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 __FBSDID("$FreeBSD$"); 38 39 #include <sys/param.h> 40 #include <sys/systm.h> 41 #include <sys/exec.h> 42 #include <sys/imgact.h> 43 #include <sys/kdb.h> 44 #include <sys/kernel.h> 45 #include <sys/ktr.h> 46 #include <sys/limits.h> 47 #include <sys/lock.h> 48 #include <sys/mutex.h> 49 #include <sys/proc.h> 50 #include <sys/ptrace.h> 51 #include <sys/reg.h> 52 #include <sys/rwlock.h> 53 #include <sys/sched.h> 54 #include <sys/signalvar.h> 55 #include <sys/syscallsubr.h> 56 #include <sys/sysent.h> 57 #include <sys/sysproto.h> 58 #include <sys/ucontext.h> 59 60 #include <machine/cpu.h> 61 #include <machine/fpe.h> 62 #include <machine/kdb.h> 63 #include <machine/pcb.h> 64 #include <machine/pte.h> 65 #include <machine/riscvreg.h> 66 #include <machine/sbi.h> 67 #include <machine/trap.h> 68 69 #include <vm/vm.h> 70 #include <vm/vm_param.h> 71 #include <vm/pmap.h> 72 #include <vm/vm_map.h> 73 74 static void get_fpcontext(struct thread *td, mcontext_t *mcp); 75 static void set_fpcontext(struct thread *td, mcontext_t *mcp); 76 77 _Static_assert(sizeof(mcontext_t) == 864, "mcontext_t size incorrect"); 78 _Static_assert(sizeof(ucontext_t) == 936, "ucontext_t size incorrect"); 79 _Static_assert(sizeof(siginfo_t) == 80, "siginfo_t size incorrect"); 80 81 int 82 fill_regs(struct thread *td, struct reg *regs) 83 { 84 struct trapframe *frame; 85 86 frame = td->td_frame; 87 regs->sepc = frame->tf_sepc; 88 regs->sstatus = frame->tf_sstatus; 89 regs->ra = frame->tf_ra; 90 regs->sp = frame->tf_sp; 91 regs->gp = frame->tf_gp; 92 regs->tp = frame->tf_tp; 93 94 memcpy(regs->t, frame->tf_t, sizeof(regs->t)); 95 memcpy(regs->s, frame->tf_s, sizeof(regs->s)); 96 memcpy(regs->a, frame->tf_a, sizeof(regs->a)); 97 98 return (0); 99 } 100 101 int 102 set_regs(struct thread *td, struct reg *regs) 103 { 104 struct trapframe *frame; 105 106 frame = td->td_frame; 107 frame->tf_sepc = regs->sepc; 108 frame->tf_ra = regs->ra; 109 frame->tf_sp = regs->sp; 110 frame->tf_gp = regs->gp; 111 frame->tf_tp = regs->tp; 112 113 memcpy(frame->tf_t, regs->t, sizeof(frame->tf_t)); 114 memcpy(frame->tf_s, regs->s, sizeof(frame->tf_s)); 115 memcpy(frame->tf_a, regs->a, sizeof(frame->tf_a)); 116 117 return (0); 118 } 119 120 int 121 fill_fpregs(struct thread *td, struct fpreg *regs) 122 { 123 struct pcb *pcb; 124 125 pcb = td->td_pcb; 126 127 if ((pcb->pcb_fpflags & PCB_FP_STARTED) != 0) { 128 /* 129 * If we have just been running FPE instructions we will 130 * need to save the state to memcpy it below. 