1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Port on Texas Instruments TMS320C6x architecture
4 *
5 * Copyright (C) 2005, 2009, 2010, 2011 Texas Instruments Incorporated
6 * Author: Thomas Charleux (thomas.charleux@jaluna.com)
7 */
8 #include <linux/moduleloader.h>
9 #include <linux/elf.h>
10 #include <linux/vmalloc.h>
11 #include <linux/kernel.h>
12
fixup_pcr(u32 * ip,Elf32_Addr dest,u32 maskbits,int shift)13 static inline int fixup_pcr(u32 *ip, Elf32_Addr dest, u32 maskbits, int shift)
14 {
15 u32 opcode;
16 long ep = (long)ip & ~31;
17 long delta = ((long)dest - ep) >> 2;
18 long mask = (1 << maskbits) - 1;
19
20 if ((delta >> (maskbits - 1)) == 0 ||
21 (delta >> (maskbits - 1)) == -1) {
22 opcode = *ip;
23 opcode &= ~(mask << shift);
24 opcode |= ((delta & mask) << shift);
25 *ip = opcode;
26
27 pr_debug("REL PCR_S%d[%p] dest[%p] opcode[%08x]\n",
28 maskbits, ip, (void *)dest, opcode);
29
30 return 0;
31 }
32 pr_err("PCR_S%d reloc %p -> %p out of range!\n",
33 maskbits, ip, (void *)dest);
34
35 return -1;
36 }
37
38 /*
39 * apply a RELA relocation
40 */
apply_relocate_add(Elf32_Shdr * sechdrs,const char * strtab,unsigned int symindex,unsigned int relsec,struct module * me)41 int apply_relocate_add(Elf32_Shdr *sechdrs,
42 const char *strtab,
43 unsigned int symindex,
44 unsigned int relsec,
45 struct module *me)
46 {
47 Elf32_Rela *rel = (void *) sechdrs[relsec].sh_addr;
48 Elf_Sym *sym;
49 u32 *location, opcode;
50 unsigned int i;
51 Elf32_Addr v;
52 Elf_Addr offset = 0;
53
54 pr_debug("Applying relocate section %u to %u with offset 0x%x\n",
55 relsec, sechdrs[relsec].sh_info, offset);
56
57 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
58 /* This is where to make the change */
59 location = (void *)sechdrs[sechdrs[relsec].sh_info].sh_addr
60 + rel[i].r_offset - offset;
61
62 /* This is the symbol it is referring to. Note that all
63 undefined symbols have been resolved. */
64 sym = (Elf_Sym *)sechdrs[symindex].sh_addr
65 + ELF32_R_SYM(rel[i].r_info);
66
67 /* this is the adjustment to be made */
68 v = sym->st_value + rel[i].r_addend;
69
70 switch (ELF32_R_TYPE(rel[i].r_info)) {
71 case R_C6000_ABS32:
72 pr_debug("RELA ABS32: [%p] = 0x%x\n", location, v);
73 *location = v;
74 break;
75 case R_C6000_ABS16:
76 pr_debug("RELA ABS16: [%p] = 0x%x\n", location, v);
77 *(u16 *)location = v;
78 break;
79 case R_C6000_ABS8:
80 pr_debug("RELA ABS8: [%p] = 0x%x\n", location, v);
81 *(u8 *)location = v;
82 break;
83 case R_C6000_ABS_L16:
84 opcode = *location;
85 opcode &= ~0x7fff80;
86 opcode |= ((v & 0xffff) << 7);
87 pr_debug("RELA ABS_L16[%p] v[0x%x] opcode[0x%x]\n",
88 location, v, opcode);
89 *location = opcode;
90 break;
91 case R_C6000_ABS_H16:
92 opcode = *location;
93 opcode &= ~0x7fff80;
94 opcode |= ((v >> 9) & 0x7fff80);
95 pr_debug("RELA ABS_H16[%p] v[0x%x] opcode[0x%x]\n",
96 location, v, opcode);
97 *location = opcode;
98 break;
99 case R_C6000_PCR_S21:
100 if (fixup_pcr(location, v, 21, 7))
101 return -ENOEXEC;
102 break;
103 case R_C6000_PCR_S12:
104 if (fixup_pcr(location, v, 12, 16))
105 return -ENOEXEC;
106 break;
107 case R_C6000_PCR_S10:
108 if (fixup_pcr(location, v, 10, 13))
109 return -ENOEXEC;
110 break;
111 default:
112 pr_err("module %s: Unknown RELA relocation: %u\n",
113 me->name, ELF32_R_TYPE(rel[i].r_info));
114 return -ENOEXEC;
115 }
116 }
117
118 return 0;
119 }
120