1 /* Kernel dynamically loadable module help for PARISC.
3 * The best reference for this stuff is probably the Processor-
4 * Specific ELF Supplement for PA-RISC:
5 * http://ftp.parisc-linux.org/docs/arch/elf-pa-hp.pdf
7 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
8 * Copyright (C) 2003 Randolph Chung <tausq at debian . org>
9 * Copyright (C) 2008 Helge Deller <deller@gmx.de>
12 * This program is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
17 * This program is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
29 * On 32bit (and sometimes 64bit) and with big kernel modules like xfs or
30 * ipv6 the relocation types R_PARISC_PCREL17F and R_PARISC_PCREL22F may
31 * fail to reach their PLT stub if we only create one big stub array for
32 * all sections at the beginning of the core or init section.
33 * Instead we now insert individual PLT stub entries directly in front of
34 * of the code sections where the stubs are actually called.
35 * This reduces the distance between the PCREL location and the stub entry
36 * so that the relocations can be fulfilled.
37 * While calculating the final layout of the kernel module in memory, the
38 * kernel module loader calls arch_mod_section_prepend() to request the
39 * to be reserved amount of memory in front of each individual section.
42 * We are not doing SEGREL32 handling correctly. According to the ABI, we
43 * should do a value offset, like this:
44 * if (in_init(me, (void *)val))
45 * val -= (uint32_t)me->init_layout.base;
47 * val -= (uint32_t)me->core_layout.base;
48 * However, SEGREL32 is used only for PARISC unwind entries, and we want
49 * those entries to have an absolute address, and not just an offset.
51 * The unwind table mechanism has the ability to specify an offset for
52 * the unwind table; however, because we split off the init functions into
53 * a different piece of memory, it is not possible to do this using a
54 * single offset. Instead, we use the above hack for now.
57 #include <linux/moduleloader.h>
58 #include <linux/elf.h>
59 #include <linux/vmalloc.h>
61 #include <linux/string.h>
62 #include <linux/kernel.h>
63 #include <linux/bug.h>
65 #include <linux/slab.h>
67 #include <asm/pgtable.h>
68 #include <asm/unwind.h>
69 #include <asm/sections.h>
74 #define DEBUGP(fmt...)
77 #define RELOC_REACHABLE(val, bits) \
78 (( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 ) || \
79 ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \
82 #define CHECK_RELOC(val, bits) \
83 if (!RELOC_REACHABLE(val, bits)) { \
84 printk(KERN_ERR "module %s relocation of symbol %s is out of range (0x%lx in %d bits)\n", \
85 me->name, strtab + sym->st_name, (unsigned long)val, bits); \
89 /* Maximum number of GOT entries. We use a long displacement ldd from
90 * the bottom of the table, which has a maximum signed displacement of
91 * 0x3fff; however, since we're only going forward, this becomes
92 * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have
93 * at most 1023 entries.
94 * To overcome this 14bit displacement with some kernel modules, we'll
95 * use instead the unusal 16bit displacement method (see reassemble_16a)
96 * which gives us a maximum positive displacement of 0x7fff, and as such
97 * allows us to allocate up to 4095 GOT entries. */
100 /* three functions to determine where in the module core
101 * or init pieces the location is */
102 static inline int in_init(struct module *me, void *loc)
104 return (loc >= me->init_layout.base &&
105 loc <= (me->init_layout.base + me->init_layout.size));
108 static inline int in_core(struct module *me, void *loc)
110 return (loc >= me->core_layout.base &&
