1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause 3 * 4 * Copyright (c) 2001 Alexander Kabaev 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 */ 28 29 #include "opt_cpu.h" 30 31 #include <sys/param.h> 32 #include <sys/systm.h> 33 #include <sys/lock.h> 34 #include <sys/mutex.h> 35 #include <sys/proc.h> 36 #include <sys/ptrace.h> 37 #include <sys/syscallsubr.h> 38 39 #include <machine/md_var.h> 40 #include <machine/pcb.h> 41 42 #include <i386/linux/linux.h> 43 #include <i386/linux/linux_proto.h> 44 #include <compat/linux/linux_signal.h> 45 46 /* 47 * Linux ptrace requests numbers. Mostly identical to FreeBSD, 48 * except for MD ones and PT_ATTACH/PT_DETACH. 49 */ 50 #define PTRACE_TRACEME 0 51 #define PTRACE_PEEKTEXT 1 52 #define PTRACE_PEEKDATA 2 53 #define PTRACE_PEEKUSR 3 54 #define PTRACE_POKETEXT 4 55 #define PTRACE_POKEDATA 5 56 #define PTRACE_POKEUSR 6 57 #define PTRACE_CONT 7 58 #define PTRACE_KILL 8 59 #define PTRACE_SINGLESTEP 9 60 61 #define PTRACE_ATTACH 16 62 #define PTRACE_DETACH 17 63 64 #define LINUX_PTRACE_SYSCALL 24 65 66 #define PTRACE_GETREGS 12 67 #define PTRACE_SETREGS 13 68 #define PTRACE_GETFPREGS 14 69 #define PTRACE_SETFPREGS 15 70 #define PTRACE_GETFPXREGS 18 71 #define PTRACE_SETFPXREGS 19 72 73 #define PTRACE_SETOPTIONS 21 74 75 /* 76 * Linux keeps debug registers at the following 77 * offset in the user struct 78 */ 79 #define LINUX_DBREG_OFFSET 252 80 #define LINUX_DBREG_SIZE (8*sizeof(l_int)) 81 82 static __inline int 83 map_signum(int signum) 84 { 85 86 signum = linux_to_bsd_signal(signum); 87 return ((signum == SIGSTOP)? 0 : signum); 88 } 89 90 struct linux_pt_reg { 91 l_long ebx; 92 l_long ecx; 93 l_long edx; 94 l_long esi; 95 l_long edi; 96 l_long ebp; 97 l_long eax; 98 l_int xds; 99 l_int xes; 100 l_int xfs; 101 l_int xgs; 102 l_long orig_eax; 103 l_long eip; 104 l_int xcs; 105 l_long eflags; 106 l_long esp; 107 l_int xss; 108 }; 109 110 /* 111 * Translate i386 ptrace registers between Linux and FreeBSD formats. 112 * The translation is pretty straighforward, for all registers, but 113 * orig_eax on Linux side and r_trapno and r_err in FreeBSD 114 */ 115 static void 116 map_regs_to_linux(struct reg *bsd_r, struct linux_pt_reg *linux_r) 117 { 118 linux_r->ebx = bsd_r->r_ebx; 119 linux_r->ecx = bsd_r->r_ecx; 120 linux_r->edx = bsd_r->r_edx; 121 linux_r->esi = bsd_r->r_esi; 122 linux_r->edi = bsd_r->r_edi; 123 linux_r->ebp = bsd_r->r_ebp; 124 linux_r->eax = bsd_r->r_eax; 125 linux_r->xds = bsd_r->r_ds; 126 linux_r->xes = bsd_r->r_es; 127 linux_r->xfs = bsd_r->r_fs; 128 linux_r->xgs = bsd_r->r_gs; 129 linux_r->orig_eax = bsd_r->r_eax; 130 linux_r->eip = bsd_r->r_eip; 131 linux_r->xcs = bsd_r->r_cs; 132 linux_r->eflags = bsd_r->r_eflags; 133 linux_r->esp = bsd_r->r_esp; 134 linux_r->xss = bsd_r->r_ss; 135 } 136 137 static void 138 map_regs_from_linux(struct reg *bsd_r, struct