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/cdefs.h> 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/exec.h> 40 #include <sys/imgact.h> 41 #include <sys/kdb.h> 42 #include <sys/kernel.h> 43 #include <sys/ktr.h> 44 #include <sys/limits.h> 45 #include <sys/lock.h> 46 #include <sys/mutex.h> 47 #include <sys/proc.h> 48 #include <sys/ptrace.h> 49 #include <sys/reg.h> 50 #include <sys/rwlock.h> 51 #include <sys/sched.h> 52 #include <sys/signalvar.h> 53 #include <sys/syscallsubr.h> 54 #include <sys/sysent.h> 55 #include <sys/sysproto.h> 56 #include <sys/ucontext.h> 57 58 #include <machine/cpu.h> 59 #include <machine/fpe.h> 60 #include <machine/kdb.h> 61 #include <machine/pcb.h> 62 #include <machine/pte.h> 63 #include <machine/riscvreg.h> 64 #include <machine/sbi.h> 65 #include <machine/trap.h> 66 67 #include <vm/vm.h> 68 #include <vm/vm_param.h> 69 #include <vm/pmap.h> 70 #include <vm/vm_map.h> 71 72 static void get_fpcontext(struct thread *td, mcontext_t *mcp); 73 static void set_fpcontext(struct thread *td, mcontext_t *mcp); 74 75 _Static_assert(sizeof(mcontext_t) == 864, "mcontext_t size incorrect"); 76 _Static_assert(sizeof(ucontext_t) == 936, "ucontext_t size incorrect"); 77 _Static_assert(sizeof(siginfo_t) == 80, "siginfo_t size incorrect"); 78 79 int 80 fill_regs(struct thread *td, struct reg *regs) 81 { 82 struct trapframe *frame; 83 84 frame = td->td_frame; 85 regs->sepc = frame->tf_sepc; 86 regs->sstatus = frame->tf_sstatus; 87 regs->ra = frame->tf_ra; 88 regs->sp = frame->tf_sp; 89 regs->gp = frame->tf_gp; 90 regs->tp = frame->tf_tp; 91 92 memcpy(regs->t, frame->tf_t, sizeof(regs->t)); 93 memcpy(regs->s, frame->tf_s, sizeof(regs->s)); 94 memcpy(regs->a, frame->tf_a, sizeof(regs->a)); 95 96 return (0); 97 } 98 99 int 100 set_regs(struct thread *td, struct reg *regs) 101 { 102 struct trapframe *frame; 103 104 frame = td->td_frame; 105 frame->tf_sepc = regs->sepc; 106 frame->tf_ra = regs->ra; 107 frame->tf_sp = regs->sp; 108 frame->tf_gp = regs->gp; 109 frame->tf_tp = regs->tp; 110 111 memcpy(frame->tf_t, regs->t, sizeof(frame->tf_t)); 112 memcpy(frame->tf_s, regs->s, sizeof(frame->tf_s)); 113 memcpy(frame->tf_a, regs->a, sizeof(frame->tf_a)); 114 115 return (0); 116 } 117 118 int 119 fill_fpregs(struct thread *td, struct fpreg *regs) 120 { 121 struct pcb *pcb; 122 123 pcb = td->td_pcb; 124 125 if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0) { 126 /* 127 * If we have just been running FPE instructions we will 128 * need to save the state to memcpy it below. 129 */ 130 if (td == curthread) 131 fpe_state_save(td); 132 133 memcpy(regs->fp_x, pcb->pcb_x, sizeof(regs->fp_x)); 134 regs->fp_fcsr = pcb->pcb_fcsr; 135 } else 136 memset(regs, 0, sizeof(*regs)); 137 138 return (0); 139 } 140 141 int 142 set_fpregs(struct thread *td, struct fpreg *regs) 143 { 144 struct trapframe *frame; 145 struct pcb *pcb; 146 147 frame = td->td_frame; 148 pcb = td->td_pcb; 149 150 memcpy(pcb->pcb_x, regs->fp_x, sizeof(regs->fp_x)); 151 pcb->pcb_fcsr = regs->fp_fcsr; 152 pcb->pcb_fpflags |= PCB_FP_STARTED; 153 frame->tf_sstatus &= ~SSTATUS_FS_MASK; 154 frame->tf_sstatus |= SSTATUS_FS_CLEAN; 155 156 return (0); 157 } 158 159 int 160 fill_dbregs(struct thread *td, struct dbreg *regs) 161 { 162 163 panic("fill_dbregs"); 164 } 165 166 int 167 set_dbregs(struct thread *td, struct dbreg *regs) 168 { 169 170 panic("set_dbregs"); 171 } 172 173 void 174 exec_setregs(struct thread *td, struct image_params *imgp, uintptr_t stack) 175 { 176 struct trapframe *tf; 177 struct pcb *pcb; 178 179 tf = td->td_frame; 180 pcb = td->td_pcb; 181 182 memset(tf, 0, sizeof(struct trapframe)); 183 184 tf->tf_a[0] = stack; 185 tf->tf_sp = STACKALIGN(stack); 186 tf->tf_ra = imgp->entry_addr; 187 tf->tf_sepc = imgp->entry_addr; 188 189 pcb->pcb_fpflags &= ~PCB_FP_STARTED; 190 } 191 192 /* Sanity check these are the same size, they will be memcpy'd to and from */ 193 CTASSERT(sizeof(((struct trapframe *)0)->tf_a) == 194 sizeof((struct gpregs *)0)->gp_a); 195 CTASSERT(sizeof(((struct trapframe *)0)->tf_s) == 196 sizeof((struct gpregs *)0)->gp_s); 197 CTASSERT(sizeof(((struct trapframe *)0)->tf_t) == 198 sizeof((struct gpregs *)0)->gp_t); 199 CTASSERT(sizeof(((struct trapframe *)0)->tf_a) == 200 sizeof((struct reg *)0)->a); 201 CTASSERT(sizeof(((struct trapframe *)0)->tf_s) == 202 sizeof((struct reg *)0)->s); 203 CTASSERT(sizeof(((struct trapframe *)0)->tf_t) == 204 sizeof((struct reg *)0)->t); 205 206 int 207 get_mcontext(struct thread *td, mcontext_t *mcp, int clear_ret) 208 { 209 struct trapframe *tf = td->td_frame; 210 211 memcpy(mcp->mc_gpregs.gp_t, tf->tf_t, sizeof(mcp->mc_gpregs.gp_t)); 212 memcpy(mcp->mc_gpregs.gp_s, tf->tf_s, sizeof(mcp->mc_gpregs.gp_s)); 213 memcpy(mcp->mc_gpregs.gp_a, tf->tf_a, sizeof(mcp->mc_gpregs.gp_a)); 214 215 if (clear_ret & GET_MC_CLEAR_RET) { 216 mcp->mc_gpregs.gp_a[0] = 0; 217 mcp->mc_gpregs.gp_t[0] = 0; /* clear syscall error */ 218 } 219 220 mcp->mc_gpregs.gp_ra = tf->tf_ra; 221 mcp->mc_gpregs.gp_sp = tf->tf_sp; 222 mcp->mc_gpregs.gp_gp = tf->tf_gp; 223 mcp->mc_gpregs.gp_tp = tf->tf_tp; 224 mcp->mc_gpregs.gp_sepc = tf->tf_sepc; 225 mcp->mc_gpregs.gp_sstatus = tf->tf_sstatus; 226 get_fpcontext(td, mcp); 227 228 return (0); 229 } 230 231 int 232 set_mcontext(struct thread *td, mcontext_t *mcp) 233 { 234 struct trapframe *tf; 235 236 tf = td->td_frame; 237 238 /* 239 * Permit changes to the USTATUS bits of SSTATUS. 240 * 241 * Ignore writes to read-only bits (SD, XS). 242 * 243 * Ignore writes to the FS field as set_fpcontext() will set 244 * it explicitly. 245 */ 246 if (((mcp->mc_gpregs.gp_sstatus ^ tf->tf_sstatus) & 247 ~(SSTATUS_SD | SSTATUS_XS_MASK | SSTATUS_FS_MASK | SSTATUS_UPIE | 248 SSTATUS_UIE)) != 0) 249 return (EINVAL); 250 251 memcpy(tf->tf_t, mcp->mc_gpregs.gp_t, sizeof(tf->tf_t)); 252 memcpy(tf->tf_s, mcp->mc_gpregs.gp_s, sizeof(tf->tf_s)); 253 memcpy(tf->tf_a, mcp->mc_gpregs.gp_a, sizeof(tf->tf_a)); 254 255 tf->tf_ra = mcp->mc_gpregs.gp_ra; 256 tf->tf_sp = mcp->mc_gpregs.gp_sp; 257 tf->tf_gp = mcp->mc_gpregs.gp_gp; 258 tf->tf_sepc = mcp->mc_gpregs.gp_sepc; 259 tf->tf_sstatus = mcp->mc_gpregs.gp_sstatus; 260 set_fpcontext(td, mcp); 261 262 return (0); 263 } 264 265 static void 266 get_fpcontext(struct thread *td, mcontext_t *mcp) 267 { 268 struct pcb *curpcb; 269 270 critical_enter(); 271 272 curpcb = curthread->td_pcb; 273 274 KASSERT(td->td_pcb == curpcb, ("Invalid fpe pcb")); 275 276 if ((curpcb->pcb_fpflags & PCB_FP_STARTED) != 0) { 277 /* 278 * If we have just been running FPE instructions we will 279 * need to save the state to memcpy it below. 