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_extern.h> 50 51 #include <machine/frame.h> 52 #include <machine/pcb.h> 53 #include <machine/pcpu.h> 54 #include <machine/vmparam.h> 55 56 #ifdef VFP 57 #include <machine/vfp.h> 58 #endif 59 60 #ifdef KDB 61 #include <machine/db_machdep.h> 62 #endif 63 64 #ifdef DDB 65 #include <ddb/db_output.h> 66 #endif 67 68 extern register_t fsu_intr_fault; 69 70 /* Called from exception.S */ 71 void do_el1h_sync(struct trapframe *); 72 void do_el0_sync(struct trapframe *); 73 void do_el0_error(struct trapframe *); 74 75 static __inline void 76 call_trapsignal(struct thread *td, int sig, u_long code) 77 { 78 ksiginfo_t ksi; 79 80 ksiginfo_init_trap(&ksi); 81 ksi.ksi_signo = sig; 82 ksi.ksi_code = (int)code; 83 trapsignal(td, &ksi); 84 } 85 86 int 87 cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa) 88 { 89 struct proc *p; 90 register_t *ap; 91 int nap; 92 93 nap = 8; 94 p = td->td_proc; 95 ap = td->td_frame->tf_x; 96 97 sa->code = td->td_frame->tf_x[8]; 98 99 if (sa->code == SYS_syscall || sa->code == SYS___syscall) { 100 sa->code = *ap++; 101 nap--; 102 } 103 104 if (p->p_sysent->sv_mask) 105 sa->code &= p->p_sysent->sv_mask; 106 if (sa->code >= p->p_sysent->sv_size) 107 sa->callp = &p->p_sysent->sv_table[0]; 108 else 109 sa->callp = &p->p_sysent->sv_table[sa->code]; 110 111 sa->narg = sa->callp->sy_narg; 112 memcpy(sa->args, ap, nap * sizeof(register_t)); 113 if (sa->narg > nap) 114 panic("TODO: Could we have more then 8 args?"); 115 116 td->td_retval[0] = 0; 117 td->td_retval[1] = 0; 118 119 return (0); 120 } 121 122 #include "../../kern/subr_syscall.c" 123 124 static void 125 svc_handler(struct trapframe *frame) 126 { 127 struct syscall_args sa; 128 struct thread *td; 129 int error; 130 131 td = curthread; 132 td->td_frame = frame; 133 134 error = syscallenter(td, &sa); 135 syscallret(td, error, &sa); 136 } 137 138 static void 139 data_abort(struct trapframe *frame, uint64_t esr, int lower) 140 { 141 struct vm_map *map; 142 struct thread *td; 143 struct proc *p; 144 struct pcb *pcb; 145 vm_prot_t ftype; 146 vm_offset_t va; 147 uint64_t far; 148 int error, sig; 149 150 td = curthread; 151 pcb = td->td_pcb; 152 153 /* 154 * Special case for fuswintr and suswintr. These can't sleep so 155 * handle them early on in the trap handler. 156 */ 157 if (__predict_false(pcb->pcb_onfault == (vm_offset_t)&fsu_intr_fault)) { 158 frame->tf_elr = pcb->pcb_onfault; 159 return; 160 } 161 162 far = READ_SPECIALREG(far_el1); 163 p = td->td_proc; 164 165 if (lower) 166 map = &td->td_proc->p_vmspace->vm_map; 167 else { 168 /* The top bit tells us which range to use */ 169 if ((far >> 63) == 1) 170 map = kernel_map; 171 else 172 map = &td->td_proc->p_vmspace->vm_map; 173 } 174 175 va = trunc_page(far); 176 ftype = ((esr >> 6) & 1) ? VM_PROT_READ | VM_PROT_WRITE : VM_PROT_READ; 177 178 if (map != kernel_map) { 179 /* 180 * Keep swapout from messing with us during this 181 * critical time. 182 */ 183 PROC_LOCK(p); 184 ++p->p_lock; 185 PROC_UNLOCK(p); 186 187 /* Fault in the user page: */ 188 error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 189 190 PROC_LOCK(p); 191 --p->p_lock; 192 PROC_UNLOCK(p); 193 } else { 194 /* 195 * Don't have to worry about process locking or stacks in the 196 * kernel. 