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 /* 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
74 *
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.
78 */
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
90
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
102
103 extern long arch_ptrace(struct task_struct *child, long request,
104 unsigned long addr, unsigned long data);
105 extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
106 extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
107 extern void ptrace_disable(struct task_struct *);
108 extern int ptrace_check_attach(struct task_struct *task, int kill);
109 extern int ptrace_request(struct task_struct *child, long request,
110 unsigned long addr, unsigned long data);
111 extern void ptrace_notify(int exit_code);
112 extern void __ptrace_link(struct task_struct *child,
113 struct task_struct *new_parent);
114 extern void __ptrace_unlink(struct task_struct *child);
115 extern void exit_ptrace(struct task_struct *tracer);
116 #define PTRACE_MODE_READ 1
117 #define PTRACE_MODE_ATTACH 2
118 /* Returns 0 on success, -errno on denial. */
119 extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
120 /* Returns true on success, false on denial. */
121 extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
122
ptrace_reparented(struct task_struct * child)123 static inline int ptrace_reparented(struct task_struct *child)
124 {
125 return child->real_parent != child->parent;
126 }
127
ptrace_unlink(struct task_struct * child)128 static inline void ptrace_unlink(struct task_struct *child)
129 {
130 if (unlikely(child->ptrace))
131 __ptrace_unlink(child);
132 }
133
134 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
135 unsigned long data);
136 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
137 unsigned long data);
138
139 /**
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 */
task_ptrace(struct task_struct * task)145 static 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 */
ptrace_event(int mask,int event,unsigned long message)163 static 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
172 /**
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 */
ptrace_init_task(struct task_struct * child,bool ptrace)182 static 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;
188 if (unlikely(ptrace) && (current->ptrace & PT_PTRACED)) {
189 child->ptrace = current->ptrace;
190 __ptrace_link(child, current->parent);
191 }
192
193 #ifdef CONFIG_HAVE_HW_BREAKPOINT
194 atomic_set(&child->ptrace_bp_refcnt, 1);
195 #endif
196 }
197
198 /**
199 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
200 * @task: task in %EXIT_DEAD state
201 *
202 * Called with write_lock(&tasklist_lock) held.
203 */
ptrace_release_task(struct task_struct * task)204 static inline void ptrace_release_task(struct task_struct *task)
205 {
206 BUG_ON(!list_empty(&task->ptraced));
207 ptrace_unlink(task);
208 BUG_ON(!list_empty(&task->ptrace_entry));
209 }
210
211 #ifndef force_successful_syscall_return
212 /*
213 * System call handlers that, upon successful completion, need to return a
214 * negative value should call force_successful_syscall_return() right before
215 * returning. On architectures where the syscall convention provides for a
216 * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
217 * others), this macro can be used to ensure that the error flag will not get
218 * set. On architectures which do not support a separate error flag, the macro
219 * is a no-op and the spurious error condition needs to be filtered out by some
220 * other means (e.g., in user-level, by passing an extra argument to the
221 * syscall handler, or something along those lines).
222 */
223 #define force_successful_syscall_return() do { } while (0)
224 #endif
225
226 /*
227 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
228 *
229 * These do-nothing inlines are used when the arch does not
230 * implement single-step. The kerneldoc comments are here
231 * to document the interface for all arch definitions.
232 */
233
234 #ifndef arch_has_single_step
235 /**
236 * arch_has_single_step - does this CPU support user-mode single-step?
237 *
238 * If this is defined, then there must be function declarations or
239 * inlines for user_enable_single_step() and user_disable_single_step().
240 * arch_has_single_step() should evaluate to nonzero iff the machine
241 * supports instruction single-step for user mode.
242 * It can be a constant or it can test a CPU feature bit.
243 */
244 #define arch_has_single_step() (0)
245
246 /**
247 * user_enable_single_step - single-step in user-mode task
248 * @task: either current or a task stopped in %TASK_TRACED
249 *
250 * This can only be called when arch_has_single_step() has returned nonzero.
251 * Set @task so that when it returns to user mode, it will trap after the
252 * next single instruction executes. If arch_has_block_step() is defined,
253 * this must clear the effects of user_enable_block_step() too.
