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Linus Torvalds1da177e2005-04-16 15:20:36 -07001#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
Roland McGrath416bc512006-09-29 02:00:45 -070019#define PTRACE_ATTACH 16
20#define PTRACE_DETACH 17
Linus Torvalds1da177e2005-04-16 15:20:36 -070021
22#define PTRACE_SYSCALL 24
Linus Torvalds1da177e2005-04-16 15:20:36 -070023
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
Suresh Siddha2225a122010-02-11 11:51:00 -080030/*
31 * Generic ptrace interface that exports the architecture specific regsets
32 * using the corresponding NT_* types (which are also used in the core dump).
Suresh Siddhac6a0dd72010-02-22 14:51:32 -080033 * 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.
Suresh Siddha2225a122010-02-11 11:51:00 -080038 *
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
Tejun Heo3544d722011-06-14 11:20:15 +020050#define PTRACE_SEIZE 0x4206
Tejun Heofca26f22011-06-14 11:20:16 +020051#define PTRACE_INTERRUPT 0x4207
Tejun Heo544b2c92011-06-14 11:20:18 +020052#define PTRACE_LISTEN 0x4208
Tejun Heo3544d722011-06-14 11:20:15 +020053
54/* flags in @data for PTRACE_SEIZE */
55#define PTRACE_SEIZE_DEVEL 0x80000000 /* temp flag for development */
56
Linus Torvalds1da177e2005-04-16 15:20:36 -070057/* 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
Tejun Heo3544d722011-06-14 11:20:15 +020075#define PTRACE_EVENT_STOP 7
Linus Torvalds1da177e2005-04-16 15:20:36 -070076
77#include <asm/ptrace.h>
78
79#ifdef __KERNEL__
80/*
81 * Ptrace flags
Eric W. Biederman260ea102006-06-23 02:05:18 -070082 *
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.
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 */
87
Tejun Heo3544d722011-06-14 11:20:15 +020088#define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */
Linus Torvalds1da177e2005-04-16 15:20:36 -070089#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 */
Tejun Heo643ad832011-06-17 16:50:35 +020093
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)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
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. */
Eric Parisd7e75282012-01-03 14:23:06 -0500115#include <linux/err.h> /* for IS_ERR_VALUE */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116
Christoph Hellwig481bed42005-11-07 00:59:47 -0800117
Namhyung Kim9b05a692010-10-27 15:33:47 -0700118extern long arch_ptrace(struct task_struct *child, long request,
119 unsigned long addr, unsigned long data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
121extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122extern void ptrace_disable(struct task_struct *);
Tejun Heo755e2762011-06-02 11:13:59 +0200123extern int ptrace_check_attach(struct task_struct *task, bool ignore_state);
Namhyung Kim4abf9862010-10-27 15:33:45 -0700124extern int ptrace_request(struct task_struct *child, long request,
125 unsigned long addr, unsigned long data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700126extern void ptrace_notify(int exit_code);
127extern void __ptrace_link(struct task_struct *child,
128 struct task_struct *new_parent);
129extern void __ptrace_unlink(struct task_struct *child);
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700130extern void exit_ptrace(struct task_struct *tracer);
Eric Paris69f594a2012-01-03 12:25:15 -0500131#define PTRACE_MODE_READ 0x01
132#define PTRACE_MODE_ATTACH 0x02
133#define PTRACE_MODE_NOAUDIT 0x04
Stephen Smalley006ebb42008-05-19 08:32:49 -0400134/* Returns 0 on success, -errno on denial. */
135extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
136/* Returns true on success, false on denial. */
137extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138
Oleg Nesterov53b6f9f2008-04-30 00:53:13 -0700139static inline int ptrace_reparented(struct task_struct *child)
140{
Oleg Nesterov0347e172011-06-24 17:34:06 +0200141 return !same_thread_group(child->real_parent, child->parent);
Oleg Nesterov53b6f9f2008-04-30 00:53:13 -0700142}
Oleg Nesterovc6a47cc2009-12-15 16:47:15 -0800143
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144static inline void ptrace_unlink(struct task_struct *child)
145{
146 if (unlikely(child->ptrace))
147 __ptrace_unlink(child);
148}
149
Namhyung Kim4abf9862010-10-27 15:33:45 -0700150int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
151 unsigned long data);
152int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
153 unsigned long data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154
Roland McGrath88ac2922008-07-25 19:45:43 -0700155/**
Tejun Heo06d98472011-06-17 16:50:40 +0200156 * 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 */
166static 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/**
Tejun Heo643ad832011-06-17 16:50:35 +0200174 * 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 */
182static inline bool ptrace_event_enabled(struct task_struct *task, int event)
183{
184 return task->ptrace & PT_EVENT_FLAG(event);
185}
186
187/**
Roland McGrath88ac2922008-07-25 19:45:43 -0700188 * ptrace_event - possibly stop for a ptrace event notification
Tejun Heo643ad832011-06-17 16:50:35 +0200189 * @event: %PTRACE_EVENT_* value to report
Roland McGrath88ac2922008-07-25 19:45:43 -0700190 * @message: value for %PTRACE_GETEVENTMSG to return
191 *
Tejun Heo643ad832011-06-17 16:50:35 +0200192 * Check whether @event is enabled and, if so, report @event and @message
193 * to the ptrace parent.
