1 /* $NetBSD: linux_ptrace.c,v 1.21 2008/04/23 14:18:50 ad Exp $ */ 2 3 /*- 4 * Copyright (c) 1999 The NetBSD Foundation, Inc. 5 * All rights reserved. 6 * 7 * This code is derived from software contributed to The NetBSD Foundation 8 * by Matthias Scheler. 9 * 10 * Redistribution and use in source and binary forms, with or without 11 * modification, are permitted provided that the following conditions 12 * are met: 13 * 1. Redistributions of source code must retain the above copyright 14 * notice, this list of conditions and the following disclaimer. 15 * 2. Redistributions in binary form must reproduce the above copyright 16 * notice, this list of conditions and the following disclaimer in the 17 * documentation and/or other materials provided with the distribution. 18 * 3. All advertising materials mentioning features or use of this software 19 * must display the following acknowledgement: 20 * This product includes software developed by the NetBSD 21 * Foundation, Inc. and its contributors. 22 * 4. Neither the name of The NetBSD Foundation nor the names of its 23 * contributors may be used to endorse or promote products derived 24 * from this software without specific prior written permission. 25 * 26 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 27 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 28 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 29 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 30 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 31 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 32 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 33 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 34 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 35 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 36 * POSSIBILITY OF SUCH DAMAGE. 37 */ 38 39 #include <sys/cdefs.h> 40 __KERNEL_RCSID(0, "$NetBSD: linux_ptrace.c,v 1.21 2008/04/23 14:18:50 ad Exp $"); 41 42 #include <sys/param.h> 43 #include <sys/malloc.h> 44 #include <sys/mount.h> 45 #include <sys/proc.h> 46 #include <sys/ptrace.h> 47 #include <sys/systm.h> 48 #include <sys/syscall.h> 49 #include <sys/syscallargs.h> 50 #include <uvm/uvm_extern.h> 51 52 #include <machine/reg.h> 53 54 #include <compat/linux/common/linux_types.h> 55 #include <compat/linux/common/linux_ptrace.h> 56 #include <compat/linux/common/linux_signal.h> 57 58 #include <compat/linux/common/linux_util.h> 59 #include <compat/linux/common/linux_machdep.h> 60 #include <compat/linux/common/linux_emuldata.h> 61 #include <compat/linux/common/linux_exec.h> /* for emul_linux */ 62 63 #include <compat/linux/linux_syscallargs.h> 64 65 #include <lib/libkern/libkern.h> /* for offsetof() */ 66 67 struct linux_reg { 68 long ebx; 69 long ecx; 70 long edx; 71 long esi; 72 long edi; 73 long ebp; 74 long eax; 75 long xds, xes; /* unsigned short ds, __ds, es, __es; */ 76 long __fs, __gs; /* unsigned short fs, __fs, gs, __gs; */ 77 long orig_eax; 78 long eip; 79 long xcs; /* unsigned short cs, __cs; */ 80 long eflags; 81 long esp; 82 long xss; /* unsigned short ss, __ss; */ 83 }; 84 85 /* structure used for storing floating point context */ 86 struct linux_fpctx { 87 long cwd; 88 long swd; 89 long twd; 90 long fip; 91 long fcs; 92 long foo; 93 long fos; 94 long st_space[20]; 95 }; 96 97 /* user struct for linux process - this is used for Linux ptrace emulation */ 98 /* most of it is junk only used by gdb */ 99 struct linux_user { 100 struct linux_reg regs; /* registers */ 101 int u_fpvalid; /* true if math co-processor being used. */ 102 struct linux_fpctx i387; /* Math Co-processor registers. */ 103 /* The rest of this junk is to help gdb figure out what goes where */ 104 #define lusr_startgdb u_tsize 105 unsigned long int u_tsize; /* Text segment size (pages). */ 106 unsigned long int u_dsize; /* Data segment size (pages). */ 107 unsigned long int u_ssize; /* Stack segment size (pages). */ 108 unsigned long start_code; /* Starting virtual address of text. */ 109 unsigned long start_stack; /* Starting virtual address of stack 110 