111 loc <= (me->core_layout.base + me->core_layout.size));
114 static inline int in_local(struct module *me, void *loc)
116 return in_init(me, loc) || in_core(me, loc);
125 Elf32_Word insns[2]; /* each stub entry has two insns */
133 Elf64_Word insns[4]; /* each stub entry has four insns */
137 /* Field selection types defined by hppa */
138 #define rnd(x) (((x)+0x1000)&~0x1fff)
139 /* fsel: full 32 bits */
140 #define fsel(v,a) ((v)+(a))
141 /* lsel: select left 21 bits */
142 #define lsel(v,a) (((v)+(a))>>11)
143 /* rsel: select right 11 bits */
144 #define rsel(v,a) (((v)+(a))&0x7ff)
145 /* lrsel with rounding of addend to nearest 8k */
146 #define lrsel(v,a) (((v)+rnd(a))>>11)
147 /* rrsel with rounding of addend to nearest 8k */
148 #define rrsel(v,a) ((((v)+rnd(a))&0x7ff)+((a)-rnd(a)))
150 #define mask(x,sz) ((x) & ~((1<<(sz))-1))
153 /* The reassemble_* functions prepare an immediate value for
154 insertion into an opcode. pa-risc uses all sorts of weird bitfields
155 in the instruction to hold the value. */
156 static inline int sign_unext(int x, int len)
160 len_ones = (1 << len) - 1;
164 static inline int low_sign_unext(int x, int len)
168 sign = (x >> (len-1)) & 1;
169 temp = sign_unext(x, len-1);
170 return (temp << 1) | sign;
173 static inline int reassemble_14(int as14)
175 return (((as14 & 0x1fff) << 1) |
176 ((as14 & 0x2000) >> 13));
179 static inline int reassemble_16a(int as16)
183 /* Unusual 16-bit encoding, for wide mode only. */
184 t = (as16 << 1) & 0xffff;
186 return (t ^ s ^ (s >> 1)) | (s >> 15);
190 static inline int reassemble_17(int as17)
192 return (((as17 & 0x10000) >> 16) |
193 ((as17 & 0x0f800) << 5) |
194 ((as17 & 0x00400) >> 8) |
195 ((as17 & 0x003ff) << 3));
198 static inline int reassemble_21(int as21)
200 return (((as21 & 0x100000) >> 20) |
201 ((as21 & 0x0ffe00) >> 8) |
202 ((as21 & 0x000180) << 7) |
203 ((as21 & 0x00007c) << 14) |
204 ((as21 & 0x000003) << 12));
207 static inline int reassemble_22(int as22)
209 return (((as22 & 0x200000) >> 21) |
210 ((as22 & 0x1f0000) << 5) |
211 ((as22 & 0x00f800) << 5) |
212 ((as22 & 0x000400) >> 8) |
213 ((as22 & 0x0003ff) << 3));
216 void *module_alloc(unsigned long size)
218 /* using RWX means less protection for modules, but it's
219 * easier than trying to map the text, data, init_text and
220 * init_data correctly */
221 return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
223 PAGE_KERNEL_RWX, 0, NUMA_NO_NODE,
224 __builtin_return_address(0));
228 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
233 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
238 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
240 unsigned long cnt = 0;
242 for (; n > 0; n--, rela++)
244 switch (ELF32_R_TYPE(rela->r_info)) {
245 case R_PARISC_PCREL17F:
246 case R_PARISC_PCREL22F:
254 static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n)
256 unsigned long cnt = 0;
258 for (; n > 0; n--, rela++)
260 switch (ELF64_R_TYPE(rela->r_info)) {
261 case R_PARISC_LTOFF21L:
262 case R_PARISC_LTOFF14R:
263 case R_PARISC_PCREL22F:
271 static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n)
273 unsigned long cnt = 0;
275 for (; n > 0; n--, rela++)
277 switch (ELF64_R_TYPE(rela->r_info)) {
278 case R_PARISC_FPTR64:
286 static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n)
288 unsigned long cnt = 0;
290 for (; n > 0; n--, rela++)
292 switch (ELF64_R_TYPE(rela->r_info)) {
293 case R_PARISC_PCREL22F:
302 void module_arch_freeing_init(struct module *mod)
304 kfree(mod->arch.section);
305 mod->arch.section = NULL;
308 /* Additional bytes needed in front of individual sections */
309 unsigned int arch_mod_section_prepend(struct module *mod,
