1 /* 2 * SuperH process tracing 3 * 4 * Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka 5 * Copyright (C) 2002 - 2009 Paul Mundt 6 * 7 * Audit support by Yuichi Nakamura <ynakam@hitachisoft.jp> 8 * 9 * This file is subject to the terms and conditions of the GNU General Public 10 * License. See the file "COPYING" in the main directory of this archive 11 * for more details. 12 */ 13 #include <linux/kernel.h> 14 #include <linux/sched.h> 15 #include <linux/mm.h> 16 #include <linux/smp.h> 17 #include <linux/errno.h> 18 #include <linux/ptrace.h> 19 #include <linux/user.h> 20 #include <linux/security.h> 21 #include <linux/signal.h> 22 #include <linux/io.h> 23 #include <linux/audit.h> 24 #include <linux/seccomp.h> 25 #include <linux/tracehook.h> 26 #include <linux/elf.h> 27 #include <linux/regset.h> 28 #include <linux/hw_breakpoint.h> 29 #include <asm/uaccess.h> 30 #include <asm/pgtable.h> 31 #include <asm/system.h> 32 #include <asm/processor.h> 33 #include <asm/mmu_context.h> 34 #include <asm/syscalls.h> 35 #include <asm/fpu.h> 36 37 #define CREATE_TRACE_POINTS 38 #include <trace/events/syscalls.h> 39 40 /* 41 * This routine will get a word off of the process kernel stack. 42 */ 43 static inline int get_stack_long(struct task_struct *task, int offset) 44 { 45 unsigned char *stack; 46 47 stack = (unsigned char *)task_pt_regs(task); 48 stack += offset; 49 return (*((int *)stack)); 50 } 51 52 /* 53 * This routine will put a word on the process kernel stack. 54 */ 55 static inline int put_stack_long(struct task_struct *task, int offset, 56 unsigned long data) 57 { 58 unsigned char *stack; 59 60 stack = (unsigned char *)task_pt_regs(task); 61 stack += offset; 62 *(unsigned long *) stack = data; 63 return 0; 64 } 65 66 void ptrace_triggered(struct perf_event *bp, int nmi, 67 struct perf_sample_data *data, struct pt_regs *regs) 68 { 69 struct perf_event_attr attr; 70 71 /* 72 * Disable the breakpoint request here since ptrace has defined a 73 * one-shot behaviour for breakpoint exceptions. 74 */ 75 attr = bp->attr; 76 attr.disabled = true; 77 modify_user_hw_breakpoint(bp, &attr); 78 } 79 80 static int set_single_step(struct task_struct *tsk, unsigned long addr) 81 { 82 struct thread_struct *thread = &tsk->thread; 83 struct perf_event *bp; 84 struct perf_event_attr attr; 85 86 bp = thread->ptrace_bps[0]; 87 if (!bp) { 88 ptrace_breakpoint_init(&attr); 89 90 attr.bp_addr = addr; 91 attr.bp_len = HW_BREAKPOINT_LEN_2; 92 attr.bp_type = HW_BREAKPOINT_R; 93 94 bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk); 95 if (IS_ERR(bp)) 96 return PTR_ERR(bp); 97 98 thread->ptrace_bps[0] = bp; 99 } else { 100 int err; 101 102 attr = bp->attr; 103 attr.bp_addr = addr; 104 err = modify_user_hw_breakpoint(bp, &attr); 105 if (unlikely(err)) 106 return err; 107 } 108 109 return 0; 110 } 111 112 void user_enable_single_step(struct task_struct *child) 113 { 114 unsigned long pc = get_stack_long(child, offsetof(struct pt_regs, pc)); 115 116 set_tsk_thread_flag(child, TIF_SINGLESTEP); 117 118 set_single_step(child, pc); 119 } 120 121 void user_disable_single_step(struct task_struct *child) 122 { 123 clear_tsk_thread_flag(child, TIF_SINGLESTEP); 124 } 125 126 /* 127 * Called by kernel/ptrace.c when detaching.. 