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 /* flags in @data for PTRACE_SEIZE */
55 #define PTRACE_SEIZE_DEVEL 0x80000000 /* temp flag for development */
56
57 /* options set using PTRACE_SETOPTIONS */
58 #define PTRACE_O_TRACESYSGOOD 0x00000001
59 #define PTRACE_O_TRACEFORK 0x00000002
60 #define PTRACE_O_TRACEVFORK 0x00000004
61 #define PTRACE_O_TRACECLONE 0x00000008
62 #define PTRACE_O_TRACEEXEC 0x00000010
63 #define PTRACE_O_TRACEVFORKDONE 0x00000020
64 #define PTRACE_O_TRACEEXIT 0x00000040
65
66 #define PTRACE_O_MASK 0x0000007f
67
68 /* Wait extended result codes for the above trace options. */
69 #define PTRACE_EVENT_FORK 1
70 #define PTRACE_EVENT_VFORK 2
71 #define PTRACE_EVENT_CLONE 3
72 #define PTRACE_EVENT_EXEC 4
73 #define PTRACE_EVENT_VFORK_DONE 5
74 #define PTRACE_EVENT_EXIT 6
75 #define PTRACE_EVENT_STOP 7
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_TRACESYSGOOD 0x00000004
92 #define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */
93
94 /* PT_TRACE_* event enable flags */
95 #define PT_EVENT_FLAG_SHIFT 4
96 #define PT_EVENT_FLAG(event) (1 << (PT_EVENT_FLAG_SHIFT + (event) - 1))
97
98 #define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK)
99 #define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK)
100 #define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE)
101 #define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC)
102 #define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE)
103 #define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT)
104
105 #define PT_TRACE_MASK 0x000003f4
106
107 /* single stepping state bits (used on ARM and PA-RISC) */
108 #define PT_SINGLESTEP_BIT 31
109 #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT)
110 #define PT_BLOCKSTEP_BIT 30
111 #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT)
112
113 #include <linux/compiler.h> /* For unlikely. */
114 #include <linux/sched.h> /* For struct task_struct. */
115 #include <linux/err.h> /* for IS_ERR_VALUE */
116
117
118 extern long arch_ptrace(struct task_struct *child, long request,
119 unsigned long addr, unsigned long data);
120 extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
121 extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
122 extern void ptrace_disable(struct task_struct *);
123 extern int ptrace_check_attach(struct task_struct *task, bool ignore_state);
124 extern int ptrace_request(struct task_struct *child, long request,
125 unsigned long addr, unsigned long data);
126 extern void ptrace_notify(int exit_code);
127 extern void __ptrace_link(struct task_struct *child,
128 struct task_struct *new_parent);
129 extern void __ptrace_unlink(struct task_struct *child);
130 extern void exit_ptrace(struct task_struct *tracer);
131 #define PTRACE_MODE_READ 0x01
132 #define PTRACE_MODE_ATTACH 0x02
133 #define PTRACE_MODE_NOAUDIT 0x04
134 /* Returns 0 on success, -errno on denial. */
135 extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
136 /* Returns true on success, false on denial. */
137 extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
138
ptrace_reparented(struct task_struct * child)139 static inline int ptrace_reparented(struct task_struct *child)
140 {
141 return !same_thread_group(child->real_parent, child->parent);
142 }
143
ptrace_unlink(struct task_struct * child)144 static inline void ptrace_unlink(struct task_struct *child)
145 {
146 if (unlikely(child->ptrace))
147 __ptrace_unlink(child);
148 }
149
150 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
151 unsigned long data);
152 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
153 unsigned long data);
154
155 /**
156 * ptrace_parent - return the task that is tracing the given task
157 * @task: task to consider
158 *
159 * Returns %NULL if no one is tracing @task, or the &struct task_struct
160 * pointer to its tracer.
161 *
162 * Must called under rcu_read_lock(). The pointer returned might be kept
163 * live only by RCU. During exec, this may be called with task_lock() held
164 * on @task, still held from when check_unsafe_exec() was called.
