1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright 1996-1998 John D. Polstra. 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 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/reg.h> 38 #include <sys/sysent.h> 39 #include <sys/imgact_elf.h> 40 #include <sys/proc.h> 41 #include <sys/syscall.h> 42 #include <sys/signalvar.h> 43 #include <sys/vnode.h> 44 45 #include <vm/vm.h> 46 #include <vm/pmap.h> 47 #include <vm/vm_param.h> 48 49 #include <machine/elf.h> 50 #include <machine/md_var.h> 51 #include <machine/stack.h> 52 #ifdef VFP 53 #include <machine/vfp.h> 54 #endif 55 56 #include "opt_ddb.h" /* for OPT_DDB */ 57 #include "opt_global.h" /* for OPT_KDTRACE_HOOKS */ 58 #include "opt_stack.h" /* for OPT_STACK */ 59 60 static boolean_t elf32_arm_abi_supported(struct image_params *, int32_t *, 61 uint32_t *); 62 63 u_long elf_hwcap; 64 u_long elf_hwcap2; 65 66 struct sysentvec elf32_freebsd_sysvec = { 67 .sv_size = SYS_MAXSYSCALL, 68 .sv_table = sysent, 69 .sv_fixup = __elfN(freebsd_fixup), 70 .sv_sendsig = sendsig, 71 .sv_sigcode = sigcode, 72 .sv_szsigcode = &szsigcode, 73 .sv_name = "FreeBSD ELF32", 74 .sv_coredump = __elfN(coredump), 75 .sv_elf_core_osabi = ELFOSABI_FREEBSD, 76 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR, 77 .sv_elf_core_prepare_notes = __elfN(prepare_notes), 78 .sv_imgact_try = NULL, 79 .sv_minsigstksz = MINSIGSTKSZ, 80 .sv_minuser = VM_MIN_ADDRESS, 81 .sv_maxuser = VM_MAXUSER_ADDRESS, 82 .sv_usrstack = USRSTACK, 83 .sv_psstrings = PS_STRINGS, 84 .sv_psstringssz = sizeof(struct ps_strings), 85 .sv_stackprot = VM_PROT_ALL, 86 .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs), 87 .sv_copyout_strings = exec_copyout_strings, 88 .sv_setregs = exec_setregs, 89 .sv_fixlimit = NULL, 90 .sv_maxssiz = NULL, 91 .sv_flags = 92 SV_ASLR | SV_SHP | SV_TIMEKEEP | SV_RNG_SEED_VER | 93 SV_ABI_FREEBSD | SV_ILP32, 94 .sv_set_syscall_retval = cpu_set_syscall_retval, 95 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 96 .sv_syscallnames = syscallnames, 97 .sv_shared_page_base = SHAREDPAGE, 98 .sv_shared_page_len = PAGE_SIZE, 99 .sv_schedtail = NULL, 100 .sv_thread_detach = NULL, 101 .sv_trap = NULL, 102 .sv_hwcap = &elf_hwcap, 103 .sv_hwcap2 = &elf_hwcap2, 104 .sv_onexec_old = exec_onexec_old, 105 .sv_onexit = exit_onexit, 106 .sv_regset_begin = SET_BEGIN(__elfN(regset)), 107 .sv_regset_end = SET_LIMIT(__elfN(regset)), 108 }; 109 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 110 111 static Elf32_Brandinfo freebsd_brand_info = { 112 .brand = ELFOSABI_FREEBSD, 113 .machine = EM_ARM, 114 .compat_3_brand = "FreeBSD", 115 .emul_path = NULL, 116 .interp_path = "/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 .header_supported= elf32_arm_abi_supported, 122 }; 123 124 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 125 (sysinit_cfunc_t) elf32_insert_brand_entry, 126 &freebsd_brand_info); 127 128 static boolean_t 129 elf32_arm_abi_supported(struct image_params *imgp, int32_t *osrel __unused, 130 uint32_t *fctl0 __unused) 131 { 132 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header; 133 134 /* 135 * When configured for EABI, FreeBSD supports EABI vesions 4 and 5. 136 */ 137 if (EF_ARM_EABI_VERSION(hdr->e_flags) < EF_ARM_EABI_FREEBSD_MIN) { 138 if (bootverbose) 139 uprintf("Attempting to execute non EABI binary (rev %d) image %s", 140 EF_ARM_EABI_VERSION(hdr->e_flags), imgp->args->fname); 141 return (FALSE); 142 } 143 return (TRUE); 144 } 145 146 void 147 elf32_dump_thread(struct thread *td __unused, void *dst __unused, 148 size_t *off __unused) 149 { 150 } 151 152 bool 153 elf_is_ifunc_reloc(Elf_Size r_info __unused) 154 { 155 156 return (false); 157 } 158 159 /* 160 * It is possible for the compiler to emit relocations for unaligned data. 161 * We handle this situation with these inlines. 