1 /* $NetBSD: linux_ptrace.c,v 1.36 2022/09/05 14:14:42 tsutsui 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 * 19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 29 * POSSIBILITY OF SUCH DAMAGE. 30 */ 31 32 #include <sys/cdefs.h> 33 __KERNEL_RCSID(0, "$NetBSD: linux_ptrace.c,v 1.36 2022/09/05 14:14:42 tsutsui Exp $"); 34 35 #include <sys/param.h> 36 #include <sys/mount.h> 37 #include <sys/proc.h> 38 #include <sys/ptrace.h> 39 #include <sys/systm.h> 40 #include <sys/syscall.h> 41 #include <sys/syscallargs.h> 42 #include <uvm/uvm_extern.h> 43 44 #include <machine/reg.h> 45 46 #include <compat/linux/common/linux_types.h> 47 #include <compat/linux/common/linux_ptrace.h> 48 #include <compat/linux/common/linux_signal.h> 49 50 #include <compat/linux/common/linux_util.h> 51 #include <compat/linux/common/linux_machdep.h> 52 #include <compat/linux/common/linux_emuldata.h> 53 #include <compat/linux/common/linux_exec.h> /* for emul_linux */ 54 55 #include <compat/linux/linux_syscallargs.h> 56 57 #include <lib/libkern/libkern.h> /* for offsetof() */ 58 59 struct linux_reg { 60 long ebx; 61 long ecx; 62 long edx; 63 long esi; 64 long edi; 65 long ebp; 66 long eax; 67 long xds, xes; /* unsigned short ds, __ds, es, __es; */ 68 long __fs, __gs; /* unsigned short fs, __fs, gs, __gs; */ 69 long orig_eax; 70 long eip; 71 long xcs; /* unsigned short cs, __cs; */ 72 long eflags; 73 long esp; 74 long xss; /* unsigned short ss, __ss; */ 75 }; 76 77 /* structure used for storing floating point context */ 78 struct linux_fpctx { 79 long cwd; 80 long swd; 81 long twd; 82 long fip; 83 long fcs; 84 long foo; 85 long fos; 86 long st_space[20]; 87 }; 88 89 /* user struct for linux process - this is used for Linux ptrace emulation */ 90 /* most of it is junk only used by gdb */ 91 struct linux_user { 92 struct linux_reg regs; /* registers */ 93 int u_fpvalid; /* true if math co-processor being used. */ 94 struct linux_fpctx i387; /* Math Co-processor registers. */ 95 /* The rest of this junk is to help gdb figure out what goes where */ 96 #define lusr_startgdb u_tsize 97 unsigned long int u_tsize; /* Text segment size (pages). */ 98 unsigned long int u_dsize; /* Data segment size (pages). */ 99 unsigned long int u_ssize; /* Stack segment size (pages). */ 100 unsigned long start_code; /* Starting virtual address of text. */ 101 unsigned long start_stack; /* Starting virtual address of stack 102 area. This is actually the bottom of 103 the stack, the top of the stack is 104 always found in the esp register. */ 105 long int __signal; /* Signal that caused the core dump. */ 106 int __reserved; /* unused */ 107 void *u_ar0; /* Used by gdb to help find the values 108 for the registers. */ 109 struct linux_fpctx *u_fpstate; /* Math Co-processor pointer. */ 110 unsigned long __magic; /* To uniquely identify a core file */ 111 char u_comm[32]; /* User command that was responsible */ 112 int u_debugreg[8]; 113 #define u_debugreg_end u_debugreg[7] 114 }; 115 116 #define LUSR_OFF(member) offsetof(struct linux_user, member) 117 118 int linux_ptrace_disabled = 1; /* bitrotted */ 119 120 int 121 linux_sys_ptrace_arch(struct lwp *l, const struct linux_sys_ptrace_args *uap, 122 register_t *retval) 123 { 124 /* { 125 syscallarg(int) request; 126 syscallarg(int) pid; 127 syscallarg(int) addr; 128 syscallarg(int) data; 129 } */ 130 struct proc *p = l->l_proc, *t; 131 struct lwp *lt; 132 struct reg *regs = NULL; 133 struct fpreg *fpregs = NULL; 134 struct linux_reg *linux_regs = NULL; 135 struct linux_fpctx *linux_fpregs = NULL; 136 struct linux_emuldata *led; 137 int request, error, addr; 138 size_t fp_size; 139 140 if (linux_ptrace_disabled) 141 return ENOSYS; 142 143 error = 0; 144 request = SCARG(uap, request); 145 146 switch (request) { 147 case LINUX_PTRACE_PEEKUSR: 148 case LINUX_PTRACE_POKEUSR: 149 break; 150 case LINUX_PTRACE_GETREGS: 151 case LINUX_PTRACE_SETREGS: 152 regs = kmem_alloc(sizeof(struct reg), KM_SLEEP); 153 linux_regs = kmem_alloc(sizeof(struct linux_reg), KM_SLEEP); 154 if (request == LINUX_PTRACE_SETREGS) { 155 error = copyin((void *)SCARG(uap, data), linux_regs, 156 sizeof(struct linux_reg)); 157 if (error) { 158 goto out; 159 } 160 } 161 break; 162 case LINUX_PTRACE_GETFPREGS: 163 case LINUX_PTRACE_SETFPREGS: 164 fpregs = kmem_alloc(sizeof(struct fpreg), KM_SLEEP); 165 linux_fpregs = kmem_alloc(sizeof(struct linux_fpctx), KM_SLEEP); 166 if (request == LINUX_PTRACE_SETFPREGS) { 167 error = copyin((void *)SCARG(uap, data), linux_fpregs, 168 sizeof(struct linux_fpctx)); 169 if (error) { 170 goto out; 171 } 172 } 173 break; 174 default: 175 error = EIO; 176 goto out; 177 } 178 179 /* Find the process we are supposed to be operating on. */ 180 mutex_enter(&proc_lock); 181 if ((t = proc_find(SCARG(uap, pid))) == NULL) { 182 mutex_exit(&proc_lock); 183 error = ESRCH; 184 goto out; 185 } 186 mutex_enter(t->p_lock); 187 188 /* 189 * You cannot do what you want to the process if: 190 * 1. It is not being traced at all, 191 */ 192 if (!ISSET(t->p_slflag, PSL_TRACED)) { 193 mutex_exit(t->p_lock); 194 mutex_exit(&proc_lock); 195 error = EPERM; 196 goto out; 197 } 198 /* 199 * 2. It is not being traced by _you_, or 200 * 3. It is not currently stopped. 201 */ 202 if (t->p_pptr != p || t->p_stat != SSTOP || !t->p_waited) { 203 mutex_exit(t->p_lock); 204 mutex_exit(&proc_lock); 205 error = EBUSY; 206 goto out; 207 } 208 mutex_exit(&proc_lock); 209 /* XXX: ptrace needs revamp for multi-threading support. */ 210 if (t->p_nlwps > 1) { 211 mutex_exit(t->p_lock); 212 error = ENOSYS; 213 goto out; 214 } 215 lt = LIST_FIRST(&t->p_lwps); 216 *retval = 0; 217 218 switch (request) { 219 case LINUX_PTRACE_GETREGS: 220 error = process_read_regs(lt, regs); 221 mutex_exit(t->p_lock); 222 if (error) { 223 break; 224 } 225 memset(linux_regs, 0, sizeof(*linux_regs)); 226 linux_regs->ebx = regs->r_ebx; 227 linux_regs->ecx = regs->r_ecx; 228 linux_regs->edx = regs->r_edx; 229 linux_regs->esi = regs->r_esi; 230 linux_regs->edi = regs->r_edi; 231 linux_regs->ebp = regs->r_ebp; 232 linux_regs->eax = regs->r_eax; 233 linux_regs->xds = regs->r_ds; 234 linux_regs->xes = regs->r_es; 235 linux_regs->orig_eax = regs->r_eax; /* XXX is this correct? */ 236 linux_regs->eip = regs->r_cs + regs->r_eip; 237 linux_regs->xcs = regs->r_cs; 238 linux_regs->eflags = regs->r_eflags; 239 linux_regs->esp = regs->r_esp; 240 linux_regs->xss = regs->r_ss; 241 242 error = copyout(linux_regs, (void *)SCARG(uap, data), 243 sizeof(struct linux_reg)); 244 break; 245 246 case LINUX_PTRACE_SETREGS: 247 regs->r_ebx = linux_regs->ebx; 248 regs->r_ecx = linux_regs->ecx; 249 regs->r_edx = linux_regs->edx; 250 regs->r_esi = linux_regs->esi; 251 regs->r_edi = linux_regs->edi; 252 regs->r_ebp = linux_regs->ebp; 253 regs->r_eax = linux_regs->eax; 254 regs->r_ds = linux_regs->xds; 255 regs->r_es = linux_regs->xes; 256 regs->r_eip = linux_regs->eip - linux_regs->xcs; 