1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 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/param.h> 29 #include <sys/kernel.h> 30 #include <sys/systm.h> 31 #include <sys/exec.h> 32 #include <sys/imgact.h> 33 #include <sys/linker.h> 34 #include <sys/reg.h> 35 #include <sys/sysent.h> 36 #include <sys/imgact_elf.h> 37 #include <sys/proc.h> 38 #include <sys/syscall.h> 39 #include <sys/signalvar.h> 40 #include <sys/vnode.h> 41 42 #include <vm/vm.h> 43 #include <vm/pmap.h> 44 #include <vm/vm_param.h> 45 46 #include <machine/elf.h> 47 #include <machine/md_var.h> 48 #include <machine/stack.h> 49 #ifdef VFP 50 #include <machine/vfp.h> 51 #endif 52 53 #include "opt_ddb.h" /* for OPT_DDB */ 54 #include "opt_global.h" /* for OPT_KDTRACE_HOOKS */ 55 #include "opt_stack.h" /* for OPT_STACK */ 56 57 static bool elf32_arm_abi_supported(struct image_params *, int32_t *, 58 uint32_t *); 59 60 u_long elf_hwcap; 61 u_long elf_hwcap2; 62 63 struct sysentvec elf32_freebsd_sysvec = { 64 .sv_size = SYS_MAXSYSCALL, 65 .sv_table = sysent, 66 .sv_fixup = __elfN(freebsd_fixup), 67 .sv_sendsig = sendsig, 68 .sv_sigcode = sigcode, 69 .sv_szsigcode = &szsigcode, 70 .sv_name = "FreeBSD ELF32", 71 .sv_coredump = __elfN(coredump), 72 .sv_elf_core_osabi = ELFOSABI_FREEBSD, 73 .sv_elf_core_abi_vendor = FREEBSD_ABI_VENDOR, 74 .sv_elf_core_prepare_notes = __elfN(prepare_notes), 75 .sv_minsigstksz = MINSIGSTKSZ, 76 .sv_minuser = VM_MIN_ADDRESS, 77 .sv_maxuser = VM_MAXUSER_ADDRESS, 78 .sv_usrstack = USRSTACK, 79 .sv_psstrings = PS_STRINGS, 80 .sv_psstringssz = sizeof(struct 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 SV_ASLR | SV_SHP | SV_TIMEKEEP | SV_RNG_SEED_VER | 89 SV_ABI_FREEBSD | SV_ILP32 | SV_SIGSYS, 90 .sv_set_syscall_retval = cpu_set_syscall_retval, 91 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 92 .sv_syscallnames = syscallnames, 93 .sv_shared_page_base = SHAREDPAGE, 94 .sv_shared_page_len = PAGE_SIZE, 95 .sv_schedtail = NULL, 96 .sv_thread_detach = NULL, 97 .sv_trap = NULL, 98 .sv_hwcap = &elf_hwcap, 99 .sv_hwcap2 = &elf_hwcap2, 100 .sv_onexec_old = exec_onexec_old, 101 .sv_onexit = exit_onexit, 102 .sv_regset_begin = SET_BEGIN(__elfN(regset)), 103 .sv_regset_end = SET_LIMIT(__elfN(regset)), 104 }; 105 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 106 107 static Elf32_Brandinfo freebsd_brand_info = { 108 .brand = ELFOSABI_FREEBSD, 109 .machine = EM_ARM, 110 .compat_3_brand = "FreeBSD", 111 .interp_path = "/libexec/ld-elf.so.1", 112 .sysvec = &elf32_freebsd_sysvec, 113 .interp_newpath = NULL, 114 .brand_note = &elf32_freebsd_brandnote, 115 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE, 116 .header_supported= elf32_arm_abi_supported, 117 }; 118 119 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 120 (sysinit_cfunc_t) elf32_insert_brand_entry, 121 &freebsd_brand_info); 122 123 static bool 124 elf32_arm_abi_supported(struct image_params *imgp, int32_t *osrel __unused, 125 uint32_t *fctl0 __unused) 126 { 127 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header; 128 129 /* 130 * When configured for EABI, FreeBSD supports EABI vesions 4 and 5. 131 */ 132 if (EF_ARM_EABI_VERSION(hdr->e_flags) < EF_ARM_EABI_FREEBSD_MIN) { 133 if (bootverbose) 134 uprintf("Attempting to execute non EABI binary (rev %d) image %s", 135 EF_ARM_EABI_VERSION(hdr->e_flags), imgp->args->fname); 136 return (false); 137 } 138 return (true); 139 } 140 141 void 142 elf32_dump_thread(struct thread *td __unused, void *dst __unused, 143 size_t *off __unused) 144 { 145 } 146 147 bool 148 elf_is_ifunc_reloc(Elf_Size r_info __unused) 149 { 150 151 return (false); 152 } 153 154 /* 155 * It is possible for the compiler to emit relocations for unaligned data. 156 * We handle this situation with these inlines. 