1/*- 2 * Copyright (c) 2014 Andrew Turner 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 AND CONTRIBUTORS ``AS IS'' AND 15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24 * SUCH DAMAGE. 25 * 26 */ 27 28#include <sys/cdefs.h> 29__FBSDID("$FreeBSD: stable/11/sys/arm64/arm64/trap.c 344905 2019-03-08 00:20:37Z jhb $"); 30 31#include <sys/param.h> 32#include <sys/systm.h> 33#include <sys/kernel.h> 34#include <sys/lock.h> 35#include <sys/mutex.h> 36#include <sys/pioctl.h> 37#include <sys/proc.h> 38#include <sys/ptrace.h> 39#include <sys/syscall.h> 40#include <sys/sysent.h> 41#ifdef KDB 42#include <sys/kdb.h> 43#endif 44 45#include <vm/vm.h> 46#include <vm/pmap.h> 47#include <vm/vm_kern.h> 48#include <vm/vm_map.h> 49#include <vm/vm_param.h> 50#include <vm/vm_extern.h> 51 52#include <machine/frame.h> 53#include <machine/pcb.h> 54#include <machine/pcpu.h> 55 56#ifdef KDTRACE_HOOKS 57#include <sys/dtrace_bsd.h> 58#endif 59 60#ifdef VFP 61#include <machine/vfp.h> 62#endif 63 64#ifdef KDB 65#include <machine/db_machdep.h> 66#endif 67 68#ifdef DDB 69#include <ddb/db_output.h> 70#endif 71 72extern register_t fsu_intr_fault; 73 74/* Called from exception.S */ 75void do_el1h_sync(struct thread *, struct trapframe *); 76void do_el0_sync(struct thread *, struct trapframe *); 77void do_el0_error(struct trapframe *); 78static void print_registers(struct trapframe *frame); 79 80int (*dtrace_invop_jump_addr)(struct trapframe *); 81 82static __inline void 83call_trapsignal(struct thread *td, int sig, int code, void *addr) 84{ 85 ksiginfo_t ksi; 86 87 ksiginfo_init_trap(&ksi); 88 ksi.ksi_signo = sig; 89 ksi.ksi_code = code; 90 ksi.ksi_addr = addr; 91 trapsignal(td, &ksi); 92} 93 94int 95cpu_fetch_syscall_args(struct thread *td) 96{ 97 struct proc *p; 98 register_t *ap; 99 struct syscall_args *sa; 100 int nap; 101 102 nap = 8; 103 p = td->td_proc; 104 ap = td->td_frame->tf_x; 105 sa = &td->td_sa; 106 107 sa->code = td->td_frame->tf_x[8]; 108 109 if (sa->code == SYS_syscall || sa->code == SYS___syscall) { 110 sa->code = *ap++; 111 nap--; 112 } 113 114 if (p->p_sysent->sv_mask) 115 sa->code &= p->p_sysent->sv_mask; 116 if (sa->code >= p->p_sysent->sv_size) 117 sa->callp = &p->p_sysent->sv_table[0]; 118 else 119 sa->callp = &p->p_sysent->sv_table[sa->code]; 120 121 sa->narg = sa->callp->sy_narg; 122 memcpy(sa->args, ap, nap * sizeof(register_t)); 123 if (sa->narg > nap) 124 panic("ARM64TODO: Could we have more than 8 args?"); 125 126 td->td_retval[0] = 0; 127 td->td_retval[1] = 0; 128 129 return (0); 130} 131 132#include "../../kern/subr_syscall.c" 133 134static void 135svc_handler(struct thread *td, struct trapframe *frame) 136{ 137 int error; 138 139 if ((frame->tf_esr & ESR_ELx_ISS_MASK) == 0) { 140 error = syscallenter(td); 141 syscallret(td, error); 142 } else { 143 call_trapsignal(td, SIGILL, ILL_ILLOPN, (void *)frame->tf_elr); 144 userret(td, frame); 145 } 146} 147 148static void 149data_abort(struct thread *td, struct trapframe *frame, uint64_t esr, 150 uint64_t far, int lower) 151{ 152 struct vm_map *map; 153 struct proc *p; 154 struct pcb *pcb; 155 vm_prot_t ftype; 156 vm_offset_t va; 157 int error, sig, ucode; 158#ifdef KDB 159 bool handled; 160#endif 161 162 /* 163 * According to the ARMv8-A rev. A.g, B2.10.5 "Load-Exclusive 164 * and Store-Exclusive instruction usage restrictions", state 165 * of the exclusive monitors after data abort exception is unknown. 