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 static inline void ptrace_link(struct task_struct *child, 109 struct task_struct *new_parent) 110 { 111 if (unlikely(child->ptrace)) 112 __ptrace_link(child, new_parent); 113 } 114 static inline void ptrace_unlink(struct task_struct *child) 115 { 116 if (unlikely(child->ptrace)) 117 __ptrace_unlink(child); 118 } 119 120 int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data); 121 int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data); 122 123 /** 124 * task_ptrace - return %PT_* flags that apply to a task 125 * @task: pointer to &task_struct in question 126 * 127 * Returns the %PT_* flags that apply to @task. 128 */ 129 static inline int task_ptrace(struct task_struct *task) 130 { 131 return task->ptrace; 132 } 133 134 /** 135 * ptrace_event - possibly stop for a ptrace event notification 136 * @mask: %PT_* bit to check in @current->ptrace 137 * @event: %PTRACE_EVENT_* value to report if @mask is set 138 * @message: value for %PTRACE_GETEVENTMSG to return 139 * 140 * This checks the @mask bit to see if ptrace wants stops for this event. 141 * If so we stop, reporting @event and @message to the ptrace parent. 142 * 143 * Returns nonzero if we did a ptrace notification, zero if not. 144 * 145 * Called without locks. 146 */ 147 static inline int ptrace_event(int mask, int event, unsigned long message) 148 { 149 if (mask && likely(!(current->ptrace & mask))) 150 return 0; 151 current->ptrace_message = message; 152 ptrace_notify((event << 8) | SIGTRAP); 153 return 1; 154 } 155 156 /** 157 * ptrace_init_task - initialize ptrace state for a new child 158 * @child: new child task 159 * @ptrace: true if child should be ptrace'd by parent's tracer 160 * 161 * This is called immediately after adding @child to its parent's children 162 * list. @ptrace is false in the normal case, and true to ptrace @child. 163 * 164 * Called with current's siglock and write_lock_irq(&tasklist_lock) held. 165 */ 166 static inline void ptrace_init_task(struct task_struct *child, bool ptrace) 167 { 168 INIT_LIST_HEAD(&child->ptrace_entry); 169 INIT_LIST_HEAD(&child->ptraced); 170 child->parent = child->real_parent; 171 child->ptrace = 0; 172 if (unlikely(ptrace)) { 173 child->ptrace = current->ptrace; 174 ptrace_link(child, current->parent); 175 } 176 } 177 178 /** 179 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped 180 * @task: task in %EXIT_DEAD state 181 * 182 * Called with write_lock(&tasklist_lock) held. 183 */ 184 static inline void ptrace_release_task(struct task_struct *task) 185 { 186 BUG_ON(!list_empty(&task->ptraced)); 187 ptrace_unlink(task); 188 BUG_ON(!list_empty(&task->ptrace_entry)); 189 } 190 191 #ifndef force_successful_syscall_return 192 /* 193 * System call handlers that, upon successful completion, need to return a 194 * negative value should call force_successful_syscall_return() right before 195 * returning. On architectures where the syscall convention provides for a 196 * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly 197 * others), this macro can be used to ensure that the error flag will not get 198 * set. On architectures which do not support a separate error flag, the macro 199 * is a no-op and the spurious error condition needs to be filtered out by some 200 * other means (e.g., in user-level, by passing an extra argument to the 201 * syscall handler, or something along those lines). 202 */ 203 #define force_successful_syscall_return() do { } while (0) 204 #endif 205 206 /* 207 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__. 208 * 209 * These do-nothing inlines are used when the arch does not 210 * implement single-step. The kerneldoc comments are here 211 * to document the interface for all arch definitions. 212 */ 213 214 #ifndef arch_has_single_step 215 /** 216 * arch_has_single_step - does this CPU support user-mode single-step? 217 * 218 * If this is defined, then there must be function declarations or 219 * inlines for user_enable_single_step() and user_disable_single_step(). 220 * arch_has_single_step() should evaluate to nonzero iff the machine 221 * supports instruction single-step for user mode. 222 * It can be a constant or it can test a CPU feature bit. 223 */ 224 #define arch_has_single_step() (0) 225 226 /** 227 * user_enable_single_step - single-step in user-mode task 228 * @task: either current or a task stopped in %TASK_TRACED 229 * 230 * This can only be called when arch_has_single_step() has returned nonzero. 