elf_machdep.c revision 331722
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: stable/11/sys/arm/arm/elf_machdep.c 331722 2018-03-29 02:50:57Z eadler $"); 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/elf.h> 47#include <machine/md_var.h> 48#ifdef VFP 49#include <machine/vfp.h> 50#endif 51 52static boolean_t elf32_arm_abi_supported(struct image_params *); 53 54u_long elf_hwcap; 55u_long elf_hwcap2; 56 57struct sysentvec elf32_freebsd_sysvec = { 58 .sv_size = SYS_MAXSYSCALL, 59 .sv_table = sysent, 60 .sv_mask = 0, 61 .sv_errsize = 0, 62 .sv_errtbl = NULL, 63 .sv_transtrap = NULL, 64 .sv_fixup = __elfN(freebsd_fixup), 65 .sv_sendsig = sendsig, 66 .sv_sigcode = sigcode, 67 .sv_szsigcode = &szsigcode, 68 .sv_name = "FreeBSD ELF32", 69 .sv_coredump = __elfN(coredump), 70 .sv_imgact_try = NULL, 71 .sv_minsigstksz = MINSIGSTKSZ, 72 .sv_pagesize = PAGE_SIZE, 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_SHP | SV_TIMEKEEP | 85#endif 86 SV_ABI_FREEBSD | SV_ILP32 | SV_HWCAP, 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}; 98INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 99 100static 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 113SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 114 (sysinit_cfunc_t) elf32_insert_brand_entry, 115 &freebsd_brand_info); 116 117static boolean_t 118elf32_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 134void 135elf32_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/* 151 * It is possible for the compiler to emit relocations for unaligned data. 152 * We handle this situation with these inlines. 153 */ 154#define RELOC_ALIGNED_P(x) \ 155 (((uintptr_t)(x) & (sizeof(void *) - 1)) == 0) 156 157static __inline Elf_Addr 158load_ptr(Elf_Addr *where) 159{ 160 Elf_Addr res; 161 162 if (RELOC_ALIGNED_P(where)) 163 return *where; 164 memcpy(&res, where, sizeof(res)); 165 return (res); 166} 167 168static __inline void 169store_ptr(Elf_Addr *where, Elf_Addr val) 170{ 171 if (RELOC_ALIGNED_P(where)) 172 *where = val; 173 else 174 memcpy(where, &val, sizeof(val)); 175} 176#undef RELOC_ALIGNED_P 177 178 179/* Process one elf relocation with addend. */ 180static int 181elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 182 int type, int local, elf_lookup_fn lookup) 183{ 184 Elf_Addr *where; 185 Elf_Addr addr; 186 Elf_Addr addend; 187 Elf_Word rtype, symidx; 188 const Elf_Rel *rel; 189 const Elf_Rela *rela; 190 int error; 191 192 switch (type) { 193 case ELF_RELOC_REL: 194 rel = (const Elf_Rel *)data; 195 where = (Elf_Addr *) (relocbase + rel->r_offset); 196 addend = load_ptr(where); 197 rtype = ELF_R_TYPE(rel->r_info); 198 symidx = ELF_R_SYM(rel->r_info); 199 break; 200 case ELF_RELOC_RELA: 201 rela = (const Elf_Rela *)data; 202 where = (Elf_Addr *) (relocbase + rela->r_offset); 203 addend = rela->r_addend; 204 rtype = ELF_R_TYPE(rela->r_info); 205 symidx = ELF_R_SYM(rela->r_info); 206 break; 207 default: 208 panic("unknown reloc type %d\n", type); 209 } 210 211 if (local) { 212 if (rtype == R_ARM_RELATIVE) { /* A + B */ 213 addr = elf_relocaddr(lf, relocbase + addend); 214 if (load_ptr(where) != addr) 215 store_ptr(where, addr); 216 } 217 return (0); 218 } 219 220 switch (rtype) { 221 222 case R_ARM_NONE: /* none */ 223 break; 224 225 case R_ARM_ABS32: 226 error = lookup(lf, symidx, 1, &addr); 227 if (error != 0) 228 return -1; 229 store_ptr(where, addr + load_ptr(where)); 230 break; 231 232 case R_ARM_COPY: /* none */ 233 /* 234 * There shouldn't be copy relocations in kernel 235 * objects. 236 */ 237 printf("kldload: unexpected R_COPY relocation\n"); 238 return -1; 239 break; 240 241 case R_ARM_JUMP_SLOT: 242 error = lookup(lf, symidx, 1, &addr); 243 if (error == 0) { 244 store_ptr(where, addr); 245 return (0); 246 } 247 return (-1); 248 case R_ARM_RELATIVE: 249 break; 250 251 default: 252 printf("kldload: unexpected relocation type %d\n", 253 rtype); 254 return -1; 255 } 256 return(0); 257} 258 259int 260elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 261 elf_lookup_fn lookup) 262{ 263 264 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup)); 265} 266 267int 268elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 269 int type, elf_lookup_fn lookup) 270{ 271 272 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup)); 273} 274 275int 276elf_cpu_load_file(linker_file_t lf) 277{ 278 279 /* 280 * The pmap code does not do an icache sync upon establishing executable 281 * mappings in the kernel pmap. It's an optimization based on the fact 282 * that kernel memory allocations always have EXECUTABLE protection even 283 * when the memory isn't going to hold executable code. The only time 284 * kernel memory holding instructions does need a sync is after loading 285 * a kernel module, and that's when this function gets called. 286 * 287 * This syncs data and instruction caches after loading a module. We 288 * don't worry about the kernel itself (lf->id is 1) as locore.S did 289 * that on entry. Even if data cache maintenance was done by IO code, 290 * the relocation fixup process creates dirty cache entries that we must 291 * write back before doing icache sync. The instruction cache sync also 292 * invalidates the branch predictor cache on platforms that have one. 293 */ 294 if (lf->id == 1) 295 return (0); 296#if __ARM_ARCH >= 6 297 dcache_wb_pou((vm_offset_t)lf->address, (vm_size_t)lf->size); 298 icache_inv_all(); 299#else 300 cpu_dcache_wb_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 301 cpu_l2cache_wb_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 302 cpu_icache_sync_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 303#endif 304 return (0); 305} 306 307int 308elf_cpu_unload_file(linker_file_t lf __unused) 309{ 310 311 return (0); 312} 313