elf_machdep.c revision 295207
1/*- 2 * Copyright 1996-1998 John D. Polstra. 3 * All rights reserved. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 17 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#include <sys/cdefs.h> 27__FBSDID("$FreeBSD: head/sys/arm/arm/elf_machdep.c 295207 2016-02-03 13:47:50Z mmel $"); 28 29#include <sys/param.h> 30#include <sys/kernel.h> 31#include <sys/systm.h> 32#include <sys/exec.h> 33#include <sys/imgact.h> 34#include <sys/linker.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/acle-compat.h> 47#include <machine/elf.h> 48#include <machine/md_var.h> 49 50static boolean_t elf32_arm_abi_supported(struct image_params *); 51 52struct sysentvec elf32_freebsd_sysvec = { 53 .sv_size = SYS_MAXSYSCALL, 54 .sv_table = sysent, 55 .sv_mask = 0, 56 .sv_errsize = 0, 57 .sv_errtbl = NULL, 58 .sv_transtrap = NULL, 59 .sv_fixup = __elfN(freebsd_fixup), 60 .sv_sendsig = sendsig, 61 .sv_sigcode = sigcode, 62 .sv_szsigcode = &szsigcode, 63 .sv_name = "FreeBSD ELF32", 64 .sv_coredump = __elfN(coredump), 65 .sv_imgact_try = NULL, 66 .sv_minsigstksz = MINSIGSTKSZ, 67 .sv_pagesize = PAGE_SIZE, 68 .sv_minuser = VM_MIN_ADDRESS, 69 .sv_maxuser = VM_MAXUSER_ADDRESS, 70 .sv_usrstack = USRSTACK, 71 .sv_psstrings = PS_STRINGS, 72 .sv_stackprot = VM_PROT_ALL, 73 .sv_copyout_strings = exec_copyout_strings, 74 .sv_setregs = exec_setregs, 75 .sv_fixlimit = NULL, 76 .sv_maxssiz = NULL, 77 .sv_flags = 78#if __ARM_ARCH >= 6 79 SV_SHP | SV_TIMEKEEP | 80#endif 81 SV_ABI_FREEBSD | SV_ILP32, 82 .sv_set_syscall_retval = cpu_set_syscall_retval, 83 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 84 .sv_syscallnames = syscallnames, 85 .sv_shared_page_base = SHAREDPAGE, 86 .sv_shared_page_len = PAGE_SIZE, 87 .sv_schedtail = NULL, 88 .sv_thread_detach = NULL, 89 .sv_trap = NULL, 90}; 91INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 92 93static Elf32_Brandinfo freebsd_brand_info = { 94 .brand = ELFOSABI_FREEBSD, 95 .machine = EM_ARM, 96 .compat_3_brand = "FreeBSD", 97 .emul_path = NULL, 98 .interp_path = "/libexec/ld-elf.so.1", 99 .sysvec = &elf32_freebsd_sysvec, 100 .interp_newpath = NULL, 101 .brand_note = &elf32_freebsd_brandnote, 102 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE, 103 .header_supported= elf32_arm_abi_supported, 104}; 105 106SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 107 (sysinit_cfunc_t) elf32_insert_brand_entry, 108 &freebsd_brand_info); 109 110static boolean_t 111elf32_arm_abi_supported(struct image_params *imgp) 112{ 113 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header; 114 115 /* 116 * When configured for EABI, FreeBSD supports EABI vesions 4 and 5. 117 */ 118 if (EF_ARM_EABI_VERSION(hdr->e_flags) < EF_ARM_EABI_FREEBSD_MIN) { 119 if (bootverbose) 120 uprintf("Attempting to execute non EABI binary (rev %d) image %s", 121 EF_ARM_EABI_VERSION(hdr->e_flags), imgp->args->fname); 122 return (FALSE); 123 } 124 return (TRUE); 125} 126 127void 128elf32_dump_thread(struct thread *td __unused, void *dst __unused, 129 size_t *off __unused) 130{ 131} 132 133/* 134 * It is possible for the compiler to emit relocations for unaligned data. 135 * We handle this situation with these inlines. 