310 unsigned int section)
312 /* size needed for all stubs of this section (including
313 * one additional for correct alignment of the stubs) */
314 return (mod->arch.section[section].stub_entries + 1)
315 * sizeof(struct stub_entry);
319 int module_frob_arch_sections(CONST Elf_Ehdr *hdr,
320 CONST Elf_Shdr *sechdrs,
321 CONST char *secstrings,
324 unsigned long gots = 0, fdescs = 0, len;
327 len = hdr->e_shnum * sizeof(me->arch.section[0]);
328 me->arch.section = kzalloc(len, GFP_KERNEL);
329 if (!me->arch.section)
332 for (i = 1; i < hdr->e_shnum; i++) {
333 const Elf_Rela *rels = (void *)sechdrs[i].sh_addr;
334 unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels);
335 unsigned int count, s;
337 if (strncmp(secstrings + sechdrs[i].sh_name,
338 ".PARISC.unwind", 14) == 0)
339 me->arch.unwind_section = i;
341 if (sechdrs[i].sh_type != SHT_RELA)
344 /* some of these are not relevant for 32-bit/64-bit
345 * we leave them here to make the code common. the
346 * compiler will do its thing and optimize out the
347 * stuff we don't need
349 gots += count_gots(rels, nrels);
350 fdescs += count_fdescs(rels, nrels);
352 /* XXX: By sorting the relocs and finding duplicate entries
353 * we could reduce the number of necessary stubs and save
355 count = count_stubs(rels, nrels);
359 /* so we need relocation stubs. reserve necessary memory. */
360 /* sh_info gives the section for which we need to add stubs. */
361 s = sechdrs[i].sh_info;
363 /* each code section should only have one relocation section */
364 WARN_ON(me->arch.section[s].stub_entries);
366 /* store number of stubs we need for this section */
367 me->arch.section[s].stub_entries += count;
370 /* align things a bit */
371 me->core_layout.size = ALIGN(me->core_layout.size, 16);
372 me->arch.got_offset = me->core_layout.size;
373 me->core_layout.size += gots * sizeof(struct got_entry);
375 me->core_layout.size = ALIGN(me->core_layout.size, 16);
376 me->arch.fdesc_offset = me->core_layout.size;
377 me->core_layout.size += fdescs * sizeof(Elf_Fdesc);
379 me->arch.got_max = gots;
380 me->arch.fdesc_max = fdescs;
386 static Elf64_Word get_got(struct module *me, unsigned long value, long addend)
389 struct got_entry *got;
395 got = me->core_layout.base + me->arch.got_offset;
396 for (i = 0; got[i].addr; i++)
397 if (got[i].addr == value)
400 BUG_ON(++me->arch.got_count > me->arch.got_max);
404 DEBUGP("GOT ENTRY %d[%x] val %lx\n", i, i*sizeof(struct got_entry),
406 return i * sizeof(struct got_entry);
408 #endif /* CONFIG_64BIT */
411 static Elf_Addr get_fdesc(struct module *me, unsigned long value)
413 Elf_Fdesc *fdesc = me->core_layout.base + me->arch.fdesc_offset;
416 printk(KERN_ERR "%s: zero OPD requested!\n", me->name);
420 /* Look for existing fdesc entry. */
421 while (fdesc->addr) {
422 if (fdesc->addr == value)
423 return (Elf_Addr)fdesc;
427 BUG_ON(++me->arch.fdesc_count > me->arch.fdesc_max);
431 fdesc->gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset;
432 return (Elf_Addr)fdesc;
434 #endif /* CONFIG_64BIT */
442 static Elf_Addr get_stub(struct module *me, unsigned long value, long addend,
443 enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec)
445 struct stub_entry *stub;
446 int __maybe_unused d;
448 /* initialize stub_offset to point in front of the section */
449 if (!me->arch.section[targetsec].stub_offset) {
450 loc0 -= (me->arch.section[targetsec].stub_entries + 1) *
451 sizeof(struct stub_entry);
452 /* get correct alignment for the stubs */
453 loc0 = ALIGN(loc0, sizeof(struct stub_entry));
454 me->arch.section[targetsec].stub_offset = loc0;
457 /* get address of stub entry */
