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_pagesize = PAGE_SIZE, 74 .sv_minuser = VM_MIN_ADDRESS, 75 .sv_maxuser = VM_MAXUSER_ADDRESS, 76 .sv_usrstack = USRSTACK, 77 .sv_psstrings = PS_STRINGS, 78 .sv_stackprot = VM_PROT_ALL, 79 .sv_copyout_strings = exec_copyout_strings, 80 .sv_setregs = exec_setregs, 81 .sv_fixlimit = NULL, 82 .sv_maxssiz = NULL, 83 .sv_flags = 84 #if __ARM_ARCH >= 6 85 SV_ASLR | SV_SHP | SV_TIMEKEEP | 86 #endif 87 SV_ABI_FREEBSD | SV_ILP32 | SV_ASLR, 88 .sv_set_syscall_retval = cpu_set_syscall_retval, 89 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 90 .sv_syscallnames = syscallnames, 91 .sv_shared_page_base = SHAREDPAGE, 92 .sv_shared_page_len = PAGE_SIZE, 93 .sv_schedtail = NULL, 94 .sv_thread_detach = NULL, 95 .sv_trap = NULL, 96 .sv_hwcap = &elf_hwcap, 97 .sv_hwcap2 = &elf_hwcap2, 98 }; 99 INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 100 101 static Elf32_Brandinfo freebsd_brand_info = { 102 .brand = ELFOSABI_FREEBSD, 103 .machine = EM_ARM, 104 .compat_3_brand = "FreeBSD", 105 .emul_path = NULL, 106 .interp_path = "/libexec/ld-elf.so.1", 107 .sysvec = &elf32_freebsd_sysvec, 108 .interp_newpath = NULL, 109 .brand_note = &elf32_freebsd_brandnote, 110 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE, 111 .header_supported= elf32_arm_abi_supported, 112 }; 113 114 SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 115 (sysinit_cfunc_t) elf32_insert_brand_entry, 116 &freebsd_brand_info); 117 118 static boolean_t 119 elf32_arm_abi_supported(struct image_params *imgp) 120 { 121 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header; 122 123 /* 124 * When configured for EABI, FreeBSD supports EABI vesions 4 and 5. 125 */ 126 if (EF_ARM_EABI_VERSION(hdr->e_flags) < EF_ARM_EABI_FREEBSD_MIN) { 127 if (bootverbose) 128 uprintf("Attempting to execute non EABI binary (rev %d) image %s", 129 EF_ARM_EABI_VERSION(hdr->e_flags), imgp->args->fname); 130 return (FALSE); 131 } 132 return (TRUE); 133 } 134 135 void 136 elf32_dump_thread(struct thread *td, void *dst, size_t *off) 137 { 138 #ifdef VFP 139 mcontext_vfp_t vfp; 140 141 if (dst != NULL) { 142 get_vfpcontext(td, &vfp); 143 *off = elf32_populate_note(NT_ARM_VFP, &vfp, dst, sizeof(vfp), 144 NULL); 145 } else 146 *off = elf32_populate_note(NT_ARM_VFP, NULL, NULL, sizeof(vfp), 147 NULL); 148 #endif 149 } 150 151 bool 152 elf_is_ifunc_reloc(Elf_Size r_info __unused) 153 { 154 155 return (false); 156 } 157 158 /* 159 * It is possible for the compiler to emit relocations for unaligned data. 160 * We handle this situation with these inlines. 161 */ 162 #define RELOC_ALIGNED_P(x) \ 163 (((uintptr_t)(x) & (sizeof(void *) - 1)) == 0) 164 165 static __inline Elf_Addr 166 load_ptr(Elf_Addr *where) 167 { 168 Elf_Addr res; 169 170 if (RELOC_ALIGNED_P(where)) 171 return *where; 172 memcpy(&res, where, sizeof(res)); 173 return (res); 174 } 175 176 static __inline void 177 store_ptr(Elf_Addr *where, Elf_Addr val) 178 { 179 if (RELOC_ALIGNED_P(where)) 180 *where = val; 181 else 182 memcpy(where, &val, sizeof(val)); 183 } 184 #undef RELOC_ALIGNED_P 185 186 187 /* 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) { 229 230 case R_ARM_NONE: /* none */ 231 break; 232 233 case R_ARM_ABS32: 234 error = lookup(lf, symidx, 1, &addr); 235 if (error != 0) 236 return -1; 237 store_ptr(where, addr + load_ptr(where)); 238 break; 239 240 case R_ARM_COPY: /* none */ 241 /* 242 * There shouldn't be copy relocations in kernel 243 * objects. 244 */ 245 printf("kldload: unexpected R_COPY relocation\n"); 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\n", 261 rtype); 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 #if __ARM_ARCH >= 6 305 dcache_wb_pou((vm_offset_t)lf->address, (vm_size_t)lf->size); 306 icache_inv_all(); 307 #else 308 cpu_dcache_wb_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 309 cpu_l2cache_wb_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 310 cpu_icache_sync_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 311 #endif 312 return (0); 313 } 314 315 int 316 elf_cpu_unload_file(linker_file_t lf __unused) 317 { 318 319 return (0); 320 } 321