Roland McGrath88ac2922008-07-25 19:45:43 -0700194 *
Roland McGrath88ac2922008-07-25 19:45:43 -0700195 * Called without locks.
196 */
Tejun Heof3c04b92011-06-17 16:50:36 +0200197static inline void ptrace_event(int event, unsigned long message)
Roland McGrath88ac2922008-07-25 19:45:43 -0700198{
Tejun Heof3c04b92011-06-17 16:50:36 +0200199 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 }
Roland McGrath88ac2922008-07-25 19:45:43 -0700206}
207
Roland McGrath09a05392008-07-25 19:45:47 -0700208/**
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 */
218static 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);
Frederic Weisbeckerbf26c012011-04-07 16:53:20 +0200222#ifdef CONFIG_HAVE_HW_BREAKPOINT
223 atomic_set(&child->ptrace_bp_refcnt, 1);
224#endif
Oleg Nesterov6634ae12011-07-08 19:13:39 +0200225 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);
Oleg Nesterovdcace062011-07-08 19:13:54 +0200232
Oleg Nesterovd184d6e2011-07-08 19:14:17 +0200233 if (child->ptrace & PT_SEIZED)
234 task_set_jobctl_pending(child, JOBCTL_TRAP_STOP);
235 else
236 sigaddset(&child->pending.signal, SIGSTOP);
237
Oleg Nesterovdcace062011-07-08 19:13:54 +0200238 set_tsk_thread_flag(child, TIF_SIGPENDING);
Oleg Nesterov6634ae12011-07-08 19:13:39 +0200239 }
Roland McGrath09a05392008-07-25 19:45:47 -0700240}
241
Roland McGrathdae33572008-07-25 19:45:48 -0700242/**
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 */
248static 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
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255#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
Eric Parisd7e75282012-01-03 14:23:06 -0500270#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
Roland McGrathfb7fa8f2008-01-30 13:30:47 +0100279/*
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
Roland McGrathdc802c22008-01-30 13:30:53 +0100305 * next single instruction executes. If arch_has_block_step() is defined,
306 * this must clear the effects of user_enable_block_step() too.
Roland McGrathfb7fa8f2008-01-30 13:30:47 +0100307 */
308static 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 *
Roland McGrathdc802c22008-01-30 13:30:53 +0100317 * 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.
Roland McGrathfb7fa8f2008-01-30 13:30:47 +0100321 */
322static inline void user_disable_single_step(struct task_struct *task)
323{
324}
Christoph Hellwigdacbe412010-03-10 15:22:46 -0800325#else
326extern void user_enable_single_step(struct task_struct *);
327extern void user_disable_single_step(struct task_struct *);
Roland McGrathfb7fa8f2008-01-30 13:30:47 +0100328#endif /* arch_has_single_step */
329
Roland McGrathdc802c22008-01-30 13:30:53 +0100330#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 */
Roland McGrath5b88abb2008-01-30 13:30:53 +0100340#define arch_has_block_step() (0)
Roland McGrathdc802c22008-01-30 13:30:53 +0100341
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 */
351static inline void user_enable_block_step(struct task_struct *task)
352{
353 BUG(); /* This can never be called. */
354}
Christoph Hellwigdacbe412010-03-10 15:22:46 -0800355#else
356extern void user_enable_block_step(struct task_struct *);
Roland McGrathdc802c22008-01-30 13:30:53 +0100357#endif /* arch_has_block_step */
358
Oleg Nesterov85ec7fd2009-12-15 16:47:17 -0800359#ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
360extern void user_single_step_siginfo(struct task_struct *tsk,
361 struct pt_regs *regs, siginfo_t *info);
362#else
363static 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
Roland McGrath1a669c22008-02-06 01:37:37 -0800371#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
Roland McGrathbbc69862008-07-25 19:45:59 -0700406extern 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
Frederic Weisbeckerbf26c012011-04-07 16:53:20 +0200410#ifdef CONFIG_HAVE_HW_BREAKPOINT
411extern int ptrace_get_breakpoints(struct task_struct *tsk);
412extern void ptrace_put_breakpoints(struct task_struct *tsk);
413#else
414static inline void ptrace_put_breakpoints(struct task_struct *tsk) { }
415#endif /* CONFIG_HAVE_HW_BREAKPOINT */
416
417#endif /* __KERNEL */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418
419#endif