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 "opt_platform.h" 29 30 #include <sys/param.h> 31 #include <sys/systm.h> 32 #include <sys/limits.h> 33 #include <sys/proc.h> 34 #include <sys/sf_buf.h> 35 #include <sys/signal.h> 36 #include <sys/sysent.h> 37 #include <sys/unistd.h> 38 39 #include <vm/vm.h> 40 #include <vm/vm_page.h> 41 #include <vm/vm_map.h> 42 #include <vm/uma.h> 43 #include <vm/uma_int.h> 44 45 #include <machine/armreg.h> 46 #include <machine/cpu.h> 47 #include <machine/md_var.h> 48 #include <machine/pcb.h> 49 #include <machine/frame.h> 50 51 #ifdef VFP 52 #include <machine/vfp.h> 53 #endif 54 55 #include <dev/psci/psci.h> 56 57 /* 58 * Finish a fork operation, with process p2 nearly set up. 59 * Copy and update the pcb, set up the stack so that the child 60 * ready to run and return to user mode. 61 */ 62 void 63 cpu_fork(struct thread *td1, struct proc *p2, struct thread *td2, int flags) 64 { 65 struct pcb *pcb2; 66 struct trapframe *tf; 67 68 if ((flags & RFPROC) == 0) 69 return; 70 71 if (td1 == curthread) { 72 /* 73 * Save the tpidr_el0 and the vfp state, these normally happen 74 * in cpu_switch, but if userland changes these then forks 75 * this may not have happened. 76 */ 77 td1->td_pcb->pcb_tpidr_el0 = READ_SPECIALREG(tpidr_el0); 78 td1->td_pcb->pcb_tpidrro_el0 = READ_SPECIALREG(tpidrro_el0); 79 #ifdef VFP 80 if ((td1->td_pcb->pcb_fpflags & PCB_FP_STARTED) != 0) 81 vfp_save_state(td1, td1->td_pcb); 82 #endif 83 } 84 85 pcb2 = (struct pcb *)(td2->td_kstack + 86 td2->td_kstack_pages * PAGE_SIZE) - 1; 87 88 td2->td_pcb = pcb2; 89 bcopy(td1->td_pcb, pcb2, sizeof(*pcb2)); 90 91 /* Clear the debug register state. */ 92 bzero(&pcb2->pcb_dbg_regs, sizeof(pcb2->pcb_dbg_regs)); 93 94 ptrauth_fork(td2, td1); 95 96 tf = (struct trapframe *)STACKALIGN((struct trapframe *)pcb2 - 1); 97 bcopy(td1->td_frame, tf, sizeof(*tf)); 98 tf->tf_x[0] = 0; 99 tf->tf_x[1] = 0; 100 tf->tf_spsr = td1->td_frame->tf_spsr & (PSR_M_32 | PSR_DAIF); 101 102 td2->td_frame = tf; 103 104 /* Set the return value registers for fork() */ 105 td2->td_pcb->pcb_x[PCB_X19] = (uintptr_t)fork_return; 106 td2->td_pcb->pcb_x[PCB_X20] = (uintptr_t)td2; 107 td2->td_pcb->pcb_x[PCB_LR] = (uintptr_t)fork_trampoline; 108 td2->td_pcb->pcb_sp = (uintptr_t)td2->td_frame; 109 110 vfp_new_thread(td2, td1, true); 111 112 /* Setup to release spin count in fork_exit(). */ 113 td2->td_md.md_spinlock_count = 1; 114 td2->td_md.md_saved_daif = PSR_DAIF_DEFAULT; 115 116 #if defined(PERTHREAD_SSP) 117 /* Set the new canary */ 118 arc4random_buf(&td2->td_md.md_canary, sizeof(td2->td_md.md_canary)); 119 #endif 120 } 121 122 void 123 cpu_reset(void) 124 { 125 126 psci_reset(); 127 128 printf("cpu_reset failed"); 129 while(1) 130 __asm volatile("wfi" ::: "memory"); 131 } 132 133 void 134 cpu_thread_swapin(struct thread *td) 135 { 136 } 137 138 void 139 cpu_thread_swapout(struct thread *td) 140 { 141 } 142 143 void 144 cpu_set_syscall_retval(struct thread *td, int error) 145 { 146 struct trapframe *frame; 147 148 frame = td->td_frame; 149 150 if (__predict_true(error == 0)) { 151 frame->tf_x[0] = td->td_retval[0]; 152 frame->tf_x[1] = td->td_retval[1]; 153 frame->tf_spsr &= ~PSR_C; /* carry bit */ 154 return; 155 } 156 157 switch (error) { 158 case ERESTART: 159 frame->tf_elr -= 4; 160 break; 161 case EJUSTRETURN: 162 break; 163 default: 164 frame->tf_spsr |= PSR_C; /* carry bit */ 165 frame->tf_x[0] = error; 166 break; 167 } 168 } 169 170 /* 171 * Initialize machine state, mostly pcb and trap frame for a new 172 * thread, about to return to userspace. Put enough state in the new 173 * thread's PCB to get it to go back to the fork_return(), which 174 * finalizes the thread state and handles peculiarities of the first 175 * return to userspace for the new thread. 