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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
1da177e4 LT |
2 | #ifndef _LINUX_PTRACE_H |
3 | #define _LINUX_PTRACE_H | |
1da177e4 | 4 | |
607ca46e DH |
5 | #include <linux/compiler.h> /* For unlikely. */ |
6 | #include <linux/sched.h> /* For struct task_struct. */ | |
3f07c014 | 7 | #include <linux/sched/signal.h> /* For send_sig(), same_thread_group(), etc. */ |
607ca46e DH |
8 | #include <linux/err.h> /* for IS_ERR_VALUE */ |
9 | #include <linux/bug.h> /* For BUG_ON. */ | |
4e52365f | 10 | #include <linux/pid_namespace.h> /* For task_active_pid_ns. */ |
607ca46e | 11 | #include <uapi/linux/ptrace.h> |
1da177e4 | 12 | |
84d77d3f EB |
13 | extern int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, |
14 | void *buf, int len, unsigned int gup_flags); | |
15 | ||
1da177e4 LT |
16 | /* |
17 | * Ptrace flags | |
260ea101 EB |
18 | * |
19 | * The owner ship rules for task->ptrace which holds the ptrace | |
20 | * flags is simple. When a task is running it owns it's task->ptrace | |
21 | * flags. When the a task is stopped the ptracer owns task->ptrace. | |
1da177e4 LT |
22 | */ |
23 | ||
3544d72a | 24 | #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */ |
1da177e4 LT |
25 | #define PT_PTRACED 0x00000001 |
26 | #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ | |
643ad838 | 27 | |
86b6c1f3 | 28 | #define PT_OPT_FLAG_SHIFT 3 |
643ad838 | 29 | /* PT_TRACE_* event enable flags */ |
86b6c1f3 DV |
30 | #define PT_EVENT_FLAG(event) (1 << (PT_OPT_FLAG_SHIFT + (event))) |
31 | #define PT_TRACESYSGOOD PT_EVENT_FLAG(0) | |
643ad838 TH |
32 | #define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK) |
33 | #define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK) | |
34 | #define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE) | |
35 | #define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC) | |
36 | #define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE) | |
37 | #define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT) | |
fb0fadf9 | 38 | #define PT_TRACE_SECCOMP PT_EVENT_FLAG(PTRACE_EVENT_SECCOMP) |
1da177e4 | 39 | |
992fb6e1 | 40 | #define PT_EXITKILL (PTRACE_O_EXITKILL << PT_OPT_FLAG_SHIFT) |
13c4a901 | 41 | #define PT_SUSPEND_SECCOMP (PTRACE_O_SUSPEND_SECCOMP << PT_OPT_FLAG_SHIFT) |
992fb6e1 | 42 | |
1da177e4 LT |
43 | /* single stepping state bits (used on ARM and PA-RISC) */ |
44 | #define PT_SINGLESTEP_BIT 31 | |
45 | #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT) | |
46 | #define PT_BLOCKSTEP_BIT 30 | |
47 | #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT) | |
48 | ||
9b05a69e NK |
49 | extern long arch_ptrace(struct task_struct *child, long request, |
50 | unsigned long addr, unsigned long data); | |
1da177e4 LT |
51 | extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len); |
52 | extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len); | |
1da177e4 | 53 | extern void ptrace_disable(struct task_struct *); |
4abf9869 NK |
54 | extern int ptrace_request(struct task_struct *child, long request, |
55 | unsigned long addr, unsigned long data); | |
1da177e4 LT |
56 | extern void ptrace_notify(int exit_code); |
57 | extern void __ptrace_link(struct task_struct *child, | |
c70d9d80 EB |
58 | struct task_struct *new_parent, |
59 | const struct cred *ptracer_cred); | |
1da177e4 | 60 | extern void __ptrace_unlink(struct task_struct *child); |
7c8bd232 | 61 | extern void exit_ptrace(struct task_struct *tracer, struct list_head *dead); |
69f594a3 EP |
62 | #define PTRACE_MODE_READ 0x01 |
63 | #define PTRACE_MODE_ATTACH 0x02 | |
64 | #define PTRACE_MODE_NOAUDIT 0x04 | |
dbfe2953 JK |
65 | #define PTRACE_MODE_FSCREDS 0x08 |
66 | #define PTRACE_MODE_REALCREDS 0x10 | |
67 | #define PTRACE_MODE_SCHED 0x20 | |
68 | #define PTRACE_MODE_IBPB 0x40 | |
caaee623 JH |
69 | |
70 | /* shorthands for READ/ATTACH and FSCREDS/REALCREDS combinations */ | |
71 | #define PTRACE_MODE_READ_FSCREDS (PTRACE_MODE_READ | PTRACE_MODE_FSCREDS) | |