280 */ 281 fpe_state_save(td); 282 283 KASSERT((curpcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0, 284 ("Non-userspace FPE flags set in get_fpcontext")); 285 memcpy(mcp->mc_fpregs.fp_x, curpcb->pcb_x, 286 sizeof(mcp->mc_fpregs.fp_x)); 287 mcp->mc_fpregs.fp_fcsr = curpcb->pcb_fcsr; 288 mcp->mc_fpregs.fp_flags = curpcb->pcb_fpflags; 289 mcp->mc_flags |= _MC_FP_VALID; 290 } 291 292 critical_exit(); 293 } 294 295 static void 296 set_fpcontext(struct thread *td, mcontext_t *mcp) 297 { 298 struct pcb *curpcb; 299 300 td->td_frame->tf_sstatus &= ~SSTATUS_FS_MASK; 301 td->td_frame->tf_sstatus |= SSTATUS_FS_OFF; 302 303 critical_enter(); 304 305 if ((mcp->mc_flags & _MC_FP_VALID) != 0) { 306 curpcb = curthread->td_pcb; 307 /* FPE usage is enabled, override registers. */ 308 memcpy(curpcb->pcb_x, mcp->mc_fpregs.fp_x, 309 sizeof(mcp->mc_fpregs.fp_x)); 310 curpcb->pcb_fcsr = mcp->mc_fpregs.fp_fcsr; 311 curpcb->pcb_fpflags = mcp->mc_fpregs.fp_flags & PCB_FP_USERMASK; 312 td->td_frame->tf_sstatus |= SSTATUS_FS_CLEAN; 313 } 314 315 critical_exit(); 316 } 317 318 int 319 sys_sigreturn(struct thread *td, struct sigreturn_args *uap) 320 { 321 ucontext_t uc; 322 int error; 323 324 if (copyin(uap->sigcntxp, &uc, sizeof(uc))) 325 return (EFAULT); 326 327 error = set_mcontext(td, &uc.uc_mcontext); 328 if (error != 0) 329 return (error); 330 331 /* Restore signal mask. */ 332 kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0); 333 334 return (EJUSTRETURN); 335 } 336 337 void 338 sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 339 { 340 struct sigframe *fp, frame; 341 struct sysentvec *sysent; 342 struct trapframe *tf; 343 struct sigacts *psp; 344 struct thread *td; 345 struct proc *p; 346 int onstack; 347 int sig; 348 349 td = curthread; 350 p = td->td_proc; 351 PROC_LOCK_ASSERT(p, MA_OWNED); 352 353 sig = ksi->ksi_signo; 354 psp = p->p_sigacts; 355 mtx_assert(&psp->ps_mtx, MA_OWNED); 356 357 tf = td->td_frame; 358 onstack = sigonstack(tf->tf_sp); 359 360 CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm, 361 catcher, sig); 362 363 /* Allocate and validate space for the signal handler context. */ 364 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !onstack && 365 SIGISMEMBER(psp->ps_sigonstack, sig)) { 366 fp = (struct sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 367 td->td_sigstk.ss_size); 368 } else { 369 fp = (struct sigframe *)td->td_frame->tf_sp; 370 } 371 372 /* Make room, keeping the stack aligned */ 373 fp--; 374 fp = (struct sigframe *)STACKALIGN(fp); 375 376 /* Fill in the frame to copy out */ 377 bzero(&frame, sizeof(frame)); 378 get_mcontext(td, &frame.sf_uc.uc_mcontext, 0); 379 frame.sf_si = ksi->ksi_info; 380 frame.sf_uc.uc_sigmask = *mask; 381 frame.sf_uc.uc_stack = td->td_sigstk; 382 frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) != 0 ? 383 (onstack ? SS_ONSTACK : 0) : SS_DISABLE; 384 mtx_unlock(&psp->ps_mtx); 385 PROC_UNLOCK(td->td_proc); 386 387 /* Copy the sigframe out to the user's stack. */ 388 if (copyout(&frame, fp, sizeof(*fp)) != 0) { 389 /* Process has trashed its stack. Kill it. */ 390 CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp); 391 PROC_LOCK(p); 392 sigexit(td, SIGILL); 393 } 394 395 tf->tf_a[0] = sig; 396 tf->tf_a[1] = (register_t)&fp->sf_si; 397 tf->tf_a[2] = (register_t)&fp->sf_uc; 398 399 tf->tf_sepc = (register_t)catcher; 400 tf->tf_sp = (register_t)fp; 401 402 sysent = p->p_sysent; 403 if (PROC_HAS_SHP(p)) 404 tf->tf_ra = (register_t)PROC_SIGCODE(p); 405 else 406 tf->tf_ra = (register_t)(PROC_PS_STRINGS(p) - 407 *(sysent->sv_szsigcode)); 408 409 CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_sepc, 410 tf->tf_sp); 411 412 PROC_LOCK(p); 413 mtx_lock(&psp->ps_mtx); 414 } 415