linux_pt_reg *linux_r) 139 { 140 bsd_r->r_ebx = linux_r->ebx; 141 bsd_r->r_ecx = linux_r->ecx; 142 bsd_r->r_edx = linux_r->edx; 143 bsd_r->r_esi = linux_r->esi; 144 bsd_r->r_edi = linux_r->edi; 145 bsd_r->r_ebp = linux_r->ebp; 146 bsd_r->r_eax = linux_r->eax; 147 bsd_r->r_ds = linux_r->xds; 148 bsd_r->r_es = linux_r->xes; 149 bsd_r->r_fs = linux_r->xfs; 150 bsd_r->r_gs = linux_r->xgs; 151 bsd_r->r_eip = linux_r->eip; 152 bsd_r->r_cs = linux_r->xcs; 153 bsd_r->r_eflags = linux_r->eflags; 154 bsd_r->r_esp = linux_r->esp; 155 bsd_r->r_ss = linux_r->xss; 156 } 157 158 struct linux_pt_fpreg { 159 l_long cwd; 160 l_long swd; 161 l_long twd; 162 l_long fip; 163 l_long fcs; 164 l_long foo; 165 l_long fos; 166 l_long st_space[2*10]; 167 }; 168 169 static void 170 map_fpregs_to_linux(struct fpreg *bsd_r, struct linux_pt_fpreg *linux_r) 171 { 172 linux_r->cwd = bsd_r->fpr_env[0]; 173 linux_r->swd = bsd_r->fpr_env[1]; 174 linux_r->twd = bsd_r->fpr_env[2]; 175 linux_r->fip = bsd_r->fpr_env[3]; 176 linux_r->fcs = bsd_r->fpr_env[4]; 177 linux_r->foo = bsd_r->fpr_env[5]; 178 linux_r->fos = bsd_r->fpr_env[6]; 179 bcopy(bsd_r->fpr_acc, linux_r->st_space, sizeof(linux_r->st_space)); 180 } 181 182 static void 183 map_fpregs_from_linux(struct fpreg *bsd_r, struct linux_pt_fpreg *linux_r) 184 { 185 bsd_r->fpr_env[0] = linux_r->cwd; 186 bsd_r->fpr_env[1] = linux_r->swd; 187 bsd_r->fpr_env[2] = linux_r->twd; 188 bsd_r->fpr_env[3] = linux_r->fip; 189 bsd_r->fpr_env[4] = linux_r->fcs; 190 bsd_r->fpr_env[5] = linux_r->foo; 191 bsd_r->fpr_env[6] = linux_r->fos; 192 bcopy(bsd_r->fpr_acc, linux_r->st_space, sizeof(bsd_r->fpr_acc)); 193 } 194 195 struct linux_pt_fpxreg { 196 l_ushort cwd; 197 l_ushort swd; 198 l_ushort twd; 199 l_ushort fop; 200 l_long fip; 201 l_long fcs; 202 l_long foo; 203 l_long fos; 204 l_long mxcsr; 205 l_long reserved; 206 l_long st_space[32]; 207 l_long xmm_space[32]; 208 l_long padding[56]; 209 }; 210 211 static int 212 linux_proc_read_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs) 213 { 214 215 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 216 if (cpu_fxsr == 0 || (td->td_proc->p_flag & P_INMEM) == 0) 217 return (EIO); 218 bcopy(&get_pcb_user_save_td(td)->sv_xmm, fpxregs, sizeof(*fpxregs)); 219 return (0); 220 } 221 222 static int 223 linux_proc_write_fpxregs(struct thread *td, struct linux_pt_fpxreg *fpxregs) 224 { 225 226 PROC_LOCK_ASSERT(td->td_proc, MA_OWNED); 227 if (cpu_fxsr == 0 || (td->td_proc->p_flag & P_INMEM) == 0) 228 return (EIO); 229 bcopy(fpxregs, &get_pcb_user_save_td(td)->sv_xmm, sizeof(*fpxregs)); 230 return (0); 231 } 232 233 int 234 linux_ptrace(struct thread *td, struct linux_ptrace_args *uap) 235 { 236 union { 237 struct linux_pt_reg reg; 238 struct linux_pt_fpreg fpreg; 239 struct linux_pt_fpxreg fpxreg; 240 } r; 241 union { 242 struct reg bsd_reg; 243 struct fpreg bsd_fpreg; 244 struct dbreg