136 */ 137#define RELOC_ALIGNED_P(x) \ 138 (((uintptr_t)(x) & (sizeof(void *) - 1)) == 0) 139 140static __inline Elf_Addr 141load_ptr(Elf_Addr *where) 142{ 143 Elf_Addr res; 144 145 if (RELOC_ALIGNED_P(where)) 146 return *where; 147 memcpy(&res, where, sizeof(res)); 148 return (res); 149} 150 151static __inline void 152store_ptr(Elf_Addr *where, Elf_Addr val) 153{ 154 if (RELOC_ALIGNED_P(where)) 155 *where = val; 156 else 157 memcpy(where, &val, sizeof(val)); 158} 159#undef RELOC_ALIGNED_P 160 161 162/* Process one elf relocation with addend. */ 163static int 164elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 165 int type, int local, elf_lookup_fn lookup) 166{ 167 Elf_Addr *where; 168 Elf_Addr addr; 169 Elf_Addr addend; 170 Elf_Word rtype, symidx; 171 const Elf_Rel *rel; 172 const Elf_Rela *rela; 173 int error; 174 175 switch (type) { 176 case ELF_RELOC_REL: 177 rel = (const Elf_Rel *)data; 178 where = (Elf_Addr *) (relocbase + rel->r_offset); 179 addend = load_ptr(where); 180 rtype = ELF_R_TYPE(rel->r_info); 181 symidx = ELF_R_SYM(rel->r_info); 182 break; 183 case ELF_RELOC_RELA: 184 rela = (const Elf_Rela *)data; 185 where = (Elf_Addr *) (relocbase + rela->r_offset); 186 addend = rela->r_addend; 187 rtype = ELF_R_TYPE(rela->r_info); 188 symidx = ELF_R_SYM(rela->r_info); 189 break; 190 default: 191 panic("unknown reloc type %d\n", type); 192 } 193 194 if (local) { 195 if (rtype == R_ARM_RELATIVE) { /* A + B */ 196 addr = elf_relocaddr(lf, relocbase + addend); 197 if (load_ptr(where) != addr) 198 store_ptr(where, addr); 199 } 200 return (0); 201 } 202 203 switch (rtype) { 204 205 case R_ARM_NONE: /* none */ 206 break; 207 208 case R_ARM_ABS32: 209 error = lookup(lf, symidx, 1, &addr); 210 if (error != 0) 211 return -1; 212 store_ptr(where, addr + load_ptr(where)); 213 break; 214 215 case R_ARM_COPY: /* none */ 216 /* 217 * There shouldn't be copy relocations in kernel 218 * objects. 219 */ 220 printf("kldload: unexpected R_COPY relocation\n"); 221 return -1; 222 break; 223 224 case R_ARM_JUMP_SLOT: 225 error = lookup(lf, symidx, 1, &addr); 226 if (error == 0) { 227 store_ptr(where, addr); 228 return (0); 229 } 230 return (-1); 231 case R_ARM_RELATIVE: 232 break; 233 234 default: 235 printf("kldload: unexpected relocation type %d\n", 236 rtype); 237 return -1; 238 } 239 return(0); 240} 241 242int 243elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 244 elf_lookup_fn lookup) 245{ 246 247 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup)); 248} 249 250int 251elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 252 int type, elf_lookup_fn lookup) 253{ 254 255 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup)); 256} 257 258int 259elf_cpu_load_file(linker_file_t lf) 260{ 261 262 /* 263 * The pmap code does not do an icache sync upon establishing executable 264 * mappings in the kernel pmap. It's an optimization based on the fact 265 * that kernel memory allocations always have EXECUTABLE protection even 266 * when the memory isn't going to hold executable code. The only time 267 * kernel memory holding instructions does need a sync is after loading 268 * a kernel module, and that's when this function gets called. 269 * 270 * This syncs data and instruction caches after loading a module. We 271 * don't worry about the kernel itself (lf->id is 1) as locore.S did 272 * that on entry. Even if data cache maintenance was done by IO code, 273 * the relocation fixup process creates dirty cache entries that we must 274 * write back before doing icache sync. The instruction cache sync also 275 * invalidates the branch predictor cache on platforms that have one. 276 */ 277 if (lf->id == 1) 278 return (0); 279#if __ARM_ARCH >= 6 280 dcache_wb_pou((vm_offset_t)lf->address, (vm_size_t)lf->size); 281 icache_inv_all(); 282#else 283 cpu_dcache_wb_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 284 cpu_l2cache_wb_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 285 cpu_icache_sync_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 286#endif 287 return (0); 288} 289 290int 291elf_cpu_unload_file(linker_file_t lf __unused) 292{ 293 294 return (0); 295} 296