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 /* Extended result codes which enabled by means other than options. */
62 #define PTRACE_EVENT_STOP 128
63
64 /* Options set using PTRACE_SETOPTIONS or using PTRACE_SEIZE @data param */
65 #define PTRACE_O_TRACESYSGOOD 1
66 #define PTRACE_O_TRACEFORK (1 << PTRACE_EVENT_FORK)
67 #define PTRACE_O_TRACEVFORK (1 << PTRACE_EVENT_VFORK)
68 #define PTRACE_O_TRACECLONE (1 << PTRACE_EVENT_CLONE)
69 #define PTRACE_O_TRACEEXEC (1 << PTRACE_EVENT_EXEC)
70 #define PTRACE_O_TRACEVFORKDONE (1 << PTRACE_EVENT_VFORK_DONE)
71 #define PTRACE_O_TRACEEXIT (1 << PTRACE_EVENT_EXIT)
72
73 #define PTRACE_O_MASK 0x0000007f
74
75 #include <asm/ptrace.h>
76
77 #ifdef __KERNEL__
78 /*
79 * Ptrace flags
80 *
81 * The owner ship rules for task->ptrace which holds the ptrace
82 * flags is simple. When a task is running it owns it's task->ptrace
83 * flags. When the a task is stopped the ptracer owns task->ptrace.
84 */
85
86 #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */
87 #define PT_PTRACED 0x00000001
88 #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
89 #define PT_PTRACE_CAP 0x00000004 /* ptracer can follow suid-exec */
90
91 #define PT_OPT_FLAG_SHIFT 3
92 /* PT_TRACE_* event enable flags */
93 #define PT_EVENT_FLAG(event) (1 << (PT_OPT_FLAG_SHIFT + (event)))
94 #define PT_TRACESYSGOOD PT_EVENT_FLAG(0)
95 #define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK)
96 #define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK)
97 #define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE)
98 #define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC)
99 #define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE)
100 #define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT)
101
102 /* single stepping state bits (used on ARM and PA-RISC) */
103 #define PT_SINGLESTEP_BIT 31
104 #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT)
105 #define PT_BLOCKSTEP_BIT 30
106 #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT)
107
108 #include <linux/compiler.h> /* For unlikely. */
109 #include <linux/sched.h> /* For struct task_struct. */
110 #include <linux/err.h> /* for IS_ERR_VALUE */
111 #include <linux/bug.h> /* For BUG_ON. */
112
113
114 extern long arch_ptrace(struct task_struct *child, long request,
115 unsigned long addr, unsigned long data);
116 extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
117 extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
118 extern void ptrace_disable(struct task_struct *);
119 extern int ptrace_check_attach(struct task_struct *task, bool ignore_state);
120 extern int ptrace_request(struct task_struct *child, long request,
121 unsigned long addr, unsigned long data);
122 extern void ptrace_notify(int exit_code);
123 extern void __ptrace_link(struct task_struct *child,
124 struct task_struct *new_parent);
125 extern void __ptrace_unlink(struct task_struct *child);
126 extern void exit_ptrace(struct task_struct *tracer);
127 #define PTRACE_MODE_READ 0x01
128 #define PTRACE_MODE_ATTACH 0x02
129 #define PTRACE_MODE_NOAUDIT 0x04
130 /* Returns 0 on success, -errno on denial. */
131 extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
132 /* Returns true on success, false on denial. */
133 extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
134
ptrace_reparented(struct task_struct * child)135 static inline int ptrace_reparented(struct task_struct *child)
136 {
137 return !same_thread_group(child->real_parent, child->parent);
138 }
139
ptrace_unlink(struct task_struct * child)140 static inline void ptrace_unlink(struct task_struct *child)
141 {
142 if (unlikely(child->ptrace))
143 __ptrace_unlink(child);
144 }
145
146 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
147 unsigned long data);
148 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
149 unsigned long data);
150
151 /**
152 * ptrace_parent - return the task that is tracing the given task
153 * @task: task to consider
154 *
155 * Returns %NULL if no one is tracing @task, or the &struct task_struct
156 * pointer to its tracer.
157 *
158 * Must called under rcu_read_lock(). The pointer returned might be kept
159 * live only by RCU. During exec, this may be called with task_lock() held
160 * on @task, still held from when check_unsafe_exec() was called.
161 */
ptrace_parent(struct task_struct * task)162 static inline struct task_struct *ptrace_parent(struct task_struct *task)
163 {
164 if (unlikely(task->ptrace))
165 return rcu_dereference(task->parent);
166 return NULL;
167 }
168
169 /**
170 * ptrace_event_enabled - test whether a ptrace event is enabled
171 * @task: ptracee of interest
172 * @event: %PTRACE_EVENT_* to test
173 *
174 * Test whether @event is enabled for ptracee @task.
