1 // SPDX-License-Identifier: GPL-2.0-only
3 * linux/arch/arm/kernel/module.c
5 * Copyright (C) 2002 Russell King.
6 * Modified for nommu by Hyok S. Choi
8 * Module allocation method suggested by Andi Kleen.
10 #include <linux/module.h>
11 #include <linux/moduleloader.h>
12 #include <linux/kernel.h>
14 #include <linux/elf.h>
15 #include <linux/vmalloc.h>
17 #include <linux/string.h>
18 #include <linux/gfp.h>
20 #include <asm/sections.h>
21 #include <asm/smp_plat.h>
22 #include <asm/unwind.h>
23 #include <asm/opcodes.h>
25 #ifdef CONFIG_XIP_KERNEL
27 * The XIP kernel text is mapped in the module area for modules and
28 * some other stuff to work without any indirect relocations.
29 * MODULES_VADDR is redefined here and not in asm/memory.h to avoid
30 * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off.
33 #define MODULES_VADDR (((unsigned long)_exiprom + ~PMD_MASK) & PMD_MASK)
37 void *module_alloc(unsigned long size)
39 gfp_t gfp_mask = GFP_KERNEL;
42 /* Silence the initial allocation */
43 if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS))
44 gfp_mask |= __GFP_NOWARN;
46 p = __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
47 gfp_mask, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
48 __builtin_return_address(0));
49 if (!IS_ENABLED(CONFIG_ARM_MODULE_PLTS) || p)
51 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
52 GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
53 __builtin_return_address(0));
57 bool module_init_section(const char *name)
59 return strstarts(name, ".init") ||
60 strstarts(name, ".ARM.extab.init") ||
61 strstarts(name, ".ARM.exidx.init");
64 bool module_exit_section(const char *name)
66 return strstarts(name, ".exit") ||
67 strstarts(name, ".ARM.extab.exit") ||
68 strstarts(name, ".ARM.exidx.exit");
72 apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
73 unsigned int relindex, struct module *module)
75 Elf32_Shdr *symsec = sechdrs + symindex;
76 Elf32_Shdr *relsec = sechdrs + relindex;
77 Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
78 Elf32_Rel *rel = (void *)relsec->sh_addr;
81 for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) {
87 #ifdef CONFIG_THUMB2_KERNEL
88 u32 upper, lower, sign, j1, j2;
91 offset = ELF32_R_SYM(rel->r_info);
92 if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
93 pr_err("%s: section %u reloc %u: bad relocation sym offset\n",
94 module->name, relindex, i);
98 sym = ((Elf32_Sym *)symsec->sh_addr) + offset;
99 symname = strtab + sym->st_name;
101 if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) {
102 pr_err("%s: section %u reloc %u sym '%s': out of bounds relocation, offset %d size %u\n",
103 module->name, relindex, i, symname,
104 rel->r_offset, dstsec->sh_size);
108 loc = dstsec->sh_addr + rel->r_offset;
110 switch (ELF32_R_TYPE(rel->r_info)) {
117 *(u32 *)loc += sym->st_value;
123 if (sym->st_value & 3) {
124 pr_err("%s: section %u reloc %u sym '%s': unsupported interworking call (ARM -> Thumb)\n",
125 module->name, relindex, i, symname);
129 offset = __mem_to_opcode_arm(*(u32 *)loc);
130 offset = (offset & 0x00ffffff) << 2;
131 if (offset & 0x02000000)
132 offset -= 0x04000000;
134 offset += sym->st_value - loc;
137 * Route through a PLT entry if 'offset' exceeds the
138 * supported range. Note that 'offset + loc + 8'
139 * contains the absolute jump target, i.e.,
140 * @sym + addend, corrected for the +8 PC bias.