254 */
user_enable_single_step(struct task_struct * task)255 static inline void user_enable_single_step(struct task_struct *task)
256 {
257 BUG(); /* This can never be called. */
258 }
259
260 /**
261 * user_disable_single_step - cancel user-mode single-step
262 * @task: either current or a task stopped in %TASK_TRACED
263 *
264 * Clear @task of the effects of user_enable_single_step() and
265 * user_enable_block_step(). This can be called whether or not either
266 * of those was ever called on @task, and even if arch_has_single_step()
267 * returned zero.
268 */
user_disable_single_step(struct task_struct * task)269 static inline void user_disable_single_step(struct task_struct *task)
270 {
271 }
272 #else
273 extern void user_enable_single_step(struct task_struct *);
274 extern void user_disable_single_step(struct task_struct *);
275 #endif /* arch_has_single_step */
276
277 #ifndef arch_has_block_step
278 /**
279 * arch_has_block_step - does this CPU support user-mode block-step?
280 *
281 * If this is defined, then there must be a function declaration or inline
282 * for user_enable_block_step(), and arch_has_single_step() must be defined
283 * too. arch_has_block_step() should evaluate to nonzero iff the machine
284 * supports step-until-branch for user mode. It can be a constant or it
285 * can test a CPU feature bit.
286 */
287 #define arch_has_block_step() (0)
288
289 /**
290 * user_enable_block_step - step until branch in user-mode task
291 * @task: either current or a task stopped in %TASK_TRACED
292 *
293 * This can only be called when arch_has_block_step() has returned nonzero,
294 * and will never be called when single-instruction stepping is being used.
295 * Set @task so that when it returns to user mode, it will trap after the
296 * next branch or trap taken.
297 */
user_enable_block_step(struct task_struct * task)298 static inline void user_enable_block_step(struct task_struct *task)
299 {
300 BUG(); /* This can never be called. */
301 }
302 #else
303 extern void user_enable_block_step(struct task_struct *);
304 #endif /* arch_has_block_step */
305
306 #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
307 extern void user_single_step_siginfo(struct task_struct *tsk,
308 struct pt_regs *regs, siginfo_t *info);
309 #else
user_single_step_siginfo(struct task_struct * tsk,struct pt_regs * regs,siginfo_t * info)310 static inline void user_single_step_siginfo(struct task_struct *tsk,
311 struct pt_regs *regs, siginfo_t *info)
312 {
313 memset(info, 0, sizeof(*info));
314 info->si_signo = SIGTRAP;
315 }
316 #endif
317
318 #ifndef arch_ptrace_stop_needed
319 /**
320 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
321 * @code: current->exit_code value ptrace will stop with
322 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
323 *
324 * This is called with the siglock held, to decide whether or not it's
325 * necessary to release the siglock and call arch_ptrace_stop() with the
326 * same @code and @info arguments. It can be defined to a constant if
327 * arch_ptrace_stop() is never required, or always is. On machines where
328 * this makes sense, it should be defined to a quick test to optimize out
329 * calling arch_ptrace_stop() when it would be superfluous. For example,
330 * if the thread has not been back to user mode since the last stop, the
331 * thread state might indicate that nothing needs to be done.
332 */
333 #define arch_ptrace_stop_needed(code, info) (0)
334 #endif
335
336 #ifndef arch_ptrace_stop
337 /**
338 * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
339 * @code: current->exit_code value ptrace will stop with
340 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
341 *
342 * This is called with no locks held when arch_ptrace_stop_needed() has
343 * just returned nonzero. It is allowed to block, e.g. for user memory
344 * access. The arch can have machine-specific work to be done before
345 * ptrace stops. On ia64, register backing store gets written back to user
346 * memory here. Since this can be costly (requires dropping the siglock),
347 * we only do it when the arch requires it for this particular stop, as
348 * indicated by arch_ptrace_stop_needed().
349 */
350 #define arch_ptrace_stop(code, info) do { } while (0)
351 #endif
352
353 extern int task_current_syscall(struct task_struct *target, long *callno,
354 unsigned long args[6], unsigned int maxargs,
355 unsigned long *sp, unsigned long *pc);
356
357 #ifdef CONFIG_HAVE_HW_BREAKPOINT
358 extern int ptrace_get_breakpoints(struct task_struct *tsk);
359 extern void ptrace_put_breakpoints(struct task_struct *tsk);
360 #else
ptrace_put_breakpoints(struct task_struct * tsk)361 static inline void ptrace_put_breakpoints(struct task_struct *tsk) { }
362 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
363
364 #endif /* __KERNEL */
365
366 #endif
367