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1da177e4 LT |
1 | #ifndef _LINUX_PTRACE_H |
2 | #define _LINUX_PTRACE_H | |
1da177e4 | 3 | |
607ca46e DH |
4 | #include <linux/compiler.h> /* For unlikely. */ |
5 | #include <linux/sched.h> /* For struct task_struct. */ | |
6 | #include <linux/err.h> /* for IS_ERR_VALUE */ | |
7 | #include <linux/bug.h> /* For BUG_ON. */ | |
4e52365f | 8 | #include <linux/pid_namespace.h> /* For task_active_pid_ns. */ |
607ca46e | 9 | #include <uapi/linux/ptrace.h> |
1da177e4 | 10 | |
1da177e4 LT |
11 | /* |
12 | * Ptrace flags | |
260ea101 EB |
13 | * |
14 | * The owner ship rules for task->ptrace which holds the ptrace | |
15 | * flags is simple. When a task is running it owns it's task->ptrace | |
16 | * flags. When the a task is stopped the ptracer owns task->ptrace. | |
1da177e4 LT |
17 | */ |
18 | ||
3544d72a | 19 | #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */ |
1da177e4 LT |
20 | #define PT_PTRACED 0x00000001 |
21 | #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ | |
86b6c1f3 | 22 | #define PT_PTRACE_CAP 0x00000004 /* ptracer can follow suid-exec */ |
643ad838 | 23 | |
86b6c1f3 | 24 | #define PT_OPT_FLAG_SHIFT 3 |
643ad838 | 25 | /* PT_TRACE_* event enable flags */ |
86b6c1f3 DV |
26 | #define PT_EVENT_FLAG(event) (1 << (PT_OPT_FLAG_SHIFT + (event))) |
27 | #define PT_TRACESYSGOOD PT_EVENT_FLAG(0) | |
643ad838 TH |
28 | #define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK) |
29 | #define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK) | |
30 | #define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE) | |
31 | #define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC) | |
32 | #define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE) | |
33 | #define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT) | |
fb0fadf9 | 34 | #define PT_TRACE_SECCOMP PT_EVENT_FLAG(PTRACE_EVENT_SECCOMP) |
1da177e4 | 35 | |
992fb6e1 | 36 | #define PT_EXITKILL (PTRACE_O_EXITKILL << PT_OPT_FLAG_SHIFT) |
13c4a901 | 37 | #define PT_SUSPEND_SECCOMP (PTRACE_O_SUSPEND_SECCOMP << PT_OPT_FLAG_SHIFT) |
992fb6e1 | 38 | |
1da177e4 LT |
39 | /* single stepping state bits (used on ARM and PA-RISC) */ |
40 | #define PT_SINGLESTEP_BIT 31 | |
41 | #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT) | |
42 | #define PT_BLOCKSTEP_BIT 30 | |
43 | #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT) | |
44 | ||
9b05a69e NK |
45 | extern long arch_ptrace(struct task_struct *child, long request, |
46 | unsigned long addr, unsigned long data); | |
1da177e4 LT |
47 | extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len); |
48 | extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len); | |
1da177e4 | 49 | extern void ptrace_disable(struct task_struct *); |
4abf9869 NK |
50 | extern int ptrace_request(struct task_struct *child, long request, |
51 | unsigned long addr, unsigned long data); | |
1da177e4 LT |
52 | extern void ptrace_notify(int exit_code); |
53 | extern void __ptrace_link(struct task_struct *child, | |
54 | struct task_struct *new_parent); | |
55 | extern void __ptrace_unlink(struct task_struct *child); | |
7c8bd232 | 56 | extern void exit_ptrace(struct task_struct *tracer, struct list_head *dead); |
69f594a3 EP |
57 | #define PTRACE_MODE_READ 0x01 |
58 | #define PTRACE_MODE_ATTACH 0x02 | |
59 | #define PTRACE_MODE_NOAUDIT 0x04 | |
caaee623 JH |
60 | #define PTRACE_MODE_FSCREDS 0x08 |
61 | #define PTRACE_MODE_REALCREDS 0x10 | |
62 | ||
63 | /* shorthands for READ/ATTACH and FSCREDS/REALCREDS combinations */ | |
64 | #define PTRACE_MODE_READ_FSCREDS (PTRACE_MODE_READ | PTRACE_MODE_FSCREDS) | |
65 | #define PTRACE_MODE_READ_REALCREDS (PTRACE_MODE_READ | PTRACE_MODE_REALCREDS) | |
66 | #define PTRACE_MODE_ATTACH_FSCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_FSCREDS) | |
67 | #define PTRACE_MODE_ATTACH_REALCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_REALCREDS) | |