131 */ 132 if (td == curthread) 133 fpe_state_save(td); 134 135 memcpy(regs->fp_x, pcb->pcb_x, sizeof(regs->fp_x)); 136 regs->fp_fcsr = pcb->pcb_fcsr; 137 } else 138 memset(regs, 0, sizeof(*regs)); 139 140 return (0); 141 } 142 143 int 144 set_fpregs(struct thread *td, struct fpreg *regs) 145 { 146 struct trapframe *frame; 147 struct pcb *pcb; 148 149 frame = td->td_frame; 150 pcb = td->td_pcb; 151 152 memcpy(pcb->pcb_x, regs->fp_x, sizeof(regs->fp_x)); 153 pcb->pcb_fcsr = regs->fp_fcsr; 154 pcb->pcb_fpflags |= PCB_FP_STARTED; 155 frame->tf_sstatus &= ~SSTATUS_FS_MASK; 156 frame->tf_sstatus |= SSTATUS_FS_CLEAN; 157 158 return (0); 159 } 160 161 int 162 fill_dbregs(struct thread *td, struct dbreg *regs) 163 { 164 165 panic("fill_dbregs"); 166 } 167 168 int 169 set_dbregs(struct thread *td, struct dbreg *regs) 170 { 171 172 panic("set_dbregs"); 173 } 174 175 void 176 exec_setregs(struct thread *td, struct image_params *imgp, uintptr_t stack) 177 { 178 struct trapframe *tf; 179 struct pcb *pcb; 180 181 tf = td->td_frame; 182 pcb = td->td_pcb; 183 184 memset(tf, 0, sizeof(struct trapframe)); 185 186 tf->tf_a[0] = stack; 187 tf->tf_sp = STACKALIGN(stack); 188 tf->tf_ra = imgp->entry_addr; 189 tf->tf_sepc = imgp->entry_addr; 190 191 pcb->pcb_fpflags &= ~PCB_FP_STARTED; 192 } 193 194 /* Sanity check these are the same size, they will be memcpy'd to and from */ 195 CTASSERT(sizeof(((struct trapframe *)0)->tf_a) == 196 sizeof((struct gpregs *)0)->gp_a); 197 CTASSERT(sizeof(((struct trapframe *)0)->tf_s) == 198 sizeof((struct gpregs *)0)->gp_s); 199 CTASSERT(sizeof(((struct trapframe *)0)->tf_t) == 200 sizeof((struct gpregs *)0)->gp_t); 201 CTASSERT(sizeof(((struct trapframe *)0)->tf_a) == 202 sizeof((struct reg *)0)->a); 203 CTASSERT(sizeof(((struct trapframe *)0)->tf_s) == 204 sizeof((struct reg *)0)->s); 205 CTASSERT(sizeof(((struct trapframe *)0)->tf_t) == 206 sizeof((struct reg *)0)->t); 207 208 int 209 get_mcontext(struct thread *td, mcontext_t *mcp, int clear_ret) 210 { 211 struct trapframe *tf = td->td_frame; 212 213 memcpy(mcp->mc_gpregs.gp_t, tf->tf_t, sizeof(mcp->mc_gpregs.gp_t)); 214 memcpy(mcp->mc_gpregs.gp_s, tf->tf_s, sizeof(mcp->mc_gpregs.gp_s)); 215 memcpy(mcp->mc_gpregs.gp_a, tf->tf_a, sizeof(mcp->mc_gpregs.gp_a)); 216 217 if (clear_ret & GET_MC_CLEAR_RET) { 218 mcp->mc_gpregs.gp_a[0] = 0; 219 mcp->mc_gpregs.gp_t[0] = 0; /* clear syscall error */ 220 } 221 222 mcp->mc_gpregs.gp_ra = tf->tf_ra; 223 mcp->mc_gpregs.gp_sp = tf->tf_sp; 224 mcp->mc_gpregs.gp_gp = tf->tf_gp; 225 mcp->mc_gpregs.gp_tp = tf->tf_tp; 226 mcp->mc_gpregs.gp_sepc = tf->tf_sepc; 227 mcp->mc_gpregs.gp_sstatus = tf->tf_sstatus; 228 get_fpcontext(td, mcp); 229 230 return (0); 231 } 232 233 int 234 set_mcontext(struct thread *td, mcontext_t *mcp) 235 { 236 struct trapframe *tf; 237 238 tf = td->td_frame; 239 240 /* 241 * Permit changes to the USTATUS bits of SSTATUS. 