166 */ 167 clrex(); 168 169#ifdef KDB 170 if (kdb_active) { 171 kdb_reenter(); 172 return; 173 } 174#endif 175 176 pcb = td->td_pcb; 177 178 /* 179 * Special case for fuswintr and suswintr. These can't sleep so 180 * handle them early on in the trap handler. 181 */ 182 if (__predict_false(pcb->pcb_onfault == (vm_offset_t)&fsu_intr_fault)) { 183 frame->tf_elr = pcb->pcb_onfault; 184 return; 185 } 186 187 p = td->td_proc; 188 if (lower) 189 map = &p->p_vmspace->vm_map; 190 else { 191 /* The top bit tells us which range to use */ 192 if ((far >> 63) == 1) 193 map = kernel_map; 194 else 195 map = &p->p_vmspace->vm_map; 196 } 197 198 if (pmap_fault(map->pmap, esr, far) == KERN_SUCCESS) 199 return; 200 201 KASSERT(td->td_md.md_spinlock_count == 0, 202 ("data abort with spinlock held")); 203 if (td->td_critnest != 0 || WITNESS_CHECK(WARN_SLEEPOK | 204 WARN_GIANTOK, NULL, "Kernel page fault") != 0) { 205 print_registers(frame); 206 printf(" far: %16lx\n", far); 207 printf(" esr: %.8lx\n", esr); 208 panic("data abort in critical section or under mutex"); 209 } 210 211 va = trunc_page(far); 212 ftype = ((esr >> 6) & 1) ? VM_PROT_READ | VM_PROT_WRITE : VM_PROT_READ; 213 214 /* Fault in the page. */ 215 error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 216 if (error != KERN_SUCCESS) { 217 if (lower) { 218 sig = SIGSEGV; 219 if (error == KERN_PROTECTION_FAILURE) 220 ucode = SEGV_ACCERR; 221 else 222 ucode = SEGV_MAPERR; 223 call_trapsignal(td, sig, ucode, (void *)far); 224 } else { 225 if (td->td_intr_nesting_level == 0 && 226 pcb->pcb_onfault != 0) { 227 frame->tf_x[0] = error; 228 frame->tf_elr = pcb->pcb_onfault; 229 return; 230 } 231 232 printf("Fatal data abort:\n"); 233 print_registers(frame); 234 printf(" far: %16lx\n", far); 235 printf(" esr: %.8lx\n", esr); 236 237#ifdef KDB 238 if (debugger_on_trap) { 239 kdb_why = KDB_WHY_TRAP; 240 handled = kdb_trap(ESR_ELx_EXCEPTION(esr), 0, 241 frame); 242 kdb_why = KDB_WHY_UNSET; 243 if (handled) 244 return; 245 } 246#endif 247 panic("vm_fault failed: %lx", frame->tf_elr); 248 } 249 } 250 251 if (lower) 252 userret(td, frame); 253} 254 255static void 256print_registers(struct trapframe *frame) 257{ 258 u_int reg; 259 260 for (reg = 0; reg < 31; reg++) { 261 printf(" %sx%d: %16lx\n", (reg < 10) ? " " : "", reg, 262 frame->tf_x[reg]); 263 } 264 printf(" sp: %16lx\n", frame->tf_sp); 265 printf(" lr: %16lx\n", frame->tf_lr); 266 printf(" elr: %16lx\n", frame->tf_elr); 267 printf("spsr: %8x\n", frame->tf_spsr); 268} 269 270void 271do_el1h_sync(struct thread *td, struct trapframe *frame) 272{ 273 uint32_t exception; 274 uint64_t esr, far; 275 276 /* Read the esr register to get the exception details */ 277 esr = frame->tf_esr; 278 exception = ESR_ELx_EXCEPTION(esr); 279 280#ifdef KDTRACE_HOOKS 281 if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, exception)) 282 return; 283#endif 284 285 CTR4(KTR_TRAP, 286 "do_el1_sync: curthread: %p, esr %lx, elr: %lx, frame: %p", td, 287 esr, frame->tf_elr, frame); 288 289 switch(exception) { 290 case EXCP_FP_SIMD: 291 case EXCP_TRAP_FP: 292 print_registers(frame); 293 printf(" esr: %.8lx\n", esr); 294 panic("VFP exception