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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
Linus Torvalds1da177e2005-04-16 15:20:36 -070050/* options set using PTRACE_SETOPTIONS */
51#define PTRACE_O_TRACESYSGOOD 0x00000001
52#define PTRACE_O_TRACEFORK 0x00000002
53#define PTRACE_O_TRACEVFORK 0x00000004
54#define PTRACE_O_TRACECLONE 0x00000008
55#define PTRACE_O_TRACEEXEC 0x00000010
56#define PTRACE_O_TRACEVFORKDONE 0x00000020
57#define PTRACE_O_TRACEEXIT 0x00000040
58
59#define PTRACE_O_MASK 0x0000007f
60
61/* Wait extended result codes for the above trace options. */
62#define PTRACE_EVENT_FORK 1
63#define PTRACE_EVENT_VFORK 2
64#define PTRACE_EVENT_CLONE 3
65#define PTRACE_EVENT_EXEC 4
66#define PTRACE_EVENT_VFORK_DONE 5
67#define PTRACE_EVENT_EXIT 6
68
69#include <asm/ptrace.h>
70
71#ifdef __KERNEL__
72/*
73 * Ptrace flags
Eric W. Biederman260ea102006-06-23 02:05:18 -070074 *
75 * The owner ship rules for task->ptrace which holds the ptrace
76 * flags is simple. When a task is running it owns it's task->ptrace
77 * flags. When the a task is stopped the ptracer owns task->ptrace.
Linus Torvalds1da177e2005-04-16 15:20:36 -070078 */
79
80#define PT_PTRACED 0x00000001
81#define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
82#define PT_TRACESYSGOOD 0x00000004
83#define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */
84#define PT_TRACE_FORK 0x00000010
85#define PT_TRACE_VFORK 0x00000020
86#define PT_TRACE_CLONE 0x00000040
87#define PT_TRACE_EXEC 0x00000080
88#define PT_TRACE_VFORK_DONE 0x00000100
89#define PT_TRACE_EXIT 0x00000200
Linus Torvalds1da177e2005-04-16 15:20:36 -070090
91#define PT_TRACE_MASK 0x000003f4
92
93/* single stepping state bits (used on ARM and PA-RISC) */
94#define PT_SINGLESTEP_BIT 31
95#define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT)
96#define PT_BLOCKSTEP_BIT 30
97#define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT)
98
99#include <linux/compiler.h> /* For unlikely. */
100#include <linux/sched.h> /* For struct task_struct. */
101
Christoph Hellwig481bed42005-11-07 00:59:47 -0800102
Namhyung Kim9b05a692010-10-27 15:33:47 -0700103extern long arch_ptrace(struct task_struct *child, long request,
104 unsigned long addr, unsigned long data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
106extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107extern void ptrace_disable(struct task_struct *);
108extern int ptrace_check_attach(struct task_struct *task, int kill);
Namhyung Kim4abf9862010-10-27 15:33:45 -0700109extern int ptrace_request(struct task_struct *child, long request,
110 unsigned long addr, unsigned long data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700111extern void ptrace_notify(int exit_code);
112extern void __ptrace_link(struct task_struct *child,
113 struct task_struct *new_parent);
114extern void __ptrace_unlink(struct task_struct *child);
Oleg Nesterov39c626a2009-04-02 16:58:18 -0700115extern void exit_ptrace(struct task_struct *tracer);
Stephen Smalley006ebb42008-05-19 08:32:49 -0400116#define PTRACE_MODE_READ 1
117#define PTRACE_MODE_ATTACH 2
118/* Returns 0 on success, -errno on denial. */
119extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
120/* Returns true on success, false on denial. */
121extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122
Oleg Nesterov53b6f9f2008-04-30 00:53:13 -0700123static inline int ptrace_reparented(struct task_struct *child)
124{
125 return child->real_parent != child->parent;
126}
Oleg Nesterovc6a47cc2009-12-15 16:47:15 -0800127
Linus Torvalds1da177e2005-04-16 15:20:36 -0700128static inline void ptrace_unlink(struct task_struct *child)
129{
130 if (unlikely(child->ptrace))
131 __ptrace_unlink(child);
132}
133
Namhyung Kim4abf9862010-10-27 15:33:45 -0700134int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
135 unsigned long data);
136int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
137 unsigned long data);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700138
Roland McGrath88ac2922008-07-25 19:45:43 -0700139/**
140 * task_ptrace - return %PT_* flags that apply to a task
141 * @task: pointer to &task_struct in question
142 *
143 * Returns the %PT_* flags that apply to @task.