68 | ||
69 | /** | |
70 | * ptrace_may_access - check whether the caller is permitted to access | |
71 | * a target task. | |
72 | * @task: target task | |
73 | * @mode: selects type of access and caller credentials | |
74 | * | |
75 | * Returns true on success, false on denial. | |
76 | * | |
77 | * One of the flags PTRACE_MODE_FSCREDS and PTRACE_MODE_REALCREDS must | |
78 | * be set in @mode to specify whether the access was requested through | |
79 | * a filesystem syscall (should use effective capabilities and fsuid | |
80 | * of the caller) or through an explicit syscall such as | |
81 | * process_vm_writev or ptrace (and should use the real credentials). | |
82 | */ | |
006ebb40 | 83 | extern bool ptrace_may_access(struct task_struct *task, unsigned int mode); |
1da177e4 | 84 | |
53b6f9fb ON |
85 | static inline int ptrace_reparented(struct task_struct *child) |
86 | { | |
0347e177 | 87 | return !same_thread_group(child->real_parent, child->parent); |
53b6f9fb | 88 | } |
c6a47cc2 | 89 | |
1da177e4 LT |
90 | static inline void ptrace_unlink(struct task_struct *child) |
91 | { | |
92 | if (unlikely(child->ptrace)) | |
93 | __ptrace_unlink(child); | |
94 | } | |
95 | ||
4abf9869 NK |
96 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
97 | unsigned long data); | |
98 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, | |
99 | unsigned long data); | |
1da177e4 | 100 | |
06d98473 TH |
101 | /** |
102 | * ptrace_parent - return the task that is tracing the given task | |
103 | * @task: task to consider | |
104 | * | |
105 | * Returns %NULL if no one is tracing @task, or the &struct task_struct | |
106 | * pointer to its tracer. | |
107 | * | |
108 | * Must called under rcu_read_lock(). The pointer returned might be kept | |
109 | * live only by RCU. During exec, this may be called with task_lock() held | |
110 | * on @task, still held from when check_unsafe_exec() was called. | |
111 | */ | |
112 | static inline struct task_struct *ptrace_parent(struct task_struct *task) | |
113 | { | |
114 | if (unlikely(task->ptrace)) | |
115 | return rcu_dereference(task->parent); | |
116 | return NULL; | |
117 | } | |
118 | ||
643ad838 TH |
119 | /** |
120 | * ptrace_event_enabled - test whether a ptrace event is enabled | |
121 | * @task: ptracee of interest | |
122 | * @event: %PTRACE_EVENT_* to test | |
123 | * | |
124 | * Test whether @event is enabled for ptracee @task. | |
125 | * | |
126 | * Returns %true if @event is enabled, %false otherwise. | |
127 | */ | |
128 | static inline bool ptrace_event_enabled(struct task_struct *task, int event) | |
129 | { | |
130 | return task->ptrace & PT_EVENT_FLAG(event); | |
131 | } | |
132 | ||
88ac2921 RM |
133 | /** |
134 | * ptrace_event - possibly stop for a ptrace event notification | |
643ad838 | 135 | * @event: %PTRACE_EVENT_* value to report |
88ac2921 RM |
136 | * @message: value for %PTRACE_GETEVENTMSG to return |
137 | * | |
643ad838 TH |
138 | * Check whether @event is enabled and, if so, report @event and @message |
139 | * to the ptrace parent. | |
88ac2921 | 140 | * |
88ac2921 RM |
141 | * Called without locks. |
142 | */ | |
f3c04b93 | 143 | static inline void ptrace_event(int event, unsigned long message) |
88ac2921 | 144 | { |
f3c04b93 TH |
145 | if (unlikely(ptrace_event_enabled(current, event))) { |
146 | current->ptrace_message = message; | |
147 | ptrace_notify((event << 8) | SIGTRAP); | |
b1845ff5 | 148 | } else if (event == PTRACE_EVENT_EXEC) { |
f3c04b93 | 149 | /* legacy EXEC report via SIGTRAP */ |
b1845ff5 ON |
150 | if ((current->ptrace & (PT_PTRACED|PT_SEIZED)) == PT_PTRACED) |
151 | send_sig(SIGTRAP, current, 0); | |
f3c04b93 | 152 | } |
88ac2921 RM |
153 | } |
154 | ||
4e52365f MD |
155 | /** |
156 | * ptrace_event_pid - possibly stop for a ptrace event notification | |
