1 /*- 2 * Copyright (c) 2014 Andrew Turner 3 * Copyright (c) 2015-2017 Ruslan Bukin <br@bsdpad.com> 4 * All rights reserved. 5 * 6 * Portions of this software were developed by SRI International and the 7 * University of Cambridge Computer Laboratory under DARPA/AFRL contract 8 * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme. 9 * 10 * Portions of this software were developed by the University of Cambridge 11 * Computer Laboratory as part of the CTSRD Project, with support from the 12 * UK Higher Education Innovation Fund (HEIF). 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/param.h> 37 #include <sys/systm.h> 38 #include <sys/exec.h> 39 #include <sys/imgact.h> 40 #include <sys/kdb.h> 41 #include <sys/kernel.h> 42 #include <sys/ktr.h> 43 #include <sys/limits.h> 44 #include <sys/lock.h> 45 #include <sys/mutex.h> 46 #include <sys/proc.h> 47 #include <sys/ptrace.h> 48 #include <sys/reg.h> 49 #include <sys/rwlock.h> 50 #include <sys/sched.h> 51 #include <sys/signalvar.h> 52 #include <sys/syscallsubr.h> 53 #include <sys/sysent.h> 54 #include <sys/sysproto.h> 55 #include <sys/ucontext.h> 56 57 #include <machine/cpu.h> 58 #include <machine/fpe.h> 59 #include <machine/kdb.h> 60 #include <machine/pcb.h> 61 #include <machine/pte.h> 62 #include <machine/riscvreg.h> 63 #include <machine/sbi.h> 64 #include <machine/trap.h> 65 66 #include <vm/vm.h> 67 #include <vm/vm_param.h> 68 #include <vm/pmap.h> 69 #include <vm/vm_map.h> 70 71 static void get_fpcontext(struct thread *td, mcontext_t *mcp); 72 static void set_fpcontext(struct thread *td, mcontext_t *mcp); 73 74 _Static_assert(sizeof(mcontext_t) == 864, "mcontext_t size incorrect"); 75 _Static_assert(sizeof(ucontext_t) == 936, "ucontext_t size incorrect"); 76 _Static_assert(sizeof(siginfo_t) == 80, "siginfo_t size incorrect"); 77 78 int 79 fill_regs(struct thread *td, struct reg *regs) 80 { 81 struct trapframe *frame; 82 83 frame = td->td_frame; 84 regs->sepc = frame->tf_sepc; 85 regs->sstatus = frame->tf_sstatus; 86 regs->ra = frame->tf_ra; 87 regs->sp = frame->tf_sp; 88 regs->gp = frame->tf_gp; 89 regs->tp = frame->tf_tp; 90 91 memcpy(regs->t, frame->tf_t, sizeof(regs->t)); 92 memcpy(regs->s, frame->tf_s, sizeof(regs->s)); 93 memcpy(regs->a, frame->tf_a, sizeof(regs->a)); 94 95 return (0); 96 } 97 98 int 99 set_regs(struct thread *td, struct reg *regs) 100 { 101 struct trapframe *frame; 102 103 frame = td->td_frame; 104 frame->tf_sepc = regs->sepc; 105 frame->tf_ra = regs->ra; 106 frame->tf_sp = regs->sp; 107 frame->tf_gp = regs->gp; 108 frame->tf_tp = regs->tp; 109 110 memcpy(frame->tf_t, regs->t, sizeof(frame->tf_t)); 111 memcpy(frame->tf_s, regs->s, sizeof(frame->tf_s)); 112 memcpy(frame->tf_a, regs->a, sizeof(frame->tf_a)); 113 114 return (0); 115 } 116 117 int 118 fill_fpregs(struct thread *td, struct fpreg *regs) 119 { 120 struct pcb *pcb; 121 122 pcb = td->td_pcb; 123 124 if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0) { 125 /* 126 * If we have just been running FPE instructions we will 127 * need to save the state to memcpy it below. 128 */ 129 if (td == curthread) 130 fpe_state_save(td); 131 132 memcpy(regs->fp_x, pcb->pcb_x, sizeof(regs->fp_x)); 133 regs->fp_fcsr = pcb->pcb_fcsr; 134 } else 135 memset(regs, 0, sizeof(*regs)); 136 137 return (0); 138 } 139 140 int 141 set_fpregs(struct thread *td, struct fpreg *regs) 142 { 143 struct trapframe *frame; 144 struct pcb *pcb; 145 146 frame = td->td_frame; 147 pcb = td->td_pcb; 148 149 memcpy(pcb->pcb_x, regs->fp_x, sizeof(regs->fp_x)); 150 pcb->pcb_fcsr = regs->fp_fcsr; 151 pcb->pcb_fpflags |= PCB_FP_STARTED; 152 frame->tf_sstatus &= ~SSTATUS_FS_MASK; 153 frame->tf_sstatus |= SSTATUS_FS_CLEAN; 154 155 return (0); 156 } 157 158 int 159 fill_dbregs(struct thread *td, struct dbreg *regs) 160 { 161 162 panic("fill_dbregs"); 163 } 164 165 int 166 set_dbregs(struct thread *td, struct dbreg *regs) 167 { 168 169 panic("set_dbregs"); 170 } 171 172 void 173 exec_setregs(struct thread *td, struct image_params *imgp, uintptr_t stack) 174 { 175 struct trapframe *tf; 176 struct pcb *pcb; 177 178 tf = td->td_frame; 179 pcb = td->td_pcb; 180 181 memset(tf, 0, sizeof(struct trapframe)); 182 183 tf->tf_a[0] = stack; 184 tf->tf_sp = STACKALIGN(stack); 185 tf->tf_ra = imgp->entry_addr; 186 tf->tf_sepc = imgp->entry_addr; 187 188 pcb->pcb_fpflags &= ~PCB_FP_STARTED; 189 } 190 191 /* Sanity check these are the same size, they will be memcpy'd to and from */ 192 CTASSERT(sizeof(((struct trapframe *)0)->tf_a) == 193 sizeof((struct gpregs *)0)->gp_a); 194 CTASSERT(sizeof(((struct trapframe *)0)->tf_s) == 195 sizeof((struct gpregs *)0)->gp_s); 196 CTASSERT(sizeof(((struct trapframe *)0)->tf_t) == 197 sizeof((struct gpregs *)0)->gp_t); 198 CTASSERT(sizeof(((struct trapframe *)0)->tf_a) == 199 sizeof((struct reg *)0)->a); 200 CTASSERT(sizeof(((struct trapframe *)0)->tf_s) == 201 sizeof((struct reg *)0)->s); 202 CTASSERT(sizeof(((struct trapframe *)0)->tf_t) == 203 sizeof((struct reg *)0)->t); 204 205 int 206 get_mcontext(struct thread *td, mcontext_t *mcp, int clear_ret) 207 { 208 struct trapframe *tf = td->td_frame; 209 210 memcpy(mcp->mc_gpregs.gp_t, tf->tf_t, sizeof(mcp->mc_gpregs.gp_t)); 211 memcpy(mcp->mc_gpregs.gp_s, tf->tf_s, sizeof(mcp->mc_gpregs.gp_s)); 212 memcpy(mcp->mc_gpregs.gp_a, tf->tf_a, sizeof(mcp->mc_gpregs.gp_a)); 213 214 if (clear_ret & GET_MC_CLEAR_RET) { 215 mcp->mc_gpregs.gp_a[0] = 0; 216 mcp->mc_gpregs.gp_t[0] = 0; /* clear syscall error */ 217 } 218 219 mcp->mc_gpregs.gp_ra = tf->tf_ra; 220 mcp->mc_gpregs.gp_sp = tf->tf_sp; 221 mcp->mc_gpregs.gp_gp = tf->tf_gp; 222 mcp->mc_gpregs.gp_tp = tf->tf_tp; 223 mcp->mc_gpregs.gp_sepc = tf->tf_sepc; 224 mcp->mc_gpregs.gp_sstatus = tf->tf_sstatus; 225 get_fpcontext(td, mcp); 226 227 return (0); 228 } 229 230 int 231 set_mcontext(struct thread *td, mcontext_t *mcp) 232 { 233 struct trapframe *tf; 234 235 tf = td->td_frame; 236 237 /* 238 * Permit changes to the USTATUS bits of SSTATUS. 239 * 240 * Ignore writes to read-only bits (SD, XS). 241 * 242 * Ignore writes to the FS field as set_fpcontext() will set 243 * it explicitly. 244 */ 245 if (((mcp->mc_gpregs.gp_sstatus ^ tf->tf_sstatus) & 246 ~(SSTATUS_SD | SSTATUS_XS_MASK | SSTATUS_FS_MASK | SSTATUS_UPIE | 247 SSTATUS_UIE)) != 0) 248 return (EINVAL); 249 250 memcpy(tf->tf_t, mcp->mc_gpregs.gp_t, sizeof(tf->tf_t)); 251 memcpy(tf->tf_s, mcp->mc_gpregs.gp_s, sizeof(tf->tf_s)); 252 memcpy(tf->tf_a, mcp->mc_gpregs.gp_a, sizeof(tf->tf_a)); 253 254 tf->tf_ra = mcp->mc_gpregs.gp_ra; 255 tf->tf_sp = mcp->mc_gpregs.gp_sp; 256 tf->tf_gp = mcp->mc_gpregs.gp_gp; 257 tf->tf_sepc = mcp->mc_gpregs.gp_sepc; 258 tf->tf_sstatus = mcp->mc_gpregs.gp_sstatus; 259 set_fpcontext(td, mcp); 260 261 return (0); 262 } 263 264 static void 265 get_fpcontext(struct thread *td, mcontext_t *mcp) 266 { 267 struct pcb *curpcb; 268 269 critical_enter(); 270 271 curpcb = curthread->td_pcb; 272 273 KASSERT(td->td_pcb == curpcb, ("Invalid fpe pcb")); 274 275 if ((curpcb->pcb_fpflags & PCB_FP_STARTED) != 0) { 276 /* 277 * If we have just been running FPE instructions we will 278 * need to save the state to memcpy it below. 