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 #ifdef VFP 51 #include <machine/vfp.h> 52 #endif 53 54 static boolean_t elf32_arm_abi_supported(struct image_params *); 55 56 u_long elf_hwcap; 57 u_long elf_hwcap2; 58 59 struct sysentvec elf32_freebsd_sysvec = { 60 .sv_size = SYS_MAXSYSCALL, 61 .sv_table = sysent, 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_name = "FreeBSD ELF32", 70 .sv_coredump = __elfN(coredump), 71 .sv_imgact_try = NULL, 72 .sv_minsigstksz = MINSIGSTKSZ, 73 .sv_minuser = VM_MIN_ADDRESS, 74 .sv_maxuser = VM_MAXUSER_ADDRESS, 75 .sv_usrstack = USRSTACK, 76 .sv_psstrings = PS_STRINGS, 77 .sv_stackprot = VM_PROT_ALL, 78 .sv_copyout_strings = exec_copyout_strings, 79 .sv_setregs = exec_setregs, 80 .sv_fixlimit = NULL, 81 .sv_maxssiz = NULL, 82 .sv_flags = 83 #if __ARM_ARCH >= 6 84 SV_ASLR | SV_SHP | SV_TIMEKEEP | 85 #endif 86 SV_ABI_FREEBSD | SV_ILP32 | SV_ASLR, 87 .sv_set_syscall_retval = cpu_set_syscall_retval, 88 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 89 .sv_syscallnames = syscallnames, 90 .sv_shared_page_base = SHAREDPAGE, 91 .sv_shared_page_len = PAGE_SIZE, 92 .sv_schedtail = NULL, 93 .sv_thread_detach = NULL, 94 .sv_trap = NULL, 95 .sv_hwcap = &elf_hwcap, 96 .sv_hwcap2 = &elf_hwcap2, 97 }; 98 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 99 100 static Elf32_Brandinfo freebsd_brand_info = { 101 .brand = ELFOSABI_FREEBSD, 102 .machine = EM_ARM, 103 .compat_3_brand = "FreeBSD", 104 .emul_path = NULL, 105 .interp_path = "/libexec/ld-elf.so.1", 106 .sysvec = &elf32_freebsd_sysvec, 107 .interp_newpath = NULL, 108 .brand_note = &elf32_freebsd_brandnote, 109 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE, 110 .header_supported= elf32_arm_abi_supported, 111 }; 112 113 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 114 (sysinit_cfunc_t) elf32_insert_brand_entry, 115 &freebsd_brand_info); 116 117 static boolean_t 118 elf32_arm_abi_supported(struct image_params *imgp) 119 { 120 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header; 121 122 /* 123 * When configured for EABI, FreeBSD supports EABI vesions 4 and 5. 124 */ 125 if (EF_ARM_EABI_VERSION(hdr->e_flags) < EF_ARM_EABI_FREEBSD_MIN) { 126 if (bootverbose) 127 uprintf("Attempting to execute non EABI binary (rev %d) image %s", 128 EF_ARM_EABI_VERSION(hdr->e_flags), imgp->args->fname); 129 return (FALSE); 130 } 131 return (TRUE); 132 } 133 134 void 135 elf32_dump_thread(struct thread *td, void *dst, size_t *off) 136 { 137 #ifdef VFP 138 mcontext_vfp_t vfp; 139 140 if (dst != NULL) { 141 get_vfpcontext(td, &vfp); 142 *off = elf32_populate_note(NT_ARM_VFP, &vfp, dst, sizeof(vfp), 143 NULL); 144 } else 145 *off = elf32_populate_note(NT_ARM_VFP, NULL, NULL, sizeof(vfp), 146 NULL); 147 #endif 148 } 149 150 bool 151 elf_is_ifunc_reloc(Elf_Size r_info __unused) 152 { 153 154 return (false); 155 } 156 157 /* 158 * It is possible for the compiler to emit relocations for unaligned data. 159 * We handle this situation with these inlines. 