/* Kernel dynamically loadable module help for PARISC. * * The best reference for this stuff is probably the Processor- * Specific ELF Supplement for PA-RISC: * http://ftp.parisc-linux.org/docs/arch/elf-pa-hp.pdf * * Linux/PA-RISC Project (http://www.parisc-linux.org/) * Copyright (C) 2003 Randolph Chung * Copyright (C) 2008 Helge Deller * * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA * * * Notes: * - PLT stub handling * On 32bit (and sometimes 64bit) and with big kernel modules like xfs or * ipv6 the relocation types R_PARISC_PCREL17F and R_PARISC_PCREL22F may * fail to reach their PLT stub if we only create one big stub array for * all sections at the beginning of the core or init section. * Instead we now insert individual PLT stub entries directly in front of * of the code sections where the stubs are actually called. * This reduces the distance between the PCREL location and the stub entry * so that the relocations can be fulfilled. * While calculating the final layout of the kernel module in memory, the * kernel module loader calls arch_mod_section_prepend() to request the * to be reserved amount of memory in front of each individual section. * * - SEGREL32 handling * We are not doing SEGREL32 handling correctly. According to the ABI, we * should do a value offset, like this: * if (in_init(me, (void *)val)) * val -= (uint32_t)me->module_init; * else * val -= (uint32_t)me->module_core; * However, SEGREL32 is used only for PARISC unwind entries, and we want * those entries to have an absolute address, and not just an offset. * * The unwind table mechanism has the ability to specify an offset for * the unwind table; however, because we split off the init functions into * a different piece of memory, it is not possible to do this using a * single offset. Instead, we use the above hack for now. */ #include #include #include #include #include #include #include #include #include #include #if 0 #define DEBUGP printk #else #define DEBUGP(fmt...) #endif #define RELOC_REACHABLE(val, bits) \ (( ( !((val) & (1<<((bits)-1))) && ((val)>>(bits)) != 0 ) || \ ( ((val) & (1<<((bits)-1))) && ((val)>>(bits)) != (((__typeof__(val))(~0))>>((bits)+2)))) ? \ 0 : 1) #define CHECK_RELOC(val, bits) \ if (!RELOC_REACHABLE(val, bits)) { \ printk(KERN_ERR "module %s relocation of symbol %s is out of range (0x%lx in %d bits)\n", \ me->name, strtab + sym->st_name, (unsigned long)val, bits); \ return -ENOEXEC; \ } /* Maximum number of GOT entries. We use a long displacement ldd from * the bottom of the table, which has a maximum signed displacement of * 0x3fff; however, since we're only going forward, this becomes * 0x1fff, and thus, since each GOT entry is 8 bytes long we can have * at most 1023 entries */ #define MAX_GOTS 1023 /* three functions to determine where in the module core * or init pieces the location is */ static inline int in_init(struct module *me, void *loc) { return (loc >= me->module_init && loc <= (me->module_init + me->init_size)); } static inline int in_core(struct module *me, void *loc) { return (loc >= me->module_core && loc <= (me->module_core + me->core_size)); } static inline int in_local(struct module *me, void *loc) { return