diff options
Diffstat (limited to 'libexec/rtld-elf/alpha/reloc.c')
| -rw-r--r-- | libexec/rtld-elf/alpha/reloc.c | 531 |
1 files changed, 0 insertions, 531 deletions
diff --git a/libexec/rtld-elf/alpha/reloc.c b/libexec/rtld-elf/alpha/reloc.c deleted file mode 100644 index 364b59a..0000000 --- a/libexec/rtld-elf/alpha/reloc.c +++ /dev/null @@ -1,531 +0,0 @@ -/*- - * Copyright 1996, 1997, 1998, 1999 John D. Polstra. - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR - * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES - * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. - * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT - * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, - * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY - * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT - * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF - * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - * - * $FreeBSD$ - */ - -/* - * Dynamic linker for ELF. - * - * John Polstra <jdp@polstra.com>. - */ - -#include <sys/param.h> -#include <sys/mman.h> - -#include <dlfcn.h> -#include <err.h> -#include <errno.h> -#include <fcntl.h> -#include <stdarg.h> -#include <stdio.h> -#include <stdlib.h> -#include <string.h> -#include <unistd.h> - -#include "debug.h" -#include "rtld.h" - -extern Elf_Dyn _GOT_END_; - -/* - * Macros for loading/storing unaligned 64-bit values. These are - * needed because relocations can point to unaligned data. This - * occurs in the DWARF2 exception frame tables generated by the - * compiler, for instance. - * - * We don't use these when relocating jump slots and GOT entries, - * since they are guaranteed to be aligned. - */ - -struct ualong { - Elf_Addr x __attribute__((packed)); -}; - -#define load64(p) (((struct ualong *)(p))->x) -#define store64(p,v) (((struct ualong *)(p))->x = (v)) - -/* Relocate a non-PLT object with addend. */ -static int -reloc_non_plt_obj(Obj_Entry *obj_rtld, Obj_Entry *obj, const Elf_Rela *rela, - SymCache *cache) -{ - Elf_Addr *where = (Elf_Addr *) (obj->relocbase + rela->r_offset); - - switch (ELF_R_TYPE(rela->r_info)) { - - case R_ALPHA_NONE: - break; - - case R_ALPHA_REFQUAD: { - const Elf_Sym *def; - const Obj_Entry *defobj; - - def = find_symdef(ELF_R_SYM(rela->r_info), obj, - &defobj, false, cache); - if (def == NULL) - return -1; - store64(where, - (Elf_Addr) (defobj->relocbase + def->st_value) + - load64(where) + rela->r_addend); - } - break; - - case R_ALPHA_GLOB_DAT: { - const Elf_Sym *def; - const Obj_Entry *defobj; - Elf_Addr val; - - def = find_symdef(ELF_R_SYM(rela->r_info), obj, - &defobj, false, cache); - if (def == NULL) - return -1; - val = (Elf_Addr) (defobj->relocbase + def->st_value + - rela->r_addend); - if (load64(where) != val) - store64(where, val); - } - break; - - case R_ALPHA_RELATIVE: { - if (obj != obj_rtld || - (caddr_t)where < (caddr_t)_GLOBAL_OFFSET_TABLE_ || - (caddr_t)where >= (caddr_t)&_GOT_END_) - store64(where, - load64(where) + (Elf_Addr) obj->relocbase); - } - break; - - case R_ALPHA_COPY: { - /* - * These are deferred until all other relocations - * have been done. All we do here is make sure - * that the COPY relocation is not in a shared - * library. They are allowed only in executable - * files. - */ - if (!obj->mainprog) { - _rtld_error("%s: Unexpected R_COPY " - " relocation in shared library", - obj->path); - return -1; - } - } - break; - - default: - _rtld_error("%s: Unsupported relocation type %u" - " in non-PLT relocations\n", obj->path, - (unsigned int)ELF_R_TYPE(rela->r_info)); - return -1; - } - return(0); -} - -/* Process the non-PLT relocations. */ -int -reloc_non_plt(Obj_Entry *obj, Obj_Entry *obj_rtld) -{ - const Elf_Rel *rellim; - const Elf_Rel *rel; - const Elf_Rela *relalim; - const Elf_Rela *rela; - SymCache *cache; - int bytes = obj->nchains * sizeof(SymCache); - int r = -1; - - /* - * The dynamic loader may be called from a thread, we have - * limited amounts of stack available so we cannot use alloca(). - */ - cache = mmap(NULL, bytes, PROT_READ|PROT_WRITE, MAP_ANON, -1, 0); - if (cache == MAP_FAILED) - cache = NULL; - - /* Perform relocations without addend if there are any: */ - rellim = (const Elf_Rel *) ((caddr_t) obj->rel + obj->relsize); - for (rel = obj->rel; obj->rel != NULL && rel < rellim; rel++) { - Elf_Rela locrela; - - locrela.r_info = rel->r_info; - locrela.r_offset = rel->r_offset; - locrela.r_addend = 0; - if (reloc_non_plt_obj(obj_rtld, obj, &locrela, cache)) - goto done; - } - - /* Perform relocations with addend if there are any: */ - relalim = (const Elf_Rela *) ((caddr_t) obj->rela + obj->relasize); - for (rela = obj->rela; obj->rela != NULL && rela < relalim; rela++) { - if (reloc_non_plt_obj(obj_rtld, obj, rela, cache)) - goto done; - } - r = 0; -done: - if (cache) - munmap(cache, bytes); - return(r); -} - -/* Process the PLT relocations. */ -int -reloc_plt(Obj_Entry *obj) -{ - /* All PLT relocations are the same kind: either Elf_Rel or Elf_Rela. */ - if (obj->pltrelsize != 0) { - const Elf_Rel *rellim; - const Elf_Rel *rel; - - rellim = (const Elf_Rel *)((char *)obj->pltrel + obj->pltrelsize); - for (rel = obj->pltrel; rel < rellim; rel++) { - Elf_Addr *where; - - assert(ELF_R_TYPE(rel->r_info) == R_ALPHA_JMP_SLOT); - - /* Relocate the GOT slot pointing into the PLT. */ - where = (Elf_Addr *)(obj->relocbase + rel->r_offset); - *where += (Elf_Addr)obj->relocbase; - } - } else { - const Elf_Rela *relalim; - const Elf_Rela *rela; - - relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize); - for (rela = obj->pltrela; rela < relalim; rela++) { - Elf_Addr *where; - - assert(ELF_R_TYPE(rela->r_info) == R_ALPHA_JMP_SLOT); - - /* Relocate the GOT slot pointing into the PLT. */ - where = (Elf_Addr *)(obj->relocbase + rela->r_offset); - *where += (Elf_Addr)obj->relocbase; - } - } - return 0; -} - -/* Relocate the jump slots in an object. */ -int -reloc_jmpslots(Obj_Entry *obj) -{ - if (obj->jmpslots_done) - return 0; - /* All PLT relocations are the same kind: either Elf_Rel or Elf_Rela. */ - if (obj->pltrelsize != 0) { - const Elf_Rel *rellim; - const Elf_Rel *rel; - - rellim = (const Elf_Rel *)((char *)obj->pltrel + obj->pltrelsize); - for (rel = obj->pltrel; rel < rellim; rel++) { - Elf_Addr *where; - const Elf_Sym *def; - const Obj_Entry *defobj; - - assert(ELF_R_TYPE(rel->r_info) == R_ALPHA_JMP_SLOT); - where = (Elf_Addr *)(obj->relocbase + rel->r_offset); - def = find_symdef(ELF_R_SYM(rel->r_info), obj, &defobj, true, - NULL); - if (def == NULL) - return -1; - reloc_jmpslot(where, - (Elf_Addr)(defobj->relocbase + def->st_value), - defobj, obj, rel); - } - } else { - const Elf_Rela *relalim; - const Elf_Rela *rela; - - relalim = (const Elf_Rela *)((char *)obj->pltrela + obj->pltrelasize); - for (rela = obj->pltrela; rela < relalim; rela++) { - Elf_Addr *where; - const Elf_Sym *def; - const Obj_Entry *defobj; - - assert(ELF_R_TYPE(rela->r_info) == R_ALPHA_JMP_SLOT); - where = (Elf_Addr *)(obj->relocbase + rela->r_offset); - def = find_symdef(ELF_R_SYM(rela->r_info), obj, &defobj, true, - NULL); - if (def == NULL) - return -1; - reloc_jmpslot(where, - (Elf_Addr)(defobj->relocbase + def->st_value), - defobj, obj, (Elf_Rel *)rela); - } - } - obj->jmpslots_done = true; - return 0; -} - -/* Fixup the jump slot at "where" to transfer control to "target". */ -Elf_Addr -reloc_jmpslot(Elf_Addr *where, Elf_Addr target, const Obj_Entry *obj, - const Obj_Entry *refobj, const Elf_Rel *rel) -{ - Elf_Addr stubaddr; - - dbg(" reloc_jmpslot: where=%p, target=%p", (void *)where, (void *)target); - stubaddr = *where; - if (stubaddr != target) { - int64_t delta; - u_int32_t inst[3]; - int instct; - Elf_Addr pc; - int64_t idisp; - u_int32_t *stubptr; - - /* Point this GOT entry directly at the target. */ - *where = target; - - /* - * There may be multiple GOT tables, each with an entry - * pointing to the stub in the PLT. But we can only find and - * fix up the first GOT entry. So we must rewrite the stub as - * well, to perform a call to the target if it is executed. - * - * When the stub gets control, register pv ($27) contains its - * address. We adjust its value so that it points to the - * target, and then jump indirect through it. - * - * Each PLT entry has room for 3 instructions. If the - * adjustment amount fits in a signed 32-bit integer, we can - * simply add it to register pv. Otherwise we must load the - * GOT entry itself into the pv register. - */ - delta = target - stubaddr; - dbg(" stubaddr=%p, where-stubaddr=%ld, delta=%ld", (void *)stubaddr, - (long)where - (long)stubaddr, (long)delta); - instct = 0; - if ((int32_t)delta == delta) { - /* - * We can adjust pv with a LDA, LDAH sequence. - * - * First build an LDA instruction to adjust the low 16 bits. - */ - inst[instct++] = 0x08 << 26 | 27 << 21 | 27 << 16 | - (delta & 0xffff); - dbg(" LDA $27,%d($27)", (int16_t)delta); - /* - * Adjust the delta to account for the effects of the LDA, - * including sign-extension. - */ - delta -= (int16_t)delta; - if (delta != 0) { - /* Build an LDAH instruction to adjust the high 16 bits. */ - inst[instct++] = 0x09 << 26 | 27 << 21 | 27 << 16 | - (delta >> 16 & 0xffff); - dbg(" LDAH $27,%d($27)", (int16_t)(delta >> 16)); - } - } else { - int64_t dhigh; - - /* We must load the GOT entry from memory. */ - delta = (Elf_Addr)where - stubaddr; - /* - * If the GOT entry is too far away from the PLT entry, - * then punt. This PLT entry will have to be looked up - * manually for all GOT entries except the first one. - * The program will still run, albeit very slowly. It's - * extremely unlikely that this case could ever arise in - * practice, but we might as well handle it correctly if - * it does. - */ - if ((int32_t)delta != delta) { - dbg(" PLT stub too far from GOT to relocate"); - return target; - } - dhigh = delta - (int16_t)delta; - if (dhigh != 0) { - /* Build an LDAH instruction to adjust the high 16 bits. */ - inst[instct++] = 0x09 << 26 | 27 << 21 | 27 << 16 | - (dhigh >> 16 & 0xffff); - dbg(" LDAH $27,%d($27)", (int16_t)(dhigh >> 16)); - } - /* Build an LDQ to load the GOT entry. */ - inst[instct++] = 0x29 << 26 | 27 << 21 | 27 << 16 | - (delta & 0xffff); - dbg(" LDQ $27,%d($27)", (int16_t)delta); - } - - /* - * Build a JMP or BR instruction to jump to the target. If - * the instruction displacement fits in a sign-extended 21-bit - * field, we can use the more efficient BR instruction. - * Otherwise we have to jump indirect through the pv register. - */ - pc = stubaddr + 4 * (instct + 1); - idisp = (int64_t)(target - pc) >> 2; - if (-0x100000 <= idisp && idisp < 0x100000) { - inst[instct++] = 0x30 << 26 | 31 << 21 | (idisp & 0x1fffff); - dbg(" BR $31,%p", (void *)target); - } else { - inst[instct++] = 0x1a << 26 | 31 << 21 | 27 << 16 | - (idisp & 0x3fff); - dbg(" JMP $31,($27),%d", (int)(idisp & 0x3fff)); - } - - /* - * Fill in the tail of the PLT entry first for reentrancy. - * Until we have overwritten the first instruction (an - * unconditional branch), the