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4febfb8d | 1 | // SPDX-License-Identifier: GPL-2.0 |
3c7f2550 MS |
2 | /* |
3 | * Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@linaro.org> | |
4 | * | |
5 | * This file implements the EFI boot stub for the arm64 kernel. | |
6 | * Adapted from ARM version by Mark Salter <msalter@redhat.com> | |
3c7f2550 | 7 | */ |
0426a4e6 | 8 | |
0426a4e6 | 9 | |
3c7f2550 | 10 | #include <linux/efi.h> |
a13b0077 | 11 | #include <asm/efi.h> |
170976bc | 12 | #include <asm/memory.h> |
6f05106e | 13 | #include <asm/sections.h> |
3c7f2550 | 14 | |
2b5fe07a AB |
15 | #include "efistub.h" |
16 | ||
5b94046e AB |
17 | /* |
18 | * Distro versions of GRUB may ignore the BSS allocation entirely (i.e., fail | |
19 | * to provide space, and fail to zero it). Check for this condition by double | |
20 | * checking that the first and the last byte of the image are covered by the | |
21 | * same EFI memory map entry. | |
22 | */ | |
23 | static bool check_image_region(u64 base, u64 size) | |
24 | { | |
eab31265 | 25 | struct efi_boot_memmap *map; |
5b94046e AB |
26 | efi_status_t status; |
27 | bool ret = false; | |
28 | int map_offset; | |
29 | ||
171539f5 | 30 | status = efi_get_memory_map(&map, false); |
5b94046e AB |
31 | if (status != EFI_SUCCESS) |
32 | return false; | |
33 | ||
eab31265 AB |
34 | for (map_offset = 0; map_offset < map->map_size; map_offset += map->desc_size) { |
35 | efi_memory_desc_t *md = (void *)map->map + map_offset; | |
5b94046e AB |
36 | u64 end = md->phys_addr + md->num_pages * EFI_PAGE_SIZE; |
37 | ||
38 | /* | |
39 | * Find the region that covers base, and return whether | |
40 | * it covers base+size bytes. | |
41 | */ | |
42 | if (base >= md->phys_addr && base < end) { | |
43 | ret = (base + size) <= end; | |
44 | break; | |
45 | } | |
46 | } | |
47 | ||
eab31265 | 48 | efi_bs_call(free_pool, map); |
5b94046e AB |
49 | |
50 | return ret; | |
51 | } | |
52 | ||
cd33a5c1 | 53 | efi_status_t handle_kernel_image(unsigned long *image_addr, |
dae31fd2 AB |
54 | unsigned long *image_size, |
55 | unsigned long *reserve_addr, | |
56 | unsigned long *reserve_size, | |
416a9f84 AB |
57 | efi_loaded_image_t *image, |
58 | efi_handle_t image_handle) | |
3c7f2550 MS |
59 | { |
60 | efi_status_t status; | |
61786170 | 61 | unsigned long kernel_size, kernel_codesize, kernel_memsize; |
5d12da9d | 62 | u32 phys_seed = 0; |
895bc3a1 | 63 | u64 min_kimg_align = efi_get_kimg_min_align(); |
3a262423 | 64 | |
2b5fe07a | 65 | if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) { |
07768c55 AB |
66 | efi_guid_t li_fixed_proto = LINUX_EFI_LOADED_IMAGE_FIXED_GUID; |
67 | void *p; | |
68 | ||
69 | if (efi_nokaslr) { | |
70 | efi_info("KASLR disabled on kernel command line\n"); | |
71 | } else if (efi_bs_call(handle_protocol, image_handle, | |
72 | &li_fixed_proto, &p) == EFI_SUCCESS) { | |
73 | efi_info("Image placement fixed by loader\n"); | |
74 | } else { | |
cd33a5c1 | 75 | status = efi_get_random_bytes(sizeof(phys_seed), |
2b5fe07a AB |
76 | (u8 *)&phys_seed); |
77 | if (status == EFI_NOT_FOUND) { | |
1c761ee9 | 78 | efi_info("EFI_RNG_PROTOCOL unavailable\n"); |
d32de913 | 79 | efi_nokaslr = true; |
2b5fe07a | 80 | } else if (status != EFI_SUCCESS) { |
1c761ee9 | 81 | efi_err("efi_get_random_bytes() failed (0x%lx)\n", |
d32de913 AB |
82 | status); |
