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/sysent.h> 38 #include <sys/imgact_elf.h> 39 #include <sys/proc.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/stack.h> 51 #ifdef VFP 52 #include <machine/vfp.h> 53 #endif 54 55 #include "opt_ddb.h" /* for OPT_DDB */ 56 #include "opt_global.h" /* for OPT_KDTRACE_HOOKS */ 57 #include "opt_stack.h" /* for OPT_STACK */ 58 59 static boolean_t elf32_arm_abi_supported(struct image_params *, int32_t *, 60 uint32_t *); 61 62 u_long elf_hwcap; 63 u_long elf_hwcap2; 64 65 struct sysentvec elf32_freebsd_sysvec = { 66 .sv_size = SYS_MAXSYSCALL, 67 .sv_table = sysent, 68 .sv_transtrap = NULL, 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_imgact_try = NULL, 76 .sv_minsigstksz = MINSIGSTKSZ, 77 .sv_minuser = VM_MIN_ADDRESS, 78 .sv_maxuser = VM_MAXUSER_ADDRESS, 79 .sv_usrstack = USRSTACK, 80 .sv_psstrings = PS_STRINGS, 81 .sv_stackprot = VM_PROT_ALL, 82 .sv_copyout_auxargs = __elfN(freebsd_copyout_auxargs), 83 .sv_copyout_strings = exec_copyout_strings, 84 .sv_setregs = exec_setregs, 85 .sv_fixlimit = NULL, 86 .sv_maxssiz = NULL, 87 .sv_flags = 88 #if __ARM_ARCH >= 6 89 SV_ASLR | SV_SHP | SV_TIMEKEEP | SV_RNG_SEED_VER | 90 #endif 91 SV_ABI_FREEBSD | SV_ILP32 | SV_ASLR, 92 .sv_set_syscall_retval = cpu_set_syscall_retval, 93 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 94 .sv_syscallnames = syscallnames, 95 .sv_shared_page_base = SHAREDPAGE, 96 .sv_shared_page_len = PAGE_SIZE, 97 .sv_schedtail = NULL, 98 .sv_thread_detach = NULL, 99 .sv_trap = NULL, 100 .sv_hwcap = &elf_hwcap, 101 .sv_hwcap2 = &elf_hwcap2, 102 }; 103 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 104 105 static Elf32_Brandinfo freebsd_brand_info = { 106 .brand = ELFOSABI_FREEBSD, 107 .machine = EM_ARM, 108 .compat_3_brand = "FreeBSD", 109 .emul_path = NULL, 110 .interp_path = "/libexec/ld-elf.so.1", 111 .sysvec = &elf32_freebsd_sysvec, 112 .interp_newpath = NULL, 113 .brand_note = &elf32_freebsd_brandnote, 114 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE, 115 .header_supported= elf32_arm_abi_supported, 116 }; 117 118 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 119 (sysinit_cfunc_t) elf32_insert_brand_entry, 120 &freebsd_brand_info); 121 122 static boolean_t 123 elf32_arm_abi_supported(struct image_params *imgp, int32_t *osrel __unused, 124 uint32_t *fctl0 __unused) 125 { 126 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header; 127 128 /* 129 * When configured for EABI, FreeBSD supports EABI vesions 4 and 5. 130 */ 131 if (EF_ARM_EABI_VERSION(hdr->e_flags) < EF_ARM_EABI_FREEBSD_MIN) { 132 if (bootverbose) 133 uprintf("Attempting to execute non EABI binary (rev %d) image %s", 134 EF_ARM_EABI_VERSION(hdr->e_flags), imgp->args->fname); 135 return (FALSE); 136 } 137 return (TRUE); 138 } 139 140 void 141 elf32_dump_thread(struct thread *td, void *dst, size_t *off) 142 { 143 #ifdef VFP 144 mcontext_vfp_t vfp; 145 146 if (dst != NULL) { 147 get_vfpcontext(td, &vfp); 148 *off = elf32_populate_note(NT_ARM_VFP, &vfp, dst, sizeof(vfp), 149 NULL); 150 } else 151 *off = elf32_populate_note(NT_ARM_VFP, NULL, NULL, sizeof(vfp), 152 NULL); 153 #endif 154 } 155 156 bool 157 elf_is_ifunc_reloc(Elf_Size r_info __unused) 158 { 159 160 return (false); 161 } 162 163 /* 164 * It is possible for the compiler to emit relocations for unaligned data. 165 * We handle this situation with these inlines. 166 */ 167 #define RELOC_ALIGNED_P(x) \ 168 (((uintptr_t)(x) & (sizeof(void *) - 1)) == 0) 169 170 static __inline Elf_Addr 171 load_ptr(Elf_Addr *where) 172 { 173 Elf_Addr res; 174 175 if (RELOC_ALIGNED_P(where)) 176 return *where; 177 memcpy(&res, where, sizeof(res)); 178 return (res); 179 } 180 181 static __inline void 182 store_ptr(Elf_Addr *where, Elf_Addr val) 183 { 184 if (RELOC_ALIGNED_P(where)) 185 *where = val; 186 else 187 memcpy(where, &val, sizeof(val)); 188 } 189 #undef RELOC_ALIGNED_P 190 191 /* Process one elf relocation with addend. */ 192 static int 193 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 194 int type, int local, elf_lookup_fn