72 | #define PTRACE_MODE_READ_REALCREDS (PTRACE_MODE_READ | PTRACE_MODE_REALCREDS) | |
73 | #define PTRACE_MODE_ATTACH_FSCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_FSCREDS) | |
74 | #define PTRACE_MODE_ATTACH_REALCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_REALCREDS) | |
dbfe2953 | 75 | #define PTRACE_MODE_SPEC_IBPB (PTRACE_MODE_ATTACH_REALCREDS | PTRACE_MODE_IBPB) |
caaee623 JH |
76 | |
77 | /** | |
78 | * ptrace_may_access - check whether the caller is permitted to access | |
79 | * a target task. | |
80 | * @task: target task | |
81 | * @mode: selects type of access and caller credentials | |
82 | * | |
83 | * Returns true on success, false on denial. | |
84 | * | |
85 | * One of the flags PTRACE_MODE_FSCREDS and PTRACE_MODE_REALCREDS must | |
86 | * be set in @mode to specify whether the access was requested through | |
87 | * a filesystem syscall (should use effective capabilities and fsuid | |
88 | * of the caller) or through an explicit syscall such as | |
89 | * process_vm_writev or ptrace (and should use the real credentials). | |
90 | */ | |
006ebb40 | 91 | extern bool ptrace_may_access(struct task_struct *task, unsigned int mode); |
1da177e4 | 92 | |
dbfe2953 JK |
93 | /** |
94 | * ptrace_may_access - check whether the caller is permitted to access | |
95 | * a target task. | |
96 | * @task: target task | |
97 | * @mode: selects type of access and caller credentials | |
98 | * | |
99 | * Returns true on success, false on denial. | |
100 | * | |
101 | * Similar to ptrace_may_access(). Only to be called from context switch | |
102 | * code. Does not call into audit and the regular LSM hooks due to locking | |
103 | * constraints. | |
104 | */ | |
105 | extern bool ptrace_may_access_sched(struct task_struct *task, unsigned int mode); | |
106 | ||
53b6f9fb ON |
107 | static inline int ptrace_reparented(struct task_struct *child) |
108 | { | |
0347e177 | 109 | return !same_thread_group(child->real_parent, child->parent); |
53b6f9fb | 110 | } |
c6a47cc2 | 111 | |
1da177e4 LT |
112 | static inline void ptrace_unlink(struct task_struct *child) |
113 | { | |
114 | if (unlikely(child->ptrace)) | |
115 | __ptrace_unlink(child); | |
116 | } | |
117 | ||
4abf9869 NK |
118 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
119 | unsigned long data); | |
120 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, | |
121 | unsigned long data); | |
1da177e4 | 122 | |
06d98473 TH |
123 | /** |
124 | * ptrace_parent - return the task that is tracing the given task | |
125 | * @task: task to consider | |
126 | * | |
127 | * Returns %NULL if no one is tracing @task, or the &struct task_struct | |
128 | * pointer to its tracer. | |
129 | * | |
130 | * Must called under rcu_read_lock(). The pointer returned might be kept | |
131 | * live only by RCU. During exec, this may be called with task_lock() held | |
132 | * on @task, still held from when check_unsafe_exec() was called. | |
133 | */ | |
134 | static inline struct task_struct *ptrace_parent(struct task_struct *task) | |
135 | { | |
136 | if (unlikely(task->ptrace)) | |
137 | return rcu_dereference(task->parent); | |
138 | return NULL; | |
139 | } | |
140 | ||
643ad838 TH |
141 | /** |
142 | * ptrace_event_enabled - test whether a ptrace event is enabled | |
143 | * @task: ptracee of interest | |
144 | * @event: %PTRACE_EVENT_* to test | |
145 | * | |
146 | * Test whether @event is enabled for ptracee @task. | |
147 | * | |
148 | * Returns %true if @event is enabled, %false otherwise. | |
149 | */ | |
150 | static inline bool ptrace_event_enabled(struct task_struct *task, int event) | |
151 | { | |
152 | return task->ptrace & PT_EVENT_FLAG(event); | |
153 | } | |
154 | ||
88ac2921 RM |
155 | /** |
156 | * ptrace_event - possibly stop for a ptrace event notification | |
643ad838 | 157 | * @event: %PTRACE_EVENT_* value to report |
88ac2921 RM |
158 | * @message: value for %PTRACE_GETEVENTMSG to return |
159 | * | |
643ad838 TH |
