1 #ifndef _LINUX_PTRACE_H 2 #define _LINUX_PTRACE_H 3 /* ptrace.h */ 4 /* structs and defines to help the user use the ptrace system call. */ 5 6 /* has the defines to get at the registers. */ 7 8 #define PTRACE_TRACEME 0 9 #define PTRACE_PEEKTEXT 1 10 #define PTRACE_PEEKDATA 2 11 #define PTRACE_PEEKUSR 3 12 #define PTRACE_POKETEXT 4 13 #define PTRACE_POKEDATA 5 14 #define PTRACE_POKEUSR 6 15 #define PTRACE_CONT 7 16 #define PTRACE_KILL 8 17 #define PTRACE_SINGLESTEP 9 18 19 #define PTRACE_ATTACH 16 20 #define PTRACE_DETACH 17 21 22 #define PTRACE_SYSCALL 24 23 24 /* 0x4200-0x4300 are reserved for architecture-independent additions. */ 25 #define PTRACE_SETOPTIONS 0x4200 26 #define PTRACE_GETEVENTMSG 0x4201 27 #define PTRACE_GETSIGINFO 0x4202 28 #define PTRACE_SETSIGINFO 0x4203 29 30 /* 31 * Generic ptrace interface that exports the architecture specific regsets 32 * using the corresponding NT_* types (which are also used in the core dump). 33 * Please note that the NT_PRSTATUS note type in a core dump contains a full 34 * 'struct elf_prstatus'. But the user_regset for NT_PRSTATUS contains just the 35 * elf_gregset_t that is the pr_reg field of 'struct elf_prstatus'. For all the 36 * other user_regset flavors, the user_regset layout and the ELF core dump note 37 * payload are exactly the same layout. 38 * 39 * This interface usage is as follows: 40 * struct iovec iov = { buf, len}; 41 * 42 * ret = ptrace(PTRACE_GETREGSET/PTRACE_SETREGSET, pid, NT_XXX_TYPE, &iov); 43 * 44 * On the successful completion, iov.len will be updated by the kernel, 45 * specifying how much the kernel has written/read to/from the user's iov.buf. 46 */ 47 #define PTRACE_GETREGSET 0x4204 48 #define PTRACE_SETREGSET 0x4205 49 50 #define PTRACE_SEIZE 0x4206 51 #define PTRACE_INTERRUPT 0x4207 52 #define PTRACE_LISTEN 0x4208 53 54 /* Wait extended result codes for the above trace options. */ 55 #define PTRACE_EVENT_FORK 1 56 #define PTRACE_EVENT_VFORK 2 57 #define PTRACE_EVENT_CLONE 3 58 #define PTRACE_EVENT_EXEC 4 59 #define PTRACE_EVENT_VFORK_DONE 5 60 #define PTRACE_EVENT_EXIT 6 61 #define PTRACE_EVENT_SECCOMP 7 62 /* Extended result codes which enabled by means other than options. */ 63 #define PTRACE_EVENT_STOP 128 64 65 /* Options set using PTRACE_SETOPTIONS or using PTRACE_SEIZE @data param */ 66 #define PTRACE_O_TRACESYSGOOD 1 67 #define PTRACE_O_TRACEFORK (1 << PTRACE_EVENT_FORK) 68 #define PTRACE_O_TRACEVFORK (1 << PTRACE_EVENT_VFORK) 69 #define PTRACE_O_TRACECLONE (1 << PTRACE_EVENT_CLONE) 70 #define PTRACE_O_TRACEEXEC (1 << PTRACE_EVENT_EXEC) 71 #define PTRACE_O_TRACEVFORKDONE (1 << PTRACE_EVENT_VFORK_DONE) 72 #define PTRACE_O_TRACEEXIT (1 << PTRACE_EVENT_EXIT) 73 #define PTRACE_O_TRACESECCOMP (1 << PTRACE_EVENT_SECCOMP) 74 75 #define PTRACE_O_MASK 0x000000ff 76 77 #include <asm/ptrace.h> 78 79 #ifdef __KERNEL__ 80 /* 81 * Ptrace flags 82 * 83 * The owner ship rules for task->ptrace which holds the ptrace 84 * flags is simple. When a task is running it owns it's task->ptrace 85 * flags. When the a task is stopped the ptracer owns task->ptrace. 86 */ 87 88 #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */ 89 #define PT_PTRACED 0x00000001 90 #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ 91 #define PT_PTRACE_CAP 0x00000004 /* ptracer can follow suid-exec */ 92 93 #define PT_OPT_FLAG_SHIFT 3 94 /* PT_TRACE_* event enable flags */ 95 #define PT_EVENT_FLAG(event) (1 << (PT_OPT_FLAG_SHIFT + (event))) 96 #define PT_TRACESYSGOOD PT_EVENT_FLAG(0) 97 #define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK) 98 #define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK) 99 #define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE) 100 #define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC) 101 #define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE) 102 #define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT) 103 #define PT_TRACE_SECCOMP PT_EVENT_FLAG(PTRACE_EVENT_SECCOMP) 104 105 /* single stepping state bits (used on ARM and PA-RISC) */ 106 #define PT_SINGLESTEP_BIT 31 107 #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT) 108 #define PT_BLOCKSTEP_BIT 30 109 #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT) 110 111 #include <linux/compiler.h> /* For unlikely. */ 112 #include <linux/sched.h> /* For struct task_struct. */ 113 #include <linux/err.h> /* for IS_ERR_VALUE */ 114 #include <linux/bug.h> /* For BUG_ON. */ 115 116 117 extern long arch_ptrace(struct task_struct *child, long request, 118 unsigned long addr, unsigned long data); 119 extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len); 120 extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len); 121 extern void ptrace_disable(struct task_struct *); 122 extern int ptrace_check_attach(struct task_struct *task, bool ignore_state); 123 extern int ptrace_request(struct task_struct *child, long request, 124 unsigned long addr, unsigned long data); 125 extern void ptrace_notify(int exit_code); 126 extern void __ptrace_link(struct task_struct *child, 127 struct task_struct *new_parent); 128 extern void __ptrace_unlink(struct task_struct *child); 129 extern void exit_ptrace(struct task_struct *tracer); 130 #define PTRACE_MODE_READ 0x01 131 #define PTRACE_MODE_ATTACH 0x02 132 #define PTRACE_MODE_NOAUDIT 0x04 133 /* Returns true on success, false on denial. */ 134 extern bool ptrace_may_access(struct task_struct *task, unsigned int mode); 135 136 static inline int ptrace_reparented(struct task_struct *child) 137 { 138 return !same_thread_group(child->real_parent, child->parent); 139 } 140 141 static inline void ptrace_unlink(struct task_struct *child) 142 { 143 if (unlikely(child->ptrace)) 144 __ptrace_unlink(child); 145 } 146 147 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 148 unsigned long data); 149 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 150 unsigned long data); 151 152 /** 153 * ptrace_parent - return the task that is tracing the given task 154 * @task: task to consider 155 * 156 * Returns %NULL if no one is tracing @task, or the &struct task_struct 157 * pointer to its tracer. 158 * 159 * Must called under rcu_read_lock(). The pointer returned might be kept 160 * live only by RCU. During exec, this may be called with task_lock() held 161 * on @task, still held from when check_unsafe_exec() was called. 162 */ 163 static inline struct task_struct *ptrace_parent(struct task_struct *task) 164 { 165 if (unlikely(task->ptrace)) 166 return rcu_dereference(task->parent); 167 return NULL; 168 } 169 170 /** 171 * ptrace_event_enabled - test whether a ptrace event is enabled 172 * @task: ptracee of interest 173 * @event: %PTRACE_EVENT_* to test 174 * 175 * Test whether @event is enabled for ptracee @task. 176 * 177 * Returns %true if @event is enabled, %false otherwise. 178 */ 179 static inline bool ptrace_event_enabled(struct task_struct *task, int event) 180 { 181 return task->ptrace & PT_EVENT_FLAG(event); 182 } 183 184 /** 185 * ptrace_event - possibly stop for a ptrace event notification 186 * @event: %PTRACE_EVENT_* value to report 187 * @message: value for %PTRACE_GETEVENTMSG to return 188 * 189 * Check whether @event is enabled and, if so, report @event and @message 190 * to the ptrace parent. 191 * 192 * Called without locks. 193 */ 194 static inline void ptrace_event(int event, unsigned long message) 195 { 196 if (unlikely(ptrace_event_enabled(current, event))) { 197 current->ptrace_message = message; 198 ptrace_notify((event << 8) | SIGTRAP); 199 } else if (event == PTRACE_EVENT_EXEC) { 200 /* legacy EXEC report via SIGTRAP */ 201 if ((current->ptrace & (PT_PTRACED|PT_SEIZED)) == PT_PTRACED) 202 send_sig(SIGTRAP, current, 0); 203 } 204 } 205 206 /** 207 * ptrace_init_task - initialize ptrace state for a new child 208 * @child: new child task 209 * @ptrace: true if child should be ptrace'd by parent's tracer 210 * 211 * This is called immediately after adding @child to its parent's children 212 * list. @ptrace is false in the normal case, and true to ptrace @child. 