165 */
ptrace_parent(struct task_struct * task)166 static inline struct task_struct *ptrace_parent(struct task_struct *task)
167 {
168 if (unlikely(task->ptrace))
169 return rcu_dereference(task->parent);
170 return NULL;
171 }
172
173 /**
174 * ptrace_event_enabled - test whether a ptrace event is enabled
175 * @task: ptracee of interest
176 * @event: %PTRACE_EVENT_* to test
177 *
178 * Test whether @event is enabled for ptracee @task.
179 *
180 * Returns %true if @event is enabled, %false otherwise.
181 */
ptrace_event_enabled(struct task_struct * task,int event)182 static inline bool ptrace_event_enabled(struct task_struct *task, int event)
183 {
184 return task->ptrace & PT_EVENT_FLAG(event);
185 }
186
187 /**
188 * ptrace_event - possibly stop for a ptrace event notification
189 * @event: %PTRACE_EVENT_* value to report
190 * @message: value for %PTRACE_GETEVENTMSG to return
191 *
192 * Check whether @event is enabled and, if so, report @event and @message
193 * to the ptrace parent.
194 *
195 * Called without locks.
196 */
ptrace_event(int event,unsigned long message)197 static inline void ptrace_event(int event, unsigned long message)
198 {
199 if (unlikely(ptrace_event_enabled(current, event))) {
200 current->ptrace_message = message;
201 ptrace_notify((event << 8) | SIGTRAP);
202 } else if (event == PTRACE_EVENT_EXEC && unlikely(current->ptrace)) {
203 /* legacy EXEC report via SIGTRAP */
204 send_sig(SIGTRAP, current, 0);
205 }
206 }
207
208 /**
209 * ptrace_init_task - initialize ptrace state for a new child
210 * @child: new child task
211 * @ptrace: true if child should be ptrace'd by parent's tracer
212 *
213 * This is called immediately after adding @child to its parent's children
214 * list. @ptrace is false in the normal case, and true to ptrace @child.
215 *
216 * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
217 */
ptrace_init_task(struct task_struct * child,bool ptrace)218 static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
219 {
220 INIT_LIST_HEAD(&child->ptrace_entry);
221 INIT_LIST_HEAD(&child->ptraced);
222 #ifdef CONFIG_HAVE_HW_BREAKPOINT
223 atomic_set(&child->ptrace_bp_refcnt, 1);
224 #endif
225 child->jobctl = 0;
226 child->ptrace = 0;
227 child->parent = child->real_parent;
228
229 if (unlikely(ptrace) && current->ptrace) {
230 child->ptrace = current->ptrace;
231 __ptrace_link(child, current->parent);
232
233 if (child->ptrace & PT_SEIZED)
234 task_set_jobctl_pending(child, JOBCTL_TRAP_STOP);
235 else
236 sigaddset(&child->pending.signal, SIGSTOP);
237
238 set_tsk_thread_flag(child, TIF_SIGPENDING);
239 }
240 }
241
242 /**
243 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
244 * @task: task in %EXIT_DEAD state
245 *
246 * Called with write_lock(&tasklist_lock) held.
247 */
ptrace_release_task(struct task_struct * task)248 static inline void ptrace_release_task(struct task_struct *task)
249 {
250 BUG_ON(!list_empty(&task->ptraced));
251 ptrace_unlink(task);
252 BUG_ON(!list_empty(&task->ptrace_entry));
253 }
254
255 #ifndef force_successful_syscall_return
256 /*
257 * System call handlers that, upon successful completion, need to return a
258 * negative value should call force_successful_syscall_return() right before
259 * returning. On architectures where the syscall convention provides for a
260 * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
261 * others), this macro can be used to ensure that the error flag will not get
262 * set. On architectures which do not support a separate error flag, the macro
263 * is a no-op and the spurious error condition needs to be filtered out by some
264 * other means (e.g., in user-level, by passing an extra argument to the
265 * syscall handler, or something along those lines).
266 */
267 #define force_successful_syscall_return() do { } while (0)
268 #endif
269
270 #ifndef is_syscall_success
271 /*
272 * On most systems we can tell if a syscall is a success based on if the retval
273 * is an error value. On some systems like ia64 and powerpc they have different
274 * indicators of success/failure and must define their own.
