Merge tag 'modules-for-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu...
[sfrench/cifs-2.6.git] / arch / arm / kernel / module.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/arch/arm/kernel/module.c
4  *
5  *  Copyright (C) 2002 Russell King.
6  *  Modified for nommu by Hyok S. Choi
7  *
8  * Module allocation method suggested by Andi Kleen.
9  */
10 #include <linux/module.h>
11 #include <linux/moduleloader.h>
12 #include <linux/kernel.h>
13 #include <linux/mm.h>
14 #include <linux/elf.h>
15 #include <linux/vmalloc.h>
16 #include <linux/fs.h>
17 #include <linux/string.h>
18 #include <linux/gfp.h>
19
20 #include <asm/pgtable.h>
21 #include <asm/sections.h>
22 #include <asm/smp_plat.h>
23 #include <asm/unwind.h>
24 #include <asm/opcodes.h>
25
26 #ifdef CONFIG_XIP_KERNEL
27 /*
28  * The XIP kernel text is mapped in the module area for modules and
29  * some other stuff to work without any indirect relocations.
30  * MODULES_VADDR is redefined here and not in asm/memory.h to avoid
31  * recompiling the whole kernel when CONFIG_XIP_KERNEL is turned on/off.
32  */
33 #undef MODULES_VADDR
34 #define MODULES_VADDR   (((unsigned long)_exiprom + ~PMD_MASK) & PMD_MASK)
35 #endif
36
37 #ifdef CONFIG_MMU
38 void *module_alloc(unsigned long size)
39 {
40         gfp_t gfp_mask = GFP_KERNEL;
41         void *p;
42
43         /* Silence the initial allocation */
44         if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS))
45                 gfp_mask |= __GFP_NOWARN;
46
47         p = __vmalloc_node_range(size, 1, MODULES_VADDR, MODULES_END,
48                                 gfp_mask, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
49                                 __builtin_return_address(0));
50         if (!IS_ENABLED(CONFIG_ARM_MODULE_PLTS) || p)
51                 return p;
52         return __vmalloc_node_range(size, 1,  VMALLOC_START, VMALLOC_END,
53                                 GFP_KERNEL, PAGE_KERNEL_EXEC, 0, NUMA_NO_NODE,
54                                 __builtin_return_address(0));
55 }
56 #endif
57
58 bool module_exit_section(const char *name)
59 {
60         return strstarts(name, ".exit") ||
61                 strstarts(name, ".ARM.extab.exit") ||
62                 strstarts(name, ".ARM.exidx.exit");
63 }
64
65 int
66 apply_relocate(Elf32_Shdr *sechdrs, const char *strtab, unsigned int symindex,
67                unsigned int relindex, struct module *module)
68 {
69         Elf32_Shdr *symsec = sechdrs + symindex;
70         Elf32_Shdr *relsec = sechdrs + relindex;
71         Elf32_Shdr *dstsec = sechdrs + relsec->sh_info;
72         Elf32_Rel *rel = (void *)relsec->sh_addr;
73         unsigned int i;
74
75         for (i = 0; i < relsec->sh_size / sizeof(Elf32_Rel); i++, rel++) {
76                 unsigned long loc;
77                 Elf32_Sym *sym;
78                 const char *symname;
79                 s32 offset;
80                 u32 tmp;
81 #ifdef CONFIG_THUMB2_KERNEL
82                 u32 upper, lower, sign, j1, j2;
83 #endif
84
85                 offset = ELF32_R_SYM(rel->r_info);
86                 if (offset < 0 || offset > (symsec->sh_size / sizeof(Elf32_Sym))) {
87                         pr_err("%s: section %u reloc %u: bad relocation sym offset\n",
88                                 module->name, relindex, i);
89                         return -ENOEXEC;
90                 }
91
92                 sym = ((Elf32_Sym *)symsec->sh_addr) + offset;
93                 symname = strtab + sym->st_name;
94
95                 if (rel->r_offset < 0 || rel->r_offset > dstsec->sh_size - sizeof(u32)) {
96                         pr_err("%s: section %u reloc %u sym '%s': out of bounds relocation, offset %d size %u\n",
97                                module->name, relindex, i, symname,
98                                rel->r_offset, dstsec->sh_size);
99                         return -ENOEXEC;
100                 }
101
102                 loc = dstsec->sh_addr + rel->r_offset;
103
104                 switch (ELF32_R_TYPE(rel->r_info)) {
105                 case R_ARM_NONE:
106                         /* ignore */
107                         break;
108
109                 case R_ARM_ABS32:
110                 case R_ARM_TARGET1:
111                         *(u32 *)loc += sym->st_value;
112                         break;
113
114                 case R_ARM_PC24:
115                 case R_ARM_CALL:
116                 case R_ARM_JUMP24:
117                         if (sym->st_value & 3) {
118                                 pr_err("%s: section %u reloc %u sym '%s': unsupported interworking call (ARM -> Thumb)\n",
119                                        module->name, relindex, i, symname);
120                                 return -ENOEXEC;
121                         }
122
123                         offset = __mem_to_opcode_arm(*(u32 *)loc);
124                         offset = (offset & 0x00ffffff) << 2;
125                         if (offset & 0x02000000)
126                                 offset -= 0x04000000;
127
128                         offset += sym->st_value - loc;
129
130                         /*
131                          * Route through a PLT entry if 'offset' exceeds the
132                          * supported range. Note that 'offset + loc + 8'
133                          * contains the absolute jump target, i.e.,
134                          * @sym + addend, corrected for the +8 PC bias.