157 | * @event: %PTRACE_EVENT_* value to report | |
158 | * @pid: process identifier for %PTRACE_GETEVENTMSG to return | |
159 | * | |
160 | * Check whether @event is enabled and, if so, report @event and @pid | |
161 | * to the ptrace parent. @pid is reported as the pid_t seen from the | |
162 | * the ptrace parent's pid namespace. | |
163 | * | |
164 | * Called without locks. | |
165 | */ | |
166 | static inline void ptrace_event_pid(int event, struct pid *pid) | |
167 | { | |
168 | /* | |
169 | * FIXME: There's a potential race if a ptracer in a different pid | |
170 | * namespace than parent attaches between computing message below and | |
171 | * when we acquire tasklist_lock in ptrace_stop(). If this happens, | |
172 | * the ptracer will get a bogus pid from PTRACE_GETEVENTMSG. | |
173 | */ | |
174 | unsigned long message = 0; | |
175 | struct pid_namespace *ns; | |
176 | ||
177 | rcu_read_lock(); | |
178 | ns = task_active_pid_ns(rcu_dereference(current->parent)); | |
179 | if (ns) | |
180 | message = pid_nr_ns(pid, ns); | |
181 | rcu_read_unlock(); | |
182 | ||
183 | ptrace_event(event, message); | |
184 | } | |
185 | ||
09a05394 RM |
186 | /** |
187 | * ptrace_init_task - initialize ptrace state for a new child | |
188 | * @child: new child task | |
189 | * @ptrace: true if child should be ptrace'd by parent's tracer | |
190 | * | |
191 | * This is called immediately after adding @child to its parent's children | |
192 | * list. @ptrace is false in the normal case, and true to ptrace @child. | |
193 | * | |
194 | * Called with current's siglock and write_lock_irq(&tasklist_lock) held. | |
195 | */ | |
196 | static inline void ptrace_init_task(struct task_struct *child, bool ptrace) | |
197 | { | |
198 | INIT_LIST_HEAD(&child->ptrace_entry); | |
199 | INIT_LIST_HEAD(&child->ptraced); | |
6634ae10 | 200 | child->jobctl = 0; |
09a05394 | 201 | child->ptrace = 0; |
6634ae10 ON |
202 | child->parent = child->real_parent; |
203 | ||
204 | if (unlikely(ptrace) && current->ptrace) { | |
09a05394 | 205 | child->ptrace = current->ptrace; |
c6a47cc2 | 206 | __ptrace_link(child, current->parent); |
dcace06c | 207 | |
d184d6eb ON |
208 | if (child->ptrace & PT_SEIZED) |
209 | task_set_jobctl_pending(child, JOBCTL_TRAP_STOP); | |
210 | else | |
211 | sigaddset(&child->pending.signal, SIGSTOP); | |
212 | ||
dcace06c | 213 | set_tsk_thread_flag(child, TIF_SIGPENDING); |
09a05394 RM |
214 | } |
215 | } | |
216 | ||
dae33574 RM |
217 | /** |
218 | * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped | |
219 | * @task: task in %EXIT_DEAD state | |
220 | * | |
221 | * Called with write_lock(&tasklist_lock) held. | |
222 | */ | |
223 | static inline void ptrace_release_task(struct task_struct *task) | |
224 | { | |
225 | BUG_ON(!list_empty(&task->ptraced)); | |
226 | ptrace_unlink(task); | |
227 | BUG_ON(!list_empty(&task->ptrace_entry)); | |
228 | } | |
229 | ||
1da177e4 LT |
230 | #ifndef force_successful_syscall_return |
231 | /* | |
232 | * System call handlers that, upon successful completion, need to return a | |
233 | * negative value should call force_successful_syscall_return() right before | |
234 | * returning. On architectures where the syscall convention provides for a | |
235 | * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly | |
236 | * others), this macro can be used to ensure that the error flag will not get | |
237 | * set. On architectures which do not support a separate error flag, the macro | |
238 | * is a no-op and the spurious error condition needs to be filtered out by some | |
239 | * other means (e.g., in user-level, by passing an extra argument to the | |
240 | * syscall handler, or something along those lines). | |
241 | */ | |
242 | #define force_successful_syscall_return() do { } while (0) | |
243 | #endif | |
244 | ||
d7e7528b EP |
245 | #ifndef is_syscall_success |
246 | /* | |
