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;
189 *(u32
*)loc
+= sym
->st_value
- loc
;
192 case R_ARM_MOVW_ABS_NC
:
194 case R_ARM_MOVW_PREL_NC
:
195 case R_ARM_MOVT_PREL
:
196 offset
= tmp
= __mem_to_opcode_arm(*(u32
*)loc
);
197 offset
= ((offset
& 0xf0000) >> 4) | (offset
& 0xfff);
198 offset
= (offset
^ 0x8000) - 0x8000;
200 offset
+= sym
->st_value
;
201 if (ELF32_R_TYPE(rel
->r_info
) == R_ARM_MOVT_PREL
||
202 ELF32_R_TYPE(rel
->r_info
) == R_ARM_MOVW_PREL_NC
)
204 if (ELF32_R_TYPE(rel
->r_info
) == R_ARM_MOVT_ABS
||
205 ELF32_R_TYPE(rel
->r_info
) == R_ARM_MOVT_PREL
)
209 tmp
|= ((offset
& 0xf000) << 4) |
212 *(u32
*)loc
= __opcode_to_mem_arm(tmp
);
215 #ifdef CONFIG_THUMB2_KERNEL
217 case R_ARM_THM_JUMP24
:
219 * For function symbols, only Thumb addresses are
220 * allowed (no interworking).
222 * For non-function symbols, the destination
223 * has no specific ARM/Thumb disposition, so
224 * the branch is resolved under the assumption
225 * that interworking is not required.
227 if (ELF32_ST_TYPE(sym
->st_info
) == STT_FUNC
&&
228 !(sym
->st_value
& 1)) {
229 pr_err("%s: section %u reloc %u sym '%s': unsupported interworking call (Thumb -> ARM)\n",
230 module
->name
, relindex
, i
, symname
);
234 upper
= __mem_to_opcode_thumb16(*(u16
*)loc
);
235 lower
= __mem_to_opcode_thumb16(*(u16
*)(loc
+ 2));
238 * 25 bit signed address range (Thumb-2 BL and B.W
240 * S:I1:I2:imm10:imm11:0
242 * S = upper[10] = offset[24]
243 * I1 = ~(J1 ^ S) = offset[23]
244 * I2 = ~(J2 ^ S) = offset[22]
245 * imm10 = upper[9:0] = offset[21:12]
246 * imm11 = lower[10:0] = offset[11:1]
250 sign
= (upper
>> 10) & 1;
251 j1
= (lower
>> 13) & 1;
252 j2
= (lower
>> 11) & 1;
253 offset
= (sign
<< 24) | ((~(j1
^ sign
) & 1) << 23) |
254 ((~(j2
^ sign
) & 1) << 22) |
255 ((upper
& 0x03ff) << 12) |
256 ((lower
& 0x07ff) << 1);
257 if (offset
& 0x01000000)
258 offset
-= 0x02000000;
259 offset
+= sym
->st_value
- loc
;
262 * Route through a PLT entry if 'offset' exceeds the
265 if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS
) &&
266 (offset
<= (s32
)0xff000000 ||
267 offset
>= (s32
)0x01000000))
268 offset
= get_module_plt(module
, loc
,
272 if (offset
<= (s32
)0xff000000 ||
273 offset
>= (s32
)0x01000000) {
274 pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n",
275 module
->name
, relindex
, i
, symname
,
276 ELF32_R_TYPE(rel
->r_info
), loc
,
281 sign
= (offset
>> 24) & 1;
282 j1
= sign
^ (~(offset
>> 23) & 1);
283 j2
= sign
^ (~(offset
>> 22) & 1);
284 upper
= (u16
)((upper
& 0xf800) | (sign
<< 10) |
285 ((offset
>> 12) & 0x03ff));
286 lower
= (u16
)((lower
& 0xd000) |
287 (j1
<< 13) | (j2
<< 11) |
288 ((offset
>> 1) & 0x07ff));
290 *(u16
*)loc
= __opcode_to_mem_thumb16(upper
);
291 *(u16
*)(loc
+ 2) = __opcode_to_mem_thumb16(lower
);
294 case R_ARM_THM_MOVW_ABS_NC
:
295 case R_ARM_THM_MOVT_ABS
:
296 case R_ARM_THM_MOVW_PREL_NC
:
297 case R_ARM_THM_MOVT_PREL
:
298 upper
= __mem_to_opcode_thumb16(*(u16
*)loc
);
299 lower
= __mem_to_opcode_thumb16(*(u16
*)(loc
+ 2));
302 * MOVT/MOVW instructions encoding in Thumb-2:
306 * imm3 = lower[14:12]
309 * imm16 = imm4:i:imm3:imm8
311 offset
= ((upper
& 0x000f) << 12) |
312 ((upper
& 0x0400) << 1) |
313 ((lower
& 0x7000) >> 4) | (lower
& 0x00ff);
314 offset
= (offset
^ 0x8000) - 0x8000;
315 offset
+= sym
->st_value
;
317 if (ELF32_R_TYPE(rel
->r_info
) == R_ARM_THM_MOVT_PREL
||
318 ELF32_R_TYPE(rel
->r_info
) == R_ARM_THM_MOVW_PREL_NC