bsd_dbreg; 245 } u; 246 void *addr; 247 pid_t pid; 248 int error, req; 249 250 error = 0; 251 252 /* by default, just copy data intact */ 253 req = uap->req; 254 pid = (pid_t)uap->pid; 255 addr = (void *)uap->addr; 256 257 switch (req) { 258 case PTRACE_TRACEME: 259 case PTRACE_POKETEXT: 260 case PTRACE_POKEDATA: 261 case PTRACE_KILL: 262 error = kern_ptrace(td, req, pid, addr, uap->data); 263 break; 264 case PTRACE_PEEKTEXT: 265 case PTRACE_PEEKDATA: { 266 /* need to preserve return value */ 267 int rval = td->td_retval[0]; 268 error = kern_ptrace(td, req, pid, addr, 0); 269 if (error == 0) 270 error = copyout(td->td_retval, (void *)uap->data, 271 sizeof(l_int)); 272 td->td_retval[0] = rval; 273 break; 274 } 275 case PTRACE_DETACH: 276 error = kern_ptrace(td, PT_DETACH, pid, (void *)1, 277 map_signum(uap->data)); 278 break; 279 case PTRACE_SINGLESTEP: 280 case PTRACE_CONT: 281 error = kern_ptrace(td, req, pid, (void *)1, 282 map_signum(uap->data)); 283 break; 284 case PTRACE_ATTACH: 285 error = kern_ptrace(td, PT_ATTACH, pid, addr, uap->data); 286 break; 287 case PTRACE_GETREGS: 288 /* Linux is using data where FreeBSD is using addr */ 289 error = kern_ptrace(td, PT_GETREGS, pid, &u.bsd_reg, 0); 290 if (error == 0) { 291 map_regs_to_linux(&u.bsd_reg, &r.reg); 292 error = copyout(&r.reg, (void *)uap->data, 293 sizeof(r.reg)); 294 } 295 break; 296 case PTRACE_SETREGS: 297 /* Linux is using data where FreeBSD is using addr */ 298 error = copyin((void *)uap->data, &r.reg, sizeof(r.reg)); 299 if (error == 0) { 300 map_regs_from_linux(&u.bsd_reg, &r.reg); 301 error = kern_ptrace(td, PT_SETREGS, pid, &u.bsd_reg, 0); 302 } 303 break; 304 case PTRACE_GETFPREGS: 305 /* Linux is using data where FreeBSD is using addr */ 306 error = kern_ptrace(td, PT_GETFPREGS, pid, &u.bsd_fpreg, 0); 307 if (error == 0) { 308 map_fpregs_to_linux(&u.bsd_fpreg, &r.fpreg); 309 error = copyout(&r.fpreg, (void *)uap->data, 310 sizeof(r.fpreg)); 311 } 312 break; 313 case PTRACE_SETFPREGS: 314 /* Linux is using data where FreeBSD is using addr */ 315 error = copyin((void *)uap->data, &r.fpreg, sizeof(r.fpreg)); 316 if (error == 0) { 317 map_fpregs_from_linux(&u.bsd_fpreg, &r.fpreg); 318 error = kern_ptrace(td, PT_SETFPREGS, pid, 319 &u.bsd_fpreg, 0); 320 } 321 break; 322 case PTRACE_SETFPXREGS: 323 error = copyin((void *)uap->data, &r.fpxreg, sizeof(r.fpxreg)); 324 if (error) 325 break; 326 /* FALL THROUGH */ 327 case PTRACE_GETFPXREGS: { 328 struct proc *p; 329 struct thread *td2; 330 331 if (sizeof(struct linux_pt_fpxreg) != sizeof(struct savexmm)) { 332 static int once = 0; 333 if (!once) { 334 printf("linux: savexmm != linux_pt_fpxreg\n"); 335 once = 1; 336 } 337 error = EIO; 338 break; 339 } 340 341 if ((p = pfind(uap->pid)) == NULL) { 342 error = ESRCH; 343 break; 344 } 345 346 /* Exiting processes can't be debugged. */ 347 if ((p->p_flag & P_WEXIT) != 