1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * Remote processor elf helpers defines
4  *
5  * Copyright (C) 2020 Kalray, Inc.
6  */
7 
8 #ifndef REMOTEPROC_ELF_LOADER_H
9 #define REMOTEPROC_ELF_LOADER_H
10 
11 #include <linux/elf.h>
12 #include <linux/types.h>
13 
14 /**
15  * fw_elf_get_class - Get elf class
16  * @fw: the ELF firmware image
17  *
18  * Note that we use elf32_hdr to access the class since the start of the
19  * struct is the same for both elf class
20  *
21  * Return: elf class of the firmware
22  */
23 static inline u8 fw_elf_get_class(const struct firmware *fw)
24 {
25 	struct elf32_hdr *ehdr = (struct elf32_hdr *)fw->data;
26 
27 	return ehdr->e_ident[EI_CLASS];
28 }
29 
30 static inline void elf_hdr_init_ident(struct elf32_hdr *hdr, u8 class)
31 {
32 	memcpy(hdr->e_ident, ELFMAG, SELFMAG);
33 	hdr->e_ident[EI_CLASS] = class;
34 	hdr->e_ident[EI_DATA] = ELFDATA2LSB;
35 	hdr->e_ident[EI_VERSION] = EV_CURRENT;
36 	hdr->e_ident[EI_OSABI] = ELFOSABI_NONE;
37 }
38 
39 /* Generate getter and setter for a specific elf struct/field */
40 #define ELF_GEN_FIELD_GET_SET(__s, __field, __type) \
41 static inline __type elf_##__s##_get_##__field(u8 class, const void *arg) \
42 { \
43 	if (class == ELFCLASS32) \
44 		return (__type) ((const struct elf32_##__s *) arg)->__field; \
45 	else \
46 		return (__type) ((const struct elf64_##__s *) arg)->__field; \
47 } \
48 static inline void elf_##__s##_set_##__field(u8 class, void *arg, \
49 					     __type value) \
50 { \
51 	if (class == ELFCLASS32) \
52 		((struct elf32_##__s *) arg)->__field = (__type) value; \
53 	else \
54 		((struct elf64_##__s *) arg)->__field = (__type) value; \
55 }
56 
57 ELF_GEN_FIELD_GET_SET(hdr, e_entry, u64)
58 ELF_GEN_FIELD_GET_SET(hdr, e_phnum, u16)
59 ELF_GEN_FIELD_GET_SET(hdr, e_shnum, u16)
60 ELF_GEN_FIELD_GET_SET(hdr, e_phoff, u64)
61 ELF_GEN_FIELD_GET_SET(hdr, e_shoff, u64)
62 ELF_GEN_FIELD_GET_SET(hdr, e_shstrndx, u16)
63 ELF_GEN_FIELD_GET_SET(hdr, e_machine, u16)
64 ELF_GEN_FIELD_GET_SET(hdr, e_type, u16)
65 ELF_GEN_FIELD_GET_SET(hdr, e_version, u32)
66 ELF_GEN_FIELD_GET_SET(hdr, e_ehsize, u32)
67 ELF_GEN_FIELD_GET_SET(hdr, e_phentsize, u16)
68 ELF_GEN_FIELD_GET_SET(hdr, e_shentsize, u16)
69 
70 ELF_GEN_FIELD_GET_SET(phdr, p_paddr, u64)
71 ELF_GEN_FIELD_GET_SET(phdr, p_vaddr, u64)
72 ELF_GEN_FIELD_GET_SET(phdr, p_filesz, u64)
73 ELF_GEN_FIELD_GET_SET(phdr, p_memsz, u64)
74 ELF_GEN_FIELD_GET_SET(phdr, p_type, u32)
75 ELF_GEN_FIELD_GET_SET(phdr, p_offset, u64)
76 ELF_GEN_FIELD_GET_SET(phdr, p_flags, u32)
77 ELF_GEN_FIELD_GET_SET(phdr, p_align, u64)
78 
79 ELF_GEN_FIELD_GET_SET(shdr, sh_type, u32)
80 ELF_GEN_FIELD_GET_SET(shdr, sh_flags, u32)
81 ELF_GEN_FIELD_GET_SET(shdr, sh_entsize, u16)
82 ELF_GEN_FIELD_GET_SET(shdr, sh_size, u64)
83 ELF_GEN_FIELD_GET_SET(shdr, sh_offset, u64)
84 ELF_GEN_FIELD_GET_SET(shdr, sh_name, u32)
85 ELF_GEN_FIELD_GET_SET(shdr, sh_addr, u64)
86 
87 #define ELF_STRUCT_SIZE(__s) \
88 static inline unsigned long elf_size_of_##__s(u8 class) \
89 { \
90 	if (class == ELFCLASS32)\
91 		return sizeof(struct elf32_##__s); \
92 	else \
93 		return sizeof(struct elf64_##__s); \
94 }
95 
96 ELF_STRUCT_SIZE(shdr)
97 ELF_STRUCT_SIZE(phdr)
98 ELF_STRUCT_SIZE(hdr)
99 
100 static inline unsigned int elf_strtbl_add(const char *name, void *ehdr, u8 class, size_t *index)
101 {
102 	u16 shstrndx = elf_hdr_get_e_shstrndx(class, ehdr);
103 	void *shdr;
104 	char *strtab;
105 	size_t idx, ret;
106 
107 	shdr = ehdr + elf_size_of_hdr(class) + shstrndx * elf_size_of_shdr(class);
108 	strtab = ehdr + elf_shdr_get_sh_offset(class, shdr);
109 	idx = index ? *index : 0;
110 	if (!strtab || !name)
111 		return 0;
112 
113 	ret = idx;
114 	strcpy((strtab + idx), name);
115 	idx += strlen(name) + 1;
116 	if (index)
117 		*index = idx;
118 
119 	return ret;
120 }
121 
122 #endif /* REMOTEPROC_ELF_LOADER_H */
123