458 stub = (void *) me->arch.section[targetsec].stub_offset;
459 me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry);
461 /* do not write outside available stub area */
462 BUG_ON(0 == me->arch.section[targetsec].stub_entries--);
466 /* for 32-bit the stub looks like this:
468 * be,n R'XXX(%sr4,%r1)
470 //value = *(unsigned long *)((value + addend) & ~3); /* why? */
472 stub->insns[0] = 0x20200000; /* ldil L'XXX,%r1 */
473 stub->insns[1] = 0xe0202002; /* be,n R'XXX(%sr4,%r1) */
475 stub->insns[0] |= reassemble_21(lrsel(value, addend));
476 stub->insns[1] |= reassemble_17(rrsel(value, addend) / 4);
479 /* for 64-bit we have three kinds of stubs:
480 * for normal function calls:
492 * for direct branches (jumps between different section of the
500 d = get_got(me, value, addend);
503 stub->insns[0] = 0x0f6010db; /* ldd 0(%dp),%dp */
504 stub->insns[0] |= low_sign_unext(d, 5) << 16;
507 stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp */
508 stub->insns[0] |= reassemble_16a(d);
510 stub->insns[1] = 0x53610020; /* ldd 10(%dp),%r1 */
511 stub->insns[2] = 0xe820d000; /* bve (%r1) */
512 stub->insns[3] = 0x537b0030; /* ldd 18(%dp),%dp */
515 stub->insns[0] = 0x20200000; /* ldil 0,%r1 */
516 stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */
517 stub->insns[2] = 0x50210020; /* ldd 10(%r1),%r1 */
518 stub->insns[3] = 0xe820d002; /* bve,n (%r1) */
520 stub->insns[0] |= reassemble_21(lrsel(value, addend));
521 stub->insns[1] |= reassemble_14(rrsel(value, addend));
523 case ELF_STUB_DIRECT:
524 stub->insns[0] = 0x20200000; /* ldil 0,%r1 */
525 stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */
526 stub->insns[2] = 0xe820d002; /* bve,n (%r1) */
528 stub->insns[0] |= reassemble_21(lrsel(value, addend));
529 stub->insns[1] |= reassemble_14(rrsel(value, addend));
535 return (Elf_Addr)stub;
539 int apply_relocate_add(Elf_Shdr *sechdrs,
541 unsigned int symindex,
546 Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr;
553 unsigned int targetsec = sechdrs[relsec].sh_info;
554 //unsigned long dp = (unsigned long)$global$;
555 register unsigned long dp asm ("r27");
557 DEBUGP("Applying relocate section %u to %u\n", relsec,
559 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
560 /* This is where to make the change */
561 loc = (void *)sechdrs[targetsec].sh_addr
563 /* This is the start of the target section */
564 loc0 = sechdrs[targetsec].sh_addr;
565 /* This is the symbol it is referring to */
566 sym = (Elf32_Sym *)sechdrs[symindex].sh_addr
567 + ELF32_R_SYM(rel[i].r_info);
568 if (!sym->st_value) {
569 printk(KERN_WARNING "%s: Unknown symbol %s\n",
570 me->name, strtab + sym->st_name);
573 //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
574 dot = (Elf32_Addr)loc & ~0x03;
577 addend = rel[i].r_addend;
580 #define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t :
581 DEBUGP("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n",
582 strtab + sym->st_name,
583 (uint32_t)loc, val, addend,
597 switch (ELF32_R_TYPE(rel[i].r_info)) {
598 case R_PARISC_PLABEL32:
599 /* 32-bit function address */
600 /* no function descriptors... */
601 *loc = fsel(val, addend);
604 /* direct 32-bit ref */
605 *loc = fsel(val, addend);
607 case R_PARISC_DIR21L:
608 /* left 21 bits of effective address */
609 val = lrsel(val, addend);
610 *loc = mask(*loc, 21) | reassemble_21(val);
612 case R_PARISC_DIR14R:
613 /* right 14 bits of effective address */
614 val = rrsel(val, addend);
615 *loc = mask(*loc, 14) | reassemble_14(val);
617 case R_PARISC_SEGREL32:
618 /* 32-bit segment relative address */
619 /* See note about special handling of SEGREL32 at
620 * the beginning of this file.