279 */ 280 fpe_state_save(td); 281 282 KASSERT((curpcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0, 283 ("Non-userspace FPE flags set in get_fpcontext")); 284 memcpy(mcp->mc_fpregs.fp_x, curpcb->pcb_x, 285 sizeof(mcp->mc_fpregs.fp_x)); 286 mcp->mc_fpregs.fp_fcsr = curpcb->pcb_fcsr; 287 mcp->mc_fpregs.fp_flags = curpcb->pcb_fpflags; 288 mcp->mc_flags |= _MC_FP_VALID; 289 } 290 291 critical_exit(); 292 } 293 294 static void 295 set_fpcontext(struct thread *td, mcontext_t *mcp) 296 { 297 struct pcb *curpcb; 298 299 td->td_frame->tf_sstatus &= ~SSTATUS_FS_MASK; 300 td->td_frame->tf_sstatus |= SSTATUS_FS_OFF; 301 302 critical_enter(); 303 304 if ((mcp->mc_flags & _MC_FP_VALID) != 0) { 305 curpcb = curthread->td_pcb; 306 /* FPE usage is enabled, override registers. */ 307 memcpy(curpcb->pcb_x, mcp->mc_fpregs.fp_x, 308 sizeof(mcp->mc_fpregs.fp_x)); 309 curpcb->pcb_fcsr = mcp->mc_fpregs.fp_fcsr; 310 curpcb->pcb_fpflags = mcp->mc_fpregs.fp_flags & PCB_FP_USERMASK; 311 td->td_frame->tf_sstatus |= SSTATUS_FS_CLEAN; 312 } 313 314 critical_exit(); 315 } 316 317 int 318 sys_sigreturn(struct thread *td, struct sigreturn_args *uap) 319 { 320 ucontext_t uc; 321 int error; 322 323 if (copyin(uap->sigcntxp, &uc, sizeof(uc))) 324 return (EFAULT); 325 326 error = set_mcontext(td, &uc.uc_mcontext); 327 if (error != 0) 328 return (error); 329 330 /* Restore signal mask. */ 331 kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0); 332 333 return (EJUSTRETURN); 334 } 335 336 void 337 sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 338 { 339 struct sigframe *fp, frame; 340 struct sysentvec *sysent; 341 struct trapframe *tf; 342 struct sigacts *psp; 343 struct thread *td; 344 struct proc *p; 345 int onstack; 346 int sig; 347 348 td = curthread; 349 p = td->td_proc; 350 PROC_LOCK_ASSERT(p, MA_OWNED); 351 352 sig = ksi->ksi_signo; 353 psp = p->p_sigacts; 354 mtx_assert(&psp->ps_mtx, MA_OWNED); 355 356 tf = td->td_frame; 357 onstack = sigonstack(tf->tf_sp); 358 359 CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm, 360 catcher, sig); 361 362 /* Allocate and validate space for the signal handler context. */ 363 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !onstack && 364 SIGISMEMBER(psp->ps_sigonstack, sig)) { 365 fp = (struct sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 366 td->td_sigstk.ss_size); 367 } else { 368 fp = (struct sigframe *)td->td_frame->tf_sp; 369 } 370 371 /* Make room, keeping the stack aligned */ 372 fp--; 373 fp = (struct sigframe *)STACKALIGN(fp); 374 375 /* Fill in the frame to copy out */ 376 bzero(&frame, sizeof(frame)); 377 get_mcontext(td, &frame.sf_uc.uc_mcontext, 0); 378 frame.sf_si = ksi->ksi_info; 379 frame.sf_uc.uc_sigmask = *mask; 380 frame.sf_uc.uc_stack = td->td_sigstk; 381 frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) != 0 ? 382 (onstack ? SS_ONSTACK : 0) : SS_DISABLE; 383 mtx_unlock(&psp->ps_mtx); 384 PROC_UNLOCK(td->td_proc); 385 386 /* Copy the sigframe out to the user's stack. */ 387 if (copyout(&frame, fp, sizeof(*fp)) != 0) { 388 /* Process has trashed its stack. Kill it. */ 389 CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp); 390 PROC_LOCK(p); 391 sigexit(td, SIGILL); 392 } 393 394 tf->tf_a[0] = sig; 395 tf->tf_a[1] = (register_t)&fp->sf_si; 396 tf->tf_a[2] = (register_t)&fp->sf_uc; 397 398 tf->tf_sepc = (register_t)catcher; 399 tf->tf_sp = (register_t)fp; 400 401 sysent = p->p_sysent; 402 if (PROC_HAS_SHP(p)) 403 tf->tf_ra = (register_t)PROC_SIGCODE(p); 404 else 405 tf->tf_ra = (register_t)(PROC_PS_STRINGS(p) - 406 *(sysent->sv_szsigcode)); 407 408 CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_sepc, 409 tf->tf_sp); 410 411 PROC_LOCK(p); 412 mtx_lock(&psp->ps_mtx); 413 } 414