142 if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS) &&
143 (offset <= (s32)0xfe000000 ||
144 offset >= (s32)0x02000000))
145 offset = get_module_plt(module, loc,
149 if (offset <= (s32)0xfe000000 ||
150 offset >= (s32)0x02000000) {
151 pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n",
152 module->name, relindex, i, symname,
153 ELF32_R_TYPE(rel->r_info), loc,
159 offset &= 0x00ffffff;
161 *(u32 *)loc &= __opcode_to_mem_arm(0xff000000);
162 *(u32 *)loc |= __opcode_to_mem_arm(offset);
166 /* Preserve Rm and the condition code. Alter
167 * other bits to re-code instruction as
170 *(u32 *)loc &= __opcode_to_mem_arm(0xf000000f);
171 *(u32 *)loc |= __opcode_to_mem_arm(0x01a0f000);
175 offset = (*(s32 *)loc << 1) >> 1; /* sign extend */
176 offset += sym->st_value - loc;
177 if (offset >= 0x40000000 || offset < -0x40000000) {
178 pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n",
179 module->name, relindex, i, symname,
180 ELF32_R_TYPE(rel->r_info), loc,
184 *(u32 *)loc &= 0x80000000;
185 *(u32 *)loc |= offset & 0x7fffffff;
188 case R_ARM_MOVW_ABS_NC:
190 offset = tmp = __mem_to_opcode_arm(*(u32 *)loc);
191 offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff);
192 offset = (offset ^ 0x8000) - 0x8000;
194 offset += sym->st_value;
195 if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS)
199 tmp |= ((offset & 0xf000) << 4) |
202 *(u32 *)loc = __opcode_to_mem_arm(tmp);
205 #ifdef CONFIG_THUMB2_KERNEL
207 case R_ARM_THM_JUMP24:
209 * For function symbols, only Thumb addresses are
210 * allowed (no interworking).
212 * For non-function symbols, the destination
213 * has no specific ARM/Thumb disposition, so
214 * the branch is resolved under the assumption
215 * that interworking is not required.
217 if (ELF32_ST_TYPE(sym->st_info) == STT_FUNC &&
218 !(sym->st_value & 1)) {
219 pr_err("%s: section %u reloc %u sym '%s': unsupported interworking call (Thumb -> ARM)\n",
220 module->name, relindex, i, symname);
224 upper = __mem_to_opcode_thumb16(*(u16 *)loc);
225 lower = __mem_to_opcode_thumb16(*(u16 *)(loc + 2));
228 * 25 bit signed address range (Thumb-2 BL and B.W
230 * S:I1:I2:imm10:imm11:0
232 * S = upper[10] = offset[24]
233 * I1 = ~(J1 ^ S) = offset[23]
234 * I2 = ~(J2 ^ S) = offset[22]
235 * imm10 = upper[9:0] = offset[21:12]
236 * imm11 = lower[10:0] = offset[11:1]
240 sign = (upper >> 10) & 1;
241 j1 = (lower >> 13) & 1;
242 j2 = (lower >> 11) & 1;
243 offset = (sign << 24) | ((~(j1 ^ sign) & 1) << 23) |
244 ((~(j2 ^ sign) & 1) << 22) |
245 ((upper & 0x03ff) << 12) |
246 ((lower & 0x07ff) << 1);
247 if (offset & 0x01000000)
248 offset -= 0x02000000;
249 offset += sym->st_value - loc;
252 * Route through a PLT entry if 'offset' exceeds the
255 if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS) &&
256 (offset <= (s32)0xff000000 ||
257 offset >= (s32)0x01000000))
258 offset = get_module_plt(module, loc,
262 if (offset <= (s32)0xff000000 ||
263 offset >= (s32)0x01000000) {
264 pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n",
265 module->name, relindex, i, symname,
266 ELF32_R_TYPE(rel->r_info), loc,
271 sign = (offset >> 24) & 1;
272 j1 = sign ^ (~(offset >> 23) & 1);
273 j2 = sign ^ (~(offset >> 22) & 1);
274 upper = (u16)((upper & 0xf800) | (sign << 10) |
275 ((offset >> 12) & 0x03ff));
276 lower = (u16)((lower & 0xd000) |
277 (j1 << 13) | (j2 << 11) |
278 ((offset >> 1) & 0x07ff));
280 *(u16 *)loc = __opcode_to_mem_thumb16(upper);
281 *(u16 *)(loc + 2) = __opcode_to_mem_thumb16(lower);
284 case R_ARM_THM_MOVW_ABS_NC:
285 case R_ARM_THM_MOVT_ABS:
