to save reboot_code_buffer */ @@ -288,7 +298,8 @@ void machine_kexec(struct kimage *image) local_irq_disable(); =20 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: %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/ke= rnel/machine_kexec_file.c new file mode 100644 index 000000000000..a713acf32db8 --- /dev/null +++ b/arch/loongarch/kernel/machine_kexec_file.c @@ -0,0 +1,117 @@ +// 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[] =3D { + &kexec_efi_ops, + NULL +}; + +int arch_kimage_file_post_load_cleanup(struct kimage *image) +{ + vfree(image->elf_headers); + image->elf_headers =3D NULL; + image->elf_headers_sz =3D 0; + + return kexec_image_post_load_cleanup_default(image); +} + +/* Adds the "initrd=3Dstart,size" command line parameter to command line. = */ +static void cmdline_add_initrd(struct kimage *image, unsigned long *cmdlin= e_tmplen, + char *modified_cmdline, unsigned long initrd) +{ + int initrd_strlen; + + initrd_strlen =3D sprintf(modified_cmdline + (*cmdline_tmplen), "initrd= =3D0x%lx,0x%lx ", + initrd, image->initrd_buf_len); + *cmdline_tmplen +=3D initrd_strlen; +} + +/* + * Tries to add the initrd to the image. If it is not possible to find + * valid locations, this function will undo changes to the image and retur= n non + * zero. + */ +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) +{ + struct kexec_buf kbuf; + unsigned long orig_segments =3D image->nr_segments; + char *modified_cmdline =3D NULL; + unsigned long cmdline_tmplen =3D 0; + unsigned long initrd_load_addr =3D 0; + int ret =3D 0; + + + kbuf.image =3D image; + /* not allocate anything below the kernel */ + kbuf.buf_min =3D kernel_load_addr + kernel_size; + + modified_cmdline =3D kzalloc(COMMAND_LINE_SIZE, GFP_KERNEL); + if (!modified_cmdline) + return -EINVAL; + + /* Ensure it's nul terminated */ + modified_cmdline[COMMAND_LINE_SIZE - 1] =3D '\0'; + + /* load initrd */ + if (initrd) { + kbuf.buffer =3D initrd; + kbuf.bufsz =3D initrd_len; + kbuf.mem =3D KEXEC_BUF_MEM_UNKNOWN; + kbuf.memsz =3D initrd_len; + kbuf.buf_align =3D 0; + /* within 1GB-aligned window of up to 32GB in size */ + kbuf.buf_max =3D round_down(kernel_load_addr, SZ_1G) + + (unsigned long)SZ_1G * 32; + kbuf.top_down =3D false; + + ret =3D kexec_add_buffer(&kbuf); + if (ret) + goto out_err; + initrd_load_addr =3D kbuf.mem; + + kexec_dprintk("Loaded initrd at 0x%lx bufsz=3D0x%lx memsz=3D0x%lx\n", + initrd_load_addr, kbuf.bufsz, kbuf.memsz); + + /* Add the initrd=3Dstart,size parameter to the command line */ + cmdline_add_initrd(image, &cmdline_tmplen, modified_cmdline, initrd_load= _addr); + } + + if (cmdline_len + cmdline_tmplen > COMMAND_LINE_SIZE) { + pr_err("Appending command line exceeds cmdline size\n"); + ret =3D -EINVAL; + goto out_err; + } + memcpy(modified_cmdline + cmdline_tmplen, cmdline, cmdline_len); + cmdline =3D modified_cmdline; + image->arch.cmdline_ptr =3D (unsigned long)cmdline; + + return 0; + +out_err: + image->nr_segments =3D orig_segments; + kfree(modified_cmdline); + return ret; +} --=20 2.43.0