0) { 348 error = ESRCH; 349 goto fail; 350 } 351 352 if ((error = p_candebug(td, p)) != 0) 353 goto fail; 354 355 /* System processes can't be debugged. */ 356 if ((p->p_flag & P_SYSTEM) != 0) { 357 error = EINVAL; 358 goto fail; 359 } 360 361 /* not being traced... */ 362 if ((p->p_flag & P_TRACED) == 0) { 363 error = EPERM; 364 goto fail; 365 } 366 367 /* not being traced by YOU */ 368 if (p->p_pptr != td->td_proc) { 369 error = EBUSY; 370 goto fail; 371 } 372 373 /* not currently stopped */ 374 if (!P_SHOULDSTOP(p) || (p->p_flag & P_WAITED) == 0) { 375 error = EBUSY; 376 goto fail; 377 } 378 379 if (req == PTRACE_GETFPXREGS) { 380 _PHOLD(p); /* may block */ 381 td2 = FIRST_THREAD_IN_PROC(p); 382 error = linux_proc_read_fpxregs(td2, &r.fpxreg); 383 _PRELE(p); 384 PROC_UNLOCK(p); 385 if (error == 0) 386 error = copyout(&r.fpxreg, (void *)uap->data, 387 sizeof(r.fpxreg)); 388 } else { 389 /* clear dangerous bits exactly as Linux does*/ 390 r.fpxreg.mxcsr &= 0xffbf; 391 _PHOLD(p); /* may block */ 392 td2 = FIRST_THREAD_IN_PROC(p); 393 error = linux_proc_write_fpxregs(td2, &r.fpxreg); 394 _PRELE(p); 395 PROC_UNLOCK(p); 396 } 397 break; 398 399 fail: 400 PROC_UNLOCK(p); 401 break; 402 } 403 case PTRACE_PEEKUSR: 404 case PTRACE_POKEUSR: { 405 error = EIO; 406 407 /* check addr for alignment */ 408 if (uap->addr < 0 || uap->addr & (sizeof(l_int) - 1)) 409 break; 410 /* 411 * Allow Linux programs to access register values in 412 * user struct. We simulate this through PT_GET/SETREGS 413 * as necessary. 414 */ 415 if (uap->addr < sizeof(struct linux_pt_reg)) { 416 error = kern_ptrace(td, PT_GETREGS, pid, &u.bsd_reg, 0); 417 if (error != 0) 418 break; 419 420 map_regs_to_linux(&u.bsd_reg, &r.reg); 421 if (req == PTRACE_PEEKUSR) { 422 error = copyout((char *)&r.reg + uap->addr, 423 (void *)uap->data, sizeof(l_int)); 424 break; 425 } 426 427 *(l_int *)((char *)&r.reg + uap->addr) = 428 (l_int)uap->data; 429 430 map_regs_from_linux(&u.bsd_reg, &r.reg); 431 error = kern_ptrace(td, PT_SETREGS, pid, &u.bsd_reg, 0); 432 } 433 434 /* 435 * Simulate debug registers access 436 */ 437 if (uap->addr >= LINUX_DBREG_OFFSET && 438 uap->addr <= LINUX_DBREG_OFFSET + LINUX_DBREG_SIZE) { 439 error = kern_ptrace(td, PT_GETDBREGS, pid, &u.bsd_dbreg, 440 0); 441 if (error != 0) 442 break; 443 444 uap->addr -= LINUX_DBREG_OFFSET; 445 if (req == PTRACE_PEEKUSR) { 446 error = copyout((char *)&u.bsd_dbreg + 447 uap->addr, (void *)uap->data, 448 sizeof(l_int)); 449 break; 450 } 451 452 *(l_int *)((char *)&u.bsd_dbreg + uap->addr) = 453 uap->data; 454 error = kern_ptrace(td, PT_SETDBREGS, pid, 455 &u.bsd_dbreg, 0); 456 } 457 458 break; 459 } 460 case LINUX_PTRACE_SYSCALL: 461 /* fall through */ 462 default: 463 printf("linux: ptrace(%u, ...) not implemented\n", 464 (unsigned int)uap->req); 465 error = EINVAL; 466 break; 467 } 468 469 return (error); 470 } 471