144 */
145static inline int task_ptrace(struct task_struct *task)
146{
147 return task->ptrace;
148}
149
150/**
151 * ptrace_event - possibly stop for a ptrace event notification
152 * @mask: %PT_* bit to check in @current->ptrace
153 * @event: %PTRACE_EVENT_* value to report if @mask is set
154 * @message: value for %PTRACE_GETEVENTMSG to return
155 *
156 * This checks the @mask bit to see if ptrace wants stops for this event.
157 * If so we stop, reporting @event and @message to the ptrace parent.
158 *
159 * Returns nonzero if we did a ptrace notification, zero if not.
160 *
161 * Called without locks.
162 */
163static inline int ptrace_event(int mask, int event, unsigned long message)
164{
165 if (mask && likely(!(current->ptrace & mask)))
166 return 0;
167 current->ptrace_message = message;
168 ptrace_notify((event << 8) | SIGTRAP);
169 return 1;
170}
171
Roland McGrath09a05392008-07-25 19:45:47 -0700172/**
173 * ptrace_init_task - initialize ptrace state for a new child
174 * @child: new child task
175 * @ptrace: true if child should be ptrace'd by parent's tracer
176 *
177 * This is called immediately after adding @child to its parent's children
178 * list. @ptrace is false in the normal case, and true to ptrace @child.
179 *
180 * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
181 */
182static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
183{
184 INIT_LIST_HEAD(&child->ptrace_entry);
185 INIT_LIST_HEAD(&child->ptraced);
186 child->parent = child->real_parent;
187 child->ptrace = 0;
Oleg Nesterovc6a47cc2009-12-15 16:47:15 -0800188 if (unlikely(ptrace) && (current->ptrace & PT_PTRACED)) {
Roland McGrath09a05392008-07-25 19:45:47 -0700189 child->ptrace = current->ptrace;
Oleg Nesterovc6a47cc2009-12-15 16:47:15 -0800190 __ptrace_link(child, current->parent);
Roland McGrath09a05392008-07-25 19:45:47 -0700191 }
192}
193
Roland McGrathdae33572008-07-25 19:45:48 -0700194/**
195 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
196 * @task: task in %EXIT_DEAD state
197 *
198 * Called with write_lock(&tasklist_lock) held.
199 */
200static inline void ptrace_release_task(struct task_struct *task)
201{
202 BUG_ON(!list_empty(&task->ptraced));
203 ptrace_unlink(task);
204 BUG_ON(!list_empty(&task->ptrace_entry));
205}
206
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207#ifndef force_successful_syscall_return
208/*
209 * System call handlers that, upon successful completion, need to return a
210 * negative value should call force_successful_syscall_return() right before
211 * returning. On architectures where the syscall convention provides for a
212 * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
213 * others), this macro can be used to ensure that the error flag will not get
214 * set. On architectures which do not support a separate error flag, the macro
215 * is a no-op and the spurious error condition needs to be filtered out by some
216 * other means (e.g., in user-level, by passing an extra argument to the
217 * syscall handler, or something along those lines).
218 */
219#define force_successful_syscall_return() do { } while (0)
220#endif
221
Roland McGrathfb7fa8f2008-01-30 13:30:47 +0100222/*
223 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
224 *
225 * These do-nothing inlines are used when the arch does not
226 * implement single-step. The kerneldoc comments are here
227 * to document the interface for all arch definitions.
228 */
229
230#ifndef arch_has_single_step
231/**
232 * arch_has_single_step - does this CPU support user-mode single-step?
233 *
234 * If this is defined, then there must be function declarations or
235 * inlines for user_enable_single_step() and user_disable_single_step().
236 * arch_has_single_step() should evaluate to nonzero iff the machine
237 * supports instruction single-step for user mode.
238 * It can be a constant or it can test a CPU feature bit.
239 */
240#define arch_has_single_step() (0)
241
242/**
243 * user_enable_single_step - single-step in user-mode task
244 * @task: either current or a task stopped in %TASK_TRACED
245 *
246 * This can only be called when arch_has_single_step() has returned nonzero.
247 * Set @task so that when it returns to user mode, it will trap after the
Roland McGrathdc802c22008-01-30 13:30:53 +0100248 * next single instruction executes. If arch_has_block_step() is defined,
249 * this must clear the effects of user_enable_block_step() too.
