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 /* options set using PTRACE_SETOPTIONS */ 31 #define PTRACE_O_TRACESYSGOOD 0x00000001 32 #define PTRACE_O_TRACEFORK 0x00000002 33 #define PTRACE_O_TRACEVFORK 0x00000004 34 #define PTRACE_O_TRACECLONE 0x00000008 35 #define PTRACE_O_TRACEEXEC 0x00000010 36 #define PTRACE_O_TRACEVFORKDONE 0x00000020 37 #define PTRACE_O_TRACEEXIT 0x00000040 38 39 #define PTRACE_O_MASK 0x0000007f 40 41 /* Wait extended result codes for the above trace options. */ 42 #define PTRACE_EVENT_FORK 1 43 #define PTRACE_EVENT_VFORK 2 44 #define PTRACE_EVENT_CLONE 3 45 #define PTRACE_EVENT_EXEC 4 46 #define PTRACE_EVENT_VFORK_DONE 5 47 #define PTRACE_EVENT_EXIT 6 48 49 #include <asm/ptrace.h> 50 51 #ifdef __KERNEL__ 52 /* 53 * Ptrace flags 54 * 55 * The owner ship rules for task->ptrace which holds the ptrace 56 * flags is simple. When a task is running it owns it's task->ptrace 57 * flags. When the a task is stopped the ptracer owns task->ptrace. 58 */ 59 60 #define PT_PTRACED 0x00000001 61 #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ 62 #define PT_TRACESYSGOOD 0x00000004 63 #define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */ 64 #define PT_TRACE_FORK 0x00000010 65 #define PT_TRACE_VFORK 0x00000020 66 #define PT_TRACE_CLONE 0x00000040 67 #define PT_TRACE_EXEC 0x00000080 68 #define PT_TRACE_VFORK_DONE 0x00000100 69 #define PT_TRACE_EXIT 0x00000200 70 71 #define PT_TRACE_MASK 0x000003f4 72 73 /* single stepping state bits (used on ARM and PA-RISC) */ 74 #define PT_SINGLESTEP_BIT 31 75 #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT) 76 #define PT_BLOCKSTEP_BIT 30 77 #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT) 78 79 #include <linux/compiler.h> /* For unlikely. */ 80 #include <linux/sched.h> /* For struct task_struct. */ 81 82 83 extern long arch_ptrace(struct task_struct *child, long request, long addr, long data); 84 extern int ptrace_traceme(void); 85 extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len); 86 extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len); 87 extern int ptrace_attach(struct task_struct *tsk); 88 extern int ptrace_detach(struct task_struct *, unsigned int); 89 extern void ptrace_disable(struct task_struct *); 90 extern int ptrace_check_attach(struct task_struct *task, int kill); 91 extern int ptrace_request(struct task_struct *child, long request, long addr, long data); 92 extern void ptrace_notify(int exit_code); 93 extern void __ptrace_link(struct task_struct *child, 94 struct task_struct *new_parent); 95 extern void __ptrace_unlink(struct task_struct *child); 96 extern void exit_ptrace(struct task_struct *tracer); 97 #define PTRACE_MODE_READ 1 98 #define PTRACE_MODE_ATTACH 2 99 /* Returns 0 on success, -errno on denial. */ 100 extern int __ptrace_may_access(struct task_struct *task, unsigned int mode); 101 /* Returns true on success, false on denial. */ 102 extern bool ptrace_may_access(struct task_struct *task, unsigned int mode); 103 104 static inline int ptrace_reparented(struct task_struct *child) 105 { 106 return child->real_parent != child->parent; 107 } 108 109 static inline void ptrace_unlink(struct task_struct *child) 110 { 111 if (unlikely(child->ptrace)) 112 __ptrace_unlink(child); 113 } 114 115 int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data); 116 int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data); 117 118 /** 119 * task_ptrace - return %PT_* flags that apply to a task 120 * @task: pointer to &task_struct in question 121 * 122 * Returns the %PT_* flags that apply to @task. 123 */ 124 static inline int task_ptrace(struct task_struct *task) 125 { 126 return task->ptrace; 127 } 128 129 /** 130 * ptrace_event - possibly stop for a ptrace event notification 131 * @mask: %PT_* bit to check in @current->ptrace 132 * @event: %PTRACE_EVENT_* value to report if @mask is set 133 * @message: value for %PTRACE_GETEVENTMSG to return 134 * 135 * This checks the @mask bit to see if ptrace wants stops for this event. 