175 *
176 * Returns %true if @event is enabled, %false otherwise.
177 */
ptrace_event_enabled(struct task_struct * task,int event)178 static inline bool ptrace_event_enabled(struct task_struct *task, int event)
179 {
180 return task->ptrace & PT_EVENT_FLAG(event);
181 }
182
183 /**
184 * ptrace_event - possibly stop for a ptrace event notification
185 * @event: %PTRACE_EVENT_* value to report
186 * @message: value for %PTRACE_GETEVENTMSG to return
187 *
188 * Check whether @event is enabled and, if so, report @event and @message
189 * to the ptrace parent.
190 *
191 * Called without locks.
192 */
ptrace_event(int event,unsigned long message)193 static inline void ptrace_event(int event, unsigned long message)
194 {
195 if (unlikely(ptrace_event_enabled(current, event))) {
196 current->ptrace_message = message;
197 ptrace_notify((event << 8) | SIGTRAP);
198 } else if (event == PTRACE_EVENT_EXEC) {
199 /* legacy EXEC report via SIGTRAP */
200 if ((current->ptrace & (PT_PTRACED|PT_SEIZED)) == PT_PTRACED)
201 send_sig(SIGTRAP, current, 0);
202 }
203 }
204
205 /**
206 * ptrace_init_task - initialize ptrace state for a new child
207 * @child: new child task
208 * @ptrace: true if child should be ptrace'd by parent's tracer
209 *
210 * This is called immediately after adding @child to its parent's children
211 * list. @ptrace is false in the normal case, and true to ptrace @child.
212 *
213 * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
214 */
ptrace_init_task(struct task_struct * child,bool ptrace)215 static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
216 {
217 INIT_LIST_HEAD(&child->ptrace_entry);
218 INIT_LIST_HEAD(&child->ptraced);
219 #ifdef CONFIG_HAVE_HW_BREAKPOINT
220 atomic_set(&child->ptrace_bp_refcnt, 1);
221 #endif
222 child->jobctl = 0;
223 child->ptrace = 0;
224 child->parent = child->real_parent;
225
226 if (unlikely(ptrace) && current->ptrace) {
227 child->ptrace = current->ptrace;
228 __ptrace_link(child, current->parent);
229
230 if (child->ptrace & PT_SEIZED)
231 task_set_jobctl_pending(child, JOBCTL_TRAP_STOP);
232 else
233 sigaddset(&child->pending.signal, SIGSTOP);
234
235 set_tsk_thread_flag(child, TIF_SIGPENDING);
236 }
237 }
238
239 /**
240 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
241 * @task: task in %EXIT_DEAD state
242 *
243 * Called with write_lock(&tasklist_lock) held.
244 */
ptrace_release_task(struct task_struct * task)245 static inline void ptrace_release_task(struct task_struct *task)
246 {
247 BUG_ON(!list_empty(&task->ptraced));
248 ptrace_unlink(task);
249 BUG_ON(!list_empty(&task->ptrace_entry));
250 }
251
252 #ifndef force_successful_syscall_return
253 /*
254 * System call handlers that, upon successful completion, need to return a
255 * negative value should call force_successful_syscall_return() right before
256 * returning. On architectures where the syscall convention provides for a
257 * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
258 * others), this macro can be used to ensure that the error flag will not get
259 * set. On architectures which do not support a separate error flag, the macro
260 * is a no-op and the spurious error condition needs to be filtered out by some
261 * other means (e.g., in user-level, by passing an extra argument to the
262 * syscall handler, or something along those lines).
263 */
264 #define force_successful_syscall_return() do { } while (0)
265 #endif
266
267 #ifndef is_syscall_success
268 /*
269 * On most systems we can tell if a syscall is a success based on if the retval
270 * is an error value. On some systems like ia64 and powerpc they have different
271 * indicators of success/failure and must define their own.
272 */
273 #define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs))))
274 #endif
275
276 /*
277 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
278 *
279 * These do-nothing inlines are used when the arch does not
280 * implement single-step. The kerneldoc comments are here
281 * to document the interface for all arch definitions.
282 */
283
284 #ifndef arch_has_single_step
285 /**
286 * arch_has_single_step - does this CPU support user-mode single-step?
287 *
288 * If this is defined, then there must be function declarations or
289 * inlines for user_enable_single_step() and user_disable_single_step().
290 * arch_has_single_step() should evaluate to nonzero iff the machine
291 * supports instruction single-step for user mode.
292 * It can be a constant or it can test a CPU feature bit.
293 */
294 #define arch_has_single_step() (0)
295
296 /**
297 * user_enable_single_step - single-step in user-mode task
298 * @task: either current or a task stopped in %TASK_TRACED
299 *
300 * This can only be called when arch_has_single_step() has returned nonzero.
301 * Set @task so that when it returns to user mode, it will trap after the
302 * next single instruction executes. If arch_has_block_step() is defined,
303 * this must clear the effects of user_enable_block_step() too.