135                          */
136                         if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS) &&
137                             (offset <= (s32)0xfe000000 ||
138                              offset >= (s32)0x02000000))
139                                 offset = get_module_plt(module, loc,
140                                                         offset + loc + 8)
141                                          - loc - 8;
142
143                         if (offset <= (s32)0xfe000000 ||
144                             offset >= (s32)0x02000000) {
145                                 pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n",
146                                        module->name, relindex, i, symname,
147                                        ELF32_R_TYPE(rel->r_info), loc,
148                                        sym->st_value);
149                                 return -ENOEXEC;
150                         }
151
152                         offset >>= 2;
153                         offset &= 0x00ffffff;
154
155                         *(u32 *)loc &= __opcode_to_mem_arm(0xff000000);
156                         *(u32 *)loc |= __opcode_to_mem_arm(offset);
157                         break;
158
159                case R_ARM_V4BX:
160                        /* Preserve Rm and the condition code. Alter
161                         * other bits to re-code instruction as
162                         * MOV PC,Rm.
163                         */
164                        *(u32 *)loc &= __opcode_to_mem_arm(0xf000000f);
165                        *(u32 *)loc |= __opcode_to_mem_arm(0x01a0f000);
166                        break;
167
168                 case R_ARM_PREL31:
169                         offset = (*(s32 *)loc << 1) >> 1; /* sign extend */
170                         offset += sym->st_value - loc;
171                         if (offset >= 0x40000000 || offset < -0x40000000) {
172                                 pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n",
173                                        module->name, relindex, i, symname,
174                                        ELF32_R_TYPE(rel->r_info), loc,
175                                        sym->st_value);
176                                 return -ENOEXEC;
177                         }
178                         *(u32 *)loc &= 0x80000000;
179                         *(u32 *)loc |= offset & 0x7fffffff;
180                         break;
181
182                 case R_ARM_MOVW_ABS_NC:
183                 case R_ARM_MOVT_ABS:
184                         offset = tmp = __mem_to_opcode_arm(*(u32 *)loc);
185                         offset = ((offset & 0xf0000) >> 4) | (offset & 0xfff);
186                         offset = (offset ^ 0x8000) - 0x8000;
187
188                         offset += sym->st_value;
189                         if (ELF32_R_TYPE(rel->r_info) == R_ARM_MOVT_ABS)
190                                 offset >>= 16;
191
192                         tmp &= 0xfff0f000;
193                         tmp |= ((offset & 0xf000) << 4) |
194                                 (offset & 0x0fff);
195
196                         *(u32 *)loc = __opcode_to_mem_arm(tmp);
197                         break;
198
199 #ifdef CONFIG_THUMB2_KERNEL
200                 case R_ARM_THM_CALL:
201                 case R_ARM_THM_JUMP24:
202                         /*
203                          * For function symbols, only Thumb addresses are
204                          * allowed (no interworking).
205                          *
206                          * For non-function symbols, the destination
207                          * has no specific ARM/Thumb disposition, so
208                          * the branch is resolved under the assumption
209                          * that interworking is not required.
