Unverified Commit 809a11ee authored by Song Shuai's avatar Song Shuai Committed by Palmer Dabbelt
Browse files

riscv: kexec_file: Support loading Image binary file 



This patch creates image_kexec_ops to load Image binary file
for kexec_file_load() syscall.

Signed-off-by: default avatarSong Shuai <songshuaishuai@tinylab.org>
Signed-off-by: default avatarBjörn Töpel <bjorn@rivosinc.com>
Link: https://lore.kernel.org/r/20250409193004.643839-3-bjorn@kernel.org


Signed-off-by: default avatarAlexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: default avatarPalmer Dabbelt <palmer@dabbelt.com>
parent 1df45f8a

arch/riscv/include/asm/image.h

+2 −0
Original line number Diff line number Diff line
@@ -30,6 +30,8 @@ 
			      RISCV_HEADER_VERSION_MINOR)



#ifndef __ASSEMBLY__

#define riscv_image_flag_field(flags, field)\

			       (((flags) >> field##_SHIFT) & field##_MASK)

/**

 * struct riscv_image_header - riscv kernel image header

 * @code0:		Executable code

arch/riscv/include/asm/kexec.h

+1 −0
Original line number Diff line number Diff line
@@ -56,6 +56,7 @@ extern riscv_kexec_method riscv_kexec_norelocate; 


#ifdef CONFIG_KEXEC_FILE

extern const struct kexec_file_ops elf_kexec_ops;

extern const struct kexec_file_ops image_kexec_ops;



struct purgatory_info;

int arch_kexec_apply_relocations_add(struct purgatory_info *pi,

arch/riscv/kernel/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -107,7 +107,7 @@ obj-$(CONFIG_HOTPLUG_CPU) += cpu-hotplug.o 
obj-$(CONFIG_PARAVIRT)		+= paravirt.o

obj-$(CONFIG_KGDB)		+= kgdb.o

obj-$(CONFIG_KEXEC_CORE)	+= kexec_relocate.o crash_save_regs.o machine_kexec.o

obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o machine_kexec_file.o

obj-$(CONFIG_KEXEC_FILE)	+= kexec_elf.o kexec_image.o machine_kexec_file.o

obj-$(CONFIG_CRASH_DUMP)	+= crash_dump.o

obj-$(CONFIG_VMCORE_INFO)	+= vmcore_info.o

arch/riscv/kernel/kexec_image.c

0 → 100644
+96 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * RISC-V Kexec image loader

 *

 */



#define pr_fmt(fmt)	"kexec_file(Image): " fmt



#include <linux/err.h>

#include <linux/errno.h>

#include <linux/kernel.h>

#include <linux/kexec.h>

#include <linux/pe.h>

#include <linux/string.h>

#include <asm/byteorder.h>

#include <asm/image.h>



static int image_probe(const char *kernel_buf, unsigned long kernel_len)

{

	const struct riscv_image_header *h = (const struct riscv_image_header *)kernel_buf;



	if (!h || kernel_len < sizeof(*h))

		return -EINVAL;



	/* According to Documentation/riscv/boot-image-header.rst,

	 * use "magic2" field to check when version >= 0.2.

	 */



	if (h->version >= RISCV_HEADER_VERSION &&

	    memcmp(&h->magic2, RISCV_IMAGE_MAGIC2, sizeof(h->magic2)))

		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 riscv_image_header *h;

	u64 flags;

	bool be_image, be_kernel;

	struct kexec_buf kbuf;

	int ret;



	/* Check Image header */

	h = (struct riscv_image_header *)kernel;

	if (!h->image_size) {

		ret = -EINVAL;

		goto out;

	}



	/* Check endianness */

	flags = le64_to_cpu(h->flags);

	be_image = riscv_image_flag_field(flags, RISCV_IMAGE_FLAG_BE);

	be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);

	if (be_image != be_kernel) {

		ret = -EINVAL;

		goto out;

	}



	/* Load the kernel image */

	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);

	kbuf.buf_align = le64_to_cpu(h->text_offset);



	ret = kexec_add_buffer(&kbuf);

	if (ret) {

		pr_err("Error add kernel image ret=%d\n", ret);

		goto out;

	}



	image->start = kbuf.mem;



	pr_info("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",

		kbuf.mem, kbuf.bufsz, kbuf.memsz);



	ret = load_extra_segments(image, kbuf.mem, kbuf.memsz,

				  initrd, initrd_len, cmdline, cmdline_len);



out:

	return ret ? ERR_PTR(ret) : NULL;

}



const struct kexec_file_ops image_kexec_ops = {

	.probe = image_probe,

	.load = image_load,

};

arch/riscv/kernel/machine_kexec_file.c

+1 −0
Original line number Diff line number Diff line
@@ -18,6 +18,7 @@ 


const struct kexec_file_ops * const kexec_file_loaders[] = {

	&elf_kexec_ops,

	&image_kexec_ops,

	NULL

};