247 | * On most systems we can tell if a syscall is a success based on if the retval | |
248 | * is an error value. On some systems like ia64 and powerpc they have different | |
249 | * indicators of success/failure and must define their own. | |
250 | */ | |
251 | #define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs)))) | |
252 | #endif | |
253 | ||
fb7fa8f1 RM |
254 | /* |
255 | * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__. | |
256 | * | |
257 | * These do-nothing inlines are used when the arch does not | |
258 | * implement single-step. The kerneldoc comments are here | |
259 | * to document the interface for all arch definitions. | |
260 | */ | |
261 | ||
262 | #ifndef arch_has_single_step | |
263 | /** | |
264 | * arch_has_single_step - does this CPU support user-mode single-step? | |
265 | * | |
266 | * If this is defined, then there must be function declarations or | |
267 | * inlines for user_enable_single_step() and user_disable_single_step(). | |
268 | * arch_has_single_step() should evaluate to nonzero iff the machine | |
269 | * supports instruction single-step for user mode. | |
270 | * It can be a constant or it can test a CPU feature bit. | |
271 | */ | |
272 | #define arch_has_single_step() (0) | |
273 | ||
274 | /** | |
275 | * user_enable_single_step - single-step in user-mode task | |
276 | * @task: either current or a task stopped in %TASK_TRACED | |
277 | * | |
278 | * This can only be called when arch_has_single_step() has returned nonzero. | |
279 | * Set @task so that when it returns to user mode, it will trap after the | |
dc802c2d RM |
280 | * next single instruction executes. If arch_has_block_step() is defined, |
281 | * this must clear the effects of user_enable_block_step() too. | |
fb7fa8f1 RM |
282 | */ |
283 | static inline void user_enable_single_step(struct task_struct *task) | |
284 | { | |
285 | BUG(); /* This can never be called. */ | |
286 | } | |
287 | ||
288 | /** | |
289 | * user_disable_single_step - cancel user-mode single-step | |
290 | * @task: either current or a task stopped in %TASK_TRACED | |
291 | * | |
dc802c2d RM |
292 | * Clear @task of the effects of user_enable_single_step() and |
293 | * user_enable_block_step(). This can be called whether or not either | |
294 | * of those was ever called on @task, and even if arch_has_single_step() | |
295 | * returned zero. | |
fb7fa8f1 RM |
296 | */ |
297 | static inline void user_disable_single_step(struct task_struct *task) | |
298 | { | |
299 | } | |
dacbe41f CH |
300 | #else |
301 | extern void user_enable_single_step(struct task_struct *); | |
302 | extern void user_disable_single_step(struct task_struct *); | |
fb7fa8f1 RM |
303 | #endif /* arch_has_single_step */ |
304 | ||
dc802c2d RM |
305 | #ifndef arch_has_block_step |
306 | /** | |
307 | * arch_has_block_step - does this CPU support user-mode block-step? | |
308 | * | |
309 | * If this is defined, then there must be a function declaration or inline | |
310 | * for user_enable_block_step(), and arch_has_single_step() must be defined | |
311 | * too. arch_has_block_step() should evaluate to nonzero iff the machine | |
312 | * supports step-until-branch for user mode. It can be a constant or it | |
313 | * can test a CPU feature bit. | |
314 | */ | |
5b88abbf | 315 | #define arch_has_block_step() (0) |
dc802c2d RM |
316 | |
317 | /** | |
318 | * user_enable_block_step - step until branch in user-mode task | |
319 | * @task: either current or a task stopped in %TASK_TRACED | |
320 | * | |
321 | * This can only be called when arch_has_block_step() has returned nonzero, | |
322 | * and will never be called when single-instruction stepping is being used. | |
323 | * Set @task so that when it returns to user mode, it will trap after the | |
324 | * next branch or trap taken. | |
325 | */ | |
326 | static inline void user_enable_block_step(struct task_struct *task) | |