197 */ 198 error = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 199 } 200 201 if (error != 0) { 202 if (lower) { 203 if (error == ENOMEM) 204 sig = SIGKILL; 205 else 206 sig = SIGSEGV; 207 call_trapsignal(td, sig, 0); 208 } else { 209 if (td->td_intr_nesting_level == 0 && 210 pcb->pcb_onfault != 0) { 211 frame->tf_x[0] = error; 212 frame->tf_elr = pcb->pcb_onfault; 213 return; 214 } 215 panic("vm_fault failed: %lx", frame->tf_elr); 216 } 217 } 218 219 if (lower) 220 userret(td, frame); 221 } 222 223 void 224 do_el1h_sync(struct trapframe *frame) 225 { 226 uint32_t exception; 227 uint64_t esr; 228 229 /* Read the esr register to get the exception details */ 230 esr = READ_SPECIALREG(esr_el1); 231 exception = ESR_ELx_EXCEPTION(esr); 232 233 /* 234 * Sanity check we are in an exception er can handle. The IL bit 235 * is used to indicate the instruction length, except in a few 236 * exceptions described in the ARMv8 ARM. 237 * 238 * It is unclear in some cases if the bit is implementation defined. 239 * The Foundation Model and QEMU disagree on if the IL bit should 240 * be set when we are in a data fault from the same EL and the ISV 241 * bit (bit 24) is also set. 242 */ 243 KASSERT((esr & ESR_ELx_IL) == ESR_ELx_IL || 244 (exception == EXCP_DATA_ABORT && ((esr & ISS_DATA_ISV) == 0)), 245 ("Invalid instruction length in exception")); 246 247 switch(exception) { 248 case EXCP_FP_SIMD: 249 case EXCP_TRAP_FP: 250 panic("VFP exception in the kernel"); 251 case EXCP_DATA_ABORT: 252 data_abort(frame, esr, 0); 253 break; 254 case EXCP_BRK: 255 case EXCP_WATCHPT_EL1: 256 case EXCP_SOFTSTP_EL1: 257 #ifdef KDB 258 kdb_trap(exception, 0, frame); 259 #else 260 panic("No debugger in kernel.\n"); 261 #endif 262 break; 263 default: 264 panic("Unknown kernel exception %x esr_el1 %lx\n", exception, 265 esr); 266 } 267 } 268 269 void 270 do_el0_sync(struct trapframe *frame) 271 { 272 uint32_t exception; 273 uint64_t esr; 274 275 /* Check we have a sane environment when entering from userland */ 276 KASSERT((uintptr_t)get_pcpu() >= VM_MIN_KERNEL_ADDRESS, 277 ("Invalid pcpu address from userland: %p (tpidr %lx)", 278 get_pcpu(), READ_SPECIALREG(tpidr_el1))); 279 280 esr = READ_SPECIALREG(esr_el1); 281 exception = ESR_ELx_EXCEPTION(esr); 282 283 switch(exception) { 284 case EXCP_FP_SIMD: 285 case EXCP_TRAP_FP: 286 #ifdef VFP 287 vfp_restore_state(); 288 #else 289 panic("VFP exception in userland"); 290 #endif 291 break; 292 case EXCP_SVC: 293 svc_handler(frame); 294 break; 295 case EXCP_INSN_ABORT_L: 296 case EXCP_DATA_ABORT_L: 297 data_abort(frame, esr, 1); 298 break; 299 default: 300 panic("Unknown userland exception %x esr_el1 %lx\n", exception, 301 esr); 302 } 303 } 304 305 void 306 do_el0_error(struct trapframe *frame) 307 { 308 309 panic("do_el0_error"); 310 } 311 312