162 */ 163 #define RELOC_ALIGNED_P(x) \ 164 (((uintptr_t)(x) & (sizeof(void *) - 1)) == 0) 165 166 static __inline Elf_Addr 167 load_ptr(Elf_Addr *where) 168 { 169 Elf_Addr res; 170 171 if (RELOC_ALIGNED_P(where)) 172 return *where; 173 memcpy(&res, where, sizeof(res)); 174 return (res); 175 } 176 177 static __inline void 178 store_ptr(Elf_Addr *where, Elf_Addr val) 179 { 180 if (RELOC_ALIGNED_P(where)) 181 *where = val; 182 else 183 memcpy(where, &val, sizeof(val)); 184 } 185 #undef RELOC_ALIGNED_P 186 187 /* Process one elf relocation with addend. */ 188 static int 189 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 190 int type, int local, elf_lookup_fn lookup) 191 { 192 Elf_Addr *where; 193 Elf_Addr addr; 194 Elf_Addr addend; 195 Elf_Word rtype, symidx; 196 const Elf_Rel *rel; 197 const Elf_Rela *rela; 198 int error; 199 200 switch (type) { 201 case ELF_RELOC_REL: 202 rel = (const Elf_Rel *)data; 203 where = (Elf_Addr *) (relocbase + rel->r_offset); 204 addend = load_ptr(where); 205 rtype = ELF_R_TYPE(rel->r_info); 206 symidx = ELF_R_SYM(rel->r_info); 207 break; 208 case ELF_RELOC_RELA: 209 rela = (const Elf_Rela *)data; 210 where = (Elf_Addr *) (relocbase + rela->r_offset); 211 addend = rela->r_addend; 212 rtype = ELF_R_TYPE(rela->r_info); 213 symidx = ELF_R_SYM(rela->r_info); 214 break; 215 default: 216 panic("unknown reloc type %d\n", type); 217 } 218 219 if (local) { 220 if (rtype == R_ARM_RELATIVE) { /* A + B */ 221 addr = elf_relocaddr(lf, relocbase + addend); 222 if (load_ptr(where) != addr) 223 store_ptr(where, addr); 224 } 225 return (0); 226 } 227 228 switch (rtype) { 229 case R_ARM_NONE: /* none */ 230 break; 231 232 case R_ARM_ABS32: 233 error = lookup(lf, symidx, 1, &addr); 234 if (error != 0) 235 return (-1); 236 store_ptr(where, addr + load_ptr(where)); 237 break; 238 239 case R_ARM_COPY: /* none */ 240 /* 241 * There shouldn't be copy relocations in kernel 242 * objects. 243 */ 244 printf("kldload: unexpected R_COPY relocation, " 245 "symbol index %d\n", symidx); 246 return (-1); 247 break; 248 249 case R_ARM_JUMP_SLOT: 250 error = lookup(lf, symidx, 1, &addr); 251 if (error == 0) { 252 store_ptr(where, addr); 253 return (0); 254 } 255 return (-1); 256 case R_ARM_RELATIVE: 257 break; 258 259 default: 260 printf("kldload: unexpected relocation type %d, " 261 "symbol index %d\n", rtype, symidx); 262 return (-1); 263 } 264 return(0); 265 } 266 267 int 268 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 269 elf_lookup_fn lookup) 270 { 271 272 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup)); 273 } 274 275 int 276 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 277 int type, elf_lookup_fn lookup) 278 { 279 280 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup)); 281 } 282 283 int 284 elf_cpu_load_file(linker_file_t lf) 285 { 286 287 /* 288 * The pmap code does not do an icache sync upon establishing executable 289 * mappings in the kernel pmap. It's an optimization based on the fact 290 * that kernel memory allocations always have EXECUTABLE protection even 291 * when the memory isn't going to hold executable code. The only time 292 * kernel memory holding instructions does need a sync is after loading 293 * a kernel module, and that's when this function gets called. 294 * 295 * This syncs data and instruction caches after loading a module. We 296 * don't worry about the kernel itself (lf->id is 1) as locore.S did 297 * that on entry. Even if data cache maintenance was done by IO code, 298 * the relocation fixup process creates dirty cache entries that we must 299 * write back before doing icache sync. The instruction cache sync also 300 * invalidates the branch predictor cache on platforms that have one. 301 */ 302 if (lf->id == 1) 303 return (0); 304 dcache_wb_pou((vm_offset_t)lf->address, (vm_size_t)lf->size); 305 icache_inv_all(); 306 307 #if defined(DDB) || defined(KDTRACE_HOOKS) || defined(STACK) 308 /* 309 * Inform the stack(9) code of the new module, so it can acquire its 310 * per-module unwind data. 311 */ 312 unwind_module_loaded(lf); 313 #endif 314 315 return (0); 316 } 317 318 int 319 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused) 320 { 321 322 return (0); 323 } 324 325 int 326 elf_cpu_unload_file(linker_file_t lf) 327 { 328 329 #if defined(DDB) || defined(KDTRACE_HOOKS) || defined(STACK) 330 /* Inform the stack(9) code that this module is gone. */ 331 unwind_module_unloaded(lf); 332 #endif 333 return (0); 334 } 335