286 upper = __mem_to_opcode_thumb16(*(u16 *)loc);
287 lower = __mem_to_opcode_thumb16(*(u16 *)(loc + 2));
290 * MOVT/MOVW instructions encoding in Thumb-2:
294 * imm3 = lower[14:12]
297 * imm16 = imm4:i:imm3:imm8
299 offset = ((upper & 0x000f) << 12) |
300 ((upper & 0x0400) << 1) |
301 ((lower & 0x7000) >> 4) | (lower & 0x00ff);
302 offset = (offset ^ 0x8000) - 0x8000;
303 offset += sym->st_value;
305 if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS)
308 upper = (u16)((upper & 0xfbf0) |
309 ((offset & 0xf000) >> 12) |
310 ((offset & 0x0800) >> 1));
311 lower = (u16)((lower & 0x8f00) |
312 ((offset & 0x0700) << 4) |
314 *(u16 *)loc = __opcode_to_mem_thumb16(upper);
315 *(u16 *)(loc + 2) = __opcode_to_mem_thumb16(lower);
320 pr_err("%s: unknown relocation: %u\n",
321 module->name, ELF32_R_TYPE(rel->r_info));
328 struct mod_unwind_map {
329 const Elf_Shdr *unw_sec;
330 const Elf_Shdr *txt_sec;
333 static const Elf_Shdr *find_mod_section(const Elf32_Ehdr *hdr,
334 const Elf_Shdr *sechdrs, const char *name)
336 const Elf_Shdr *s, *se;
337 const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
339 for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++)
340 if (strcmp(name, secstrs + s->sh_name) == 0)
346 extern void fixup_pv_table(const void *, unsigned long);
347 extern void fixup_smp(const void *, unsigned long);
349 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
352 const Elf_Shdr *s = NULL;
353 #ifdef CONFIG_ARM_UNWIND
354 const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
355 const Elf_Shdr *sechdrs_end = sechdrs + hdr->e_shnum;
356 struct mod_unwind_map maps[ARM_SEC_MAX];
359 memset(maps, 0, sizeof(maps));
361 for (s = sechdrs; s < sechdrs_end; s++) {
362 const char *secname = secstrs + s->sh_name;
364 if (!(s->sh_flags & SHF_ALLOC))
367 if (strcmp(".ARM.exidx.init.text", secname) == 0)
368 maps[ARM_SEC_INIT].unw_sec = s;
369 else if (strcmp(".ARM.exidx", secname) == 0)
370 maps[ARM_SEC_CORE].unw_sec = s;
371 else if (strcmp(".ARM.exidx.exit.text", secname) == 0)
372 maps[ARM_SEC_EXIT].unw_sec = s;
373 else if (strcmp(".ARM.exidx.text.unlikely", secname) == 0)
374 maps[ARM_SEC_UNLIKELY].unw_sec = s;
375 else if (strcmp(".ARM.exidx.text.hot", secname) == 0)
376 maps[ARM_SEC_HOT].unw_sec = s;
377 else if (strcmp(".init.text", secname) == 0)
378 maps[ARM_SEC_INIT].txt_sec = s;
379 else if (strcmp(".text", secname) == 0)
380 maps[ARM_SEC_CORE].txt_sec = s;
381 else if (strcmp(".exit.text", secname) == 0)
382 maps[ARM_SEC_EXIT].txt_sec = s;
383 else if (strcmp(".text.unlikely", secname) == 0)
384 maps[ARM_SEC_UNLIKELY].txt_sec = s;
385 else if (strcmp(".text.hot", secname) == 0)
386 maps[ARM_SEC_HOT].txt_sec = s;
389 for (i = 0; i < ARM_SEC_MAX; i++)
390 if (maps[i].unw_sec && maps[i].txt_sec)
391 mod->arch.unwind[i] =
392 unwind_table_add(maps[i].unw_sec->sh_addr,
393 maps[i].unw_sec->sh_size,
394 maps[i].txt_sec->sh_addr,
395 maps[i].txt_sec->sh_size);
397 #ifdef CONFIG_ARM_PATCH_PHYS_VIRT
398 s = find_mod_section(hdr, sechdrs, ".pv_table");
400 fixup_pv_table((void *)s->sh_addr, s->sh_size);
402 s = find_mod_section(hdr, sechdrs, ".alt.smp.init");
404 #ifdef CONFIG_SMP_ON_UP
405 fixup_smp((void *)s->sh_addr, s->sh_size);
413 module_arch_cleanup(struct module *mod)
415 #ifdef CONFIG_ARM_UNWIND
418 for (i = 0; i < ARM_SEC_MAX; i++) {
419 unwind_table_del(mod->arch.unwind[i]);
420 mod->arch.unwind[i] = NULL;
425 void __weak module_arch_freeing_init(struct module *mod)
427 #ifdef CONFIG_ARM_UNWIND
428 unwind_table_del(mod->arch.unwind[ARM_SEC_INIT]);
429 mod->arch.unwind[ARM_SEC_INIT] = NULL;