elf_machdep.c revision 294136
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 294136 2016-01-16 07:56:49Z 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 .sv_trap = NULL, 93}; 94INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 95 96static Elf32_Brandinfo freebsd_brand_info = { 97 .brand = ELFOSABI_FREEBSD, 98 .machine = EM_386, 99 .compat_3_brand = "FreeBSD", 100 .emul_path = NULL, 101 .interp_path = "/libexec/ld-elf.so.1", 102 .sysvec = &elf32_freebsd_sysvec, 103 .interp_newpath = NULL, 104 .brand_note = &elf32_freebsd_brandnote, 105 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 106}; 107 108SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 109 (sysinit_cfunc_t) elf32_insert_brand_entry, 110 &freebsd_brand_info); 111 112static Elf32_Brandinfo freebsd_brand_oinfo = { 113 .brand = ELFOSABI_FREEBSD, 114 .machine = EM_386, 115 .compat_3_brand = "FreeBSD", 116 .emul_path = NULL, 117 .interp_path = "/usr/libexec/ld-elf.so.1", 118 .sysvec = &elf32_freebsd_sysvec, 119 .interp_newpath = NULL, 120 .brand_note = &elf32_freebsd_brandnote, 121 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE 122}; 123 124SYSINIT(oelf32, SI_SUB_EXEC, SI_ORDER_ANY, 125 (sysinit_cfunc_t) elf32_insert_brand_entry, 126 &freebsd_brand_oinfo); 127 128static Elf32_Brandinfo kfreebsd_brand_info = { 129 .brand = ELFOSABI_FREEBSD, 130 .machine = EM_386, 131 .compat_3_brand = "FreeBSD", 132 .emul_path = NULL, 133 .interp_path = "/lib/ld.so.1", 134 .sysvec = &elf32_freebsd_sysvec, 135 .interp_newpath = NULL, 136 .brand_note = &elf32_kfreebsd_brandnote, 137 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE_MANDATORY 138}; 139 140SYSINIT(kelf32, SI_SUB_EXEC, SI_ORDER_ANY, 141 (sysinit_cfunc_t) elf32_insert_brand_entry, 142 &kfreebsd_brand_info); 143 144 145void 146elf32_dump_thread(struct thread *td, void *dst, size_t *off) 147{ 148#ifdef CPU_ENABLE_SSE 149 void *buf; 150#endif 151 size_t len; 152 153 len = 0; 154#ifdef CPU_ENABLE_SSE 155 if (use_xsave) { 156 if (dst != NULL) { 157 npxgetregs(td); 158 len += elf32_populate_note(NT_X86_XSTATE, 159 get_pcb_user_save_td(td), dst, 160 cpu_max_ext_state_size, &buf); 161 *(uint64_t *)((char *)buf + X86_XSTATE_XCR0_OFFSET) = 162 xsave_mask; 163 } else 164 len += elf32_populate_note(NT_X86_XSTATE, NULL, NULL, 165 cpu_max_ext_state_size, NULL); 166 } 167#endif 168 *off = len; 169} 170 171/* Process one elf relocation with addend. */ 172static int 173elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 174 int type, int local, elf_lookup_fn lookup) 175{ 176 Elf_Addr *where; 177 Elf_Addr addr; 178 Elf_Addr addend; 179 Elf_Word rtype, symidx; 180 const Elf_Rel *rel; 181 const Elf_Rela *rela; 182 int error; 183 184 switch (type) { 185 case ELF_RELOC_REL: 186 rel = (const Elf_Rel *)data; 187 where = (Elf_Addr *) (relocbase + rel->r_offset); 188 addend = *where; 189 rtype = ELF_R_TYPE(rel->r_info); 190 symidx = ELF_R_SYM(rel->r_info); 191 break; 192 case ELF_RELOC_RELA: 193 rela = (const Elf_Rela *)data; 194 where = (Elf_Addr *) (relocbase + rela->r_offset); 195 addend = rela->r_addend; 196 rtype = ELF_R_TYPE(rela->r_info); 197 symidx = ELF_R_SYM(rela->r_info); 198 break; 199 default: 200 panic("unknown reloc type %d\n", type); 201 } 202 203 if (local) { 204 if (rtype == R_386_RELATIVE) { /* A + B */ 205 addr = elf_relocaddr(lf, relocbase + addend); 206 if (*where != addr) 207 *where = addr; 208 } 209 return (0); 210 } 211 212 switch (rtype) { 213 214 case R_386_NONE: /* none */ 215 break; 216 217 case R_386_32: /* S + A */ 218 error = lookup(lf, symidx, 1, &addr); 219 if (error != 0) 220 return -1; 221 addr += addend; 222 if (*where != addr) 223 *where = addr; 224 break; 225 226 case R_386_PC32: /* S + A - P */ 227 error = lookup(lf, symidx, 1, &addr); 228 if (error != 0) 229 return -1; 230 addr += addend - (Elf_Addr)where; 231 if (*where != addr) 232 *where = addr; 233 break; 234 235 case R_386_COPY: /* none */ 236 /* 237 * There shouldn't be copy relocations in kernel 238 * objects. 239 */ 240 printf("kldload: unexpected R_COPY relocation\n"); 241 return -1; 242 break; 243 244 case R_386_GLOB_DAT: /* S */ 245 error = lookup(lf, symidx, 1, &addr); 246 if (error != 0) 247 return -1; 248 if (*where != addr) 249 *where = addr; 250 break; 251 252 case R_386_RELATIVE: 253 break; 254 255 default: 256 printf("kldload: unexpected relocation type %d\n", 257 rtype); 258 return -1; 259 } 260 return(0); 261} 262 263int 264elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 265 elf_lookup_fn lookup) 266{ 267 268 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup)); 269} 270 271int 272elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 273 int type, elf_lookup_fn lookup) 274{ 275 276 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup)); 277} 278 279int 280elf_cpu_load_file(linker_file_t lf __unused) 281{ 282 283 return (0); 284} 285 286int 287elf_cpu_unload_file(linker_file_t lf __unused) 288{ 289 290 return (0); 291} 292