lookup) 195 { 196 Elf_Addr *where; 197 Elf_Addr addr; 198 Elf_Addr addend; 199 Elf_Word rtype, symidx; 200 const Elf_Rel *rel; 201 const Elf_Rela *rela; 202 int error; 203 204 switch (type) { 205 case ELF_RELOC_REL: 206 rel = (const Elf_Rel *)data; 207 where = (Elf_Addr *) (relocbase + rel->r_offset); 208 addend = load_ptr(where); 209 rtype = ELF_R_TYPE(rel->r_info); 210 symidx = ELF_R_SYM(rel->r_info); 211 break; 212 case ELF_RELOC_RELA: 213 rela = (const Elf_Rela *)data; 214 where = (Elf_Addr *) (relocbase + rela->r_offset); 215 addend = rela->r_addend; 216 rtype = ELF_R_TYPE(rela->r_info); 217 symidx = ELF_R_SYM(rela->r_info); 218 break; 219 default: 220 panic("unknown reloc type %d\n", type); 221 } 222 223 if (local) { 224 if (rtype == R_ARM_RELATIVE) { /* A + B */ 225 addr = elf_relocaddr(lf, relocbase + addend); 226 if (load_ptr(where) != addr) 227 store_ptr(where, addr); 228 } 229 return (0); 230 } 231 232 switch (rtype) { 233 case R_ARM_NONE: /* none */ 234 break; 235 236 case R_ARM_ABS32: 237 error = lookup(lf, symidx, 1, &addr); 238 if (error != 0) 239 return (-1); 240 store_ptr(where, addr + load_ptr(where)); 241 break; 242 243 case R_ARM_COPY: /* none */ 244 /* 245 * There shouldn't be copy relocations in kernel 246 * objects. 247 */ 248 printf("kldload: unexpected R_COPY relocation, " 249 "symbol index %d\n", symidx); 250 return (-1); 251 break; 252 253 case R_ARM_JUMP_SLOT: 254 error = lookup(lf, symidx, 1, &addr); 255 if (error == 0) { 256 store_ptr(where, addr); 257 return (0); 258 } 259 return (-1); 260 case R_ARM_RELATIVE: 261 break; 262 263 default: 264 printf("kldload: unexpected relocation type %d, " 265 "symbol index %d\n", rtype, symidx); 266 return (-1); 267 } 268 return(0); 269 } 270 271 int 272 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 273 elf_lookup_fn lookup) 274 { 275 276 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup)); 277 } 278 279 int 280 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 281 int type, elf_lookup_fn lookup) 282 { 283 284 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup)); 285 } 286 287 int 288 elf_cpu_load_file(linker_file_t lf) 289 { 290 291 /* 292 * The pmap code does not do an icache sync upon establishing executable 293 * mappings in the kernel pmap. It's an optimization based on the fact 294 * that kernel memory allocations always have EXECUTABLE protection even 295 * when the memory isn't going to hold executable code. The only time 296 * kernel memory holding instructions does need a sync is after loading 297 * a kernel module, and that's when this function gets called. 298 * 299 * This syncs data and instruction caches after loading a module. We 300 * don't worry about the kernel itself (lf->id is 1) as locore.S did 301 * that on entry. Even if data cache maintenance was done by IO code, 302 * the relocation fixup process creates dirty cache entries that we must 303 * write back before doing icache sync. The instruction cache sync also 304 * invalidates the branch predictor cache on platforms that have one. 305 */ 306 if (lf->id == 1) 307 return (0); 308 #if __ARM_ARCH >= 6 309 dcache_wb_pou((vm_offset_t)lf->address, (vm_size_t)lf->size); 310 icache_inv_all(); 311 #else 312 cpu_dcache_wb_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 313 cpu_l2cache_wb_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 314 cpu_icache_sync_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 315 #endif 316 317 #if defined(DDB) || defined(KDTRACE_HOOKS) || defined(STACK) 318 /* 319 * Inform the stack(9) code of the new module, so it can acquire its 320 * per-module unwind data. 321 */ 322 unwind_module_loaded(lf); 323 #endif 324 325 return (0); 326 } 327 328 int 329 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused) 330 { 331 332 return (0); 333 } 334 335 int 336 elf_cpu_unload_file(linker_file_t lf) 337 { 338 339 #if defined(DDB) || defined(KDTRACE_HOOKS) || defined(STACK) 340 /* Inform the stack(9) code that this module is gone. */ 341 unwind_module_unloaded(lf); 342 #endif 343 return (0); 344 } 345