160 | * Check whether @event is enabled and, if so, report @event and @message |
161 | * to the ptrace parent. | |
88ac2921 | 162 | * |
88ac2921 RM |
163 | * Called without locks. |
164 | */ | |
f3c04b93 | 165 | static inline void ptrace_event(int event, unsigned long message) |
88ac2921 | 166 | { |
f3c04b93 TH |
167 | if (unlikely(ptrace_event_enabled(current, event))) { |
168 | current->ptrace_message = message; | |
169 | ptrace_notify((event << 8) | SIGTRAP); | |
b1845ff5 | 170 | } else if (event == PTRACE_EVENT_EXEC) { |
f3c04b93 | 171 | /* legacy EXEC report via SIGTRAP */ |
b1845ff5 ON |
172 | if ((current->ptrace & (PT_PTRACED|PT_SEIZED)) == PT_PTRACED) |
173 | send_sig(SIGTRAP, current, 0); | |
f3c04b93 | 174 | } |
88ac2921 RM |
175 | } |
176 | ||
4e52365f MD |
177 | /** |
178 | * ptrace_event_pid - possibly stop for a ptrace event notification | |
179 | * @event: %PTRACE_EVENT_* value to report | |
180 | * @pid: process identifier for %PTRACE_GETEVENTMSG to return | |
181 | * | |
182 | * Check whether @event is enabled and, if so, report @event and @pid | |
183 | * to the ptrace parent. @pid is reported as the pid_t seen from the | |
184 | * the ptrace parent's pid namespace. | |
185 | * | |
186 | * Called without locks. | |
187 | */ | |
188 | static inline void ptrace_event_pid(int event, struct pid *pid) | |
189 | { | |
190 | /* | |
191 | * FIXME: There's a potential race if a ptracer in a different pid | |
192 | * namespace than parent attaches between computing message below and | |
193 | * when we acquire tasklist_lock in ptrace_stop(). If this happens, | |
194 | * the ptracer will get a bogus pid from PTRACE_GETEVENTMSG. | |
195 | */ | |
196 | unsigned long message = 0; | |
197 | struct pid_namespace *ns; | |
198 | ||
199 | rcu_read_lock(); | |
200 | ns = task_active_pid_ns(rcu_dereference(current->parent)); | |
201 | if (ns) | |
202 | message = pid_nr_ns(pid, ns); | |
203 | rcu_read_unlock(); | |
204 | ||
205 | ptrace_event(event, message); | |
206 | } | |
207 | ||
09a05394 RM |
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 | */ | |
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); | |
6634ae10 | 222 | child->jobctl = 0; |
09a05394 | 223 | child->ptrace = 0; |
6634ae10 ON |
224 | child->parent = child->real_parent; |
225 | ||
226 | if (unlikely(ptrace) && current->ptrace) { | |
09a05394 | 227 | child->ptrace = current->ptrace; |
c70d9d80 | 228 | __ptrace_link(child, current->parent, current->ptracer_cred); |
dcace06c | 229 | |
d184d6eb ON |
230 | if (child->ptrace & PT_SEIZED) |
231 | task_set_jobctl_pending(child, JOBCTL_TRAP_STOP); | |
232 | else | |
233 | sigaddset(&child->pending.signal, SIGSTOP); | |
09a05394 | 234 | } |
c70d9d80 EB |
235 | else |
236 | child->ptracer_cred = NULL; | |
09a05394 RM |
237 | } |
238 | ||
dae33574 RM |
239 | /** |
240 | * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped | |
241 | * @task: task in %EXIT_DEAD state | |
242 | * | |
243 | * Called with write_lock(&tasklist_lock) held. | |
244 | */ | |
245 | static inline void ptrace_release_task(struct task_struct *task) | |
246 | { | |
247 | BUG_ON(!list_empty(&task->ptraced)); | |
248 | ptrace_unlink(task); | |
249 | BUG_ON(!list_empty(&task->ptrace_entry)); | |
250 | } | |
251 | ||
1da177e4 LT |
252 | #ifndef force_successful_syscall_return |
253 | /* | |
254 | * System call handlers that, upon successful completion, need to return a | |
255 | * negative value should call force_successful_syscall_return() right before | |
256 | * returning. On architectures where the syscall convention provides for a | |
257 | * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly | |
258 | * others), this macro can be used to ensure that the error flag will not get | |
259 | * set. On architectures which do not support a separate error flag, the macro | |
260 | * is a no-op and the spurious error condition needs to be filtered out by some | |
261 | * other means (e.g., in user-level, by passing an extra argument to the | |