area. This is actually the bottom of 111 the stack, the top of the stack is 112 always found in the esp register. */ 113 long int __signal; /* Signal that caused the core dump. */ 114 int __reserved; /* unused */ 115 void *u_ar0; /* Used by gdb to help find the values 116 for the registers. */ 117 struct linux_fpctx *u_fpstate; /* Math Co-processor pointer. */ 118 unsigned long __magic; /* To uniquely identify a core file */ 119 char u_comm[32]; /* User command that was responsible */ 120 int u_debugreg[8]; 121 #define u_debugreg_end u_debugreg[7] 122 }; 123 124 #define LUSR_OFF(member) offsetof(struct linux_user, member) 125 #define ISSET(t, f) ((t) & (f)) 126 127 int linux_ptrace_disabled = 1; /* bitrotted */ 128 129 int 130 linux_sys_ptrace_arch(struct lwp *l, const struct linux_sys_ptrace_args *uap, register_t *retval) 131 { 132 /* { 133 syscallarg(int) request; 134 syscallarg(int) pid; 135 syscallarg(int) addr; 136 syscallarg(int) data; 137 } */ 138 struct proc *p = l->l_proc; 139 int request, error; 140 struct proc *t; /* target process */ 141 struct lwp *lt; 142 struct reg *regs = NULL; 143 struct fpreg *fpregs = NULL; 144 struct linux_reg *linux_regs = NULL; 145 struct linux_fpctx *linux_fpregs = NULL; 146 int addr; 147 148 if (linux_ptrace_disabled) 149 return ENOSYS; 150 151 request = SCARG(uap, request); 152 153 if ((request != LINUX_PTRACE_PEEKUSR) && 154 (request != LINUX_PTRACE_POKEUSR) && 155 (request != LINUX_PTRACE_GETREGS) && 156 (request != LINUX_PTRACE_SETREGS) && 157 (request != LINUX_PTRACE_GETFPREGS) && 158 (request != LINUX_PTRACE_SETFPREGS)) 159 return EIO; 160 161 /* XXXAD locking */ 162 163 /* Find the process we're supposed to be operating on. */ 164 if ((t = pfind(SCARG(uap, pid))) == NULL) 165 return ESRCH; 166 167 /* 168 * You can't do what you want to the process if: 169 * (1) It's not being traced at all, 170 */ 171 if (!ISSET(t->p_slflag, PSL_TRACED)) 172 return EPERM; 173 174 /* 175 * (2) it's being traced by procfs (which has 176 * different signal delivery semantics), 177 */ 178 if (ISSET(t->p_slflag, PSL_FSTRACE)) 179 return EBUSY; 180 181 /* 182 * (3) it's not being traced by _you_, or 183 */ 184 if (t->p_pptr != p) 185 return EBUSY; 186 187 /* 188 * (4) it's not currently stopped. 189 */ 190 if (t->p_stat != SSTOP || !t->p_waited /* XXXSMP */) 191 return EBUSY; 192 193 /* XXX NJWLWP 194 * The entire ptrace interface needs work to be useful to 195 * a process with multiple LWPs. For the moment, we'll 196 * just kluge this and fail on others. 197 */ 198 199 if (p->p_nlwps > 1) 200 return (ENOSYS); 201 202 lt = LIST_FIRST(&t->p_lwps); 203 204 *retval = 0; 205 206 switch (request) { 207 case LINUX_PTRACE_GETREGS: 208 MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK); 209 MALLOC(linux_regs, struct linux_reg*, sizeof(struct linux_reg), 210 M_TEMP, M_WAITOK); 211 212 error = process_read_regs(lt, regs); 213 if (error != 0) 214 goto out; 215 216 linux_regs->ebx = regs->r_ebx; 217 linux_regs->ecx = regs->r_ecx; 218 linux_regs->edx = regs->r_edx; 219 linux_regs->esi = regs->r_esi; 220 linux_regs->edi = regs->r_edi; 221 linux_regs->ebp = regs->r_ebp; 222 linux_regs->eax = regs->r_eax; 223 linux_regs->xds = regs->r_ds; 224 linux_regs->xes = regs->r_es; 225 linux_regs->orig_eax = regs->r_eax; /* XXX is this correct? */ 226 linux_regs->eip = regs->r_cs + regs->r_eip; 227 linux_regs->xcs = regs->r_cs; 228 linux_regs->eflags = regs->r_eflags; 229 linux_regs->esp = regs->r_esp; 230 linux_regs->xss = regs->r_ss; 231 232 error = copyout(linux_regs, (void *)SCARG(uap, data), 233 sizeof(struct linux_reg)); 234 goto out; 235 236 case LINUX_PTRACE_SETREGS: 237 MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK); 238 MALLOC(linux_regs, struct linux_reg *, sizeof(struct linux_reg), 239 M_TEMP, M_WAITOK); 240 241 error = copyin((void *)SCARG(uap, data), linux_regs, 242 sizeof(struct linux_reg)); 243 if (error != 0) 244 goto out; 245 246 regs->r_ebx = linux_regs->ebx; 247 regs->r_ecx = linux_regs->ecx; 248 regs->r_edx = linux_regs->edx; 249 regs->r_esi = linux_regs->esi; 