)
320 if (ELF32_R_TYPE(rel
->r_info
) == R_ARM_THM_MOVT_ABS
||
321 ELF32_R_TYPE(rel
->r_info
) == R_ARM_THM_MOVT_PREL
)
324 upper
= (u16
)((upper
& 0xfbf0) |
325 ((offset
& 0xf000) >> 12) |
326 ((offset
& 0x0800) >> 1));
327 lower
= (u16
)((lower
& 0x8f00) |
328 ((offset
& 0x0700) << 4) |
330 *(u16
*)loc
= __opcode_to_mem_thumb16(upper
);
331 *(u16
*)(loc
+ 2) = __opcode_to_mem_thumb16(lower
);
336 pr_err("%s: unknown relocation: %u\n",
337 module
->name
, ELF32_R_TYPE(rel
->r_info
));
344 struct mod_unwind_map
{
345 const Elf_Shdr
*unw_sec
;
346 const Elf_Shdr
*txt_sec
;
349 static const Elf_Shdr
*find_mod_section(const Elf32_Ehdr
*hdr
,
350 const Elf_Shdr
*sechdrs
, const char *name
)
352 const Elf_Shdr
*s
, *se
;
353 const char *secstrs
= (void *)hdr
+ sechdrs
[hdr
->e_shstrndx
].sh_offset
;
355 for (s
= sechdrs
, se
= sechdrs
+ hdr
->e_shnum
; s
< se
; s
++)
356 if (strcmp(name
, secstrs
+ s
->sh_name
) == 0)
362 extern void fixup_pv_table(const void *, unsigned long);
363 extern void fixup_smp(const void *, unsigned long);
365 int module_finalize(const Elf32_Ehdr
*hdr
, const Elf_Shdr
*sechdrs
,
368 const Elf_Shdr
*s
= NULL
;
369 #ifdef CONFIG_ARM_UNWIND
370 const char *secstrs
= (void *)hdr
+ sechdrs
[hdr
->e_shstrndx
].sh_offset
;
371 const Elf_Shdr
*sechdrs_end
= sechdrs
+ hdr
->e_shnum
;
372 struct mod_unwind_map maps
[ARM_SEC_MAX
];
375 memset(maps
, 0, sizeof(maps
));
377 for (s
= sechdrs
; s
< sechdrs_end
; s
++) {
378 const char *secname
= secstrs
+ s
->sh_name
;
380 if (!(s
->sh_flags
& SHF_ALLOC
))
383 if (strcmp(".ARM.exidx.init.text", secname
) == 0)
384 maps
[ARM_SEC_INIT
].unw_sec
= s
;
385 else if (strcmp(".ARM.exidx", secname
) == 0)
386 maps
[ARM_SEC_CORE
].unw_sec
= s
;
387 else if (strcmp(".ARM.exidx.exit.text", secname
) == 0)
388 maps
[ARM_SEC_EXIT
].unw_sec
= s
;
389 else if (strcmp(".ARM.exidx.text.unlikely", secname
) == 0)
390 maps
[ARM_SEC_UNLIKELY
].unw_sec
= s
;
391 else if (strcmp(".ARM.exidx.text.hot", secname
) == 0)
392 maps
[ARM_SEC_HOT
].unw_sec
= s
;
393 else if (strcmp(".init.text", secname
) == 0)
394 maps
[ARM_SEC_INIT
].txt_sec
= s
;
395 else if (strcmp(".text", secname
) == 0)
396 maps
[ARM_SEC_CORE
].txt_sec
= s
;
397 else if (strcmp(".exit.text", secname
) == 0)
398 maps
[ARM_SEC_EXIT
].txt_sec
= s
;
399 else if (strcmp(".text.unlikely", secname
) == 0)
400 maps
[ARM_SEC_UNLIKELY
].txt_sec
= s
;
401 else if (strcmp(".text.hot", secname
) == 0)
402 maps
[ARM_SEC_HOT
].txt_sec
= s
;
405 for (i
= 0; i
< ARM_SEC_MAX
; i
++)
406 if (maps
[i
].unw_sec
&& maps
[i
].txt_sec
)
407 mod
->arch
.unwind
[i
] =
408 unwind_table_add(maps
[i
].unw_sec
->sh_addr
,
409 maps
[i
].unw_sec
->sh_size
,
410 maps
[i
].txt_sec
->sh_addr
,
411 maps
[i
].txt_sec
->sh_size
);
413 #ifdef CONFIG_ARM_PATCH_PHYS_VIRT
414 s
= find_mod_section(hdr
, sechdrs
, ".pv_table");
416 fixup_pv_table((void *)s
->sh_addr
, s
->sh_size
);
418 s
= find_mod_section(hdr
, sechdrs
, ".alt.smp.init");
420 #ifdef CONFIG_SMP_ON_UP
421 fixup_smp((void *)s
->sh_addr
, s
->sh_size
);
429 module_arch_cleanup(struct module
*mod
)
431 #ifdef CONFIG_ARM_UNWIND
434 for (i
= 0; i
< ARM_SEC_MAX
; i
++) {
435 unwind_table_del(mod
->arch
.unwind
[i
]);
436 mod
->arch
.unwind
[i
] = NULL
;
441 void __weak
module_arch_freeing_init(struct module
*mod
)
443 #ifdef CONFIG_ARM_UNWIND
444 unwind_table_del(mod
->arch
.unwind
[ARM_SEC_INIT
]);
445 mod
->arch
.unwind
[ARM_SEC_INIT
] = NULL
;