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 /* options set using PTRACE_SETOPTIONS */ 51 #define PTRACE_O_TRACESYSGOOD 0x00000001 52 #define PTRACE_O_TRACEFORK 0x00000002 53 #define PTRACE_O_TRACEVFORK 0x00000004 54 #define PTRACE_O_TRACECLONE 0x00000008 55 #define PTRACE_O_TRACEEXEC 0x00000010 56 #define PTRACE_O_TRACEVFORKDONE 0x00000020 57 #define PTRACE_O_TRACEEXIT 0x00000040 58 59 #define PTRACE_O_MASK 0x0000007f 60 61 /* Wait extended result codes for the above trace options. */ 62 #define PTRACE_EVENT_FORK 1 63 #define PTRACE_EVENT_VFORK 2 64 #define PTRACE_EVENT_CLONE 3 65 #define PTRACE_EVENT_EXEC 4 66 #define PTRACE_EVENT_VFORK_DONE 5 67 #define PTRACE_EVENT_EXIT 6 68 69 #include <asm/ptrace.h> 70 71 #ifdef __KERNEL__ 72 /* 73 * Ptrace flags 74 * 75 * The owner ship rules for task->ptrace which holds the ptrace 76 * flags is simple. When a task is running it owns it's task->ptrace 77 * flags. When the a task is stopped the ptracer owns task->ptrace. 78 */ 79 80 #define PT_PTRACED 0x00000001 81 #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ 82 #define PT_TRACESYSGOOD 0x00000004 83 #define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */ 84 #define PT_TRACE_FORK 0x00000010 85 #define PT_TRACE_VFORK 0x00000020 86 #define PT_TRACE_CLONE 0x00000040 87 #define PT_TRACE_EXEC 0x00000080 88 #define PT_TRACE_VFORK_DONE 0x00000100 89 #define PT_TRACE_EXIT 0x00000200 90 91 #define PT_TRACE_MASK 0x000003f4 92 93 /* single stepping state bits (used on ARM and PA-RISC) */ 94 #define PT_SINGLESTEP_BIT 31 95 #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT) 96 #define PT_BLOCKSTEP_BIT 30 97 #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT) 98 99 #include <linux/compiler.h> /* For unlikely. */ 100 #include <linux/sched.h> /* For struct task_struct. */ 101 102 103 extern long arch_ptrace(struct task_struct *child, long request, 104 unsigned long addr, unsigned long data); 105 extern int ptrace_traceme(void); 106 extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len); 107 extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len); 108 extern int ptrace_attach(struct task_struct *tsk); 109 extern int ptrace_detach(struct task_struct *, unsigned int); 110 extern void ptrace_disable(struct task_struct *); 111 extern int ptrace_check_attach(struct task_struct *task, int kill); 112 extern int ptrace_request(struct task_struct *child, long request, 113 unsigned long addr, unsigned long data); 114 extern void ptrace_notify(int exit_code); 115 extern void __ptrace_link(struct task_struct *child, 116 struct task_struct *new_parent); 117 extern void __ptrace_unlink(struct task_struct *child); 118 extern void exit_ptrace(struct task_struct *tracer); 119 #define PTRACE_MODE_READ 1 120 #define PTRACE_MODE_ATTACH 2 121 /* Returns 0 on success, -errno on denial. */ 122 extern int __ptrace_may_access(struct task_struct *task, unsigned int mode); 123 /* Returns true on success, false on denial. */ 124 extern bool ptrace_may_access(struct task_struct *task, unsigned int mode); 125 126 static inline int ptrace_reparented(struct task_struct *child) 127 { 128 return child->real_parent != child->parent; 129 } 130 131 static inline void ptrace_unlink(struct task_struct *child) 132 { 133 if (unlikely(child->ptrace)) 134 __ptrace_unlink(child); 135 } 136 137 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 138 unsigned long data); 139 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 140 unsigned long data); 141 142 /** 143 * task_ptrace - return %PT_* flags that apply to a task 144 * @task: pointer to &task_struct in question 145 * 146 * Returns the %PT_* flags that apply to @task. 147 */ 148 static inline int task_ptrace(struct task_struct *task) 149 { 150 return task->ptrace; 151 } 152 153 /** 154 * ptrace_event - possibly stop for a ptrace event notification 155 * @mask: %PT_* bit to check in @current->ptrace 156 * @event: %PTRACE_EVENT_* value to report if @mask is set 157 * @message: value for %PTRACE_GETEVENTMSG to return 158 * 159 * This checks the @mask bit to see if ptrace wants stops for this event. 