262 | * syscall handler, or something along those lines). | |
263 | */ | |
264 | #define force_successful_syscall_return() do { } while (0) | |
265 | #endif | |
266 | ||
d7e7528b EP |
267 | #ifndef is_syscall_success |
268 | /* | |
269 | * On most systems we can tell if a syscall is a success based on if the retval | |
270 | * is an error value. On some systems like ia64 and powerpc they have different | |
271 | * indicators of success/failure and must define their own. | |
272 | */ | |
273 | #define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs)))) | |
274 | #endif | |
275 | ||
fb7fa8f1 RM |
276 | /* |
277 | * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__. | |
278 | * | |
279 | * These do-nothing inlines are used when the arch does not | |
280 | * implement single-step. The kerneldoc comments are here | |
281 | * to document the interface for all arch definitions. | |
282 | */ | |
283 | ||
284 | #ifndef arch_has_single_step | |
285 | /** | |
286 | * arch_has_single_step - does this CPU support user-mode single-step? | |
287 | * | |
288 | * If this is defined, then there must be function declarations or | |
289 | * inlines for user_enable_single_step() and user_disable_single_step(). | |
290 | * arch_has_single_step() should evaluate to nonzero iff the machine | |
291 | * supports instruction single-step for user mode. | |
292 | * It can be a constant or it can test a CPU feature bit. | |
293 | */ | |
294 | #define arch_has_single_step() (0) | |
295 | ||
296 | /** | |
297 | * user_enable_single_step - single-step in user-mode task | |
298 | * @task: either current or a task stopped in %TASK_TRACED | |
299 | * | |
300 | * This can only be called when arch_has_single_step() has returned nonzero. | |
301 | * Set @task so that when it returns to user mode, it will trap after the | |
dc802c2d RM |
302 | * next single instruction executes. If arch_has_block_step() is defined, |
303 | * this must clear the effects of user_enable_block_step() too. | |
fb7fa8f1 RM |
304 | */ |
305 | static inline void user_enable_single_step(struct task_struct *task) | |
306 | { | |
307 | BUG(); /* This can never be called. */ | |
308 | } | |
309 | ||
310 | /** | |
311 | * user_disable_single_step - cancel user-mode single-step | |
312 | * @task: either current or a task stopped in %TASK_TRACED | |
313 | * | |
dc802c2d RM |
314 | * Clear @task of the effects of user_enable_single_step() and |
315 | * user_enable_block_step(). This can be called whether or not either | |
316 | * of those was ever called on @task, and even if arch_has_single_step() | |
317 | * returned zero. | |
fb7fa8f1 RM |
318 | */ |
319 | static inline void user_disable_single_step(struct task_struct *task) | |
320 | { | |
321 | } | |
dacbe41f CH |
322 | #else |
323 | extern void user_enable_single_step(struct task_struct *); | |
324 | extern void user_disable_single_step(struct task_struct *); | |
fb7fa8f1 RM |
325 | #endif /* arch_has_single_step */ |
326 | ||
dc802c2d RM |
327 | #ifndef arch_has_block_step |
328 | /** | |
329 | * arch_has_block_step - does this CPU support user-mode block-step? | |
330 | * | |
331 | * If this is defined, then there must be a function declaration or inline | |
332 | * for user_enable_block_step(), and arch_has_single_step() must be defined | |
333 | * too. arch_has_block_step() should evaluate to nonzero iff the machine | |
334 | * supports step-until-branch for user mode. It can be a constant or it | |
335 | * can test a CPU feature bit. | |
336 | */ | |
5b88abbf | 337 | #define arch_has_block_step() (0) |
dc802c2d RM |
338 | |
339 | /** | |
340 | * user_enable_block_step - step until branch in user-mode task | |
341 | * @task: either current or a task stopped in %TASK_TRACED | |
342 | * | |
343 | * This can only be called when arch_has_block_step() has returned nonzero, | |
344 | * and will never be called when single-instruction stepping is being used. | |
345 | * Set @task so that when it returns to user mode, it will trap after the | |
