Merge branches 'pm-cpufreq', 'pm-cpuidle', 'pm-opp' and 'powercap'
[linux-2.6-microblaze.git] / arch / arm64 / kernel / kexec_image.c
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Kexec image loader
4
5  * Copyright (C) 2018 Linaro Limited
6  * Author: AKASHI Takahiro <takahiro.akashi@linaro.org>
7  */
8
9 #define pr_fmt(fmt)     "kexec_file(Image): " fmt
10
11 #include <linux/err.h>
12 #include <linux/errno.h>
13 #include <linux/kernel.h>
14 #include <linux/kexec.h>
15 #include <linux/pe.h>
16 #include <linux/string.h>
17 #include <linux/verification.h>
18 #include <asm/byteorder.h>
19 #include <asm/cpufeature.h>
20 #include <asm/image.h>
21 #include <asm/memory.h>
22
23 static int image_probe(const char *kernel_buf, unsigned long kernel_len)
24 {
25         const struct arm64_image_header *h =
26                 (const struct arm64_image_header *)(kernel_buf);
27
28         if (!h || (kernel_len < sizeof(*h)))
29                 return -EINVAL;
30
31         if (memcmp(&h->magic, ARM64_IMAGE_MAGIC, sizeof(h->magic)))
32                 return -EINVAL;
33
34         return 0;
35 }
36
37 static void *image_load(struct kimage *image,
38                                 char *kernel, unsigned long kernel_len,
39                                 char *initrd, unsigned long initrd_len,
40                                 char *cmdline, unsigned long cmdline_len)
41 {
42         struct arm64_image_header *h;
43         u64 flags, value;
44         bool be_image, be_kernel;
45         struct kexec_buf kbuf;
46         unsigned long text_offset;
47         struct kexec_segment *kernel_segment;
48         int ret;
49
50         /*
51          * We require a kernel with an unambiguous Image header. Per
52          * Documentation/arm64/booting.rst, this is the case when image_size
53          * is non-zero (practically speaking, since v3.17).
54          */
55         h = (struct arm64_image_header *)kernel;
56         if (!h->image_size)
57                 return ERR_PTR(-EINVAL);
58
59         /* Check cpu features */
60         flags = le64_to_cpu(h->flags);
61         be_image = arm64_image_flag_field(flags, ARM64_IMAGE_FLAG_BE);
62         be_kernel = IS_ENABLED(CONFIG_CPU_BIG_ENDIAN);
63         if ((be_image != be_kernel) && !system_supports_mixed_endian())
64                 return ERR_PTR(-EINVAL);
65
66         value = arm64_image_flag_field(flags, ARM64_IMAGE_FLAG_PAGE_SIZE);
67         if (((value == ARM64_IMAGE_FLAG_PAGE_SIZE_4K) &&
68                         !system_supports_4kb_granule()) ||
69             ((value == ARM64_IMAGE_FLAG_PAGE_SIZE_64K) &&
70                         !system_supports_64kb_granule()) ||
71             ((value == ARM64_IMAGE_FLAG_PAGE_SIZE_16K) &&
72                         !system_supports_16kb_granule()))
73                 return ERR_PTR(-EINVAL);
74
75         /* Load the kernel */
76         kbuf.image = image;
77         kbuf.buf_min = 0;
78         kbuf.buf_max = ULONG_MAX;
79         kbuf.top_down = false;
80
81         kbuf.buffer = kernel;
82         kbuf.bufsz = kernel_len;
83         kbuf.mem = KEXEC_BUF_MEM_UNKNOWN;
84         kbuf.memsz = le64_to_cpu(h->image_size);
85         text_offset = le64_to_cpu(h->text_offset);
86         kbuf.buf_align = MIN_KIMG_ALIGN;
87
88         /* Adjust kernel segment with TEXT_OFFSET */
89         kbuf.memsz += text_offset;
90
91         ret = kexec_add_buffer(&kbuf);
92         if (ret)
93                 return ERR_PTR(ret);
94
95         kernel_segment = &image->segment[image->nr_segments - 1];
96         kernel_segment->mem += text_offset;
97         kernel_segment->memsz -= text_offset;
98         image->start = kernel_segment->mem;
99
100         pr_debug("Loaded kernel at 0x%lx bufsz=0x%lx memsz=0x%lx\n",
101                                 kernel_segment->mem, kbuf.bufsz,
102                                 kernel_segment->memsz);
103
104         /* Load additional data */
105         ret = load_other_segments(image,
106                                 kernel_segment->mem, kernel_segment->memsz,
107                                 initrd, initrd_len, cmdline);
108
109         return ERR_PTR(ret);
110 }
111
112 #ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG
113 static int image_verify_sig(const char *kernel, unsigned long kernel_len)
114 {
115         return verify_pefile_signature(kernel, kernel_len, NULL,
116                                        VERIFYING_KEXEC_PE_SIGNATURE);
117 }
118 #endif
119
120 const struct kexec_file_ops kexec_image_ops = {
121         .probe = image_probe,
122         .load = image_load,
123 #ifdef CONFIG_KEXEC_IMAGE_VERIFY_SIG
124         .verify_sig = image_verify_sig,
125 #endif
126 };