242 * 243 * Ignore writes to read-only bits (SD, XS). 244 * 245 * Ignore writes to the FS field as set_fpcontext() will set 246 * it explicitly. 247 */ 248 if (((mcp->mc_gpregs.gp_sstatus ^ tf->tf_sstatus) & 249 ~(SSTATUS_SD | SSTATUS_XS_MASK | SSTATUS_FS_MASK | SSTATUS_UPIE | 250 SSTATUS_UIE)) != 0) 251 return (EINVAL); 252 253 memcpy(tf->tf_t, mcp->mc_gpregs.gp_t, sizeof(tf->tf_t)); 254 memcpy(tf->tf_s, mcp->mc_gpregs.gp_s, sizeof(tf->tf_s)); 255 memcpy(tf->tf_a, mcp->mc_gpregs.gp_a, sizeof(tf->tf_a)); 256 257 tf->tf_ra = mcp->mc_gpregs.gp_ra; 258 tf->tf_sp = mcp->mc_gpregs.gp_sp; 259 tf->tf_gp = mcp->mc_gpregs.gp_gp; 260 tf->tf_sepc = mcp->mc_gpregs.gp_sepc; 261 tf->tf_sstatus = mcp->mc_gpregs.gp_sstatus; 262 set_fpcontext(td, mcp); 263 264 return (0); 265 } 266 267 static void 268 get_fpcontext(struct thread *td, mcontext_t *mcp) 269 { 270 struct pcb *curpcb; 271 272 critical_enter(); 273 274 curpcb = curthread->td_pcb; 275 276 KASSERT(td->td_pcb == curpcb, ("Invalid fpe pcb")); 277 278 if ((curpcb->pcb_fpflags & PCB_FP_STARTED) != 0) { 279 /* 280 * If we have just been running FPE instructions we will 281 * need to save the state to memcpy it below. 282 */ 283 fpe_state_save(td); 284 285 KASSERT((curpcb->pcb_fpflags & ~PCB_FP_USERMASK) == 0, 286 ("Non-userspace FPE flags set in get_fpcontext")); 287 memcpy(mcp->mc_fpregs.fp_x, curpcb->pcb_x, 288 sizeof(mcp->mc_fpregs.fp_x)); 289 mcp->mc_fpregs.fp_fcsr = curpcb->pcb_fcsr; 290 mcp->mc_fpregs.fp_flags = curpcb->pcb_fpflags; 291 mcp->mc_flags |= _MC_FP_VALID; 292 } 293 294 critical_exit(); 295 } 296 297 static void 298 set_fpcontext(struct thread *td, mcontext_t *mcp) 299 { 300 struct pcb *curpcb; 301 302 td->td_frame->tf_sstatus &= ~SSTATUS_FS_MASK; 303 td->td_frame->tf_sstatus |= SSTATUS_FS_OFF; 304 305 critical_enter(); 306 307 if ((mcp->mc_flags & _MC_FP_VALID) != 0) { 308 curpcb = curthread->td_pcb; 309 /* FPE usage is enabled, override registers. */ 310 memcpy(curpcb->pcb_x, mcp->mc_fpregs.fp_x, 311 sizeof(mcp->mc_fpregs.fp_x)); 312 curpcb->pcb_fcsr = mcp->mc_fpregs.fp_fcsr; 313 curpcb->pcb_fpflags = mcp->mc_fpregs.fp_flags & PCB_FP_USERMASK; 314 td->td_frame->tf_sstatus |= SSTATUS_FS_CLEAN; 315 } 316 317 critical_exit(); 318 } 319 320 int 321 sys_sigreturn(struct thread *td, struct sigreturn_args *uap) 322 { 