remaining instructions have no - * effect. - */ - stubptr = (u_int32_t *)stubaddr; - while (instct > 1) { - instct--; - stubptr[instct] = inst[instct]; - } - /* - * Commit the tail of the instruction sequence to memory - * before overwriting the first instruction. - */ - __asm__ __volatile__("wmb" : : : "memory"); - stubptr[0] = inst[0]; - } - - return target; -} - -/* Process an R_ALPHA_COPY relocation. */ -static int -do_copy_relocation(Obj_Entry *dstobj, const Elf_Rela *rela) -{ - void *dstaddr; - const Elf_Sym *dstsym; - const char *name; - unsigned long hash; - size_t size; - const void *srcaddr; - const Elf_Sym *srcsym; - const Ver_Entry *ve; - Obj_Entry *srcobj; - - dstaddr = (void *) (dstobj->relocbase + rela->r_offset); - dstsym = dstobj->symtab + ELF_R_SYM(rela->r_info); - name = dstobj->strtab + dstsym->st_name; - hash = elf_hash(name); - size = dstsym->st_size; - ve = fetch_ventry(dstobj, ELF_R_SYM(rela->r_info)); - - for (srcobj = dstobj->next; srcobj != NULL; srcobj = srcobj->next) - if ((srcsym = symlook_obj(name, hash, srcobj, ve, 0)) != NULL) - break; - - if (srcobj == NULL) { - _rtld_error("Undefined symbol \"%s\" referenced from COPY" - " relocation in %s", name, dstobj->path); - return -1; - } - - srcaddr = (const void *) (srcobj->relocbase + srcsym->st_value); - memcpy(dstaddr, srcaddr, size); - return 0; -} - -/* - * Process the special R_ALPHA_COPY relocations in the main program. These - * copy data from a shared object into a region in the main program's BSS - * segment. - * - * Returns 0 on success, -1 on failure. - */ -int -do_copy_relocations(Obj_Entry *dstobj) -{ - const Elf_Rel *rellim; - const Elf_Rel *rel; - const Elf_Rela *relalim; - const Elf_Rela *rela; - - assert(dstobj->mainprog); /* COPY relocations are invalid elsewhere */ - - rellim = (const Elf_Rel *) ((caddr_t) dstobj->rel + dstobj->relsize); - for (rel = dstobj->rel; dstobj->rel != NULL && rel < rellim; rel++) { - if (ELF_R_TYPE(rel->r_info) == R_ALPHA_COPY) { - Elf_Rela locrela; - - locrela.r_info = rel->r_info; - locrela.r_offset = rel->r_offset; - locrela.r_addend = 0; - if (do_copy_relocation(dstobj, &locrela)) - return -1; - } - } - - relalim = (const Elf_Rela *) ((caddr_t) dstobj->rela + - dstobj->relasize); - for (rela = dstobj->rela; dstobj->rela != NULL && rela < relalim; - rela++) { - if (ELF_R_TYPE(rela->r_info) == R_ALPHA_COPY) { - if (do_copy_relocation(dstobj, rela)) - return -1; - } - } - - return 0; -} - -/* Initialize the special PLT entries. */ -void -init_pltgot(Obj_Entry *obj) -{ - u_int32_t *pltgot; - - if (obj->pltgot != NULL && - (obj->pltrelsize != 0 || obj->pltrelasize != 0)) { - /* - * This function will be called to perform the relocation. - * Look for the ldah instruction from the old PLT format since - * that will tell us what format we are trying to relocate. - */ - pltgot = (u_int32_t *) obj->pltgot; - if ((pltgot[8] & 0xffff0000) == 0x279f0000) - obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start_old; - else - obj->pltgot[2] = (Elf_Addr) &_rtld_bind_start; - /* Identify this shared object */ - obj->pltgot[3] = (Elf_Addr) obj; - } -} - -void -allocate_initial_tls(Obj_Entry *list) -{ - void *tls; - - /* - * Fix the size of the static TLS block by using the maximum - * offset allocated so far and adding a bit for dynamic modules to - * use. - */ - tls_static_space = tls_last_offset + tls_last_size + RTLD_STATIC_TLS_EXTRA; - tls = allocate_tls(list, 0, 16, 16); - alpha_pal_wrunique((u_int64_t) tls); -} - -void *__tls_get_addr(tls_index* ti) -{ - Elf_Addr** tp = (Elf_Addr**) alpha_pal_rdunique(); - - return tls_get_addr_common(tp, ti->ti_module, ti->ti_offset); -} |
