mirror of https://github.com/torvalds/linux.git
114 lines
3.0 KiB
C
114 lines
3.0 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Load EFI vmlinux file for the kexec_file_load syscall.
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*
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* Author: Youling Tang <tangyouling@kylinos.cn>
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* Copyright (C) 2025 KylinSoft Corporation.
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*/
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#define pr_fmt(fmt) "kexec_file(EFI): " fmt
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#include <linux/err.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/kexec.h>
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#include <linux/pe.h>
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#include <linux/string.h>
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#include <asm/byteorder.h>
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#include <asm/cpufeature.h>
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#include <asm/image.h>
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static int efi_kexec_probe(const char *kernel_buf, unsigned long kernel_len)
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{
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const struct loongarch_image_header *h = (const struct loongarch_image_header *)kernel_buf;
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if (!h || (kernel_len < sizeof(*h))) {
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kexec_dprintk("No LoongArch image header.\n");
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return -EINVAL;
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}
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if (!loongarch_header_check_dos_sig(h)) {
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kexec_dprintk("No LoongArch PE image header.\n");
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return -EINVAL;
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}
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return 0;
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}
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static void *efi_kexec_load(struct kimage *image,
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char *kernel, unsigned long kernel_len,
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char *initrd, unsigned long initrd_len,
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char *cmdline, unsigned long cmdline_len)
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{
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int ret;
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unsigned long text_offset, kernel_segment_number;
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struct kexec_buf kbuf = {};
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struct kexec_segment *kernel_segment;
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struct loongarch_image_header *h;
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h = (struct loongarch_image_header *)kernel;
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if (!h->kernel_asize)
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return ERR_PTR(-EINVAL);
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/*
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* Load the kernel
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* FIXME: Non-relocatable kernel rejected for kexec_file (require CONFIG_RELOCATABLE)
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*/
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kbuf.image = image;
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kbuf.buf_max = ULONG_MAX;
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kbuf.top_down = false;
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kbuf.buffer = kernel;
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kbuf.bufsz = kernel_len;
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kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
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kbuf.memsz = le64_to_cpu(h->kernel_asize);
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text_offset = le64_to_cpu(h->text_offset);
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kbuf.buf_min = text_offset;
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kbuf.buf_align = SZ_2M;
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kernel_segment_number = image->nr_segments;
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/*
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* The location of the kernel segment may make it impossible to
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* satisfy the other segment requirements, so we try repeatedly
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* to find a location that will work.
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*/
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while ((ret = kexec_add_buffer(&kbuf)) == 0) {
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/* Try to load additional data */
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kernel_segment = &image->segment[kernel_segment_number];
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ret = load_other_segments(image, kernel_segment->mem,
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kernel_segment->memsz, initrd,
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initrd_len, cmdline, cmdline_len);
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if (!ret)
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break;
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/*
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* We couldn't find space for the other segments; erase the
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* kernel segment and try the next available hole.
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*/
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image->nr_segments -= 1;
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kbuf.buf_min = kernel_segment->mem + kernel_segment->memsz;
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kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
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}
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if (ret < 0) {
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pr_err("Could not find any suitable kernel location!");
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return ERR_PTR(ret);
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}
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kernel_segment = &image->segment[kernel_segment_number];
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/* Make sure the second kernel jumps to the correct "kernel_entry" */
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image->start = kernel_segment->mem + h->kernel_entry - text_offset;
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kexec_dprintk("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
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kernel_segment->mem, kbuf.bufsz, kernel_segment->memsz);
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return NULL;
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}
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const struct kexec_file_ops kexec_efi_ops = {
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.probe = efi_kexec_probe,
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.load = efi_kexec_load,
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};
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