346 | * next branch or trap taken. | |
347 | */ | |
348 | static inline void user_enable_block_step(struct task_struct *task) | |
349 | { | |
350 | BUG(); /* This can never be called. */ | |
351 | } | |
dacbe41f CH |
352 | #else |
353 | extern void user_enable_block_step(struct task_struct *); | |
dc802c2d RM |
354 | #endif /* arch_has_block_step */ |
355 | ||
efc463ad EB |
356 | #ifdef ARCH_HAS_USER_SINGLE_STEP_REPORT |
357 | extern void user_single_step_report(struct pt_regs *regs); | |
85ec7fd9 | 358 | #else |
efc463ad | 359 | static inline void user_single_step_report(struct pt_regs *regs) |
85ec7fd9 | 360 | { |
ae7795bc | 361 | kernel_siginfo_t info; |
efc463ad EB |
362 | clear_siginfo(&info); |
363 | info.si_signo = SIGTRAP; | |
364 | info.si_errno = 0; | |
365 | info.si_code = SI_USER; | |
366 | info.si_pid = 0; | |
367 | info.si_uid = 0; | |
368 | force_sig_info(info.si_signo, &info, current); | |
85ec7fd9 ON |
369 | } |
370 | #endif | |
371 | ||
1a669c2f RM |
372 | #ifndef arch_ptrace_stop_needed |
373 | /** | |
374 | * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called | |
375 | * @code: current->exit_code value ptrace will stop with | |
376 | * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with | |
377 | * | |
378 | * This is called with the siglock held, to decide whether or not it's | |
379 | * necessary to release the siglock and call arch_ptrace_stop() with the | |
380 | * same @code and @info arguments. It can be defined to a constant if | |
381 | * arch_ptrace_stop() is never required, or always is. On machines where | |
382 | * this makes sense, it should be defined to a quick test to optimize out | |
383 | * calling arch_ptrace_stop() when it would be superfluous. For example, | |
384 | * if the thread has not been back to user mode since the last stop, the | |
385 | * thread state might indicate that nothing needs to be done. | |
b9cd18de TH |
386 | * |
387 | * This is guaranteed to be invoked once before a task stops for ptrace and | |
388 | * may include arch-specific operations necessary prior to a ptrace stop. | |
1a669c2f RM |
389 | */ |
390 | #define arch_ptrace_stop_needed(code, info) (0) | |
391 | #endif | |
392 | ||
393 | #ifndef arch_ptrace_stop | |
394 | /** | |
395 | * arch_ptrace_stop - Do machine-specific work before stopping for ptrace | |
396 | * @code: current->exit_code value ptrace will stop with | |
397 | * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with | |
398 | * | |
399 | * This is called with no locks held when arch_ptrace_stop_needed() has | |
400 | * just returned nonzero. It is allowed to block, e.g. for user memory | |
401 | * access. The arch can have machine-specific work to be done before | |
402 | * ptrace stops. On ia64, register backing store gets written back to user | |
403 | * memory here. Since this can be costly (requires dropping the siglock), | |
404 | * we only do it when the arch requires it for this particular stop, as | |
405 | * indicated by arch_ptrace_stop_needed(). | |
406 | */ | |
407 | #define arch_ptrace_stop(code, info) do { } while (0) | |
408 | #endif | |
409 | ||
a3460a59 AV |
410 | #ifndef current_pt_regs |
411 | #define current_pt_regs() task_pt_regs(current) | |
412 | #endif | |
413 | ||
22062a96 AV |
414 | /* |
415 | * unlike current_pt_regs(), this one is equal to task_pt_regs(current) | |
416 | * on *all* architectures; the only reason to have a per-arch definition | |
417 | * is optimisation. | |
418 | */ | |
419 | #ifndef signal_pt_regs | |
420 | #define signal_pt_regs() task_pt_regs(current) | |
421 | #endif | |
422 | ||
1ca97bb5 AV |
423 | #ifndef current_user_stack_pointer |
424 | #define current_user_stack_pointer() user_stack_pointer(current_pt_regs()) | |
425 | #endif | |
426 | ||
bbc69863 RM |
427 | extern int task_current_syscall(struct task_struct *target, long *callno, |
428 | unsigned long args[6], unsigned int maxargs, | |
429 | unsigned long *sp, unsigned long *pc); | |
430 | ||
1da177e4 | 431 | #endif |