160 */ 161 #define RELOC_ALIGNED_P(x) \ 162 (((uintptr_t)(x) & (sizeof(void *) - 1)) == 0) 163 164 static __inline Elf_Addr 165 load_ptr(Elf_Addr *where) 166 { 167 Elf_Addr res; 168 169 if (RELOC_ALIGNED_P(where)) 170 return *where; 171 memcpy(&res, where, sizeof(res)); 172 return (res); 173 } 174 175 static __inline void 176 store_ptr(Elf_Addr *where, Elf_Addr val) 177 { 178 if (RELOC_ALIGNED_P(where)) 179 *where = val; 180 else 181 memcpy(where, &val, sizeof(val)); 182 } 183 #undef RELOC_ALIGNED_P 184 185 186 /* Process one elf relocation with addend. */ 187 static int 188 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 189 int type, int local, elf_lookup_fn lookup) 190 { 191 Elf_Addr *where; 192 Elf_Addr addr; 193 Elf_Addr addend; 194 Elf_Word rtype, symidx; 195 const Elf_Rel *rel; 196 const Elf_Rela *rela; 197 int error; 198 199 switch (type) { 200 case ELF_RELOC_REL: 201 rel = (const Elf_Rel *)data; 202 where = (Elf_Addr *) (relocbase + rel->r_offset); 203 addend = load_ptr(where); 204 rtype = ELF_R_TYPE(rel->r_info); 205 symidx = ELF_R_SYM(rel->r_info); 206 break; 207 case ELF_RELOC_RELA: 208 rela = (const Elf_Rela *)data; 209 where = (Elf_Addr *) (relocbase + rela->r_offset); 210 addend = rela->r_addend; 211 rtype = ELF_R_TYPE(rela->r_info); 212 symidx = ELF_R_SYM(rela->r_info); 213 break; 214 default: 215 panic("unknown reloc type %d\n", type); 216 } 217 218 if (local) { 219 if (rtype == R_ARM_RELATIVE) { /* A + B */ 220 addr = elf_relocaddr(lf, relocbase + addend); 221 if (load_ptr(where) != addr) 222 store_ptr(where, addr); 223 } 224 return (0); 225 } 226 227 switch (rtype) { 228 229 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\n"); 245 return -1; 246 break; 247 248 case R_ARM_JUMP_SLOT: 249 error = lookup(lf, symidx, 1, &addr); 250 if (error == 0) { 251 store_ptr(where, addr); 252 return (0); 253 } 254 return (-1); 255 case R_ARM_RELATIVE: 256 break; 257 258 default: 259 printf("kldload: unexpected relocation type %d\n", 260 rtype); 261 return -1; 262 } 263 return(0); 264 } 265 266 int 267 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 268 elf_lookup_fn lookup) 269 { 270 271 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup)); 272 } 273 274 int 275 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 276 int type, elf_lookup_fn lookup) 277 { 278 279 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup)); 280 } 281 282 int 283 elf_cpu_load_file(linker_file_t lf) 284 { 285 286 /* 287 * The pmap code does not do an icache sync upon establishing executable 288 * mappings in the kernel pmap. It's an optimization based on the fact 289 * that kernel memory allocations always have EXECUTABLE protection even 290 * when the memory isn't going to hold executable code. The only time 291 * kernel memory holding instructions does need a sync is after loading 292 * a kernel module, and that's when this function gets called. 293 * 294 * This syncs data and instruction caches after loading a module. We 295 * don't worry about the kernel itself (lf->id is 1) as locore.S did 296 * that on entry. Even if data cache maintenance was done by IO code, 297 * the relocation fixup process creates dirty cache entries that we must 298 * write back before doing icache sync. The instruction cache sync also 299 * invalidates the branch predictor cache on platforms that have one. 300 */ 301 if (lf->id == 1) 302 return (0); 303 #if __ARM_ARCH >= 6 304 dcache_wb_pou((vm_offset_t)lf->address, (vm_size_t)lf->size); 305 icache_inv_all(); 306 #else 307 cpu_dcache_wb_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 308 cpu_l2cache_wb_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 309 cpu_icache_sync_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 310 #endif 311 return (0); 312 } 313 314 int 315 elf_cpu_unload_file(linker_file_t lf __unused) 316 { 317 318 return (0); 319 } 320