83 | efi_nokaslr = true; | |
2b5fe07a | 84 | } |
2b5fe07a AB |
85 | } |
86 | } | |
73effccb | 87 | |
82046702 | 88 | if (image->image_base != _text) |
793473c2 | 89 | efi_err("FIRMWARE BUG: efi_loaded_image_t::image_base has bogus value\n"); |
3c7f2550 | 90 | |
e9b7c3a4 MC |
91 | if (!IS_ALIGNED((u64)_text, SEGMENT_ALIGN)) |
92 | efi_err("FIRMWARE BUG: kernel image not aligned on %dk boundary\n", | |
93 | SEGMENT_ALIGN >> 10); | |
c32ac11d | 94 | |
3c7f2550 | 95 | kernel_size = _edata - _text; |
61786170 | 96 | kernel_codesize = __inittext_end - _text; |
2b5fe07a | 97 | kernel_memsize = kernel_size + (_end - _edata); |
120dc60d | 98 | *reserve_size = kernel_memsize; |
2b5fe07a AB |
99 | |
100 | if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && phys_seed != 0) { | |
101 | /* | |
102 | * If KASLR is enabled, and we have some randomness available, | |
103 | * locate the kernel at a randomized offset in physical memory. | |
104 | */ | |
3a262423 | 105 | status = efi_random_alloc(*reserve_size, min_kimg_align, |
9cf42bca AB |
106 | reserve_addr, phys_seed, |
107 | EFI_LOADER_CODE); | |
ff80ef5b AB |
108 | if (status != EFI_SUCCESS) |
109 | efi_warn("efi_random_alloc() failed: 0x%lx\n", status); | |
2b5fe07a | 110 | } else { |
82046702 | 111 | status = EFI_OUT_OF_RESOURCES; |
2b5fe07a | 112 | } |
e38457c3 | 113 | |
2b5fe07a | 114 | if (status != EFI_SUCCESS) { |
5b94046e AB |
115 | if (!check_image_region((u64)_text, kernel_memsize)) { |
116 | efi_err("FIRMWARE BUG: Image BSS overlaps adjacent EFI memory region\n"); | |
a37dac5c AB |
117 | } else if (IS_ALIGNED((u64)_text, min_kimg_align) && |
118 | (u64)_end < EFI_ALLOC_LIMIT) { | |
82046702 AB |
119 | /* |
120 | * Just execute from wherever we were loaded by the | |
a37dac5c | 121 | * UEFI PE/COFF loader if the placement is suitable. |
82046702 AB |
122 | */ |
123 | *image_addr = (u64)_text; | |
124 | *reserve_size = 0; | |
61786170 | 125 | return EFI_SUCCESS; |
82046702 AB |
126 | } |
127 | ||
e71356fe | 128 | status = efi_allocate_pages_aligned(*reserve_size, reserve_addr, |
9cf42bca AB |
129 | ULONG_MAX, min_kimg_align, |
130 | EFI_LOADER_CODE); | |
2b5fe07a AB |
131 | |
132 | if (status != EFI_SUCCESS) { | |
793473c2 | 133 | efi_err("Failed to relocate kernel\n"); |
2b5fe07a AB |
134 | *reserve_size = 0; |
135 | return status; | |
3c7f2550 | 136 | } |
3c7f2550 | 137 | } |
c2136dce | 138 | |
120dc60d | 139 | *image_addr = *reserve_addr; |
c2136dce | 140 | memcpy((void *)*image_addr, _text, kernel_size); |
61786170 | 141 | caches_clean_inval_pou(*image_addr, *image_addr + kernel_codesize); |
3c60f67b | 142 | efi_remap_image(*image_addr, *reserve_size, kernel_codesize); |
3c7f2550 | 143 | |
61786170 AB |
144 | return EFI_SUCCESS; |
145 | } | |
146 | ||
147 | asmlinkage void primary_entry(void); | |
148 | ||
149 | unsigned long primary_entry_offset(void) | |
150 | { | |
aaeb3fc6 | 151 | /* |
61786170 AB |
152 | * When built as part of the kernel, the EFI stub cannot branch to the |
153 | * kernel proper via the image header, as the PE/COFF header is | |
154 | * strictly not part of the in-memory presentation of the image, only | |
155 | * of the file representation. So instead, we need to jump to the | |
156 | * actual entrypoint in the .text region of the image. | |
aaeb3fc6 | 157 | */ |
61786170 | 158 | return (char *)primary_entry - _text; |
3c7f2550 | 159 | } |