128 * 129 * Make sure single step bits etc are not set. 130 */ 131 void ptrace_disable(struct task_struct *child) 132 { 133 user_disable_single_step(child); 134 } 135 136 static int genregs_get(struct task_struct *target, 137 const struct user_regset *regset, 138 unsigned int pos, unsigned int count, 139 void *kbuf, void __user *ubuf) 140 { 141 const struct pt_regs *regs = task_pt_regs(target); 142 int ret; 143 144 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 145 regs->regs, 146 0, 16 * sizeof(unsigned long)); 147 if (!ret) 148 /* PC, PR, SR, GBR, MACH, MACL, TRA */ 149 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 150 ®s->pc, 151 offsetof(struct pt_regs, pc), 152 sizeof(struct pt_regs)); 153 if (!ret) 154 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 155 sizeof(struct pt_regs), -1); 156 157 return ret; 158 } 159 160 static int genregs_set(struct task_struct *target, 161 const struct user_regset *regset, 162 unsigned int pos, unsigned int count, 163 const void *kbuf, const void __user *ubuf) 164 { 165 struct pt_regs *regs = task_pt_regs(target); 166 int ret; 167 168 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 169 regs->regs, 170 0, 16 * sizeof(unsigned long)); 171 if (!ret && count > 0) 172 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 173 ®s->pc, 174 offsetof(struct pt_regs, pc), 175 sizeof(struct pt_regs)); 176 if (!ret) 177 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 178 sizeof(struct pt_regs), -1); 179 180 return ret; 181 } 182 183 #ifdef CONFIG_SH_FPU 184 int fpregs_get(struct task_struct *target, 185 const struct user_regset *regset, 186 unsigned int pos, unsigned int count, 187 void *kbuf, void __user *ubuf) 188 { 189 int ret; 190 191 ret = init_fpu(target); 192 if (ret) 193 return ret; 194 195 if ((boot_cpu_data.flags & CPU_HAS_FPU)) 196 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, 197 &target->thread.xstate->hardfpu, 0, -1); 198 199 return user_regset_copyout(&pos, &count, &kbuf, &ubuf, 200 &target->thread.xstate->softfpu, 0, -1); 201 } 202 203 static int fpregs_set(struct task_struct *target, 204 const struct user_regset *regset, 205 unsigned int pos, unsigned int count, 206 const void *kbuf, const void __user *ubuf) 207 { 208 int ret; 209 210 ret = init_fpu(target); 211 if (ret) 212 return ret; 213 214 set_stopped_child_used_math(target); 215 216 if ((boot_cpu_data.flags & CPU_HAS_FPU)) 217 return user_regset_copyin(&pos, &count, &kbuf, &ubuf, 218 &target->thread.xstate->hardfpu, 0, -1); 219 220 return user_regset_copyin(&pos, &count, &kbuf, &ubuf, 221 &target->thread.xstate->softfpu, 0, -1); 222 } 223 224 static int fpregs_active(struct task_struct *target, 225 const struct user_regset *regset) 226 { 227 return tsk_used_math(target) ? regset->n : 0; 228 } 229 #endif 230 231 #ifdef CONFIG_SH_DSP 232 static int dspregs_get(struct task_struct *target, 233 const struct user_regset *regset, 234 unsigned int pos, unsigned int count, 235 void *kbuf, void __user *ubuf) 236 { 237 const struct pt_dspregs *regs = 238 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs; 239 int ret; 240 241 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 242 0, sizeof(struct pt_dspregs)); 243 if (!ret) 244 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 245 sizeof(struct pt_dspregs), -1); 246 247 return