231 * Set @task so that when it returns to user mode, it will trap after the 232 * next single instruction executes. If arch_has_block_step() is defined, 233 * this must clear the effects of user_enable_block_step() too. 234 */ 235 static inline void user_enable_single_step(struct task_struct *task) 236 { 237 BUG(); /* This can never be called. */ 238 } 239 240 /** 241 * user_disable_single_step - cancel user-mode single-step 242 * @task: either current or a task stopped in %TASK_TRACED 243 * 244 * Clear @task of the effects of user_enable_single_step() and 245 * user_enable_block_step(). This can be called whether or not either 246 * of those was ever called on @task, and even if arch_has_single_step() 247 * returned zero. 248 */ 249 static inline void user_disable_single_step(struct task_struct *task) 250 { 251 } 252 #endif /* arch_has_single_step */ 253 254 #ifndef arch_has_block_step 255 /** 256 * arch_has_block_step - does this CPU support user-mode block-step? 257 * 258 * If this is defined, then there must be a function declaration or inline 259 * for user_enable_block_step(), and arch_has_single_step() must be defined 260 * too. arch_has_block_step() should evaluate to nonzero iff the machine 261 * supports step-until-branch for user mode. It can be a constant or it 262 * can test a CPU feature bit. 263 */ 264 #define arch_has_block_step() (0) 265 266 /** 267 * user_enable_block_step - step until branch in user-mode task 268 * @task: either current or a task stopped in %TASK_TRACED 269 * 270 * This can only be called when arch_has_block_step() has returned nonzero, 271 * and will never be called when single-instruction stepping is being used. 272 * Set @task so that when it returns to user mode, it will trap after the 273 * next branch or trap taken. 274 */ 275 static inline void user_enable_block_step(struct task_struct *task) 276 { 277 BUG(); /* This can never be called. */ 278 } 279 #endif /* arch_has_block_step */ 280 281 #ifndef arch_ptrace_stop_needed 282 /** 283 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called 284 * @code: current->exit_code value ptrace will stop with 285 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with 286 * 287 * This is called with the siglock held, to decide whether or not it's 288 * necessary to release the siglock and call arch_ptrace_stop() with the 289 * same @code and @info arguments. It can be defined to a constant if 290 * arch_ptrace_stop() is never required, or always is. On machines where 291 * this makes sense, it should be defined to a quick test to optimize out 292 * calling arch_ptrace_stop() when it would be superfluous. For example, 293 * if the thread has not been back to user mode since the last stop, the 294 * thread state might indicate that nothing needs to be done. 295 */ 296 #define arch_ptrace_stop_needed(code, info) (0) 297 #endif 298 299 #ifndef arch_ptrace_stop 300 /** 301 * arch_ptrace_stop - Do machine-specific work before stopping for ptrace 302 * @code: current->exit_code value ptrace will stop with 303 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with 304 * 305 * This is called with no locks held when arch_ptrace_stop_needed() has 306 * just returned nonzero. It is allowed to block, e.g. for user memory 307 * access. The arch can have machine-specific work to be done before 308 * ptrace stops. On ia64, register backing store gets written back to user 309 * memory here. Since this can be costly (requires dropping the siglock), 310 * we only do it when the arch requires it for this particular stop, as 311 * indicated by arch_ptrace_stop_needed(). 312 */ 313 #define arch_ptrace_stop(code, info) do { } while (0) 314 #endif 315 316 #ifndef arch_ptrace_untrace 317 /* 318 * Do machine-specific work before untracing child. 319 * 320 * This is called for a normal detach as well as from ptrace_exit() 321 * when the tracing task dies. 322 * 323 * Called with write_lock(&tasklist_lock) held. 324 */ 325 #define arch_ptrace_untrace(task) do { } while (0) 326 #endif 327 328 extern int task_current_syscall(struct task_struct *target, long *callno, 329 unsigned long args[6], unsigned int maxargs, 330 unsigned long *sp, unsigned long *pc); 331 332 #endif 333 334 #endif 335