in_init(me, loc) || in_core(me, loc); } #ifndef CONFIG_64BIT struct got_entry { Elf32_Addr addr; }; #define Elf_Fdesc Elf32_Fdesc struct stub_entry { Elf32_Word insns[2]; /* each stub entry has two insns */ }; #else struct got_entry { Elf64_Addr addr; }; #define Elf_Fdesc Elf64_Fdesc struct stub_entry { Elf64_Word insns[4]; /* each stub entry has four insns */ }; #endif /* Field selection types defined by hppa */ #define rnd(x) (((x)+0x1000)&~0x1fff) /* fsel: full 32 bits */ #define fsel(v,a) ((v)+(a)) /* lsel: select left 21 bits */ #define lsel(v,a) (((v)+(a))>>11) /* rsel: select right 11 bits */ #define rsel(v,a) (((v)+(a))&0x7ff) /* lrsel with rounding of addend to nearest 8k */ #define lrsel(v,a) (((v)+rnd(a))>>11) /* rrsel with rounding of addend to nearest 8k */ #define rrsel(v,a) ((((v)+rnd(a))&0x7ff)+((a)-rnd(a))) #define mask(x,sz) ((x) & ~((1<<(sz))-1)) /* The reassemble_* functions prepare an immediate value for insertion into an opcode. pa-risc uses all sorts of weird bitfields in the instruction to hold the value. */ static inline int reassemble_14(int as14) { return (((as14 & 0x1fff) << 1) | ((as14 & 0x2000) >> 13)); } static inline int reassemble_17(int as17) { return (((as17 & 0x10000) >> 16) | ((as17 & 0x0f800) << 5) | ((as17 & 0x00400) >> 8) | ((as17 & 0x003ff) << 3)); } static inline int reassemble_21(int as21) { return (((as21 & 0x100000) >> 20) | ((as21 & 0x0ffe00) >> 8) | ((as21 & 0x000180) << 7) | ((as21 & 0x00007c) << 14) | ((as21 & 0x000003) << 12)); } static inline int reassemble_22(int as22) { return (((as22 & 0x200000) >> 21) | ((as22 & 0x1f0000) << 5) | ((as22 & 0x00f800) << 5) | ((as22 & 0x000400) >> 8) | ((as22 & 0x0003ff) << 3)); } void *module_alloc(unsigned long size) { if (size == 0) return NULL; return vmalloc(size); } #ifndef CONFIG_64BIT static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n) { return 0; } static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n) { return 0; } static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n) { unsigned long cnt = 0; for (; n > 0; n--, rela++) { switch (ELF32_R_TYPE(rela->r_info)) { case R_PARISC_PCREL17F: case R_PARISC_PCREL22F: cnt++; } } return cnt; } #else static inline unsigned long count_gots(const Elf_Rela *rela, unsigned long n) { unsigned long cnt = 0; for (; n > 0; n--, rela++) { switch (ELF64_R_TYPE(rela->r_info)) { case R_PARISC_LTOFF21L: case R_PARISC_LTOFF14R: case R_PARISC_PCREL22F: cnt++; } } return cnt; } static inline unsigned long count_fdescs(const Elf_Rela *rela, unsigned long n) { unsigned long cnt = 0; for (; n > 0; n--, rela++) { switch (ELF64_R_TYPE(rela->r_info)) { case R_PARISC_FPTR64: cnt++; } } return cnt; } static inline unsigned long count_stubs(const Elf_Rela *rela, unsigned long n) { unsigned long cnt = 0; for (; n > 0; n--, rela++) { switch (ELF64_R_TYPE(rela->r_info)) { case R_PARISC_PCREL22F: cnt++; } } return cnt; } #endif /* Free memory returned from module_alloc */ void module_free(struct module *mod, void *module_region) { kfree(mod->arch.section); mod->arch.section = NULL; vfree(module_region); /* FIXME: If module_region == mod->init_region, trim exception table entries. */ } /* Additional bytes needed in front of