136 * If so we stop, reporting @event and @message to the ptrace parent. 137 * 138 * Returns nonzero if we did a ptrace notification, zero if not. 139 * 140 * Called without locks. 141 */ 142 static inline int ptrace_event(int mask, int event, unsigned long message) 143 { 144 if (mask && likely(!(current->ptrace & mask))) 145 return 0; 146 current->ptrace_message = message; 147 ptrace_notify((event << 8) | SIGTRAP); 148 return 1; 149 } 150 151 /** 152 * ptrace_init_task - initialize ptrace state for a new child 153 * @child: new child task 154 * @ptrace: true if child should be ptrace'd by parent's tracer 155 * 156 * This is called immediately after adding @child to its parent's children 157 * list. @ptrace is false in the normal case, and true to ptrace @child. 158 * 159 * Called with current's siglock and write_lock_irq(&tasklist_lock) held. 160 */ 161 static inline void ptrace_init_task(struct task_struct *child, bool ptrace) 162 { 163 INIT_LIST_HEAD(&child->ptrace_entry); 164 INIT_LIST_HEAD(&child->ptraced); 165 child->parent = child->real_parent; 166 child->ptrace = 0; 167 if (unlikely(ptrace) && (current->ptrace & PT_PTRACED)) { 168 child->ptrace = current->ptrace; 169 __ptrace_link(child, current->parent); 170 } 171 } 172 173 /** 174 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped 175 * @task: task in %EXIT_DEAD state 176 * 177 * Called with write_lock(&tasklist_lock) held. 178 */ 179 static inline void ptrace_release_task(struct task_struct *task) 180 { 181 BUG_ON(!list_empty(&task->ptraced)); 182 ptrace_unlink(task); 183 BUG_ON(!list_empty(&task->ptrace_entry)); 184 } 185 186 #ifndef force_successful_syscall_return 187 /* 188 * System call handlers that, upon successful completion, need to return a 189 * negative value should call force_successful_syscall_return() right before 190 * returning. On architectures where the syscall convention provides for a 191 * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly 192 * others), this macro can be used to ensure that the error flag will not get 193 * set. On architectures which do not support a separate error flag, the macro 194 * is a no-op and the spurious error condition needs to be filtered out by some 195 * other means (e.g., in user-level, by passing an extra argument to the 196 * syscall handler, or something along those lines). 197 */ 198 #define force_successful_syscall_return() do { } while (0) 199 #endif 200 201 /* 202 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__. 203 * 204 * These do-nothing inlines are used when the arch does not 205 * implement single-step. The kerneldoc comments are here 206 * to document the interface for all arch definitions. 207 */ 208 209 #ifndef arch_has_single_step 210 /** 211 * arch_has_single_step - does this CPU support user-mode single-step? 212 * 213 * If this is defined, then there must be function declarations or 214 * inlines for user_enable_single_step() and user_disable_single_step(). 215 * arch_has_single_step() should evaluate to nonzero iff the machine 216 * supports instruction single-step for user mode. 217 * It can be a constant or it can test a CPU feature bit. 218 */ 219 #define arch_has_single_step() (0) 220 221 /** 222 * user_enable_single_step - single-step in user-mode task 223 * @task: either current or a task stopped in %TASK_TRACED 224 * 225 * This can only be called when arch_has_single_step() has returned nonzero. 226 * Set @task so that when it returns to user mode, it will trap after the 227 * next single instruction executes. If arch_has_block_step() is defined, 228 * this must clear the effects of user_enable_block_step() too. 229 */ 230 static inline void user_enable_single_step(struct task_struct *task) 231 { 232 BUG(); /* This can never be called. */ 233 } 234 235 /** 236 * user_disable_single_step - cancel user-mode single-step 237 * @task: either current or a task stopped in %TASK_TRACED 238 * 239 * Clear @task of the effects of user_enable_single_step() and 240 * user_enable_block_step(). This