275 */
276 #define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs))))
277 #endif
278
279 /*
280 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
281 *
282 * These do-nothing inlines are used when the arch does not
283 * implement single-step. The kerneldoc comments are here
284 * to document the interface for all arch definitions.
285 */
286
287 #ifndef arch_has_single_step
288 /**
289 * arch_has_single_step - does this CPU support user-mode single-step?
290 *
291 * If this is defined, then there must be function declarations or
292 * inlines for user_enable_single_step() and user_disable_single_step().
293 * arch_has_single_step() should evaluate to nonzero iff the machine
294 * supports instruction single-step for user mode.
295 * It can be a constant or it can test a CPU feature bit.
296 */
297 #define arch_has_single_step() (0)
298
299 /**
300 * user_enable_single_step - single-step in user-mode task
301 * @task: either current or a task stopped in %TASK_TRACED
302 *
303 * This can only be called when arch_has_single_step() has returned nonzero.
304 * Set @task so that when it returns to user mode, it will trap after the
305 * next single instruction executes. If arch_has_block_step() is defined,
306 * this must clear the effects of user_enable_block_step() too.
307 */
user_enable_single_step(struct task_struct * task)308 static inline void user_enable_single_step(struct task_struct *task)
309 {
310 BUG(); /* This can never be called. */
311 }
312
313 /**
314 * user_disable_single_step - cancel user-mode single-step
315 * @task: either current or a task stopped in %TASK_TRACED
316 *
317 * Clear @task of the effects of user_enable_single_step() and
318 * user_enable_block_step(). This can be called whether or not either
319 * of those was ever called on @task, and even if arch_has_single_step()
320 * returned zero.
321 */
user_disable_single_step(struct task_struct * task)322 static inline void user_disable_single_step(struct task_struct *task)
323 {
324 }
325 #else
326 extern void user_enable_single_step(struct task_struct *);
327 extern void user_disable_single_step(struct task_struct *);
328 #endif /* arch_has_single_step */
329
330 #ifndef arch_has_block_step
331 /**
332 * arch_has_block_step - does this CPU support user-mode block-step?
333 *
334 * If this is defined, then there must be a function declaration or inline
335 * for user_enable_block_step(), and arch_has_single_step() must be defined
336 * too. arch_has_block_step() should evaluate to nonzero iff the machine
337 * supports step-until-branch for user mode. It can be a constant or it
338 * can test a CPU feature bit.
339 */
340 #define arch_has_block_step() (0)
341
342 /**
343 * user_enable_block_step - step until branch in user-mode task
344 * @task: either current or a task stopped in %TASK_TRACED
345 *
346 * This can only be called when arch_has_block_step() has returned nonzero,
347 * and will never be called when single-instruction stepping is being used.
348 * Set @task so that when it returns to user mode, it will trap after the
349 * next branch or trap taken.
350 */
user_enable_block_step(struct task_struct * task)351 static inline void user_enable_block_step(struct task_struct *task)
352 {
353 BUG(); /* This can never be called. */
354 }
355 #else
356 extern void user_enable_block_step(struct task_struct *);
357 #endif /* arch_has_block_step */
358
359 #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
360 extern void user_single_step_siginfo(struct task_struct *tsk,
361 struct pt_regs *regs, siginfo_t *info);
362 #else
user_single_step_siginfo(struct task_struct * tsk,struct pt_regs * regs,siginfo_t * info)363 static inline void user_single_step_siginfo(struct task_struct *tsk,
364 struct pt_regs *regs, siginfo_t *info)
365 {
366 memset(info, 0, sizeof(*info));
367 info->si_signo = SIGTRAP;
368 }
369 #endif
370
371 #ifndef arch_ptrace_stop_needed
372 /**
373 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
374 * @code: current->exit_code value ptrace will stop with
375 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
376 *
377 * This is called with the siglock held, to decide whether or not it's
378 * necessary to release the siglock and call arch_ptrace_stop() with the
379 * same @code and @info arguments. It can be defined to a constant if
380 * arch_ptrace_stop() is never required, or always is. On machines where
381 * this makes sense, it should be defined to a quick test to optimize out
382 * calling arch_ptrace_stop() when it would be superfluous. For example,
383 * if the thread has not been back to user mode since the last stop, the
384 * thread state might indicate that nothing needs to be done.
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