160 * If so we stop, reporting @event and @message to the ptrace parent. 161 * 162 * Returns nonzero if we did a ptrace notification, zero if not. 163 * 164 * Called without locks. 165 */ 166 static inline int ptrace_event(int mask, int event, unsigned long message) 167 { 168 if (mask && likely(!(current->ptrace & mask))) 169 return 0; 170 current->ptrace_message = message; 171 ptrace_notify((event << 8) | SIGTRAP); 172 return 1; 173 } 174 175 /** 176 * ptrace_init_task - initialize ptrace state for a new child 177 * @child: new child task 178 * @ptrace: true if child should be ptrace'd by parent's tracer 179 * 180 * This is called immediately after adding @child to its parent's children 181 * list. @ptrace is false in the normal case, and true to ptrace @child. 182 * 183 * Called with current's siglock and write_lock_irq(&tasklist_lock) held. 184 */ 185 static inline void ptrace_init_task(struct task_struct *child, bool ptrace) 186 { 187 INIT_LIST_HEAD(&child->ptrace_entry); 188 INIT_LIST_HEAD(&child->ptraced); 189 child->parent = child->real_parent; 190 child->ptrace = 0; 191 if (unlikely(ptrace) && (current->ptrace & PT_PTRACED)) { 192 child->ptrace = current->ptrace; 193 __ptrace_link(child, current->parent); 194 } 195 } 196 197 /** 198 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped 199 * @task: task in %EXIT_DEAD state 200 * 201 * Called with write_lock(&tasklist_lock) held. 202 */ 203 static inline void ptrace_release_task(struct task_struct *task) 204 { 205 BUG_ON(!list_empty(&task->ptraced)); 206 ptrace_unlink(task); 207 BUG_ON(!list_empty(&task->ptrace_entry)); 208 } 209 210 #ifndef force_successful_syscall_return 211 /* 212 * System call handlers that, upon successful completion, need to return a 213 * negative value should call force_successful_syscall_return() right before 214 * returning. On architectures where the syscall convention provides for a 215 * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly 216 * others), this macro can be used to ensure that the error flag will not get 217 * set. On architectures which do not support a separate error flag, the macro 218 * is a no-op and the spurious error condition needs to be filtered out by some 219 * other means (e.g., in user-level, by passing an extra argument to the 220 * syscall handler, or something along those lines). 221 */ 222 #define force_successful_syscall_return() do { } while (0) 223 #endif 224 225 /* 226 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__. 227 * 228 * These do-nothing inlines are used when the arch does not 229 * implement single-step. The kerneldoc comments are here 230 * to document the interface for all arch definitions. 231 */ 232 233 #ifndef arch_has_single_step 234 /** 235 * arch_has_single_step - does this CPU support user-mode single-step? 236 * 237 * If this is defined, then there must be function declarations or 238 * inlines for user_enable_single_step() and user_disable_single_step(). 239 * arch_has_single_step() should evaluate to nonzero iff the machine 240 * supports instruction single-step for user mode. 241 * It can be a constant or it can test a CPU feature bit. 242 */ 243 #define arch_has_single_step() (0) 244 245 /** 246 * user_enable_single_step - single-step in user-mode task 247 * @task: either current or a task stopped in %TASK_TRACED 248 * 249 * This can only be called when arch_has_single_step() has returned nonzero. 