210                          */
211                         if (ELF32_ST_TYPE(sym->st_info) == STT_FUNC &&
212                             !(sym->st_value & 1)) {
213                                 pr_err("%s: section %u reloc %u sym '%s': unsupported interworking call (Thumb -> ARM)\n",
214                                        module->name, relindex, i, symname);
215                                 return -ENOEXEC;
216                         }
217
218                         upper = __mem_to_opcode_thumb16(*(u16 *)loc);
219                         lower = __mem_to_opcode_thumb16(*(u16 *)(loc + 2));
220
221                         /*
222                          * 25 bit signed address range (Thumb-2 BL and B.W
223                          * instructions):
224                          *   S:I1:I2:imm10:imm11:0
225                          * where:
226                          *   S     = upper[10]   = offset[24]
227                          *   I1    = ~(J1 ^ S)   = offset[23]
228                          *   I2    = ~(J2 ^ S)   = offset[22]
229                          *   imm10 = upper[9:0]  = offset[21:12]
230                          *   imm11 = lower[10:0] = offset[11:1]
231                          *   J1    = lower[13]
232                          *   J2    = lower[11]
233                          */
234                         sign = (upper >> 10) & 1;
235                         j1 = (lower >> 13) & 1;
236                         j2 = (lower >> 11) & 1;
237                         offset = (sign << 24) | ((~(j1 ^ sign) & 1) << 23) |
238                                 ((~(j2 ^ sign) & 1) << 22) |
239                                 ((upper & 0x03ff) << 12) |
240                                 ((lower & 0x07ff) << 1);
241                         if (offset & 0x01000000)
242                                 offset -= 0x02000000;
243                         offset += sym->st_value - loc;
244
245                         /*
246                          * Route through a PLT entry if 'offset' exceeds the
247                          * supported range.
248                          */
249                         if (IS_ENABLED(CONFIG_ARM_MODULE_PLTS) &&
250                             (offset <= (s32)0xff000000 ||
251                              offset >= (s32)0x01000000))
252                                 offset = get_module_plt(module, loc,
253                                                         offset + loc + 4)
254                                          - loc - 4;
255
256                         if (offset <= (s32)0xff000000 ||
257                             offset >= (s32)0x01000000) {
258                                 pr_err("%s: section %u reloc %u sym '%s': relocation %u out of range (%#lx -> %#x)\n",
259                                        module->name, relindex, i, symname,
260                                        ELF32_R_TYPE(rel->r_info), loc,
261                                        sym->st_value);
262                                 return -ENOEXEC;
263                         }
264
265                         sign = (offset >> 24) & 1;
266                         j1 = sign ^ (~(offset >> 23) & 1);
267                         j2 = sign ^ (~(offset >> 22) & 1);
268                         upper = (u16)((upper & 0xf800) | (sign << 10) |
269                                             ((offset >> 12) & 0x03ff));
270                         lower = (u16)((lower & 0xd000) |
271                                       (j1 << 13) | (j2 << 11) |
272                                       ((offset >> 1) & 0x07ff));
273
274                         *(u16 *)loc = __opcode_to_mem_thumb16(upper);
275                         *(u16 *)(loc + 2) = __opcode_to_mem_thumb16(lower);
276                         break;
277
278                 case R_ARM_THM_MOVW_ABS_NC:
279                 case R_ARM_THM_MOVT_ABS:
280                         upper = __mem_to_opcode_thumb16(*(u16 *)loc);
281                         lower = __mem_to_opcode_thumb16(*(u16 *)(loc + 2));
282
283                         /*
284                          * MOVT/MOVW instructions encoding in Thumb-2:
285                          *
286                          * i    = upper[10]
287                          * imm4 = upper[3:0]
288                          * imm3 = lower[14:12]
289                          * imm8 = lower[7:0]
290                          *
291                          * imm16 = imm4:i:imm3:imm8
292                          */
293                         offset = ((upper & 0x000f) << 12) |
294                                 ((upper & 0x0400) << 1) |
295                                 ((lower & 0x7000) >> 4) | (lower & 0x00ff);
296                         offset = (offset ^ 0x8000) - 0x8000;
297                         offset += sym->st_value;
298
299                         if (ELF32_R_TYPE(rel->r_info) == R_ARM_THM_MOVT_ABS)