can be called whether or not either 241 * of those was ever called on @task, and even if arch_has_single_step() 242 * returned zero. 243 */ 244 static inline void user_disable_single_step(struct task_struct *task) 245 { 246 } 247 #endif /* arch_has_single_step */ 248 249 #ifndef arch_has_block_step 250 /** 251 * arch_has_block_step - does this CPU support user-mode block-step? 252 * 253 * If this is defined, then there must be a function declaration or inline 254 * for user_enable_block_step(), and arch_has_single_step() must be defined 255 * too. arch_has_block_step() should evaluate to nonzero iff the machine 256 * supports step-until-branch for user mode. It can be a constant or it 257 * can test a CPU feature bit. 258 */ 259 #define arch_has_block_step() (0) 260 261 /** 262 * user_enable_block_step - step until branch in user-mode task 263 * @task: either current or a task stopped in %TASK_TRACED 264 * 265 * This can only be called when arch_has_block_step() has returned nonzero, 266 * and will never be called when single-instruction stepping is being used. 267 * Set @task so that when it returns to user mode, it will trap after the 268 * next branch or trap taken. 269 */ 270 static inline void user_enable_block_step(struct task_struct *task) 271 { 272 BUG(); /* This can never be called. */ 273 } 274 #endif /* arch_has_block_step */ 275 276 #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO 277 extern void user_single_step_siginfo(struct task_struct *tsk, 278 struct pt_regs *regs, siginfo_t *info); 279 #else 280 static inline void user_single_step_siginfo(struct task_struct *tsk, 281 struct pt_regs *regs, siginfo_t *info) 282 { 283 memset(info, 0, sizeof(*info)); 284 info->si_signo = SIGTRAP; 285 } 286 #endif 287 288 #ifndef arch_ptrace_stop_needed 289 /** 290 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called 291 * @code: current->exit_code value ptrace will stop with 292 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with 293 * 294 * This is called with the siglock held, to decide whether or not it's 295 * necessary to release the siglock and call arch_ptrace_stop() with the 296 * same @code and @info arguments. It can be defined to a constant if 297 * arch_ptrace_stop() is never required, or always is. On machines where 298 * this makes sense, it should be defined to a quick test to optimize out 299 * calling arch_ptrace_stop() when it would be superfluous. For example, 300 * if the thread has not been back to user mode since the last stop, the 301 * thread state might indicate that nothing needs to be done. 302 */ 303 #define arch_ptrace_stop_needed(code, info) (0) 304 #endif 305 306 #ifndef arch_ptrace_stop 307 /** 308 * arch_ptrace_stop - Do machine-specific work before stopping for ptrace 309 * @code: current->exit_code value ptrace will stop with 310 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with 311 * 312 * This is called with no locks held when arch_ptrace_stop_needed() has 313 * just returned nonzero. It is allowed to block, e.g. for user memory 314 * access. The arch can have machine-specific work to be done before 315 * ptrace stops. On ia64, register backing store gets written back to user 316 * memory here. Since this can be costly (requires dropping the siglock), 317 * we only do it when the arch requires it for this particular stop, as 318 * indicated by arch_ptrace_stop_needed(). 319 */ 320 #define arch_ptrace_stop(code, info) do { } while (0) 321 #endif 322 323 #ifndef arch_ptrace_untrace 324 /* 325 * Do machine-specific work before untracing child. 326 * 327 * This is called for a normal detach as well as from ptrace_exit() 328 * when the tracing task dies. 329 * 330 * Called with write_lock(&tasklist_lock) held. 331 */ 332 #define arch_ptrace_untrace(task) do { } while (0) 333 #endif 334 335 extern int task_current_syscall(struct task_struct *target, long *callno, 336 unsigned long args[6], unsigned int maxargs, 337 unsigned long *sp, unsigned long *pc); 338 339 #endif 340 341 #endif 342