individual sections */ unsigned int arch_mod_section_prepend(struct module *mod, unsigned int section) { /* size needed for all stubs of this section (including * one additional for correct alignment of the stubs) */ return (mod->arch.section[section].stub_entries + 1) * sizeof(struct stub_entry); } #define CONST int module_frob_arch_sections(CONST Elf_Ehdr *hdr, CONST Elf_Shdr *sechdrs, CONST char *secstrings, struct module *me) { unsigned long gots = 0, fdescs = 0, len; unsigned int i; len = hdr->e_shnum * sizeof(me->arch.section[0]); me->arch.section = kzalloc(len, GFP_KERNEL); if (!me->arch.section) return -ENOMEM; for (i = 1; i < hdr->e_shnum; i++) { const Elf_Rela *rels = (void *)sechdrs[i].sh_addr; unsigned long nrels = sechdrs[i].sh_size / sizeof(*rels); unsigned int count, s; if (strncmp(secstrings + sechdrs[i].sh_name, ".PARISC.unwind", 14) == 0) me->arch.unwind_section = i; if (sechdrs[i].sh_type != SHT_RELA) continue; /* some of these are not relevant for 32-bit/64-bit * we leave them here to make the code common. the * compiler will do its thing and optimize out the * stuff we don't need */ gots += count_gots(rels, nrels); fdescs += count_fdescs(rels, nrels); /* XXX: By sorting the relocs and finding duplicate entries * we could reduce the number of necessary stubs and save * some memory. */ count = count_stubs(rels, nrels); if (!count) continue; /* so we need relocation stubs. reserve necessary memory. */ /* sh_info gives the section for which we need to add stubs. */ s = sechdrs[i].sh_info; /* each code section should only have one relocation section */ WARN_ON(me->arch.section[s].stub_entries); /* store number of stubs we need for this section */ me->arch.section[s].stub_entries += count; } /* align things a bit */ me->core_size = ALIGN(me->core_size, 16); me->arch.got_offset = me->core_size; me->core_size += gots * sizeof(struct got_entry); me->core_size = ALIGN(me->core_size, 16); me->arch.fdesc_offset = me->core_size; me->core_size += fdescs * sizeof(Elf_Fdesc); me->arch.got_max = gots; me->arch.fdesc_max = fdescs; return 0; } #ifdef CONFIG_64BIT static Elf64_Word get_got(struct module *me, unsigned long value, long addend) { unsigned int i; struct got_entry *got; value += addend; BUG_ON(value == 0); got = me->module_core + me->arch.got_offset; for (i = 0; got[i].addr; i++) if (got[i].addr == value) goto out; BUG_ON(++me->arch.got_count > me->arch.got_max); got[i].addr = value; out: DEBUGP("GOT ENTRY %d[%x] val %lx\n", i, i*sizeof(struct got_entry), value); return i * sizeof(struct got_entry); } #endif /* CONFIG_64BIT */ #ifdef CONFIG_64BIT static Elf_Addr get_fdesc(struct module *me, unsigned long value) { Elf_Fdesc *fdesc = me->module_core + me->arch.fdesc_offset; if (!value) { printk(KERN_ERR "%s: zero OPD requested!