elf_machdep.c revision 325810
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 325810 2017-11-14 16:03:07Z jhb $"); 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 49static boolean_t elf32_arm_abi_supported(struct image_params *); 50 51u_long elf_hwcap; 52u_long elf_hwcap2; 53 54struct sysentvec elf32_freebsd_sysvec = { 55 .sv_size = SYS_MAXSYSCALL, 56 .sv_table = sysent, 57 .sv_mask = 0, 58 .sv_errsize = 0, 59 .sv_errtbl = NULL, 60 .sv_transtrap = NULL, 61 .sv_fixup = __elfN(freebsd_fixup), 62 .sv_sendsig = sendsig, 63 .sv_sigcode = sigcode, 64 .sv_szsigcode = &szsigcode, 65 .sv_name = "FreeBSD ELF32", 66 .sv_coredump = __elfN(coredump), 67 .sv_imgact_try = NULL, 68 .sv_minsigstksz = MINSIGSTKSZ, 69 .sv_pagesize = PAGE_SIZE, 70 .sv_minuser = VM_MIN_ADDRESS, 71 .sv_maxuser = VM_MAXUSER_ADDRESS, 72 .sv_usrstack = USRSTACK, 73 .sv_psstrings = PS_STRINGS, 74 .sv_stackprot = VM_PROT_ALL, 75 .sv_copyout_strings = exec_copyout_strings, 76 .sv_setregs = exec_setregs, 77 .sv_fixlimit = NULL, 78 .sv_maxssiz = NULL, 79 .sv_flags = 80#if __ARM_ARCH >= 6 81 SV_SHP | SV_TIMEKEEP | 82#endif 83 SV_ABI_FREEBSD | SV_ILP32 | SV_HWCAP, 84 .sv_set_syscall_retval = cpu_set_syscall_retval, 85 .sv_fetch_syscall_args = cpu_fetch_syscall_args, 86 .sv_syscallnames = syscallnames, 87 .sv_shared_page_base = SHAREDPAGE, 88 .sv_shared_page_len = PAGE_SIZE, 89 .sv_schedtail = NULL, 90 .sv_thread_detach = NULL, 91 .sv_trap = NULL, 92 .sv_hwcap = &elf_hwcap, 93 .sv_hwcap2 = &elf_hwcap2, 94}; 95INIT_SYSENTVEC(elf32_sysvec, &elf32_freebsd_sysvec); 96 97static Elf32_Brandinfo freebsd_brand_info = { 98 .brand = ELFOSABI_FREEBSD, 99 .machine = EM_ARM, 100 .compat_3_brand = "FreeBSD", 101 .emul_path = NULL, 102 .interp_path = "/libexec/ld-elf.so.1", 103 .sysvec = &elf32_freebsd_sysvec, 104 .interp_newpath = NULL, 105 .brand_note = &elf32_freebsd_brandnote, 106 .flags = BI_CAN_EXEC_DYN | BI_BRAND_NOTE, 107 .header_supported= elf32_arm_abi_supported, 108}; 109 110SYSINIT(elf32, SI_SUB_EXEC, SI_ORDER_FIRST, 111 (sysinit_cfunc_t) elf32_insert_brand_entry, 112 &freebsd_brand_info); 113 114static boolean_t 115elf32_arm_abi_supported(struct image_params *imgp) 116{ 117 const Elf_Ehdr *hdr = (const Elf_Ehdr *)imgp->image_header; 118 119 /* 120 * When configured for EABI, FreeBSD supports EABI vesions 4 and 5. 121 */ 122 if (EF_ARM_EABI_VERSION(hdr->e_flags) < EF_ARM_EABI_FREEBSD_MIN) { 123 if (bootverbose) 124 uprintf("Attempting to execute non EABI binary (rev %d) image %s", 125 EF_ARM_EABI_VERSION(hdr->e_flags), imgp->args->fname); 126 return (FALSE); 127 } 128 return (TRUE); 129} 130 131void 132elf32_dump_thread(struct thread *td __unused, void *dst __unused, 133 size_t *off __unused) 134{ 135} 136 137/* 138 * It is possible for the compiler to emit relocations for unaligned data. 139 * We handle this situation with these inlines. 140 */ 141#define RELOC_ALIGNED_P(x) \ 142 (((uintptr_t)(x) & (sizeof(void *) - 1)) == 0) 143 144static __inline Elf_Addr 145load_ptr(Elf_Addr *where) 146{ 147 Elf_Addr res; 148 149 if (RELOC_ALIGNED_P(where)) 150 return *where; 151 memcpy(&res, where, sizeof(res)); 152 return (res); 153} 154 155static __inline void 156store_ptr(Elf_Addr *where, Elf_Addr val) 157{ 158 if (RELOC_ALIGNED_P(where)) 159 *where = val; 160 else 161 memcpy(where, &val, sizeof(val)); 162} 163#undef RELOC_ALIGNED_P 164 165 166/* Process one elf relocation with addend. */ 167static int 168elf_reloc_internal(linker_file_t lf, Elf_Addr relocbase, const void *data, 169 int type, int local, elf_lookup_fn