213 * 214 * Called with current's siglock and write_lock_irq(&tasklist_lock) held. 215 */ 216 static inline void ptrace_init_task(struct task_struct *child, bool ptrace) 217 { 218 INIT_LIST_HEAD(&child->ptrace_entry); 219 INIT_LIST_HEAD(&child->ptraced); 220 #ifdef CONFIG_HAVE_HW_BREAKPOINT 221 atomic_set(&child->ptrace_bp_refcnt, 1); 222 #endif 223 child->jobctl = 0; 224 child->ptrace = 0; 225 child->parent = child->real_parent; 226 227 if (unlikely(ptrace) && current->ptrace) { 228 child->ptrace = current->ptrace; 229 __ptrace_link(child, current->parent); 230 231 if (child->ptrace & PT_SEIZED) 232 task_set_jobctl_pending(child, JOBCTL_TRAP_STOP); 233 else 234 sigaddset(&child->pending.signal, SIGSTOP); 235 236 set_tsk_thread_flag(child, TIF_SIGPENDING); 237 } 238 } 239 240 /** 241 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped 242 * @task: task in %EXIT_DEAD state 243 * 244 * Called with write_lock(&tasklist_lock) held. 245 */ 246 static inline void ptrace_release_task(struct task_struct *task) 247 { 248 BUG_ON(!list_empty(&task->ptraced)); 249 ptrace_unlink(task); 250 BUG_ON(!list_empty(&task->ptrace_entry)); 251 } 252 253 #ifndef force_successful_syscall_return 254 /* 255 * System call handlers that, upon successful completion, need to return a 256 * negative value should call force_successful_syscall_return() right before 257 * returning. On architectures where the syscall convention provides for a 258 * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly 259 * others), this macro can be used to ensure that the error flag will not get 260 * set. On architectures which do not support a separate error flag, the macro 261 * is a no-op and the spurious error condition needs to be filtered out by some 262 * other means (e.g., in user-level, by passing an extra argument to the 263 * syscall handler, or something along those lines). 264 */ 265 #define force_successful_syscall_return() do { } while (0) 266 #endif 267 268 #ifndef is_syscall_success 269 /* 270 * On most systems we can tell if a syscall is a success based on if the retval 271 * is an error value. On some systems like ia64 and powerpc they have different 272 * indicators of success/failure and must define their own. 273 */ 274 #define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs)))) 275 #endif 276 277 /* 278 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__. 279 * 280 * These do-nothing inlines are used when the arch does not 281 * implement single-step. The kerneldoc comments are here 282 * to document the interface for all arch definitions. 283 */ 284 285 #ifndef arch_has_single_step 286 /** 287 * arch_has_single_step - does this CPU support user-mode single-step? 288 * 289 * If this is defined, then there must be function declarations or 290 * inlines for user_enable_single_step() and user_disable_single_step(). 291 * arch_has_single_step() should evaluate to nonzero iff the machine 292 * supports instruction single-step for user mode. 293 * It can be a constant or it can test a CPU feature bit. 294 */ 295 #define arch_has_single_step() (0) 296 297 /** 298 * user_enable_single_step - single-step in user-mode task 299 * @task: either current or a task stopped in %TASK_TRACED 300 * 301 * This can only be called when arch_has_single_step() has returned nonzero. 302 * Set @task so that when it returns to user mode, it will trap after the 303 * next single instruction executes. If arch_has_block_step() is defined, 304 * this must clear the effects of user_enable_block_step() too. 305 */ 306 static inline void user_enable_single_step(struct task_struct *task) 307 { 308 BUG(); /* This can never be called. */ 309 } 310 311 /** 312 * user_disable_single_step - cancel user-mode single-step 313 * @task: either current or a task stopped in %TASK_TRACED 314 * 315 * Clear @task of the effects of user_enable_single_step() and 316 * user_enable_block_step(). This can be called whether or not either 317 * of those was ever called on @task, and even if arch_has_single_step() 318 * returned zero. 319 */ 320 static inline void