300                                 offset >>= 16;
301
302                         upper = (u16)((upper & 0xfbf0) |
303                                       ((offset & 0xf000) >> 12) |
304                                       ((offset & 0x0800) >> 1));
305                         lower = (u16)((lower & 0x8f00) |
306                                       ((offset & 0x0700) << 4) |
307                                       (offset & 0x00ff));
308                         *(u16 *)loc = __opcode_to_mem_thumb16(upper);
309                         *(u16 *)(loc + 2) = __opcode_to_mem_thumb16(lower);
310                         break;
311 #endif
312
313                 default:
314                         pr_err("%s: unknown relocation: %u\n",
315                                module->name, ELF32_R_TYPE(rel->r_info));
316                         return -ENOEXEC;
317                 }
318         }
319         return 0;
320 }
321
322 struct mod_unwind_map {
323         const Elf_Shdr *unw_sec;
324         const Elf_Shdr *txt_sec;
325 };
326
327 static const Elf_Shdr *find_mod_section(const Elf32_Ehdr *hdr,
328         const Elf_Shdr *sechdrs, const char *name)
329 {
330         const Elf_Shdr *s, *se;
331         const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
332
333         for (s = sechdrs, se = sechdrs + hdr->e_shnum; s < se; s++)
334                 if (strcmp(name, secstrs + s->sh_name) == 0)
335                         return s;
336
337         return NULL;
338 }
339
340 extern void fixup_pv_table(const void *, unsigned long);
341 extern void fixup_smp(const void *, unsigned long);
342
343 int module_finalize(const Elf32_Ehdr *hdr, const Elf_Shdr *sechdrs,
344                     struct module *mod)
345 {
346         const Elf_Shdr *s = NULL;
347 #ifdef CONFIG_ARM_UNWIND
348         const char *secstrs = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset;
349         const Elf_Shdr *sechdrs_end = sechdrs + hdr->e_shnum;
350         struct mod_unwind_map maps[ARM_SEC_MAX];
351         int i;
352
353         memset(maps, 0, sizeof(maps));
354
355         for (s = sechdrs; s < sechdrs_end; s++) {
356                 const char *secname = secstrs + s->sh_name;
357
358                 if (!(s->sh_flags & SHF_ALLOC))
359                         continue;
360
361                 if (strcmp(".ARM.exidx.init.text", secname) == 0)
362                         maps[ARM_SEC_INIT].unw_sec = s;
363                 else if (strcmp(".ARM.exidx", secname) == 0)
364                         maps[ARM_SEC_CORE].unw_sec = s;
365                 else if (strcmp(".ARM.exidx.exit.text", secname) == 0)
366                         maps[ARM_SEC_EXIT].unw_sec = s;
367                 else if (strcmp(".ARM.exidx.text.unlikely", secname) == 0)
368                         maps[ARM_SEC_UNLIKELY].unw_sec = s;
369                 else if (strcmp(".ARM.exidx.text.hot", secname) == 0)
370                         maps[ARM_SEC_HOT].unw_sec = s;
371                 else if (strcmp(".init.text", secname) == 0)
372                         maps[ARM_SEC_INIT].txt_sec = s;
373                 else if (strcmp(".text", secname) == 0)
374                         maps[ARM_SEC_CORE].txt_sec = s;
375                 else if (strcmp(".exit.text", secname) == 0)
376                         maps[ARM_SEC_EXIT].txt_sec = s;
377                 else if (strcmp(".text.unlikely", secname) == 0)
378                         maps[ARM_SEC_UNLIKELY].txt_sec = s;
379                 else if (strcmp(".text.hot", secname) == 0)
380                         maps[ARM_SEC_HOT].txt_sec = s;
381         }
382
383         for (i = 0; i < ARM_SEC_MAX; i++)
384                 if (maps[i].unw_sec && maps[i].txt_sec)
385                         mod->arch.unwind[i] =
386                                 unwind_table_add(maps[i].unw_sec->sh_addr,
387                                                  maps[i].unw_sec->sh_size,
388                                                  maps[i].txt_sec->sh_addr,
389                                                  maps[i].txt_sec->sh_size);
390 #endif
391 #ifdef CONFIG_ARM_PATCH_PHYS_VIRT
392         s = find_mod_section(hdr, sechdrs, ".pv_table");
393         if (s)
394                 fixup_pv_table((void *)s->sh_addr, s->sh_size);
395 #endif
396         s = find_mod_section(hdr, sechdrs, ".alt.smp.init");
397         if (s && !is_smp())
398 #ifdef CONFIG_SMP_ON_UP
399                 fixup_smp((void *)s->sh_addr, s->sh_size);
400 #else
401                 return -EINVAL;
402 #endif
403         return 0;
404 }
405
406 void
407 module_arch_cleanup(struct module *mod)
408 {
409 #ifdef CONFIG_ARM_UNWIND
410         int i;
411
412         for (i = 0; i < ARM_SEC_MAX; i++)
413                 if (mod->arch.unwind[i])
414                         unwind_table_del(mod->arch.unwind[i]);
415 #endif
416 }