250 * Set @task so that when it returns to user mode, it will trap after the 251 * next single instruction executes. If arch_has_block_step() is defined, 252 * this must clear the effects of user_enable_block_step() too. 253 */ 254 static inline void user_enable_single_step(struct task_struct *task) 255 { 256 BUG(); /* This can never be called. */ 257 } 258 259 /** 260 * user_disable_single_step - cancel user-mode single-step 261 * @task: either current or a task stopped in %TASK_TRACED 262 * 263 * Clear @task of the effects of user_enable_single_step() and 264 * user_enable_block_step(). This can be called whether or not either 265 * of those was ever called on @task, and even if arch_has_single_step() 266 * returned zero. 267 */ 268 static inline void user_disable_single_step(struct task_struct *task) 269 { 270 } 271 #else 272 extern void user_enable_single_step(struct task_struct *); 273 extern void user_disable_single_step(struct task_struct *); 274 #endif /* arch_has_single_step */ 275 276 #ifndef arch_has_block_step 277 /** 278 * arch_has_block_step - does this CPU support user-mode block-step? 279 * 280 * If this is defined, then there must be a function declaration or inline 281 * for user_enable_block_step(), and arch_has_single_step() must be defined 282 * too. arch_has_block_step() should evaluate to nonzero iff the machine 283 * supports step-until-branch for user mode. It can be a constant or it 284 * can test a CPU feature bit. 285 */ 286 #define arch_has_block_step() (0) 287 288 /** 289 * user_enable_block_step - step until branch in user-mode task 290 * @task: either current or a task stopped in %TASK_TRACED 291 * 292 * This can only be called when arch_has_block_step() has returned nonzero, 293 * and will never be called when single-instruction stepping is being used. 294 * Set @task so that when it returns to user mode, it will trap after the 295 * next branch or trap taken. 296 */ 297 static inline void user_enable_block_step(struct task_struct *task) 298 { 299 BUG(); /* This can never be called. */ 300 } 301 #else 302 extern void user_enable_block_step(struct task_struct *); 303 #endif /* arch_has_block_step */ 304 305 #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO 306 extern void user_single_step_siginfo(struct task_struct *tsk, 307 struct pt_regs *regs, siginfo_t *info); 308 #else 309 static inline void user_single_step_siginfo(struct task_struct *tsk, 310 struct pt_regs *regs, siginfo_t *info) 311 { 312 memset(info, 0, sizeof(*info)); 313 info->si_signo = SIGTRAP; 314 } 315 #endif 316 317 #ifndef arch_ptrace_stop_needed 318 /** 319 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called 320 * @code: current->exit_code value ptrace will stop with 321 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with 322 * 323 * This is called with the siglock held, to decide whether or not it's 324 * necessary to release the siglock and call arch_ptrace_stop() with the 325 * same @code and @info arguments. It can be defined to a constant if 326 * arch_ptrace_stop() is never required, or always is. On machines where 327 * this makes sense, it should be defined to a quick test to optimize out 328 * calling arch_ptrace_stop() when it would be superfluous. For example, 329 * if the thread has not been back to user mode since the last stop, the 330 * thread state might indicate that nothing needs to be done. 331 */ 332 #define arch_ptrace_stop_needed(code, info) (0) 333 #endif 334 335 #ifndef arch_ptrace_stop 336 /** 337 * arch_ptrace_stop - Do machine-specific work before stopping for ptrace 338 * @code: current->exit_code value ptrace will stop with 339 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with 340 * 341 * This is called with no locks held when arch_ptrace_stop_needed() has 342 * just returned nonzero. It is allowed to block, e.g. for user memory 343 * access. The arch can have machine-specific work to be done before 344 * ptrace stops. On ia64, register backing store gets written back to user 345 * memory here. Since this can be costly (requires dropping the siglock), 346 * we only do it when the arch requires it for this particular stop, as 347 * indicated by arch_ptrace_stop_needed(). 348 */ 349 #define arch_ptrace_stop(code, info) do { } while (0) 350 #endif 351 352 extern int task_current_syscall(struct task_struct *target, long *callno, 353 unsigned long args[6], unsigned int maxargs, 354 unsigned long *sp, unsigned long *pc); 355 356 #endif 357 358 #endif 359