linux_ptrace.c revision 1.18
1 /* $NetBSD: linux_ptrace.c,v 1.18 2007/07/09 21:10:46 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 1.18 2007/07/09 21:10:46 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 128 linux_sys_ptrace_arch(l, v, retval) 129 struct lwp *l; 130 void *v; 131 register_t *retval; 132 { 133 struct linux_sys_ptrace_args /* { 134 syscallarg(int) request; 135 syscallarg(int) pid; 136 syscallarg(int) addr; 137 syscallarg(int) data; 138 } */ *uap = v; 139 struct proc *p = l->l_proc; 140 int request, error; 141 struct proc *t; /* target process */ 142 struct lwp *lt; 143 struct reg *regs = NULL; 144 struct fpreg *fpregs = NULL; 145 struct linux_reg *linux_regs = NULL; 146 struct linux_fpctx *linux_fpregs = NULL; 147 int addr; 148 149 request = SCARG(uap, request); 150 151 if ((request != LINUX_PTRACE_PEEKUSR) && 152 (request != LINUX_PTRACE_POKEUSR) && 153 (request != LINUX_PTRACE_GETREGS) && 154 (request != LINUX_PTRACE_SETREGS) && 155 (request != LINUX_PTRACE_GETFPREGS) && 156 (request != LINUX_PTRACE_SETFPREGS)) 157 return EIO; 158 159 /* XXXAD locking */ 160 161 /* Find the process we're supposed to be operating on. */ 162 if ((t = pfind(SCARG(uap, pid))) == NULL) 163 return ESRCH; 164 165 /* 166 * You can't do what you want to the process if: 167 * (1) It's not being traced at all, 168 */ 169 if (!ISSET(t->p_slflag, PSL_TRACED)) 170 return EPERM; 171 172 /* 173 * (2) it's being traced by procfs (which has 174 * different signal delivery semantics), 175 */ 176 if (ISSET(t->p_slflag, PSL_FSTRACE)) 177 return EBUSY; 178 179 /* 180 * (3) it's not being traced by _you_, or 181 */ 182 if (t->p_pptr != p) 183 return EBUSY; 184 185 /* 186 * (4) it's not currently stopped. 187 */ 188 if (t->p_stat != SSTOP || !t->p_waited /* XXXSMP */) 189 return EBUSY; 190 191 /* XXX NJWLWP 192 * The entire ptrace interface needs work to be useful to 193 * a process with multiple LWPs. For the moment, we'll 194 * just kluge this and fail on others. 195 */ 196 197 if (p->p_nlwps > 1) 198 return (ENOSYS); 199 200 lt = LIST_FIRST(&t->p_lwps); 201 202 *retval = 0; 203 204 switch (request) { 205 case LINUX_PTRACE_GETREGS: 206 MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK); 207 MALLOC(linux_regs, struct linux_reg*, sizeof(struct linux_reg), 208 M_TEMP, M_WAITOK); 209 210 error = process_read_regs(lt, regs); 211 if (error != 0) 212 goto out; 213 214 linux_regs->ebx = regs->r_ebx; 215 linux_regs->ecx = regs->r_ecx; 216 linux_regs->edx = regs->r_edx; 217 linux_regs->esi = regs->r_esi; 218 linux_regs->edi = regs->r_edi; 219 linux_regs->ebp = regs->r_ebp; 220 linux_regs->eax = regs->r_eax; 221 linux_regs->xds = regs->r_ds; 222 linux_regs->xes = regs->r_es; 223 linux_regs->orig_eax = regs->r_eax; /* XXX is this correct? */ 224 linux_regs->eip = regs->r_cs + regs->r_eip; 225 linux_regs->xcs = regs->r_cs; 226 linux_regs->eflags = regs->r_eflags; 227 linux_regs->esp = regs->r_esp; 228 linux_regs->xss = regs->r_ss; 229 230 error = copyout(linux_regs, (void *)SCARG(uap, data), 231 sizeof(struct linux_reg)); 232 goto out; 233 234 case LINUX_PTRACE_SETREGS: 235 MALLOC(regs, struct reg*, sizeof(struct reg), M_TEMP, M_WAITOK); 236 MALLOC(linux_regs, struct linux_reg *, sizeof(struct linux_reg), 237 M_TEMP, M_WAITOK); 238 239 error = copyin((void *)SCARG(uap, data), linux_regs, 240 sizeof(struct linux_reg)); 241 if (error != 0) 242 goto out; 243 244 regs->r_ebx = linux_regs->ebx; 245 regs->r_ecx = linux_regs->ecx; 246 regs->r_edx = linux_regs->edx; 247 regs->r_esi = linux_regs->esi; 248 regs->r_edi = linux_regs->edi; 249 regs->r_ebp = linux_regs->ebp; 250 regs->r_eax = linux_regs->eax; 251 regs->r_ds = linux_regs->xds; 252 regs->r_es = linux_regs->xes; 253 regs->r_eip = linux_regs->eip - linux_regs->xcs; 254 regs->r_cs = linux_regs->xcs; 255 regs->r_eflags = linux_regs->eflags; 256 regs->r_esp = linux_regs->esp; 257 regs->r_ss = linux_regs->xss; 258 259 error = process_write_regs(lt, regs); 260 goto out; 261 262 case LINUX_PTRACE_GETFPREGS: 263 MALLOC(fpregs, struct fpreg *, sizeof(struct fpreg), 264 M_TEMP, M_WAITOK); 265 MALLOC(linux_fpregs, struct linux_fpctx *, 266 sizeof(struct linux_fpctx), M_TEMP, M_WAITOK); 267 268 error = process_read_fpregs(lt, fpregs); 269 if (error != 0) 270 goto out; 271 272 /* zero the contents if NetBSD fpreg structure is smaller */ 273 if (sizeof(struct fpreg) < sizeof(struct linux_fpctx)) 274 memset(linux_fpregs, '\0', sizeof(struct linux_fpctx)); 275 276 memcpy(linux_fpregs, fpregs, 277 min(sizeof(struct linux_fpctx), sizeof(struct fpreg))); 278 error = copyout(linux_fpregs, (void *)SCARG(uap, data), 279 sizeof(struct linux_fpctx)); 280 goto out; 281 282 case LINUX_PTRACE_SETFPREGS: 283 MALLOC(fpregs, struct fpreg *, sizeof(struct fpreg), 284 M_TEMP, M_WAITOK); 285 MALLOC(linux_fpregs, struct linux_fpctx *, 286 sizeof(struct linux_fpctx), M_TEMP, M_WAITOK); 287 error = copyin((void *)SCARG(uap, data), linux_fpregs, 288 sizeof(struct linux_fpctx)); 289 if (error != 0) 290 goto out; 291 292 memset(fpregs, '\0', sizeof(struct fpreg)); 293 memcpy(fpregs, linux_fpregs, 294 min(sizeof(struct linux_fpctx), sizeof(struct fpreg))); 295 296 error = process_write_regs(lt, regs); 297 goto out; 298 299 case LINUX_PTRACE_PEEKUSR: 300 addr = SCARG(uap, addr); 301 302 uvm_lwp_hold(lt); /* need full process info */ 303 error = 0; 304 if (addr < LUSR_OFF(lusr_startgdb)) { 305 /* XXX should provide appropriate register */ 306 error = 1; 307 } else if (addr == LUSR_OFF(u_tsize)) 308 *retval = p->p_vmspace->vm_tsize; 309 else if (addr == LUSR_OFF(u_dsize)) 310 *retval = p->p_vmspace->vm_dsize; 311 else if (addr == LUSR_OFF(u_ssize)) 312 *retval = p->p_vmspace->vm_ssize; 313 else if (addr == LUSR_OFF(start_code)) 314 *retval = (register_t) p->p_vmspace->vm_taddr; 315 else if (addr == LUSR_OFF(start_stack)) 316 *retval = (register_t) p->p_vmspace->vm_minsaddr; 317 else if (addr == LUSR_OFF(u_ar0)) 318 *retval = LUSR_OFF(regs); 319 else if (addr >= LUSR_OFF(u_debugreg) 320 && addr <= LUSR_OFF(u_debugreg_end)) { 321 int off = (addr - LUSR_OFF(u_debugreg)) / sizeof(int); 322 323 /* only do this for Linux processes */ 324 if (t->p_emul != &emul_linux) 325 error = EINVAL; 326 else { 327 *retval = ((struct linux_emuldata *) 328 t->p_emuldata)->debugreg[off]; 329 } 330 } else if (addr == LUSR_OFF(__signal)) { 331 error = 1; 332 } else if (addr == LUSR_OFF(__signal)) { 333 error = 1; 334 } else if (addr == LUSR_OFF(u_fpstate)) { 335 error = 1; 336 } else if (addr == LUSR_OFF(__magic)) { 337 error = 1; 338 } else if (addr == LUSR_OFF(u_comm)) { 339 error = 1; 340 } else { 341 #ifdef DEBUG_LINUX 342 printf("linux_ptrace: unsupported address: %d\n", addr); 343 #endif 344 error = 1; 345 } 346 347 uvm_lwp_rele(lt); 348 349 if (!error) 350 return 0; 351 352 case LINUX_PTRACE_POKEUSR: 353 /* we only support setting debugregs for now */ 354 addr = SCARG(uap, addr); 355 if (addr >= LUSR_OFF(u_debugreg) 356 && addr <= LUSR_OFF(u_debugreg_end)) { 357 int off = (addr - LUSR_OFF(u_debugreg)) / sizeof(int); 358 int data = SCARG(uap, data); 359 360 /* only do this for Linux processes */ 361 if (t->p_emul != &emul_linux) 362 return EINVAL; 363 364 uvm_lwp_hold(lt); 365 ((struct linux_emuldata *)t->p_emuldata)->debugreg[off] = data; 366 uvm_lwp_rele(lt); 367 return (0); 368 } 369 370 break; 371 default: 372 /* never reached */ 373 break; 374 } 375 376 return EIO; 377 378 out: 379 if (regs) 380 FREE(regs, M_TEMP); 381 if (fpregs) 382 FREE(fpregs, M_TEMP); 383 if (linux_regs) 384 FREE(linux_regs, M_TEMP); 385 if (linux_fpregs) 386 FREE(linux_fpregs, M_TEMP); 387 return (error); 388 } 389
Indexes created Mon Sep 22 13:09:51 GMT 2025