lookup) 170{ 171 Elf_Addr *where; 172 Elf_Addr addr; 173 Elf_Addr addend; 174 Elf_Word rtype, symidx; 175 const Elf_Rel *rel; 176 const Elf_Rela *rela; 177 int error; 178 179 switch (type) { 180 case ELF_RELOC_REL: 181 rel = (const Elf_Rel *)data; 182 where = (Elf_Addr *) (relocbase + rel->r_offset); 183 addend = load_ptr(where); 184 rtype = ELF_R_TYPE(rel->r_info); 185 symidx = ELF_R_SYM(rel->r_info); 186 break; 187 case ELF_RELOC_RELA: 188 rela = (const Elf_Rela *)data; 189 where = (Elf_Addr *) (relocbase + rela->r_offset); 190 addend = rela->r_addend; 191 rtype = ELF_R_TYPE(rela->r_info); 192 symidx = ELF_R_SYM(rela->r_info); 193 break; 194 default: 195 panic("unknown reloc type %d\n", type); 196 } 197 198 if (local) { 199 if (rtype == R_ARM_RELATIVE) { /* A + B */ 200 addr = elf_relocaddr(lf, relocbase + addend); 201 if (load_ptr(where) != addr) 202 store_ptr(where, addr); 203 } 204 return (0); 205 } 206 207 switch (rtype) { 208 209 case R_ARM_NONE: /* none */ 210 break; 211 212 case R_ARM_ABS32: 213 error = lookup(lf, symidx, 1, &addr); 214 if (error != 0) 215 return -1; 216 store_ptr(where, addr + load_ptr(where)); 217 break; 218 219 case R_ARM_COPY: /* none */ 220 /* 221 * There shouldn't be copy relocations in kernel 222 * objects. 223 */ 224 printf("kldload: unexpected R_COPY relocation\n"); 225 return -1; 226 break; 227 228 case R_ARM_JUMP_SLOT: 229 error = lookup(lf, symidx, 1, &addr); 230 if (error == 0) { 231 store_ptr(where, addr); 232 return (0); 233 } 234 return (-1); 235 case R_ARM_RELATIVE: 236 break; 237 238 default: 239 printf("kldload: unexpected relocation type %d\n", 240 rtype); 241 return -1; 242 } 243 return(0); 244} 245 246int 247elf_reloc(linker_file_t lf, Elf_Addr relocbase, const void *data, int type, 248 elf_lookup_fn lookup) 249{ 250 251 return (elf_reloc_internal(lf, relocbase, data, type, 0, lookup)); 252} 253 254int 255elf_reloc_local(linker_file_t lf, Elf_Addr relocbase, const void *data, 256 int type, elf_lookup_fn lookup) 257{ 258 259 return (elf_reloc_internal(lf, relocbase, data, type, 1, lookup)); 260} 261 262int 263elf_cpu_load_file(linker_file_t lf) 264{ 265 266 /* 267 * The pmap code does not do an icache sync upon establishing executable 268 * mappings in the kernel pmap. It's an optimization based on the fact 269 * that kernel memory allocations always have EXECUTABLE protection even 270 * when the memory isn't going to hold executable code. The only time 271 * kernel memory holding instructions does need a sync is after loading 272 * a kernel module, and that's when this function gets called. 273 * 274 * This syncs data and instruction caches after loading a module. We 275 * don't worry about the kernel itself (lf->id is 1) as locore.S did 276 * that on entry. Even if data cache maintenance was done by IO code, 277 * the relocation fixup process creates dirty cache entries that we must 278 * write back before doing icache sync. The instruction cache sync also 279 * invalidates the branch predictor cache on platforms that have one. 280 */ 281 if (lf->id == 1) 282 return (0); 283#if __ARM_ARCH >= 6 284 dcache_wb_pou((vm_offset_t)lf->address, (vm_size_t)lf->size); 285 icache_inv_all(); 286#else 287 cpu_dcache_wb_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 288 cpu_l2cache_wb_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 289 cpu_icache_sync_range((vm_offset_t)lf->address, (vm_size_t)lf->size); 290#endif 291 return (0); 292} 293 294int 295elf_cpu_unload_file(linker_file_t lf __unused) 296{ 297 298 return (0); 299} 300