250 regs->r_edi = linux_regs->edi; 251 regs->r_ebp = linux_regs->ebp; 252 regs->r_eax = linux_regs->eax; 253 regs->r_ds = linux_regs->xds; 254 regs->r_es = linux_regs->xes; 255 regs->r_eip = linux_regs->eip - linux_regs->xcs; 256 regs->r_cs = linux_regs->xcs; 257 regs->r_eflags = linux_regs->eflags; 258 regs->r_esp = linux_regs->esp; 259 regs->r_ss = linux_regs->xss; 260 261 error = process_write_regs(lt, regs); 262 goto out; 263 264 case LINUX_PTRACE_GETFPREGS: 265 MALLOC(fpregs, struct fpreg *, sizeof(struct fpreg), 266 M_TEMP, M_WAITOK); 267 MALLOC(linux_fpregs, struct linux_fpctx *, 268 sizeof(struct linux_fpctx), M_TEMP, M_WAITOK); 269 270 error = process_read_fpregs(lt, fpregs); 271 if (error != 0) 272 goto out; 273 274 /* zero the contents if NetBSD fpreg structure is smaller */ 275 if (sizeof(struct fpreg) < sizeof(struct linux_fpctx)) 276 memset(linux_fpregs, '\0', sizeof(struct linux_fpctx)); 277 278 memcpy(linux_fpregs, fpregs, 279 min(sizeof(struct linux_fpctx), sizeof(struct fpreg))); 280 error = copyout(linux_fpregs, (void *)SCARG(uap, data), 281 sizeof(struct linux_fpctx)); 282 goto out; 283 284 case LINUX_PTRACE_SETFPREGS: 285 MALLOC(fpregs, struct fpreg *, sizeof(struct fpreg), 286 M_TEMP, M_WAITOK); 287 MALLOC(linux_fpregs, struct linux_fpctx *, 288 sizeof(struct linux_fpctx), M_TEMP, M_WAITOK); 289 error = copyin((void *)SCARG(uap, data), linux_fpregs, 290 sizeof(struct linux_fpctx)); 291 if (error != 0) 292 goto out; 293 294 memset(fpregs, '\0', sizeof(struct fpreg)); 295 memcpy(fpregs, linux_fpregs, 296 min(sizeof(struct linux_fpctx), sizeof(struct fpreg))); 297 298 error = process_write_regs(lt, regs); 299 goto out; 300 301 case LINUX_PTRACE_PEEKUSR: 302 addr = SCARG(uap, addr); 303 304 uvm_lwp_hold(lt); /* need full process info */ 305 error = 0; 306 if (addr < LUSR_OFF(lusr_startgdb)) { 307 /* XXX should provide appropriate register */ 308 error = 1; 309 } else if (addr == LUSR_OFF(u_tsize)) 310 *retval = p->p_vmspace->vm_tsize; 311 else if (addr == LUSR_OFF(u_dsize)) 312 *retval = p->p_vmspace->vm_dsize; 313 else if (addr == LUSR_OFF(u_ssize)) 314 *retval = p->p_vmspace->vm_ssize; 315 else if (addr == LUSR_OFF(start_code)) 316 *retval = (register_t) p->p_vmspace->vm_taddr; 317 else if (addr == LUSR_OFF(start_stack)) 318 *retval = (register_t) p->p_vmspace->vm_minsaddr; 319 else if (addr == LUSR_OFF(u_ar0)) 320 *retval = LUSR_OFF(regs); 321 else if (addr >= LUSR_OFF(u_debugreg) 322 && addr <= LUSR_OFF(u_debugreg_end)) { 323 int off = (addr - LUSR_OFF(u_debugreg)) / sizeof(int); 324 325 /* only do this for Linux processes */ 326 if (t->p_emul != &emul_linux) 327 error = EINVAL; 328 else { 329 *retval = ((struct linux_emuldata *) 330 t->p_emuldata)->debugreg[off]; 331 } 332 } else if (addr == LUSR_OFF(__signal)) { 333 error = 1; 334 } else if (addr == LUSR_OFF(__signal)) { 335 error = 1; 336 } else if (addr == LUSR_OFF(u_fpstate)) { 337 error = 1; 338 } else if (addr == LUSR_OFF(__magic)) { 339 error = 1; 340 } else if (addr == LUSR_OFF(u_comm)) { 341 error = 1; 342 } else { 343 #ifdef DEBUG_LINUX 344 printf("linux_ptrace: unsupported address: %d\n", addr); 345 #endif 346 error = 1; 347 } 348 349 uvm_lwp_rele(lt); 350 351 if (!error) 352 return 0; 353 354 case LINUX_PTRACE_POKEUSR: 355 /* we only support setting debugregs for now */ 356 addr = SCARG(uap, addr); 357 if (addr >= LUSR_OFF(u_debugreg) 358 && addr <= LUSR_OFF(u_debugreg_end)) { 359 int off = (addr - LUSR_OFF(u_debugreg)) / sizeof(int); 360 int data = SCARG(uap, data); 361 362 /* only do this for Linux processes */ 363 if (t->p_emul != &emul_linux) 364 return EINVAL; 365 366 uvm_lwp_hold(lt); 367 ((struct linux_emuldata *)t->p_emuldata)->debugreg[off] = data; 368 uvm_lwp_rele(lt); 369 return (0); 370 } 371 372 break; 373 default: 374 /* never reached */ 375 break; 376 } 377 378 return EIO; 379 380 out: 381 if (regs) 382 FREE(regs, M_TEMP); 383 if (fpregs) 384 FREE(fpregs, M_TEMP); 385 if (linux_regs) 386 FREE(linux_regs, M_TEMP); 387 if (linux_fpregs) 388 FREE(linux_fpregs, M_TEMP); 389 return (error); 390 } 391