622 *loc = fsel(val, addend);
624 case R_PARISC_SECREL32:
625 /* 32-bit section relative address. */
626 *loc = fsel(val, addend);
628 case R_PARISC_DPREL21L:
629 /* left 21 bit of relative address */
630 val = lrsel(val - dp, addend);
631 *loc = mask(*loc, 21) | reassemble_21(val);
633 case R_PARISC_DPREL14R:
634 /* right 14 bit of relative address */
635 val = rrsel(val - dp, addend);
636 *loc = mask(*loc, 14) | reassemble_14(val);
638 case R_PARISC_PCREL17F:
639 /* 17-bit PC relative address */
640 /* calculate direct call offset */
642 val = (val - dot - 8)/4;
643 if (!RELOC_REACHABLE(val, 17)) {
644 /* direct distance too far, create
645 * stub entry instead */
646 val = get_stub(me, sym->st_value, addend,
647 ELF_STUB_DIRECT, loc0, targetsec);
648 val = (val - dot - 8)/4;
649 CHECK_RELOC(val, 17);
651 *loc = (*loc & ~0x1f1ffd) | reassemble_17(val);
653 case R_PARISC_PCREL22F:
654 /* 22-bit PC relative address; only defined for pa20 */
655 /* calculate direct call offset */
657 val = (val - dot - 8)/4;
658 if (!RELOC_REACHABLE(val, 22)) {
659 /* direct distance too far, create
660 * stub entry instead */
661 val = get_stub(me, sym->st_value, addend,
662 ELF_STUB_DIRECT, loc0, targetsec);
663 val = (val - dot - 8)/4;
664 CHECK_RELOC(val, 22);
666 *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
668 case R_PARISC_PCREL32:
669 /* 32-bit PC relative address */
670 *loc = val - dot - 8 + addend;
674 printk(KERN_ERR "module %s: Unknown relocation: %u\n",
675 me->name, ELF32_R_TYPE(rel[i].r_info));
684 int apply_relocate_add(Elf_Shdr *sechdrs,
686 unsigned int symindex,
691 Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr;
699 unsigned int targetsec = sechdrs[relsec].sh_info;
701 DEBUGP("Applying relocate section %u to %u\n", relsec,
703 for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) {
704 /* This is where to make the change */
705 loc = (void *)sechdrs[targetsec].sh_addr
707 /* This is the start of the target section */
708 loc0 = sechdrs[targetsec].sh_addr;
709 /* This is the symbol it is referring to */
710 sym = (Elf64_Sym *)sechdrs[symindex].sh_addr
711 + ELF64_R_SYM(rel[i].r_info);
712 if (!sym->st_value) {
713 printk(KERN_WARNING "%s: Unknown symbol %s\n",
714 me->name, strtab + sym->st_name);
717 //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03;
718 dot = (Elf64_Addr)loc & ~0x03;
719 loc64 = (Elf64_Xword *)loc;
722 addend = rel[i].r_addend;
725 #define r(t) ELF64_R_TYPE(rel[i].r_info)==t ? #t :
726 printk("Symbol %s loc %p val 0x%Lx addend 0x%Lx: %s\n",
727 strtab + sym->st_name,
739 switch (ELF64_R_TYPE(rel[i].r_info)) {
740 case R_PARISC_LTOFF21L:
741 /* LT-relative; left 21 bits */
742 val = get_got(me, val, addend);
743 DEBUGP("LTOFF21L Symbol %s loc %p val %lx\n",
744 strtab + sym->st_name,
747 *loc = mask(*loc, 21) | reassemble_21(val);
749 case R_PARISC_LTOFF14R:
750 /* L(ltoff(val+addend)) */
751 /* LT-relative; right 14 bits */
752 val = get_got(me, val, addend);
754 DEBUGP("LTOFF14R Symbol %s loc %p val %lx\n",
755 strtab + sym->st_name,
757 *loc = mask(*loc, 14) | reassemble_14(val);
759 case R_PARISC_PCREL22F:
760 /* PC-relative; 22 bits */
761 DEBUGP("PCREL22F Symbol %s loc %p val %lx\n",
762 strtab + sym->st_name,
765 /* can we reach it locally? */
766 if (in_local(me, (void *)val)) {
767 /* this is the case where the symbol is local
768 * to the module, but in a different section,
769 * so stub the jump in case it's more than 22
771 val = (val - dot - 8)/4;
772 if (!RELOC_REACHABLE(val, 22)) {
773 /* direct distance too far, create
774 * stub entry instead */
775 val = get_stub(me, sym->st_value,
776 addend, ELF_STUB_DIRECT,
779 /* Ok, we can reach it directly. */
785 if (strncmp(strtab + sym->st_name, "$$", 2)
787 val = get_stub(me, val, addend, ELF_STUB_MILLI,
790 val = get_stub(me, val, addend, ELF_STUB_GOT,
793 DEBUGP("STUB FOR %s loc %lx, val %lx+%lx at %lx\n",
794 strtab + sym->st_name, loc, sym->st_value,
796 val = (val - dot - 8)/4;
797 CHECK_RELOC(val, 22);
798 *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val);
800 case R_PARISC_PCREL32:
801 /* 32-bit PC relative address */
802 *loc = val - dot - 8 + addend;
805 /* 64-bit effective address */
806 *loc64 = val + addend;
808 case R_PARISC_SEGREL32:
809 /* 32-bit segment relative address */
810 /* See note about special handling of SEGREL32 at
811 * the beginning of this file.
