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_mask = 0, 63 .sv_errsize = 0, 64 .sv_errtbl = NULL, 65 .sv_transtrap = NULL, 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_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 = 85 #if __ARM_ARCH >= 6 86 SV_SHP | SV_TIMEKEEP | 87 #endif 88 SV_ABI_FREEBSD | SV_ILP32, 89 .sv_set_syscall_retval = cpu_set_syscall_retval, 90 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 91 .sv_syscallnames = syscallnames, 92 .sv_shared_page_base = SHAREDPAGE, 93 .sv_shared_page_len = PAGE_SIZE, 94 .sv_schedtail = NULL, 95 .sv_thread_detach = NULL, 96 .sv_trap = NULL, 97 .sv_hwcap = &elf_hwcap, 98 .sv_hwcap2 = &elf_hwcap2, 99 }; 100 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 101 102 static Elf32_Brandinfo freebsd_brand_info = { 103 .brand = ELFOSABI_FREEBSD, 104 .machine = EM_ARM, 105 .compat_3_brand = "FreeBSD", 106 .emul_path = NULL, 107 .interp_path = "/libexec/ld-elf.so.1", 108 .sysvec = &elf32_freebsd_sysvec, 109 .interp_newpath = NULL, 110 .brand_note = &elf32_freebsd_brandnote, 111 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE, 112 .header_supported= elf32_arm_abi_supported, 113 }; 114 115 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 116 (sysinit_cfunc_t) elf32_insert_brand_entry, 117 &freebsd_brand_info); 118 119 static boolean_t 120 elf32_arm_abi_supported(struct image_params *imgp) 121 { 122 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header; 123 124 /* 125 * When configured for EABI, FreeBSD supports EABI vesions 4 and 5. 126 */ 127 if (EF_ARM_EABI_VERSION(hdr->e_flags) < EF_ARM_EABI_FREEBSD_MIN) { 128 if (bootverbose) 129 uprintf("Attempting to execute non EABI binary (rev %d) image %s", 130 EF_ARM_EABI_VERSION(hdr->e_flags), imgp->args->fname); 131 return (FALSE); 132 } 133 return (TRUE); 134 } 135 136 void 137 elf32_dump_thread(struct thread *td, void *dst, size_t *off) 138 { 139 #ifdef VFP 140 mcontext_vfp_t vfp; 141 142 if (dst != NULL) { 143 get_vfpcontext(td, &vfp); 144 *off = elf32_populate_note(NT_ARM_VFP, &vfp, dst, sizeof(vfp), 145 NULL); 146 } else 147 *off = elf32_populate_note(NT_ARM_VFP, NULL, NULL, sizeof(vfp), 148 NULL); 149 #endif 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 186 187 188 /* Process one elf relocation with addend. */ 189 static int 190 elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 191 int type, int local, elf_lookup_fn lookup) 192 { 193 Elf_Addr *where; 194 Elf_Addr addr; 195 Elf_Addr addend; 196 Elf_Word rtype, symidx; 197 const Elf_Rel *rel; 198 const Elf_Rela *rela; 199 int error; 200 201 switch (type) { 202 case ELF_RELOC_REL: 203 rel = (const Elf_Rel *)data; 204 where = (Elf_Addr *) (relocbase + rel->r_offset); 205 addend = load_ptr(where); 206 rtype = ELF_R_TYPE(rel->r_info); 207 symidx = ELF_R_SYM(rel->r_info); 208 break; 209 case ELF_RELOC_RELA: 210 rela = (const Elf_Rela *)data; 211 where = (Elf_Addr *) (relocbase + rela->r_offset); 212 addend = rela->r_addend; 213 rtype = ELF_R_TYPE(rela->r_info); 214 symidx = ELF_R_SYM(rela->r_info); 215 break; 216 default: 217 panic("unknown reloc type %d\n", type); 218 } 219 220 if (local) { 221 if (rtype == R_ARM_RELATIVE) { /* A + B */ 222 addr = elf_relocaddr(lf, relocbase + addend); 223 if (load_ptr(where) != addr) 224 store_ptr(where, addr); 225 } 226 return (0); 227 } 228 229 switch (rtype) { 230 231 case R_ARM_NONE: /* none */ 232 break; 233 234 case R_ARM_ABS32: 235 error = lookup(lf, symidx, 1, &addr); 236 if (error != 0) 237 return -1; 238 store_ptr(where, addr + load_ptr(where)); 239 break; 240 241 case R_ARM_COPY: /* none */ 242 /* 243 * There shouldn't be copy relocations in kernel 244 * objects. 245 */ 246 printf("kldload: unexpected R_COPY relocation\n"); 247 return -1; 248 break; 249 250 case R_ARM_JUMP_SLOT: 251 error = lookup(lf, symidx, 1, &addr); 252 if (error == 0) { 253 store_ptr(where, addr); 254 return (0); 255 } 256 return (-1); 257 case R_ARM_RELATIVE: 258 break; 259 260 default: 261 printf("kldload: unexpected relocation type %d\n", 262 rtype); 263 return -1; 264 } 265 return(0); 266 } 267 268 int 269 elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 270 elf_lookup_fn lookup) 271 { 272 273 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup)); 274 } 275 276 int 277 elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 278 int type, elf_lookup_fn lookup) 279 { 280 281 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup)); 282 } 283 284 int 285 elf_cpu_load_file(linker_file_t lf) 286 { 287 288 /* 289 * The pmap code does not do an icache sync upon establishing executable 290 * mappings in the kernel pmap. It's an optimization based on the fact 291 * that kernel memory allocations always have EXECUTABLE protection even 292 * when the memory isn't going to hold executable code. The only time 293 * kernel memory holding instructions does need a sync is after loading 294 * a kernel module, and that's when this function gets called. 295 * 296 * This syncs data and instruction caches after loading a module. We 297 * don't worry about the kernel itself (lf->id is 1) as locore.S did 298 * that on entry. Even if data cache maintenance was done by IO code, 299 * the relocation fixup process creates dirty cache entries that we must 300 * write back before doing icache sync. The instruction cache sync also 301 * invalidates the branch predictor cache on platforms that have one. 302 */ 303 if (lf->id == 1) 304 return (0); 305 #if __ARM_ARCH >= 6 306 dcache_wb_pou((vm_offset_t)lf->address, (vm_size_t)lf->size); 307 icache_inv_all(); 308 #else 309 cpu_dcache_wb_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 310 cpu_l2cache_wb_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 311 cpu_icache_sync_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 312 #endif 313 return (0); 314 } 315 316 int 317 elf_cpu_unload_file(linker_file_t lf __unused) 318 { 319 320 return (0); 321 } 322