176 */ 177 void 178 cpu_copy_thread(struct thread *td, struct thread *td0) 179 { 180 bcopy(td0->td_frame, td->td_frame, sizeof(struct trapframe)); 181 bcopy(td0->td_pcb, td->td_pcb, sizeof(struct pcb)); 182 183 td->td_pcb->pcb_x[PCB_X19] = (uintptr_t)fork_return; 184 td->td_pcb->pcb_x[PCB_X20] = (uintptr_t)td; 185 td->td_pcb->pcb_x[PCB_LR] = (uintptr_t)fork_trampoline; 186 td->td_pcb->pcb_sp = (uintptr_t)td->td_frame; 187 188 /* Update VFP state for the new thread */ 189 vfp_new_thread(td, td0, false); 190 191 /* Setup to release spin count in fork_exit(). */ 192 td->td_md.md_spinlock_count = 1; 193 td->td_md.md_saved_daif = PSR_DAIF_DEFAULT; 194 195 #if defined(PERTHREAD_SSP) 196 /* Set the new canary */ 197 arc4random_buf(&td->td_md.md_canary, sizeof(td->td_md.md_canary)); 198 #endif 199 200 /* Generate new pointer authentication keys. */ 201 ptrauth_copy_thread(td, td0); 202 } 203 204 /* 205 * Set that machine state for performing an upcall that starts 206 * the entry function with the given argument. 207 */ 208 int 209 cpu_set_upcall(struct thread *td, void (*entry)(void *), void *arg, 210 stack_t *stack) 211 { 212 struct trapframe *tf = td->td_frame; 213 214 /* 32bits processes use r13 for sp */ 215 if (td->td_frame->tf_spsr & PSR_M_32) { 216 tf->tf_x[13] = STACKALIGN((uintptr_t)stack->ss_sp + 217 stack->ss_size); 218 if ((register_t)entry & 1) 219 tf->tf_spsr |= PSR_T; 220 } else 221 tf->tf_sp = STACKALIGN((uintptr_t)stack->ss_sp + 222 stack->ss_size); 223 tf->tf_elr = (register_t)entry; 224 tf->tf_x[0] = (register_t)arg; 225 tf->tf_x[29] = 0; 226 tf->tf_lr = 0; 227 return (0); 228 } 229 230 int 231 cpu_set_user_tls(struct thread *td, void *tls_base) 232 { 233 struct pcb *pcb; 234 235 if ((uintptr_t)tls_base >= VM_MAXUSER_ADDRESS) 236 return (EINVAL); 237 238 pcb = td->td_pcb; 239 if (td->td_frame->tf_spsr & PSR_M_32) { 240 /* 32bits arm stores the user TLS into tpidrro */ 241 pcb->pcb_tpidrro_el0 = (register_t)tls_base; 242 pcb->pcb_tpidr_el0 = (register_t)tls_base; 243 if (td == curthread) { 244 WRITE_SPECIALREG(tpidrro_el0, tls_base); 245 WRITE_SPECIALREG(tpidr_el0, tls_base); 246 } 247 } else { 248 pcb->pcb_tpidr_el0 = (register_t)tls_base; 249 if (td == curthread) 250 WRITE_SPECIALREG(tpidr_el0, tls_base); 251 } 252 253 return (0); 254 } 255 256 void 257 cpu_thread_exit(struct thread *td) 258 { 259 } 260 261 void 262 cpu_thread_alloc(struct thread *td) 263 { 264 265 td->td_pcb = (struct pcb *)(td->td_kstack + 266 td->td_kstack_pages * PAGE_SIZE) - 1; 267 td->td_frame = (struct trapframe *)STACKALIGN( 268 (struct trapframe *)td->td_pcb - 1); 269 ptrauth_thread_alloc(td); 270 } 271 272 void 273 cpu_thread_free(struct thread *td) 274 { 275 } 276 277 void 278 cpu_thread_clean(struct thread *td) 279 { 280 } 281 282 /* 283 * Intercept the return address from a freshly forked process that has NOT 284 * been scheduled yet. 285 * 286 * This is needed to make kernel threads stay in kernel mode. 287 */ 288 void 289 cpu_fork_kthread_handler(struct thread *td, void (*func)(void *), void *arg) 290 { 291 292 td->td_pcb->pcb_x[PCB_X19] = (uintptr_t)func; 293 td->td_pcb->pcb_x[PCB_X20] = (uintptr_t)arg; 294 } 295 296 void 297 cpu_exit(struct thread *td) 298 { 299 } 300 301 bool 302 cpu_exec_vmspace_reuse(struct proc *p __unused, vm_map_t map __unused) 303 { 304 305 return (true); 306 } 307 308 int 309 cpu_procctl(struct thread *td __unused, int idtype __unused, id_t id __unused, 310 int com __unused, void *data __unused) 311 { 312 313 return (EINVAL); 314 } 315 316 void 317 cpu_sync_core(void) 318 { 319 /* 320 * Do nothing. According to ARM ARMv8 D1.11 Exception return 321 * If FEAT_ExS is not implemented, or if FEAT_ExS is 322 * implemented and the SCTLR_ELx.EOS field is set, exception 323 * return from ELx is a context synchronization event. 324 */ 325 } 326