user_disable_single_step(struct task_struct *task) 321 { 322 } 323 #else 324 extern void user_enable_single_step(struct task_struct *); 325 extern void user_disable_single_step(struct task_struct *); 326 #endif /* arch_has_single_step */ 327 328 #ifndef arch_has_block_step 329 /** 330 * arch_has_block_step - does this CPU support user-mode block-step? 331 * 332 * If this is defined, then there must be a function declaration or inline 333 * for user_enable_block_step(), and arch_has_single_step() must be defined 334 * too. arch_has_block_step() should evaluate to nonzero iff the machine 335 * supports step-until-branch for user mode. It can be a constant or it 336 * can test a CPU feature bit. 337 */ 338 #define arch_has_block_step() (0) 339 340 /** 341 * user_enable_block_step - step until branch in user-mode task 342 * @task: either current or a task stopped in %TASK_TRACED 343 * 344 * This can only be called when arch_has_block_step() has returned nonzero, 345 * and will never be called when single-instruction stepping is being used. 346 * Set @task so that when it returns to user mode, it will trap after the 347 * next branch or trap taken. 348 */ 349 static inline void user_enable_block_step(struct task_struct *task) 350 { 351 BUG(); /* This can never be called. */ 352 } 353 #else 354 extern void user_enable_block_step(struct task_struct *); 355 #endif /* arch_has_block_step */ 356 357 #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO 358 extern void user_single_step_siginfo(struct task_struct *tsk, 359 struct pt_regs *regs, siginfo_t *info); 360 #else 361 static inline void user_single_step_siginfo(struct task_struct *tsk, 362 struct pt_regs *regs, siginfo_t *info) 363 { 364 memset(info, 0, sizeof(*info)); 365 info->si_signo = SIGTRAP; 366 } 367 #endif 368 369 #ifndef arch_ptrace_stop_needed 370 /** 371 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called 372 * @code: current->exit_code value ptrace will stop with 373 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with 374 * 375 * This is called with the siglock held, to decide whether or not it's 376 * necessary to release the siglock and call arch_ptrace_stop() with the 377 * same @code and @info arguments. It can be defined to a constant if 378 * arch_ptrace_stop() is never required, or always is. On machines where 379 * this makes sense, it should be defined to a quick test to optimize out 380 * calling arch_ptrace_stop() when it would be superfluous. For example, 381 * if the thread has not been back to user mode since the last stop, the 382 * thread state might indicate that nothing needs to be done. 383 */ 384 #define arch_ptrace_stop_needed(code, info) (0) 385 #endif 386 387 #ifndef arch_ptrace_stop 388 /** 389 * arch_ptrace_stop - Do machine-specific work before stopping for ptrace 390 * @code: current->exit_code value ptrace will stop with 391 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with 392 * 393 * This is called with no locks held when arch_ptrace_stop_needed() has 394 * just returned nonzero. It is allowed to block, e.g. for user memory 395 * access. The arch can have machine-specific work to be done before 396 * ptrace stops. On ia64, register backing store gets written back to user 397 * memory here. Since this can be costly (requires dropping the siglock), 398 * we only do it when the arch requires it for this particular stop, as 399 * indicated by arch_ptrace_stop_needed(). 400 */ 401 #define arch_ptrace_stop(code, info) do { } while (0) 402 #endif 403 404 extern int task_current_syscall(struct task_struct *target, long *callno, 405 unsigned long args[6], unsigned int maxargs, 406 unsigned long *sp, unsigned long *pc); 407 408 #ifdef CONFIG_HAVE_HW_BREAKPOINT 409 extern int ptrace_get_breakpoints(struct task_struct *tsk); 410 extern void ptrace_put_breakpoints(struct task_struct *tsk); 411 #else 412 static inline void ptrace_put_breakpoints(struct task_struct *tsk) { } 413 #endif /* CONFIG_HAVE_HW_BREAKPOINT */ 414 415 #endif /* __KERNEL */ 416 417 #endif 418