elf_machdep.c revision 279211
1/*- 2 * Copyright 1996-1998 John D. Polstra. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#include <sys/cdefs.h> 27__FBSDID("$FreeBSD: stable/10/sys/i386/i386/elf_machdep.c 279211 2015-02-23 18:38:41Z jhb $"); 28 29#include "opt_cpu.h" 30 31#include <sys/param.h> 32#include <sys/kernel.h> 33#include <sys/systm.h> 34#include <sys/exec.h> 35#include <sys/imgact.h> 36#include <sys/linker.h> 37#include <sys/proc.h> 38#include <sys/sysent.h> 39#include <sys/imgact_elf.h> 40#include <sys/syscall.h> 41#include <sys/signalvar.h> 42#include <sys/vnode.h> 43 44#include <vm/vm.h> 45#include <vm/pmap.h> 46#include <vm/vm_param.h> 47 48#include <machine/elf.h> 49#include <machine/md_var.h> 50#include <machine/npx.h> 51 52#if !defined(CPU_DISABLE_SSE) && defined(I686_CPU) 53#define CPU_ENABLE_SSE 54#endif 55 56struct sysentvec elf32_freebsd_sysvec = { 57 .sv_size = SYS_MAXSYSCALL, 58 .sv_table = sysent, 59 .sv_mask = 0, 60 .sv_sigsize = 0, 61 .sv_sigtbl = NULL, 62 .sv_errsize = 0, 63 .sv_errtbl = NULL, 64 .sv_transtrap = NULL, 65 .sv_fixup = __elfN(freebsd_fixup), 66 .sv_sendsig = sendsig, 67 .sv_sigcode = sigcode, 68 .sv_szsigcode = &szsigcode, 69 .sv_prepsyscall = NULL, 70 .sv_name = "FreeBSD ELF32", 71 .sv_coredump = __elfN(coredump), 72 .sv_imgact_try = NULL, 73 .sv_minsigstksz = MINSIGSTKSZ, 74 .sv_pagesize = PAGE_SIZE, 75 .sv_minuser = VM_MIN_ADDRESS, 76 .sv_maxuser = VM_MAXUSER_ADDRESS, 77 .sv_usrstack = USRSTACK, 78 .sv_psstrings = PS_STRINGS, 79 .sv_stackprot = VM_PROT_ALL, 80 .sv_copyout_strings = exec_copyout_strings, 81 .sv_setregs = exec_setregs, 82 .sv_fixlimit = NULL, 83 .sv_maxssiz = NULL, 84 .sv_flags = SV_ABI_FREEBSD | SV_IA32 | SV_ILP32 | SV_SHP, 85 .sv_set_syscall_retval = cpu_set_syscall_retval, 86 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 87 .sv_syscallnames = syscallnames, 88 .sv_shared_page_base = SHAREDPAGE, 89 .sv_shared_page_len = PAGE_SIZE, 90 .sv_schedtail = NULL, 91}; 92INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 93 94static Elf32_Brandinfo freebsd_brand_info = { 95 .brand = ELFOSABI_FREEBSD, 96 .machine = EM_386, 97 .compat_3_brand = "FreeBSD", 98 .emul_path = NULL, 99 .interp_path = "/libexec/ld-elf.so.1", 100 .sysvec = &elf32_freebsd_sysvec, 101 .interp_newpath = NULL, 102 .brand_note = &elf32_freebsd_brandnote, 103 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 104}; 105 106SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 107 (sysinit_cfunc_t) elf32_insert_brand_entry, 108 &freebsd_brand_info); 109 110static Elf32_Brandinfo freebsd_brand_oinfo = { 111 .brand = ELFOSABI_FREEBSD, 112 .machine = EM_386, 113 .compat_3_brand = "FreeBSD", 114 .emul_path = NULL, 115 .interp_path = "/usr/libexec/ld-elf.so.1", 116 .sysvec = &elf32_freebsd_sysvec, 117 .interp_newpath = NULL, 118 .brand_note = &elf32_freebsd_brandnote, 119 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 120}; 121 122SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY, 123 (sysinit_cfunc_t) elf32_insert_brand_entry, 124 &freebsd_brand_oinfo); 125 126static Elf32_Brandinfo kfreebsd_brand_info = { 127 .brand = ELFOSABI_FREEBSD, 128 .machine = EM_386, 129 .compat_3_brand = "FreeBSD", 130 .emul_path = NULL, 131 .interp_path = "/lib/ld.so.1", 132 .sysvec = &elf32_freebsd_sysvec, 133 .interp_newpath = NULL, 134 .brand_note = &elf32_kfreebsd_brandnote, 135 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY 136}; 137 138SYSINIT(kelf32, SI_SUB_EXEC, SI_ORDER_ANY, 139 (sysinit_cfunc_t) elf32_insert_brand_entry, 140 &kfreebsd_brand_info); 141 142 143void 144elf32_dump_thread(struct thread *td, void *dst, size_t *off) 145{ 146#ifdef CPU_ENABLE_SSE 147 void *buf; 148#endif 149 size_t len; 150 151 len = 0; 152#ifdef CPU_ENABLE_SSE 153 if (use_xsave) { 154 if (dst != NULL) { 155 npxgetregs(td); 156 len += elf32_populate_note(NT_X86_XSTATE, 157 get_pcb_user_save_td(td), dst, 158 cpu_max_ext_state_size, &buf); 159 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) = 160 xsave_mask; 161 } else 162 len += elf32_populate_note(NT_X86_XSTATE, NULL, NULL, 163 cpu_max_ext_state_size, NULL); 164 } 165#endif 166 *off = len; 167} 168 169/* Process one elf relocation with addend. */ 170static int 171elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 172 int type, int local, elf_lookup_fn lookup) 173{ 174 Elf_Addr *where; 175 Elf_Addr addr; 176 Elf_Addr addend; 177 Elf_Word rtype, symidx; 178 const Elf_Rel *rel; 179 const Elf_Rela *rela; 180 181 switch (type) { 182 case ELF_RELOC_REL: 183 rel = (const Elf_Rel *)data; 184 where = (Elf_Addr *) (relocbase + rel->r_offset); 185 addend = *where; 186 rtype = ELF_R_TYPE(rel->r_info); 187 symidx = ELF_R_SYM(rel->r_info); 188 break; 189 case ELF_RELOC_RELA: 190 rela = (const Elf_Rela *)data; 191 where = (Elf_Addr *) (relocbase + rela->r_offset); 192 addend = rela->r_addend; 193 rtype = ELF_R_TYPE(rela->r_info); 194 symidx = ELF_R_SYM(rela->r_info); 195 break; 196 default: 197 panic("unknown reloc type %d\n", type); 198 } 199 200 if (local) { 201 if (rtype == R_386_RELATIVE) { /* A + B */ 202 addr = elf_relocaddr(lf, relocbase + addend); 203 if (*where != addr) 204 *where = addr; 205 } 206 return (0); 207 } 208 209 switch (rtype) { 210 211 case R_386_NONE: /* none */ 212 break; 213 214 case R_386_32: /* S + A */ 215 addr = lookup(lf, symidx, 1); 216 if (addr == 0) 217 return -1; 218 addr += addend; 219 if (*where != addr) 220 *where = addr; 221 break; 222 223 case R_386_PC32: /* S + A - P */ 224 addr = lookup(lf, symidx, 1); 225 if (addr == 0) 226 return -1; 227 addr += addend - (Elf_Addr)where; 228 if (*where != addr) 229 *where = addr; 230 break; 231 232 case R_386_COPY: /* none */ 233 /* 234 * There shouldn't be copy relocations in kernel 235 * objects. 236 */ 237 printf("kldload: unexpected R_COPY relocation\n"); 238 return -1; 239 break; 240 241 case R_386_GLOB_DAT: /* S */ 242 addr = lookup(lf, symidx, 1); 243 if (addr == 0) 244 return -1; 245 if (*where != addr) 246 *where = addr; 247 break; 248 249 case R_386_RELATIVE: 250 break; 251 252 default: 253 printf("kldload: unexpected relocation type %d\n", 254 rtype); 255 return -1; 256 } 257 return(0); 258} 259 260int 261elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 262 elf_lookup_fn lookup) 263{ 264 265 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup)); 266} 267 268int 269elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 270 int type, elf_lookup_fn lookup) 271{ 272 273 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup)); 274} 275 276int 277elf_cpu_load_file(linker_file_t lf __unused) 278{ 279 280 return (0); 281} 282 283int 284elf_cpu_unload_file(linker_file_t lf __unused) 285{ 286 287 return (0); 288} 289