157 */ 158 #define RELOC_ALIGNED_P(x) \ 159 (((uintptr_t)(x) & (sizeof(void *) - 1)) == 0) 160 161 static __inline Elf_Addr 162 load_ptr(Elf_Addr *where) 163 { 164 Elf_Addr res; 165 166 if (RELOC_ALIGNED_P(where)) 167 return *where; 168 memcpy(&res, where, sizeof(res)); 169 return (res); 170 } 171 172 static __inline void 173 store_ptr(Elf_Addr *where, Elf_Addr val) 174 { 175 if (RELOC_ALIGNED_P(where)) 176 *where = val; 177 else 178 memcpy(where, &val, sizeof(val)); 179 } 180 #undef RELOC_ALIGNED_P 181 182 /* Process one elf relocation with addend. */ 183 static int 184 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 185 int type, int local, elf_lookup_fn lookup) 186 { 187 Elf_Addr *where; 188 Elf_Addr addr; 189 Elf_Addr addend; 190 Elf_Word rtype, symidx; 191 const Elf_Rel *rel; 192 const Elf_Rela *rela; 193 int error; 194 195 switch (type) { 196 case ELF_RELOC_REL: 197 rel = (const Elf_Rel *)data; 198 where = (Elf_Addr *) (relocbase + rel->r_offset); 199 addend = load_ptr(where); 200 rtype = ELF_R_TYPE(rel->r_info); 201 symidx = ELF_R_SYM(rel->r_info); 202 break; 203 case ELF_RELOC_RELA: 204 rela = (const Elf_Rela *)data; 205 where = (Elf_Addr *) (relocbase + rela->r_offset); 206 addend = rela->r_addend; 207 rtype = ELF_R_TYPE(rela->r_info); 208 symidx = ELF_R_SYM(rela->r_info); 209 break; 210 default: 211 panic("unknown reloc type %d\n", type); 212 } 213 214 if (local) { 215 if (rtype == R_ARM_RELATIVE) { /* A + B */ 216 addr = elf_relocaddr(lf, relocbase + addend); 217 if (load_ptr(where) != addr) 218 store_ptr(where, addr); 219 } 220 return (0); 221 } 222 223 switch (rtype) { 224 case R_ARM_NONE: /* none */ 225 break; 226 227 case R_ARM_ABS32: 228 error = lookup(lf, symidx, 1, &addr); 229 if (error != 0) 230 return (-1); 231 store_ptr(where, addr + load_ptr(where)); 232 break; 233 234 case R_ARM_COPY: /* none */ 235 /* 236 * There shouldn't be copy relocations in kernel 237 * objects. 238 */ 239 printf("kldload: unexpected R_COPY relocation, " 240 "symbol index %d\n", symidx); 241 return (-1); 242 break; 243 244 case R_ARM_JUMP_SLOT: 245 error = lookup(lf, symidx, 1, &addr); 246 if (error == 0) { 247 store_ptr(where, addr); 248 return (0); 249 } 250 return (-1); 251 case R_ARM_RELATIVE: 252 break; 253 254 default: 255 printf("kldload: unexpected relocation type %d, " 256 "symbol index %d\n", rtype, symidx); 257 return (-1); 258 } 259 return(0); 260 } 261 262 int 263 elf_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 } 269 270 int 271 elf_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 } 277 278 int 279 elf_cpu_load_file(linker_file_t lf) 280 { 281 282 /* 283 * The pmap code does not do an icache sync upon establishing executable 284 * mappings in the kernel pmap. It's an optimization based on the fact 285 * that kernel memory allocations always have EXECUTABLE protection even 286 * when the memory isn't going to hold executable code. The only time 287 * kernel memory holding instructions does need a sync is after loading 288 * a kernel module, and that's when this function gets called. 289 * 290 * This syncs data and instruction caches after loading a module. We 291 * don't worry about the kernel itself (lf->id is 1) as locore.S did 292 * that on entry. Even if data cache maintenance was done by IO code, 293 * the relocation fixup process creates dirty cache entries that we must 294 * write back before doing icache sync. The instruction cache sync also 295 * invalidates the branch predictor cache on platforms that have one. 296 */ 297 if (lf->id == 1) 298 return (0); 299 dcache_wb_pou((vm_offset_t)lf->address, (vm_size_t)lf->size); 300 icache_inv_all(); 301 302 #if defined(DDB) || defined(KDTRACE_HOOKS) || defined(STACK) 303 /* 304 * Inform the stack(9) code of the new module, so it can acquire its 305 * per-module unwind data. 306 */ 307 unwind_module_loaded(lf); 308 #endif 309 310 return (0); 311 } 312 313 int 314 elf_cpu_parse_dynamic(caddr_t loadbase __unused, Elf_Dyn *dynamic __unused) 315 { 316 317 return (0); 318 } 319 320 int 321 elf_cpu_unload_file(linker_file_t lf) 322 { 323 324 #if defined(DDB) || defined(KDTRACE_HOOKS) || defined(STACK) 325 /* Inform the stack(9) code that this module is gone. */ 326 unwind_module_unloaded(lf); 327 #endif 328 return (0); 329 } 330