257 regs->r_cs = linux_regs->xcs; 258 regs->r_eflags = linux_regs->eflags; 259 regs->r_esp = linux_regs->esp; 260 regs->r_ss = linux_regs->xss; 261 262 error = process_write_regs(lt, regs); 263 mutex_exit(t->p_lock); 264 break; 265 266 case LINUX_PTRACE_GETFPREGS: 267 fp_size = sizeof fpregs; 268 error = process_read_fpregs(lt, fpregs, &fp_size); 269 mutex_exit(t->p_lock); 270 if (error) { 271 break; 272 } 273 /* Zero the contents if NetBSD fpreg structure is smaller */ 274 if (fp_size < sizeof(struct linux_fpctx)) { 275 memset(linux_fpregs, '\0', sizeof(struct linux_fpctx)); 276 } 277 memcpy(linux_fpregs, fpregs, 278 uimin(sizeof(struct linux_fpctx), fp_size)); 279 error = copyout(linux_fpregs, (void *)SCARG(uap, data), 280 sizeof(struct linux_fpctx)); 281 break; 282 283 case LINUX_PTRACE_SETFPREGS: 284 memset(fpregs, '\0', sizeof(struct fpreg)); 285 memcpy(fpregs, linux_fpregs, 286 uimin(sizeof(struct linux_fpctx), sizeof(struct fpreg))); 287 error = process_write_regs(lt, regs); 288 mutex_exit(t->p_lock); 289 break; 290 291 case LINUX_PTRACE_PEEKUSR: 292 /* XXX locking */ 293 addr = SCARG(uap, addr); 294 295 error = 0; 296 if (addr < LUSR_OFF(lusr_startgdb)) { 297 /* XXX should provide appropriate register */ 298 error = ENOTSUP; 299 } else if (addr == LUSR_OFF(u_tsize)) 300 *retval = p->p_vmspace->vm_tsize; 301 else if (addr == LUSR_OFF(u_dsize)) 302 *retval = p->p_vmspace->vm_dsize; 303 else if (addr == LUSR_OFF(u_ssize)) 304 *retval = p->p_vmspace->vm_ssize; 305 else if (addr == LUSR_OFF(start_code)) 306 *retval = (register_t) p->p_vmspace->vm_taddr; 307 else if (addr == LUSR_OFF(start_stack)) 308 *retval = (register_t) p->p_vmspace->vm_minsaddr; 309 else if (addr == LUSR_OFF(u_ar0)) 310 *retval = LUSR_OFF(regs); 311 else if (addr >= LUSR_OFF(u_debugreg) 312 && addr <= LUSR_OFF(u_debugreg_end)) { 313 int off = (addr - LUSR_OFF(u_debugreg)) / sizeof(int); 314 315 /* only do this for Linux processes */ 316 if (t->p_emul != &emul_linux) { 317 mutex_exit(t->p_lock); 318 return EINVAL; 319 } 320 321 led = lt->l_emuldata; 322 *retval = led->led_debugreg[off]; 323 } else if (addr == LUSR_OFF(__signal)) { 324 error = ENOTSUP; 325 } else if (addr == LUSR_OFF(u_fpstate)) { 326 error = ENOTSUP; 327 } else if (addr == LUSR_OFF(__magic)) { 328 error = ENOTSUP; 329 } else if (addr == LUSR_OFF(u_comm)) { 330 error = ENOTSUP; 331 } else { 332 #ifdef DEBUG_LINUX 333 printf("linux_ptrace: unsupported address: %d\n", addr); 334 #endif 335 error = ENOTSUP; 336 } 337 mutex_exit(t->p_lock); 338 break; 339 340 case LINUX_PTRACE_POKEUSR: 341 /* we only support setting debugregs for now */ 342 addr = SCARG(uap, addr); 343 if (addr >= LUSR_OFF(u_debugreg) && 344 addr <= LUSR_OFF(u_debugreg_end)) { 345 int off = (addr - LUSR_OFF(u_debugreg)) / sizeof(int); 346 int data = SCARG(uap, data); 347 348 /* only do this for Linux processes */ 349 if (t->p_emul != &emul_linux) { 350 mutex_exit(t->p_lock); 351 return EINVAL; 352 } 353 led = lt->l_emuldata; 354 led->led_debugreg[off] = data; 355 } 356 mutex_exit(t->p_lock); 357 break; 358 359 default: 360 mutex_exit(t->p_lock); 361 break; 362 } 363 out: 364 if (regs) 365 kmem_free(regs, sizeof(*regs)); 366 if (linux_regs) 367 kmem_free(linux_regs, sizeof(*linux_regs)); 368 if (fpregs) 369 kmem_free(fpregs, sizeof(*fpregs)); 370 if (linux_fpregs) 371 kmem_free(linux_fpregs, sizeof(*linux_fpregs)); 372 373 return error; 374 } 375
Indexes created Sat Sep 20 22:09:52 GMT 2025