\n", me->name); return 0; } /* Look for existing fdesc entry. */ while (fdesc->addr) { if (fdesc->addr == value) return (Elf_Addr)fdesc; fdesc++; } BUG_ON(++me->arch.fdesc_count > me->arch.fdesc_max); /* Create new one */ fdesc->addr = value; fdesc->gp = (Elf_Addr)me->module_core + me->arch.got_offset; return (Elf_Addr)fdesc; } #endif /* CONFIG_64BIT */ enum elf_stub_type { ELF_STUB_GOT, ELF_STUB_MILLI, ELF_STUB_DIRECT, }; static Elf_Addr get_stub(struct module *me, unsigned long value, long addend, enum elf_stub_type stub_type, Elf_Addr loc0, unsigned int targetsec) { struct stub_entry *stub; /* initialize stub_offset to point in front of the section */ if (!me->arch.section[targetsec].stub_offset) { loc0 -= (me->arch.section[targetsec].stub_entries + 1) * sizeof(struct stub_entry); /* get correct alignment for the stubs */ loc0 = ALIGN(loc0, sizeof(struct stub_entry)); me->arch.section[targetsec].stub_offset = loc0; } /* get address of stub entry */ stub = (void *) me->arch.section[targetsec].stub_offset; me->arch.section[targetsec].stub_offset += sizeof(struct stub_entry); /* do not write outside available stub area */ BUG_ON(0 == me->arch.section[targetsec].stub_entries--); #ifndef CONFIG_64BIT /* for 32-bit the stub looks like this: * ldil L'XXX,%r1 * be,n R'XXX(%sr4,%r1) */ //value = *(unsigned long *)((value + addend) & ~3); /* why? */ stub->insns[0] = 0x20200000; /* ldil L'XXX,%r1 */ stub->insns[1] = 0xe0202002; /* be,n R'XXX(%sr4,%r1) */ stub->insns[0] |= reassemble_21(lrsel(value, addend)); stub->insns[1] |= reassemble_17(rrsel(value, addend) / 4); #else /* for 64-bit we have three kinds of stubs: * for normal function calls: * ldd 0(%dp),%dp * ldd 10(%dp), %r1 * bve (%r1) * ldd 18(%dp), %dp * * for millicode: * ldil 0, %r1 * ldo 0(%r1), %r1 * ldd 10(%r1), %r1 * bve,n (%r1) * * for direct branches (jumps between different section of the * same module): * ldil 0, %r1 * ldo 0(%r1), %r1 * bve,n (%r1) */ switch (stub_type) { case ELF_STUB_GOT: stub->insns[0] = 0x537b0000; /* ldd 0(%dp),%dp */ stub->insns[1] = 0x53610020; /* ldd 10(%dp),%r1 */ stub->insns[2] = 0xe820d000; /* bve (%r1) */ stub->insns[3] = 0x537b0030; /* ldd 18(%dp),%dp */ stub->insns[0] |= reassemble_14(get_got(me, value, addend) & 0x3fff); break; case ELF_STUB_MILLI: stub->insns[0] = 0x20200000; /* ldil 0,%r1 */ stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */ stub->insns[2] = 0x50210020; /* ldd 10(%r1),%r1 */ stub->insns[3] = 0xe820d002; /* bve,n (%r1) */ stub->insns[0] |= reassemble_21(lrsel(value, addend)); stub->insns[1] |= reassemble_14(rrsel(value, addend)); break; case ELF_STUB_DIRECT: stub->insns[0] = 0x20200000; /* ldil 0,%r1 */ stub->insns[1] = 0x34210000; /* ldo 0(%r1), %r1 */ stub->insns[2] = 0xe820d002; /* bve,n (%r1) */ stub->insns[0] |= reassemble_21(lrsel(value, addend)); stub->insns[1] |= reassemble_14(rrsel(value, addend)); break; } #endif return (Elf_Addr)stub; } int apply_relocate(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *me) { /* parisc should not need this ... */ printk(KERN_ERR "module %s: RELOCATION unsupported\n", me->name); return -ENOEXEC; } #ifndef CONFIG_64BIT int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *me) { int i; Elf32_Rela *rel = (void *)sechdrs[relsec].sh_addr; Elf32_Sym *sym; Elf32_Word *loc; Elf32_Addr val; Elf32_Sword addend; Elf32_Addr dot; Elf_Addr loc0; unsigned int targetsec = sechdrs[relsec].sh_info; //unsigned long dp = (unsigned long)$global$; register unsigned long dp asm ("r27"); DEBUGP("Applying relocate section %u to %u\n", relsec, targetsec); for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { /* This is where to make the change */ loc = (void *)sechdrs[targetsec].sh_addr + rel[i].r_offset; /* This is the start of the target section */ loc0 = sechdrs[targetsec].sh_addr; /* This is the symbol it is referring to */ sym = (Elf32_Sym *)sechdrs[symindex].sh_addr + ELF32_R_SYM(rel[i].r_info); if (!sym->st_value) { printk(KERN_WARNING "%s: Unknown symbol %s\n", me->name, strtab + sym->st_name); return -ENOENT; } //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03; dot = (Elf32_Addr)loc & ~0x03; val = sym->st_value; addend = rel[i].r_addend; #if 0 #define r(t) ELF32_R_TYPE(rel[i].r_info)==t ? #t : DEBUGP("Symbol %s loc 0x%x val 0x%x addend 0x%x: %s\n", strtab + sym->st_name, (uint32_t)loc, val, addend, r(R_PARISC_PLABEL32) r(R_PARISC_DIR32) r(R_PARISC_DIR21L) r(R_PARISC_DIR14R) r(R_PARISC_SEGREL32) r(R_PARISC_DPREL21L) r(R_PARISC_DPREL14R) r(R_PARISC_PCREL17F) r(R_PARISC_PCREL22F) "UNKNOWN"); #undef r #endif switch (ELF32_R_TYPE(rel[i].r_info)) { case R_PARISC_PLABEL32: /* 32-bit function address */ /* no function descriptors... */ *loc = fsel(val, addend); break; case R_PARISC_DIR32: /* direct 32-bit ref */ *loc = fsel(val, addend); break; case R_PARISC_DIR21L: /* left 21 bits of effective address */ val = lrsel(val, addend); *loc = mask(*loc, 21) | reassemble_21(val); break; case R_PARISC_DIR14R: /* right 14 bits of effective address */ val = rrsel(val, addend); *loc = mask(*loc, 14) | reassemble_14(val); break; case R_PARISC_SEGREL32: /* 32-bit segment relative address */ /* See note about special handling of SEGREL32 at * the beginning of this file. */ *loc = fsel(val, addend); break; case R_PARISC_DPREL21L: /* left 21 bit of relative address */ val = lrsel(val - dp, addend); *loc = mask(*loc, 21) | reassemble_21(val); break; case R_PARISC_DPREL14R: /* right 14 bit of relative address */ val = rrsel(val - dp, addend); *loc = mask(*loc, 14) | reassemble_14(val); break; case R_PARISC_PCREL17F: /* 17-bit PC relative address */ /* calculate direct call offset */ val += addend; val = (val - dot - 8)/4; if (!RELOC_REACHABLE(val, 17)) { /* direct distance too far, create * stub entry instead */ val = get_stub(me, sym->st_value, addend, ELF_STUB_DIRECT, loc0, targetsec); val = (val - dot - 8)/4; CHECK_RELOC(val, 17); } *loc = (*loc & ~0x1f1ffd) | reassemble_17(val); break; case R_PARISC_PCREL22F: /* 22-bit PC relative address; only defined for pa20 */ /* calculate direct call offset */ val += addend; val = (val - dot - 8)/4; if (!RELOC_REACHABLE(val, 22)) { /* direct distance too far, create * stub entry instead */ val = get_stub(me, sym->st_value, addend, ELF_STUB_DIRECT, loc0, targetsec); val = (val - dot - 8)/4; CHECK_RELOC(val, 22); } *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val); break; default: printk(KERN_ERR "module %s: Unknown relocation: %u\n", me->name, ELF32_R_TYPE(rel[i].r_info)); return -ENOEXEC; } } return 0; } #else int apply_relocate_add(Elf_Shdr *sechdrs, const char *strtab, unsigned int symindex, unsigned int relsec, struct module *me) { int i; Elf64_Rela *rel = (void *)sechdrs[relsec].sh_addr; Elf64_Sym *sym; Elf64_Word *loc; Elf64_Xword *loc64; Elf64_Addr val; Elf64_Sxword addend; Elf64_Addr dot; Elf_Addr