in the kernel"); 295 case EXCP_INSN_ABORT: 296 case EXCP_DATA_ABORT: 297 far = READ_SPECIALREG(far_el1); 298 intr_enable(); 299 data_abort(td, frame, esr, far, 0); 300 break; 301 case EXCP_BRK: 302#ifdef KDTRACE_HOOKS 303 if ((esr & ESR_ELx_ISS_MASK) == 0x40d && \ 304 dtrace_invop_jump_addr != 0) { 305 dtrace_invop_jump_addr(frame); 306 break; 307 } 308#endif 309 /* FALLTHROUGH */ 310 case EXCP_WATCHPT_EL1: 311 case EXCP_SOFTSTP_EL1: 312#ifdef KDB 313 kdb_trap(exception, 0, frame); 314#else 315 panic("No debugger in kernel.\n"); 316#endif 317 break; 318 default: 319 print_registers(frame); 320 panic("Unknown kernel exception %x esr_el1 %lx\n", exception, 321 esr); 322 } 323} 324 325/* 326 * The attempted execution of an instruction bit pattern that has no allocated 327 * instruction results in an exception with an unknown reason. 328 */ 329static void 330el0_excp_unknown(struct trapframe *frame, uint64_t far) 331{ 332 struct thread *td; 333 334 td = curthread; 335 call_trapsignal(td, SIGILL, ILL_ILLTRP, (void *)far); 336 userret(td, frame); 337} 338 339void 340do_el0_sync(struct thread *td, struct trapframe *frame) 341{ 342 uint32_t exception; 343 uint64_t esr, far; 344 345 /* Check we have a sane environment when entering from userland */ 346 KASSERT((uintptr_t)get_pcpu() >= VM_MIN_KERNEL_ADDRESS, 347 ("Invalid pcpu address from userland: %p (tpidr %lx)", 348 get_pcpu(), READ_SPECIALREG(tpidr_el1))); 349 350 esr = frame->tf_esr; 351 exception = ESR_ELx_EXCEPTION(esr); 352 switch (exception) { 353 case EXCP_UNKNOWN: 354 case EXCP_INSN_ABORT_L: 355 case EXCP_DATA_ABORT_L: 356 case EXCP_DATA_ABORT: 357 far = READ_SPECIALREG(far_el1); 358 } 359 intr_enable(); 360 361 CTR4(KTR_TRAP, 362 "do_el0_sync: curthread: %p, esr %lx, elr: %lx, frame: %p", td, esr, 363 frame->tf_elr, frame); 364 365 switch(exception) { 366 case EXCP_FP_SIMD: 367 case EXCP_TRAP_FP: 368#ifdef VFP 369 vfp_restore_state(); 370#else 371 panic("VFP exception in userland"); 372#endif 373 break; 374 case EXCP_SVC: 375 svc_handler(td, frame); 376 break; 377 case EXCP_INSN_ABORT_L: 378 case EXCP_DATA_ABORT_L: 379 case EXCP_DATA_ABORT: 380 data_abort(td, frame, esr, far, 1); 381 break; 382 case EXCP_UNKNOWN: 383 el0_excp_unknown(frame, far); 384 break; 385 case EXCP_SP_ALIGN: 386 call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_sp); 387 userret(td, frame); 388 break; 389 case EXCP_PC_ALIGN: 390 call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_elr); 391 userret(td, frame); 392 break; 393 case EXCP_BRK: 394 call_trapsignal(td, SIGTRAP, TRAP_BRKPT, (void *)frame->tf_elr); 395 userret(td, frame); 396 break; 397 case EXCP_MSR: 398 call_trapsignal(td, SIGILL, ILL_PRVOPC, (void *)frame->tf_elr); 399 userret(td, frame); 400 break; 401 case EXCP_SOFTSTP_EL0: 402 td->td_frame->tf_spsr &= ~PSR_SS; 403 td->td_pcb->pcb_flags &= ~PCB_SINGLE_STEP; 404 WRITE_SPECIALREG(MDSCR_EL1, 405 READ_SPECIALREG(MDSCR_EL1) & ~DBG_MDSCR_SS); 406 call_trapsignal(td, SIGTRAP, TRAP_TRACE, 407 (void *)frame->tf_elr); 408 userret(td, frame); 409 break; 410 default: 411 call_trapsignal(td, SIGBUS, BUS_OBJERR, (void *)frame->tf_elr); 412 userret(td, frame); 413 break; 414 } 415} 416 417void 418do_el0_error(struct trapframe *frame) 419{ 420 421 panic("ARM64TODO: do_el0_error"); 422} 423 424