elf_machdep.c revision 293490
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 293490 2016-01-09 14:53:08Z dchagin $"); 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 .sv_thread_detach = NULL, 92}; 93INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 94 95static Elf32_Brandinfo freebsd_brand_info = { 96 .brand = ELFOSABI_FREEBSD, 97 .machine = EM_386, 98 .compat_3_brand = "FreeBSD", 99 .emul_path = NULL, 100 .interp_path = "/libexec/ld-elf.so.1", 101 .sysvec = &elf32_freebsd_sysvec, 102 .interp_newpath = NULL, 103 .brand_note = &elf32_freebsd_brandnote, 104 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 105}; 106 107SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 108 (sysinit_cfunc_t) elf32_insert_brand_entry, 109 &freebsd_brand_info); 110 111static Elf32_Brandinfo freebsd_brand_oinfo = { 112 .brand = ELFOSABI_FREEBSD, 113 .machine = EM_386, 114 .compat_3_brand = "FreeBSD", 115 .emul_path = NULL, 116 .interp_path = "/usr/libexec/ld-elf.so.1", 117 .sysvec = &elf32_freebsd_sysvec, 118 .interp_newpath = NULL, 119 .brand_note = &elf32_freebsd_brandnote, 120 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 121}; 122 123SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY, 124 (sysinit_cfunc_t) elf32_insert_brand_entry, 125 &freebsd_brand_oinfo); 126 127static Elf32_Brandinfo kfreebsd_brand_info = { 128 .brand = ELFOSABI_FREEBSD, 129 .machine = EM_386, 130 .compat_3_brand = "FreeBSD", 131 .emul_path = NULL, 132 .interp_path = "/lib/ld.so.1", 133 .sysvec = &elf32_freebsd_sysvec, 134 .interp_newpath = NULL, 135 .brand_note = &elf32_kfreebsd_brandnote, 136 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY 137}; 138 139SYSINIT(kelf32, SI_SUB_EXEC, SI_ORDER_ANY, 140 (sysinit_cfunc_t) elf32_insert_brand_entry, 141 &kfreebsd_brand_info); 142 143 144void 145elf32_dump_thread(struct thread *td, void *dst, size_t *off) 146{ 147#ifdef CPU_ENABLE_SSE 148 void *buf; 149#endif 150 size_t len; 151 152 len = 0; 153#ifdef CPU_ENABLE_SSE 154 if (use_xsave) { 155 if (dst != NULL) { 156 npxgetregs(td); 157 len += elf32_populate_note(NT_X86_XSTATE, 158 get_pcb_user_save_td(td), dst, 159 cpu_max_ext_state_size, &buf); 160 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) = 161 xsave_mask; 162 } else 163 len += elf32_populate_note(NT_X86_XSTATE, NULL, NULL, 164 cpu_max_ext_state_size, NULL); 165 } 166#endif 167 *off = len; 168} 169 170/* Process one elf relocation with addend. */ 171static int 172elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 173 int type, int local, elf_lookup_fn lookup) 174{ 175 Elf_Addr *where; 176 Elf_Addr addr; 177 Elf_Addr addend; 178 Elf_Word rtype, symidx; 179 const Elf_Rel *rel; 180 const Elf_Rela *rela; 181 int error; 182 183 switch (type) { 184 case ELF_RELOC_REL: 185 rel = (const Elf_Rel *)data; 186 where = (Elf_Addr *) (relocbase + rel->r_offset); 187 addend = *where; 188 rtype = ELF_R_TYPE(rel->r_info); 189 symidx = ELF_R_SYM(rel->r_info); 190 break; 191 case ELF_RELOC_RELA: 192 rela = (const Elf_Rela *)data; 193 where = (Elf_Addr *) (relocbase + rela->r_offset); 194 addend = rela->r_addend; 195 rtype = ELF_R_TYPE(rela->r_info); 196 symidx = ELF_R_SYM(rela->r_info); 197 break; 198 default: 199 panic("unknown reloc type %d\n", type); 200 } 201 202 if (local) { 203 if (rtype == R_386_RELATIVE) { /* A + B */ 204 addr = elf_relocaddr(lf, relocbase + addend); 205 if (*where != addr) 206 *where = addr; 207 } 208 return (0); 209 } 210 211 switch (rtype) { 212 213 case R_386_NONE: /* none */ 214 break; 215 216 case R_386_32: /* S + A */ 217 error = lookup(lf, symidx, 1, &addr); 218 if (error != 0) 219 return -1; 220 addr += addend; 221 if (*where != addr) 222 *where = addr; 223 break; 224 225 case R_386_PC32: /* S + A - P */ 226 error = lookup(lf, symidx, 1, &addr); 227 if (error != 0) 228 return -1; 229 addr += addend - (Elf_Addr)where; 230 if (*where != addr) 231 *where = addr; 232 break; 233 234 case R_386_COPY: /* none */ 235 /* 236 * There shouldn't be copy relocations in kernel 237 * objects. 238 */ 239 printf("kldload: unexpected R_COPY relocation\n"); 240 return -1; 241 break; 242 243 case R_386_GLOB_DAT: /* S */ 244 error = lookup(lf, symidx, 1, &addr); 245 if (error != 0) 246 return -1; 247 if (*where != addr) 248 *where = addr; 249 break; 250 251 case R_386_RELATIVE: 252 break; 253 254 default: 255 printf("kldload: unexpected relocation type %d\n", 256 rtype); 257 return -1; 258 } 259 return(0); 260} 261 262int 263elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 264 elf_lookup_fn lookup) 265{ 266 267 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup)); 268} 269 270int 271elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 272 int type, elf_lookup_fn lookup) 273{ 274 275 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup)); 276} 277 278int 279elf_cpu_load_file(linker_file_t lf __unused) 280{ 281 282 return (0); 283} 284 285int 286elf_cpu_unload_file(linker_file_t lf __unused) 287{ 288 289 return (0); 290} 291