Roland McGrathfb7fa8f2008-01-30 13:30:47 +0100250 */
251static inline void user_enable_single_step(struct task_struct *task)
252{
253 BUG(); /* This can never be called. */
254}
255
256/**
257 * user_disable_single_step - cancel user-mode single-step
258 * @task: either current or a task stopped in %TASK_TRACED
259 *
Roland McGrathdc802c22008-01-30 13:30:53 +0100260 * Clear @task of the effects of user_enable_single_step() and
261 * user_enable_block_step(). This can be called whether or not either
262 * of those was ever called on @task, and even if arch_has_single_step()
263 * returned zero.
Roland McGrathfb7fa8f2008-01-30 13:30:47 +0100264 */
265static inline void user_disable_single_step(struct task_struct *task)
266{
267}
Christoph Hellwigdacbe412010-03-10 15:22:46 -0800268#else
269extern void user_enable_single_step(struct task_struct *);
270extern void user_disable_single_step(struct task_struct *);
Roland McGrathfb7fa8f2008-01-30 13:30:47 +0100271#endif /* arch_has_single_step */
272
Roland McGrathdc802c22008-01-30 13:30:53 +0100273#ifndef arch_has_block_step
274/**
275 * arch_has_block_step - does this CPU support user-mode block-step?
276 *
277 * If this is defined, then there must be a function declaration or inline
278 * for user_enable_block_step(), and arch_has_single_step() must be defined
279 * too. arch_has_block_step() should evaluate to nonzero iff the machine
280 * supports step-until-branch for user mode. It can be a constant or it
281 * can test a CPU feature bit.
282 */
Roland McGrath5b88abb2008-01-30 13:30:53 +0100283#define arch_has_block_step() (0)
Roland McGrathdc802c22008-01-30 13:30:53 +0100284
285/**
286 * user_enable_block_step - step until branch in user-mode task
287 * @task: either current or a task stopped in %TASK_TRACED
288 *
289 * This can only be called when arch_has_block_step() has returned nonzero,
290 * and will never be called when single-instruction stepping is being used.
291 * Set @task so that when it returns to user mode, it will trap after the
292 * next branch or trap taken.
293 */
294static inline void user_enable_block_step(struct task_struct *task)
295{
296 BUG(); /* This can never be called. */
297}
Christoph Hellwigdacbe412010-03-10 15:22:46 -0800298#else
299extern void user_enable_block_step(struct task_struct *);
Roland McGrathdc802c22008-01-30 13:30:53 +0100300#endif /* arch_has_block_step */
301
Oleg Nesterov85ec7fd2009-12-15 16:47:17 -0800302#ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
303extern void user_single_step_siginfo(struct task_struct *tsk,
304 struct pt_regs *regs, siginfo_t *info);
305#else
306static inline void user_single_step_siginfo(struct task_struct *tsk,
307 struct pt_regs *regs, siginfo_t *info)
308{
309 memset(info, 0, sizeof(*info));
310 info->si_signo = SIGTRAP;
311}
312#endif
313
Roland McGrath1a669c22008-02-06 01:37:37 -0800314#ifndef arch_ptrace_stop_needed
315/**
316 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
317 * @code: current->exit_code value ptrace will stop with
318 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
319 *
320 * This is called with the siglock held, to decide whether or not it's
321 * necessary to release the siglock and call arch_ptrace_stop() with the
322 * same @code and @info arguments. It can be defined to a constant if
323 * arch_ptrace_stop() is never required, or always is. On machines where
324 * this makes sense, it should be defined to a quick test to optimize out
325 * calling arch_ptrace_stop() when it would be superfluous. For example,
326 * if the thread has not been back to user mode since the last stop, the
327 * thread state might indicate that nothing needs to be done.
328 */
329#define arch_ptrace_stop_needed(code, info) (0)
330#endif
331
332#ifndef arch_ptrace_stop
333/**
334 * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
335 * @code: current->exit_code value ptrace will stop with
336 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
337 *
338 * This is called with no locks held when arch_ptrace_stop_needed() has
339 * just returned nonzero. It is allowed to block, e.g. for user memory
340 * access. The arch can have machine-specific work to be done before
341 * ptrace stops. On ia64, register backing store gets written back to user
342 * memory here. Since this can be costly (requires dropping the siglock),
343 * we only do it when the arch requires it for this particular stop, as
344 * indicated by arch_ptrace_stop_needed().
345 */
346#define arch_ptrace_stop(code, info) do { } while (0)
347#endif
348
Roland McGrathbbc69862008-07-25 19:45:59 -0700349extern int task_current_syscall(struct task_struct *target, long *callno,
350 unsigned long args[6], unsigned int maxargs,
351 unsigned long *sp, unsigned long *pc);
352
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353#endif
354
355#endif