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("$FreeBSD$"); 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 #include <machine/vmparam.h> 56 57 #ifdef KDTRACE_HOOKS 58 #include <sys/dtrace_bsd.h> 59 #endif 60 61 #ifdef VFP 62 #include <machine/vfp.h> 63 #endif 64 65 #ifdef KDB 66 #include <machine/db_machdep.h> 67 #endif 68 69 #ifdef DDB 70 #include <ddb/db_output.h> 71 #endif 72 73 extern register_t fsu_intr_fault; 74 75 /* Called from exception.S */ 76 void do_el1h_sync(struct trapframe *); 77 void do_el0_sync(struct trapframe *); 78 void do_el0_error(struct trapframe *); 79 static void print_registers(struct trapframe *frame); 80 81 int (*dtrace_invop_jump_addr)(struct trapframe *); 82 83 static __inline void 84 call_trapsignal(struct thread *td, int sig, int code, void *addr) 85 { 86 ksiginfo_t ksi; 87 88 ksiginfo_init_trap(&ksi); 89 ksi.ksi_signo = sig; 90 ksi.ksi_code = code; 91 ksi.ksi_addr = addr; 92 trapsignal(td, &ksi); 93 } 94 95 int 96 cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa) 97 { 98 struct proc *p; 99 register_t *ap; 100 int nap; 101 102 nap = 8; 103 p = td->td_proc; 104 ap = td->td_frame->tf_x; 105 106 sa->code = td->td_frame->tf_x[8]; 107 108 if (sa->code == SYS_syscall || sa->code == SYS___syscall) { 109 sa->code = *ap++; 110 nap--; 111 } 112 113 if (p->p_sysent->sv_mask) 114 sa->code &= p->p_sysent->sv_mask; 115 if (sa->code >= p->p_sysent->sv_size) 116 sa->callp = &p->p_sysent->sv_table[0]; 117 else 118 sa->callp = &p->p_sysent->sv_table[sa->code]; 119 120 sa->narg = sa->callp->sy_narg; 121 memcpy(sa->args, ap, nap * sizeof(register_t)); 122 if (sa->narg > nap) 123 panic("ARM64TODO: Could we have more than 8 args?"); 124 125 td->td_retval[0] = 0; 126 td->td_retval[1] = 0; 127 128 return (0); 129 } 130 131 #include "../../kern/subr_syscall.c" 132 133 static void 134 svc_handler(struct trapframe *frame) 135 { 136 struct syscall_args sa; 137 struct thread *td; 138 int error; 139 140 td = curthread; 141 td->td_frame = frame; 142 143 error = syscallenter(td, &sa); 144 syscallret(td, error, &sa); 145 } 146 147 static void 148 data_abort(struct trapframe *frame, uint64_t esr, uint64_t far, int lower) 149 { 150 struct vm_map *map; 151 struct thread *td; 152 struct proc *p; 153 struct pcb *pcb; 154 vm_prot_t ftype; 155 vm_offset_t va; 156 int error, sig, ucode; 157 158 /* 159 * According to the ARMv8-A rev. A.g, B2.10.5 "Load-Exclusive 160 * and Store-Exclusive instruction usage restrictions", state 161 * of the exclusive monitors after data abort exception is unknown. 162 */ 163 clrex(); 164 165 #ifdef KDB 166 if (kdb_active) { 167 kdb_reenter(); 168 return; 169 } 170 #endif 171 172 td = curthread; 173 pcb = td->td_pcb; 174 175 /* 176 * Special case for fuswintr and suswintr. These can't sleep so 177 * handle them early on in the trap handler. 178 */ 179 if (__predict_false(pcb->pcb_onfault == (vm_offset_t)&fsu_intr_fault)) { 180 frame->tf_elr = pcb->pcb_onfault; 181 return; 182 } 183 184 KASSERT(td->td_md.md_spinlock_count == 0, 185 ("data abort with spinlock held")); 186 if (td->td_critnest != 0 || WITNESS_CHECK(WARN_SLEEPOK | 187 WARN_GIANTOK, NULL, "Kernel page fault") != 0) { 188 print_registers(frame); 189 panic("data abort in critical section or under mutex"); 190 } 191 192 p = td->td_proc; 193 if (lower) 194 map = &p->p_vmspace->vm_map; 195 else { 196 /* The top bit tells us which range to use */ 197 if ((far >> 63) == 1) 198 map = kernel_map; 199 else 200 map = &p->p_vmspace->vm_map; 201 } 202 203 va = trunc_page(far); 204 ftype = ((esr >> 6) & 1) ? VM_PROT_READ | VM_PROT_WRITE : VM_PROT_READ; 205 206 /* Fault in the page. */ 207 error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 208 if (error != KERN_SUCCESS) { 209 if (lower) { 210 sig = SIGSEGV; 211 if (error == KERN_PROTECTION_FAILURE) 212 ucode = SEGV_ACCERR; 213 else 214 ucode = SEGV_MAPERR; 215 call_trapsignal(td, sig, ucode, (void *)far); 216 } else { 217 if (td->td_intr_nesting_level == 0 && 218 pcb->pcb_onfault != 0) { 219 frame->tf_x[0] = error; 220 frame->tf_elr = pcb->pcb_onfault; 221 return; 222 } 223 #ifdef KDB 224 if (debugger_on_panic || kdb_active) 225 if (kdb_trap(ESR_ELx_EXCEPTION(esr), 0, frame)) 226 return; 227 #endif 228 panic("vm_fault failed: %lx", frame->tf_elr); 229 } 230 } 231 232 if (lower) 233 userret(td, frame); 234 } 235 236 static void 237 print_registers(struct trapframe *frame) 238 { 239 u_int reg; 240 241 for (reg = 0; reg < 31; reg++) { 242 printf(" %sx%d: %16lx\n", (reg < 10) ? " " : "", reg, 243 frame->tf_x[reg]); 244 } 245 printf(" sp: %16lx\n", frame->tf_sp); 246 printf(" lr: %16lx\n", frame->tf_lr); 247 printf(" elr: %16lx\n", frame->tf_elr); 248 printf("spsr: %16lx\n", frame->tf_spsr); 249 } 250 251 void 252 do_el1h_sync(struct trapframe *frame) 253 { 254 uint32_t exception; 255 uint64_t esr, far; 256 257 /* Read the esr register to get the exception details */ 258 esr = READ_SPECIALREG(esr_el1); 259 exception = ESR_ELx_EXCEPTION(esr); 260 261 #ifdef KDTRACE_HOOKS 262 if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, exception)) 263 return; 264 #endif 265 266 /* 267 * Sanity check we are in an exception er can handle. The IL bit 268 * is used to indicate the instruction length, except in a few 269 * exceptions described in the ARMv8 ARM. 270 * 271 * It is unclear in some cases if the bit is implementation defined. 272 * The Foundation Model and QEMU disagree on if the IL bit should 273 * be set when we are in a data fault from the same EL and the ISV 274 * bit (bit 24) is also set. 275 */ 276 KASSERT((esr & ESR_ELx_IL) == ESR_ELx_IL || 277 (exception == EXCP_DATA_ABORT && ((esr & ISS_DATA_ISV) == 0)), 278 ("Invalid instruction length in exception, esr %lx", esr)); 279 280 CTR4(KTR_TRAP, 281 "do_el1_sync: curthread: %p, esr %lx, elr: %lx, frame: %p", 282 curthread, esr, frame->tf_elr, frame); 283 284 switch(exception) { 285 case EXCP_FP_SIMD: 286 case EXCP_TRAP_FP: 287 print_registers(frame); 288 panic("VFP exception in the kernel"); 289 case EXCP_DATA_ABORT: 290 far = READ_SPECIALREG(far_el1); 291 intr_enable(); 292 data_abort(frame, esr, far, 0); 293 break; 294 case EXCP_BRK: 295 #ifdef KDTRACE_HOOKS 296 if ((esr & ESR_ELx_ISS_MASK) == 0x40d && \ 297 dtrace_invop_jump_addr != 0) { 298 dtrace_invop_jump_addr(frame); 299 break; 300 } 301 #endif 302 /* FALLTHROUGH */ 303 case EXCP_WATCHPT_EL1: 304 case EXCP_SOFTSTP_EL1: 305 #ifdef KDB 306 kdb_trap(exception, 0, frame); 307 #else 308 panic("No debugger in kernel.\n"); 309 #endif 310 break; 311 default: 312 print_registers(frame); 313 panic("Unknown kernel exception %x esr_el1 %lx\n", exception, 314 esr); 315 } 316 } 317 318 /* 319 * The attempted execution of an instruction bit pattern that has no allocated 320 * instruction results in an exception with an unknown reason. 321 */ 322 static void 323 el0_excp_unknown(struct trapframe *frame) 324 { 325 struct thread *td; 326 uint64_t far; 327 328 td = curthread; 329 far = READ_SPECIALREG(far_el1); 330 call_trapsignal(td, SIGILL, ILL_ILLTRP, (void *)far); 331 userret(td, frame); 332 } 333 334 void 335 do_el0_sync(struct trapframe *frame) 336 { 337 struct thread *td; 338 uint32_t exception; 339 uint64_t esr, far; 340 341 /* Check we have a sane environment when entering from userland */ 342 KASSERT((uintptr_t)get_pcpu() >= VM_MIN_KERNEL_ADDRESS, 343 ("Invalid pcpu address from userland: %p (tpidr %lx)", 344 get_pcpu(), READ_SPECIALREG(tpidr_el1))); 345 346 esr = READ_SPECIALREG(esr_el1); 347 exception = ESR_ELx_EXCEPTION(esr); 348 switch (exception) { 349 case EXCP_INSN_ABORT_L: 350 case EXCP_DATA_ABORT_L: 351 case EXCP_DATA_ABORT: 352 far = READ_SPECIALREG(far_el1); 353 } 354 intr_enable(); 355 356 CTR4(KTR_TRAP, 357 "do_el0_sync: curthread: %p, esr %lx, elr: %lx, frame: %p", 358 curthread, esr, frame->tf_elr, frame); 359 360 switch(exception) { 361 case EXCP_FP_SIMD: 362 case EXCP_TRAP_FP: 363 #ifdef VFP 364 vfp_restore_state(); 365 #else 366 panic("VFP exception in userland"); 367 #endif 368 break; 369 case EXCP_SVC: 370 svc_handler(frame); 371 break; 372 case EXCP_INSN_ABORT_L: 373 case EXCP_DATA_ABORT_L: 374 case EXCP_DATA_ABORT: 375 data_abort(frame, esr, far, 1); 376 break; 377 case EXCP_UNKNOWN: 378 el0_excp_unknown(frame); 379 break; 380 case EXCP_PC_ALIGN: 381 td = curthread; 382 call_trapsignal(td, SIGBUS, BUS_ADRALN, (void *)frame->tf_elr); 383 userret(td, frame); 384 break; 385 case EXCP_BRK: 386 td = curthread; 387 call_trapsignal(td, SIGTRAP, TRAP_BRKPT, (void *)frame->tf_elr); 388 userret(td, frame); 389 break; 390 default: 391 print_registers(frame); 392 panic("Unknown userland exception %x esr_el1 %lx\n", exception, 393 esr); 394 } 395 } 396 397 void 398 do_el0_error(struct trapframe *frame) 399 { 400 401 panic("ARM64TODO: do_el0_error"); 402 } 403 404