ret; 248 } 249 250 static int dspregs_set(struct task_struct *target, 251 const struct user_regset *regset, 252 unsigned int pos, unsigned int count, 253 const void *kbuf, const void __user *ubuf) 254 { 255 struct pt_dspregs *regs = 256 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs; 257 int ret; 258 259 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs, 260 0, sizeof(struct pt_dspregs)); 261 if (!ret) 262 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 263 sizeof(struct pt_dspregs), -1); 264 265 return ret; 266 } 267 268 static int dspregs_active(struct task_struct *target, 269 const struct user_regset *regset) 270 { 271 struct pt_regs *regs = task_pt_regs(target); 272 273 return regs->sr & SR_DSP ? regset->n : 0; 274 } 275 #endif 276 277 /* 278 * These are our native regset flavours. 279 */ 280 enum sh_regset { 281 REGSET_GENERAL, 282 #ifdef CONFIG_SH_FPU 283 REGSET_FPU, 284 #endif 285 #ifdef CONFIG_SH_DSP 286 REGSET_DSP, 287 #endif 288 }; 289 290 static const struct user_regset sh_regsets[] = { 291 /* 292 * Format is: 293 * R0 --> R15 294 * PC, PR, SR, GBR, MACH, MACL, TRA 295 */ 296 [REGSET_GENERAL] = { 297 .core_note_type = NT_PRSTATUS, 298 .n = ELF_NGREG, 299 .size = sizeof(long), 300 .align = sizeof(long), 301 .get = genregs_get, 302 .set = genregs_set, 303 }, 304 305 #ifdef CONFIG_SH_FPU 306 [REGSET_FPU] = { 307 .core_note_type = NT_PRFPREG, 308 .n = sizeof(struct user_fpu_struct) / sizeof(long), 309 .size = sizeof(long), 310 .align = sizeof(long), 311 .get = fpregs_get, 312 .set = fpregs_set, 313 .active = fpregs_active, 314 }, 315 #endif 316 317 #ifdef CONFIG_SH_DSP 318 [REGSET_DSP] = { 319 .n = sizeof(struct pt_dspregs) / sizeof(long), 320 .size = sizeof(long), 321 .align = sizeof(long), 322 .get = dspregs_get, 323 .set = dspregs_set, 324 .active = dspregs_active, 325 }, 326 #endif 327 }; 328 329 static const struct user_regset_view user_sh_native_view = { 330 .name = "sh", 331 .e_machine = EM_SH, 332 .regsets = sh_regsets, 333 .n = ARRAY_SIZE(sh_regsets), 334 }; 335 336 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 337 { 338 return &user_sh_native_view; 339 } 340 341 long arch_ptrace(struct task_struct *child, long request, long addr, long data) 342 { 343 struct user * dummy = NULL; 344 unsigned long __user *datap = (unsigned long __user *)data; 345 int ret; 346 347 switch (request) { 348 /* read the word at location addr in the USER area. */ 349 case PTRACE_PEEKUSR: { 350 unsigned long tmp; 351 352 ret = -EIO; 353 if ((addr & 3) || addr < 0 || 354 addr > sizeof(struct user) - 3) 355 break; 356 357 if (addr < sizeof(struct pt_regs)) 358 tmp = get_stack_long(child, addr); 359 else if (addr >= (long) &dummy->fpu && 360 addr < (long) &dummy->u_fpvalid) { 361 if (!tsk_used_math(child)) { 362 if (addr == (long)&dummy->fpu.fpscr) 363 tmp = FPSCR_INIT; 364 else 365 tmp = 0; 366 } else 367 tmp = ((long *)child->thread.xstate) 368 [(addr - (long)&dummy->fpu) >> 2]; 369 } else if (addr == (long) &dummy->u_fpvalid) 370 tmp = !!tsk_used_math(child); 371 else if (addr == PT_TEXT_ADDR) 372 tmp = child->mm->start_code; 373 else if (addr == PT_DATA_ADDR) 374 tmp = child->mm->start_data; 375 else if (addr == PT_TEXT_END_ADDR) 376 tmp = child->mm->end_code; 377 else if (addr == PT_TEXT_LEN) 378 tmp = child->mm->end_code - child->mm->start_code; 379 else 380 tmp = 0; 381 ret = put_user(tmp, datap); 382 break; 383 } 384 385 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ 386 ret = -EIO; 387 if ((addr & 3) || addr < 0 || 388 addr > sizeof(struct user) - 3) 389 break; 390 391 if (addr < sizeof(struct pt_regs)) 392 ret = put_stack_long(child, addr, data); 393 else if (addr >= (long) &dummy->fpu && 394 addr < (long) &dummy->u_fpvalid) { 395 set_stopped_child_used_math(child); 396 ((long *)child->thread.xstate) 397 [(addr - (long)&dummy->fpu) >> 2] = data; 398 ret = 0; 399 } else if (addr == (long) &dummy->u_fpvalid) { 400 conditional_stopped_child_used_math(data, child); 401 ret = 0; 402 } 403 break; 404 405 case PTRACE_GETREGS: 406 return copy_regset_to_user(child, &user_sh_native_view, 407 REGSET_GENERAL, 408 0, sizeof(struct pt_regs), 409 (void __user *)data); 410 case PTRACE_SETREGS: 411 return copy_regset_from_user(child, &user_sh_native_view, 412 REGSET_GENERAL, 413 0, sizeof(struct pt_regs), 414 (const void __user *)data); 415 #ifdef CONFIG_SH_FPU 416 case PTRACE_GETFPREGS: 417 return copy_regset_to_user(child, &user_sh_native_view, 418 REGSET_FPU, 419 0, sizeof(struct user_fpu_struct), 420 (void __user *)data); 421 case PTRACE_SETFPREGS: 422 return copy_regset_from_user(child, &user_sh_native_view, 423 REGSET_FPU, 424 0, sizeof(struct user_fpu_struct), 425 (const void __user *)data); 426 #endif 427 #ifdef CONFIG_SH_DSP 428 case PTRACE_GETDSPREGS: 429 return copy_regset_to_user(child, &user_sh_native_view, 430 REGSET_DSP, 431 0, sizeof(struct pt_dspregs), 432 (void __user *)data); 433 case PTRACE_SETDSPREGS: 434 return copy_regset_from_user(child, &user_sh_native_view, 435 REGSET_DSP, 436 0, sizeof(struct pt_dspregs), 437 (const void __user *)data); 438 #endif 439 default: 440 ret = ptrace_request(child, request, addr, data); 441 break; 442 } 443 444 return ret; 445 } 446 447 static inline int audit_arch(void) 448 { 449 int arch = EM_SH; 450 451 #ifdef CONFIG_CPU_LITTLE_ENDIAN 452 arch |= __AUDIT_ARCH_LE; 453 #endif 454 455 return arch; 456 } 457 458 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) 459 { 460 long ret = 0; 461 462 secure_computing(regs->regs[0]); 463 464 if (test_thread_flag(TIF_SYSCALL_TRACE) && 465 tracehook_report_syscall_entry(regs)) 466 /* 467 * Tracing decided this syscall should not happen. 468 * We'll return a bogus call number to get an ENOSYS 469 * error, but leave the original number in regs->regs[0]. 470 */ 471 ret = -1L; 472 473 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) 474 trace_sys_enter(regs, regs->regs[0]); 475 476 if (unlikely(current->audit_context)) 477 audit_syscall_entry(audit_arch(), regs->regs[3], 478 regs->regs[4], regs->regs[5], 479 regs->regs[6], regs->regs[7]); 480 481 return ret ?: regs->regs[0]; 482 } 483 484 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) 485 { 486 int step; 487 488 if (unlikely(current->audit_context)) 489 audit_syscall_exit(AUDITSC_RESULT(regs->regs[0]), 490 regs->regs[0]); 491 492 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) 493 trace_sys_exit(regs, regs->regs[0]); 494 495 step = test_thread_flag(TIF_SINGLESTEP); 496 if (step || test_thread_flag(TIF_SYSCALL_TRACE)) 497 tracehook_report_syscall_exit(regs, step); 498 } 499