loc0; unsigned int targetsec = sechdrs[relsec].sh_info; DEBUGP("Applying relocate section %u to %u\n", relsec, targetsec); for (i = 0; i < sechdrs[relsec].sh_size / sizeof(*rel); i++) { /* This is where to make the change */ loc = (void *)sechdrs[targetsec].sh_addr + rel[i].r_offset; /* This is the start of the target section */ loc0 = sechdrs[targetsec].sh_addr; /* This is the symbol it is referring to */ sym = (Elf64_Sym *)sechdrs[symindex].sh_addr + ELF64_R_SYM(rel[i].r_info); if (!sym->st_value) { printk(KERN_WARNING "%s: Unknown symbol %s\n", me->name, strtab + sym->st_name); return -ENOENT; } //dot = (sechdrs[relsec].sh_addr + rel->r_offset) & ~0x03; dot = (Elf64_Addr)loc & ~0x03; loc64 = (Elf64_Xword *)loc; val = sym->st_value; addend = rel[i].r_addend; #if 0 #define r(t) ELF64_R_TYPE(rel[i].r_info)==t ? #t : printk("Symbol %s loc %p val 0x%Lx addend 0x%Lx: %s\n", strtab + sym->st_name, loc, val, addend, r(R_PARISC_LTOFF14R) r(R_PARISC_LTOFF21L) r(R_PARISC_PCREL22F) r(R_PARISC_DIR64) r(R_PARISC_SEGREL32) r(R_PARISC_FPTR64) "UNKNOWN"); #undef r #endif switch (ELF64_R_TYPE(rel[i].r_info)) { case R_PARISC_LTOFF21L: /* LT-relative; left 21 bits */ val = get_got(me, val, addend); DEBUGP("LTOFF21L Symbol %s loc %p val %lx\n", strtab + sym->st_name, loc, val); val = lrsel(val, 0); *loc = mask(*loc, 21) | reassemble_21(val); break; case R_PARISC_LTOFF14R: /* L(ltoff(val+addend)) */ /* LT-relative; right 14 bits */ val = get_got(me, val, addend); val = rrsel(val, 0); DEBUGP("LTOFF14R Symbol %s loc %p val %lx\n", strtab + sym->st_name, loc, val); *loc = mask(*loc, 14) | reassemble_14(val); break; case R_PARISC_PCREL22F: /* PC-relative; 22 bits */ DEBUGP("PCREL22F Symbol %s loc %p val %lx\n", strtab + sym->st_name, loc, val); val += addend; /* can we reach it locally? */ if (in_local(me, (void *)val)) { /* this is the case where the symbol is local * to the module, but in a different section, * so stub the jump in case it's more than 22 * bits away */ val = (val - dot - 8)/4; if (!RELOC_REACHABLE(val, 22)) { /* direct distance too far, create * stub entry instead */ val = get_stub(me, sym->st_value, addend, ELF_STUB_DIRECT, loc0, targetsec); } else { /* Ok, we can reach it directly. */ val = sym->st_value; val += addend; } } else { val = sym->st_value; if (strncmp(strtab + sym->st_name, "$$", 2) == 0) val = get_stub(me, val, addend, ELF_STUB_MILLI, loc0, targetsec); else val = get_stub(me, val, addend, ELF_STUB_GOT, loc0, targetsec); } DEBUGP("STUB FOR %s loc %lx, val %lx+%lx at %lx\n", strtab + sym->st_name, loc, sym->st_value, addend, val); val = (val - dot - 8)/4; CHECK_RELOC(val, 22); *loc = (*loc & ~0x3ff1ffd) | reassemble_22(val); break; case R_PARISC_DIR64: /* 64-bit effective address */ *loc64 = val + addend; break; case R_PARISC_SEGREL32: /* 32-bit segment relative address */ /* See note about special handling of SEGREL32 at * the beginning of this file. */ *loc = fsel(val, addend); break; case R_PARISC_FPTR64: /* 64-bit function address */ if(in_local(me, (void *)(val + addend))) { *loc64 = get_fdesc(me, val+addend); DEBUGP("FDESC for %s at %p points to %lx\n", strtab + sym->st_name, *loc64, ((Elf_Fdesc *)*loc64)->addr); } else { /* if