304 */
user_enable_single_step(struct task_struct * task)305 static inline void user_enable_single_step(struct task_struct *task)
306 {
307 BUG(); /* This can never be called. */
308 }
309
310 /**
311 * user_disable_single_step - cancel user-mode single-step
312 * @task: either current or a task stopped in %TASK_TRACED
313 *
314 * Clear @task of the effects of user_enable_single_step() and
315 * user_enable_block_step(). This can be called whether or not either
316 * of those was ever called on @task, and even if arch_has_single_step()
317 * returned zero.
318 */
user_disable_single_step(struct task_struct * task)319 static inline void user_disable_single_step(struct task_struct *task)
320 {
321 }
322 #else
323 extern void user_enable_single_step(struct task_struct *);
324 extern void user_disable_single_step(struct task_struct *);
325 #endif /* arch_has_single_step */
326
327 #ifndef arch_has_block_step
328 /**
329 * arch_has_block_step - does this CPU support user-mode block-step?
330 *
331 * If this is defined, then there must be a function declaration or inline
332 * for user_enable_block_step(), and arch_has_single_step() must be defined
333 * too. arch_has_block_step() should evaluate to nonzero iff the machine
334 * supports step-until-branch for user mode. It can be a constant or it
335 * can test a CPU feature bit.
336 */
337 #define arch_has_block_step() (0)
338
339 /**
340 * user_enable_block_step - step until branch in user-mode task
341 * @task: either current or a task stopped in %TASK_TRACED
342 *
343 * This can only be called when arch_has_block_step() has returned nonzero,
344 * and will never be called when single-instruction stepping is being used.
345 * Set @task so that when it returns to user mode, it will trap after the
346 * next branch or trap taken.
347 */
user_enable_block_step(struct task_struct * task)348 static inline void user_enable_block_step(struct task_struct *task)
349 {
350 BUG(); /* This can never be called. */
351 }
352 #else
353 extern void user_enable_block_step(struct task_struct *);
354 #endif /* arch_has_block_step */
355
356 #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
357 extern void user_single_step_siginfo(struct task_struct *tsk,
358 struct pt_regs *regs, siginfo_t *info);
359 #else
user_single_step_siginfo(struct task_struct * tsk,struct pt_regs * regs,siginfo_t * info)360 static inline void user_single_step_siginfo(struct task_struct *tsk,
361 struct pt_regs *regs, siginfo_t *info)
362 {
363 memset(info, 0, sizeof(*info));
364 info->si_signo = SIGTRAP;
365 }
366 #endif
367
368 #ifndef arch_ptrace_stop_needed
369 /**
370 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
371 * @code: current->exit_code value ptrace will stop with
372 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
373 *
374 * This is called with the siglock held, to decide whether or not it's
375 * necessary to release the siglock and call arch_ptrace_stop() with the
376 * same @code and @info arguments. It can be defined to a constant if
377 * arch_ptrace_stop() is never required, or always is. On machines where
378 * this makes sense, it should be defined to a quick test to optimize out
379 * calling arch_ptrace_stop() when it would be superfluous. For example,
380 * if the thread has not been back to user mode since the last stop, the
381 * thread state might indicate that nothing needs to be done.
382 *
383 * This is guaranteed to be invoked once before a task stops for ptrace and
384 * may include arch-specific operations necessary prior to a ptrace stop.
385 */
386 #define arch_ptrace_stop_needed(code, info) (0)
387 #endif
388
389 #ifndef arch_ptrace_stop
390 /**
391 * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
392 * @code: current->exit_code value ptrace will stop with
393 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
394 *
395 * This is called with no locks held when arch_ptrace_stop_needed() has
396 * just returned nonzero. It is allowed to block, e.g. for user memory
397 * access. The arch can have machine-specific work to be done before
398 * ptrace stops. On ia64, register backing store gets written back to user
399 * memory here. Since this can be costly (requires dropping the siglock),
400 * we only do it when the arch requires it for this particular stop, as
401 * indicated by arch_ptrace_stop_needed().
402 */
403 #define arch_ptrace_stop(code, info) do { } while (0)
404 #endif
405
406 extern int task_current_syscall(struct task_struct *target, long *callno,
407 unsigned long args[6], unsigned int maxargs,
408 unsigned long *sp, unsigned long *pc);
409
410 #ifdef CONFIG_HAVE_HW_BREAKPOINT
411 extern int ptrace_get_breakpoints(struct task_struct *tsk);
412 extern void ptrace_put_breakpoints(struct task_struct *tsk);
413 #else
ptrace_put_breakpoints(struct task_struct * tsk)414 static inline void ptrace_put_breakpoints(struct task_struct *tsk) { }
415 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
416
417 #endif /* __KERNEL */
418
419 #endif
420