323 ucontext_t uc; 324 int error; 325 326 if (copyin(uap->sigcntxp, &uc, sizeof(uc))) 327 return (EFAULT); 328 329 error = set_mcontext(td, &uc.uc_mcontext); 330 if (error != 0) 331 return (error); 332 333 /* Restore signal mask. */ 334 kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0); 335 336 return (EJUSTRETURN); 337 } 338 339 void 340 sendsig(sig_t catcher, ksiginfo_t *ksi, sigset_t *mask) 341 { 342 struct sigframe *fp, frame; 343 struct sysentvec *sysent; 344 struct trapframe *tf; 345 struct sigacts *psp; 346 struct thread *td; 347 struct proc *p; 348 int onstack; 349 int sig; 350 351 td = curthread; 352 p = td->td_proc; 353 PROC_LOCK_ASSERT(p, MA_OWNED); 354 355 sig = ksi->ksi_signo; 356 psp = p->p_sigacts; 357 mtx_assert(&psp->ps_mtx, MA_OWNED); 358 359 tf = td->td_frame; 360 onstack = sigonstack(tf->tf_sp); 361 362 CTR4(KTR_SIG, "sendsig: td=%p (%s) catcher=%p sig=%d", td, p->p_comm, 363 catcher, sig); 364 365 /* Allocate and validate space for the signal handler context. */ 366 if ((td->td_pflags & TDP_ALTSTACK) != 0 && !onstack && 367 SIGISMEMBER(psp->ps_sigonstack, sig)) { 368 fp = (struct sigframe *)((uintptr_t)td->td_sigstk.ss_sp + 369 td->td_sigstk.ss_size); 370 } else { 371 fp = (struct sigframe *)td->td_frame->tf_sp; 372 } 373 374 /* Make room, keeping the stack aligned */ 375 fp--; 376 fp = (struct sigframe *)STACKALIGN(fp); 377 378 /* Fill in the frame to copy out */ 379 bzero(&frame, sizeof(frame)); 380 get_mcontext(td, &frame.sf_uc.uc_mcontext, 0); 381 frame.sf_si = ksi->ksi_info; 382 frame.sf_uc.uc_sigmask = *mask; 383 frame.sf_uc.uc_stack = td->td_sigstk; 384 frame.sf_uc.uc_stack.ss_flags = (td->td_pflags & TDP_ALTSTACK) != 0 ? 385 (onstack ? SS_ONSTACK : 0) : SS_DISABLE; 386 mtx_unlock(&psp->ps_mtx); 387 PROC_UNLOCK(td->td_proc); 388 389 /* Copy the sigframe out to the user's stack. */ 390 if (copyout(&frame, fp, sizeof(*fp)) != 0) { 391 /* Process has trashed its stack. Kill it. */ 392 CTR2(KTR_SIG, "sendsig: sigexit td=%p fp=%p", td, fp); 393 PROC_LOCK(p); 394 sigexit(td, SIGILL); 395 } 396 397 tf->tf_a[0] = sig; 398 tf->tf_a[1] = (register_t)&fp->sf_si; 399 tf->tf_a[2] = (register_t)&fp->sf_uc; 400 401 tf->tf_sepc = (register_t)catcher; 402 tf->tf_sp = (register_t)fp; 403 404 sysent = p->p_sysent; 405 if (PROC_HAS_SHP(p)) 406 tf->tf_ra = (register_t)PROC_SIGCODE(p); 407 else 408 tf->tf_ra = (register_t)(PROC_PS_STRINGS(p) - 409 *(sysent->sv_szsigcode)); 410 411 CTR3(KTR_SIG, "sendsig: return td=%p pc=%#x sp=%#x", td, tf->tf_sepc, 412 tf->tf_sp); 413 414 PROC_LOCK(p); 415 mtx_lock(&psp->ps_mtx); 416 } 417