813 *loc = fsel(val, addend);
815 case R_PARISC_SECREL32:
816 /* 32-bit section relative address. */
817 *loc = fsel(val, addend);
819 case R_PARISC_FPTR64:
820 /* 64-bit function address */
821 if(in_local(me, (void *)(val + addend))) {
822 *loc64 = get_fdesc(me, val+addend);
823 DEBUGP("FDESC for %s at %p points to %lx\n",
824 strtab + sym->st_name, *loc64,
825 ((Elf_Fdesc *)*loc64)->addr);
827 /* if the symbol is not local to this
828 * module then val+addend is a pointer
829 * to the function descriptor */
830 DEBUGP("Non local FPTR64 Symbol %s loc %p val %lx\n",
831 strtab + sym->st_name,
833 *loc64 = val + addend;
838 printk(KERN_ERR "module %s: Unknown relocation: %Lu\n",
839 me->name, ELF64_R_TYPE(rel[i].r_info));
848 register_unwind_table(struct module *me,
849 const Elf_Shdr *sechdrs)
851 unsigned char *table, *end;
854 if (!me->arch.unwind_section)
857 table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr;
858 end = table + sechdrs[me->arch.unwind_section].sh_size;
859 gp = (Elf_Addr)me->core_layout.base + me->arch.got_offset;
861 DEBUGP("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n",
862 me->arch.unwind_section, table, end, gp);
863 me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end);
867 deregister_unwind_table(struct module *me)
870 unwind_table_remove(me->arch.unwind);
873 int module_finalize(const Elf_Ehdr *hdr,
874 const Elf_Shdr *sechdrs,
879 const char *strtab = NULL;
880 Elf_Sym *newptr, *oldptr;
881 Elf_Shdr *symhdr = NULL;
886 entry = (Elf_Fdesc *)me->init;
887 printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry,
888 entry->gp, entry->addr);
889 addr = (u32 *)entry->addr;
890 printk("INSNS: %x %x %x %x\n",
891 addr[0], addr[1], addr[2], addr[3]);
892 printk("got entries used %ld, gots max %ld\n"
893 "fdescs used %ld, fdescs max %ld\n",
894 me->arch.got_count, me->arch.got_max,
895 me->arch.fdesc_count, me->arch.fdesc_max);
898 register_unwind_table(me, sechdrs);
900 /* haven't filled in me->symtab yet, so have to find it
902 for (i = 1; i < hdr->e_shnum; i++) {
903 if(sechdrs[i].sh_type == SHT_SYMTAB
904 && (sechdrs[i].sh_flags & SHF_ALLOC)) {
905 int strindex = sechdrs[i].sh_link;
907 * The cast is to drop the const from
908 * the sechdrs pointer */
909 symhdr = (Elf_Shdr *)&sechdrs[i];
910 strtab = (char *)sechdrs[strindex].sh_addr;
915 DEBUGP("module %s: strtab %p, symhdr %p\n",
916 me->name, strtab, symhdr);
918 if(me->arch.got_count > MAX_GOTS) {
919 printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n",
920 me->name, me->arch.got_count, MAX_GOTS);
924 kfree(me->arch.section);
925 me->arch.section = NULL;
927 /* no symbol table */
931 oldptr = (void *)symhdr->sh_addr;
932 newptr = oldptr + 1; /* we start counting at 1 */
933 nsyms = symhdr->sh_size / sizeof(Elf_Sym);
934 DEBUGP("OLD num_symtab %lu\n", nsyms);
936 for (i = 1; i < nsyms; i++) {
937 oldptr++; /* note, count starts at 1 so preincrement */
938 if(strncmp(strtab + oldptr->st_name,
948 nsyms = newptr - (Elf_Sym *)symhdr->sh_addr;
949 DEBUGP("NEW num_symtab %lu\n", nsyms);
950 symhdr->sh_size = nsyms * sizeof(Elf_Sym);
954 void module_arch_cleanup(struct module *mod)
956 deregister_unwind_table(mod);
960 void *dereference_module_function_descriptor(struct module *mod, void *ptr)
962 unsigned long start_opd = (Elf64_Addr)mod->core_layout.base +
963 mod->arch.fdesc_offset;
964 unsigned long end_opd = start_opd +
965 mod->arch.fdesc_count * sizeof(Elf64_Fdesc);
967 if (ptr < (void *)start_opd || ptr >= (void *)end_opd)
970 return dereference_function_descriptor(ptr);