the symbol is not local to this * module then val+addend is a pointer * to the function descriptor */ DEBUGP("Non local FPTR64 Symbol %s loc %p val %lx\n", strtab + sym->st_name, loc, val); *loc64 = val + addend; } break; default: printk(KERN_ERR "module %s: Unknown relocation: %Lu\n", me->name, ELF64_R_TYPE(rel[i].r_info)); return -ENOEXEC; } } return 0; } #endif static void register_unwind_table(struct module *me, const Elf_Shdr *sechdrs) { unsigned char *table, *end; unsigned long gp; if (!me->arch.unwind_section) return; table = (unsigned char *)sechdrs[me->arch.unwind_section].sh_addr; end = table + sechdrs[me->arch.unwind_section].sh_size; gp = (Elf_Addr)me->module_core + me->arch.got_offset; DEBUGP("register_unwind_table(), sect = %d at 0x%p - 0x%p (gp=0x%lx)\n", me->arch.unwind_section, table, end, gp); me->arch.unwind = unwind_table_add(me->name, 0, gp, table, end); } static void deregister_unwind_table(struct module *me) { if (me->arch.unwind) unwind_table_remove(me->arch.unwind); } int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me) { int i; unsigned long nsyms; const char *strtab = NULL; Elf_Sym *newptr, *oldptr; Elf_Shdr *symhdr = NULL; #ifdef DEBUG Elf_Fdesc *entry; u32 *addr; entry = (Elf_Fdesc *)me->init; printk("FINALIZE, ->init FPTR is %p, GP %lx ADDR %lx\n", entry, entry->gp, entry->addr); addr = (u32 *)entry->addr; printk("INSNS: %x %x %x %x\n", addr[0], addr[1], addr[2], addr[3]); printk("got entries used %ld, gots max %ld\n" "fdescs used %ld, fdescs max %ld\n", me->arch.got_count, me->arch.got_max, me->arch.fdesc_count, me->arch.fdesc_max); #endif register_unwind_table(me, sechdrs); /* haven't filled in me->symtab yet, so have to find it * ourselves */ for (i = 1; i < hdr->e_shnum; i++) { if(sechdrs[i].sh_type == SHT_SYMTAB && (sechdrs[i].sh_type & SHF_ALLOC)) { int strindex = sechdrs[i].sh_link; /* FIXME: AWFUL HACK * The cast is to drop the const from * the sechdrs pointer */ symhdr = (Elf_Shdr *)&sechdrs[i]; strtab = (char *)sechdrs[strindex].sh_addr; break; } } DEBUGP("module %s: strtab %p, symhdr %p\n", me->name, strtab, symhdr); if(me->arch.got_count > MAX_GOTS) { printk(KERN_ERR "%s: Global Offset Table overflow (used %ld, allowed %d)\n", me->name, me->arch.got_count, MAX_GOTS); return -EINVAL; } kfree(me->arch.section); me->arch.section = NULL; /* no symbol table */ if(symhdr == NULL) return 0; oldptr = (void *)symhdr->sh_addr; newptr = oldptr + 1; /* we start counting at 1 */ nsyms = symhdr->sh_size / sizeof(Elf_Sym); DEBUGP("OLD num_symtab %lu\n", nsyms); for (i = 1; i < nsyms; i++) { oldptr++; /* note, count starts at 1 so preincrement */ if(strncmp(strtab + oldptr->st_name, ".L", 2) == 0) continue; if(newptr != oldptr) *newptr++ = *oldptr; else newptr++; } nsyms = newptr - (Elf_Sym *)symhdr->sh_addr; DEBUGP("NEW num_symtab %lu\n", nsyms); symhdr->sh_size = nsyms * sizeof(Elf_Sym); return module_bug_finalize(hdr, sechdrs, me); } void module_arch_cleanup(struct module *mod) { deregister_unwind_table(mod); module_bug_cleanup(mod); } #ifdef CONFIG_64BIT void *dereference_function_descriptor(void *ptr) { Elf64_Fdesc *desc = ptr; void *p; if (!probe_kernel_address(&desc->addr, p)) ptr = p; return ptr; } #endif