327 | { | |
328 | BUG(); /* This can never be called. */ | |
329 | } | |
dacbe41f CH |
330 | #else |
331 | extern void user_enable_block_step(struct task_struct *); | |
dc802c2d RM |
332 | #endif /* arch_has_block_step */ |
333 | ||
85ec7fd9 ON |
334 | #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO |
335 | extern void user_single_step_siginfo(struct task_struct *tsk, | |
336 | struct pt_regs *regs, siginfo_t *info); | |
337 | #else | |
338 | static inline void user_single_step_siginfo(struct task_struct *tsk, | |
339 | struct pt_regs *regs, siginfo_t *info) | |
340 | { | |
341 | memset(info, 0, sizeof(*info)); | |
342 | info->si_signo = SIGTRAP; | |
343 | } | |
344 | #endif | |
345 | ||
1a669c2f RM |
346 | #ifndef arch_ptrace_stop_needed |
347 | /** | |
348 | * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called | |
349 | * @code: current->exit_code value ptrace will stop with | |
350 | * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with | |
351 | * | |
352 | * This is called with the siglock held, to decide whether or not it's | |
353 | * necessary to release the siglock and call arch_ptrace_stop() with the | |
354 | * same @code and @info arguments. It can be defined to a constant if | |
355 | * arch_ptrace_stop() is never required, or always is. On machines where | |
356 | * this makes sense, it should be defined to a quick test to optimize out | |
357 | * calling arch_ptrace_stop() when it would be superfluous. For example, | |
358 | * if the thread has not been back to user mode since the last stop, the | |
359 | * thread state might indicate that nothing needs to be done. | |
b9cd18de TH |
360 | * |
361 | * This is guaranteed to be invoked once before a task stops for ptrace and | |
362 | * may include arch-specific operations necessary prior to a ptrace stop. | |
1a669c2f RM |
363 | */ |
364 | #define arch_ptrace_stop_needed(code, info) (0) | |
365 | #endif | |
366 | ||
367 | #ifndef arch_ptrace_stop | |
368 | /** | |
369 | * arch_ptrace_stop - Do machine-specific work before stopping for ptrace | |
370 | * @code: current->exit_code value ptrace will stop with | |
371 | * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with | |
372 | * | |
373 | * This is called with no locks held when arch_ptrace_stop_needed() has | |
374 | * just returned nonzero. It is allowed to block, e.g. for user memory | |
375 | * access. The arch can have machine-specific work to be done before | |
376 | * ptrace stops. On ia64, register backing store gets written back to user | |
377 | * memory here. Since this can be costly (requires dropping the siglock), | |
378 | * we only do it when the arch requires it for this particular stop, as | |
379 | * indicated by arch_ptrace_stop_needed(). | |
380 | */ | |
381 | #define arch_ptrace_stop(code, info) do { } while (0) | |
382 | #endif | |
383 | ||
a3460a59 AV |
384 | #ifndef current_pt_regs |
385 | #define current_pt_regs() task_pt_regs(current) | |
386 | #endif | |
387 | ||
4f4202fe | 388 | #ifndef ptrace_signal_deliver |
b7f9591c | 389 | #define ptrace_signal_deliver() ((void)0) |
4f4202fe AV |
390 | #endif |
391 | ||
22062a96 AV |
392 | /* |
393 | * unlike current_pt_regs(), this one is equal to task_pt_regs(current) | |
394 | * on *all* architectures; the only reason to have a per-arch definition | |
395 | * is optimisation. | |
396 | */ | |
397 | #ifndef signal_pt_regs | |
398 | #define signal_pt_regs() task_pt_regs(current) | |
399 | #endif | |
400 | ||
1ca97bb5 AV |
401 | #ifndef current_user_stack_pointer |
402 | #define current_user_stack_pointer() user_stack_pointer(current_pt_regs()) | |
403 | #endif | |
404 | ||
bbc69863 RM |
405 | extern int task_current_syscall(struct task_struct *target, long *callno, |
406 | unsigned long args[6], unsigned int maxargs, | |
407 | unsigned long *sp, unsigned long *pc); | |
408 | ||
1da177e4 | 409 | #endif |