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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 | |
caaee623 JH |
67 | |
68 | /* shorthands for READ/ATTACH and FSCREDS/REALCREDS combinations */ | |
69 | #define PTRACE_MODE_READ_FSCREDS (PTRACE_MODE_READ | PTRACE_MODE_FSCREDS) | |
70 | #define PTRACE_MODE_READ_REALCREDS (PTRACE_MODE_READ | PTRACE_MODE_REALCREDS) | |
71 | #define PTRACE_MODE_ATTACH_FSCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_FSCREDS) | |
72 | #define PTRACE_MODE_ATTACH_REALCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_REALCREDS) | |
73 | ||
74 | /** | |
75 | * ptrace_may_access - check whether the caller is permitted to access | |
76 | * a target task. | |
77 | * @task: target task | |
78 | * @mode: selects type of access and caller credentials | |
79 | * | |
80 | * Returns true on success, false on denial. | |
81 | * | |
82 | * One of the flags PTRACE_MODE_FSCREDS and PTRACE_MODE_REALCREDS must | |
83 | * be set in @mode to specify whether the access was requested through | |
84 | * a filesystem syscall (should use effective capabilities and fsuid | |
85 | * of the caller) or through an explicit syscall such as | |
86 | * process_vm_writev or ptrace (and should use the real credentials). | |
87 | */ | |
006ebb40 | 88 | extern bool ptrace_may_access(struct task_struct *task, unsigned int mode); |
dbfe2953 | 89 | |
53b6f9fb ON |
90 | static inline int ptrace_reparented(struct task_struct *child) |
91 | { | |
0347e177 | 92 | return !same_thread_group(child->real_parent, child->parent); |
53b6f9fb | 93 | } |
c6a47cc2 | 94 | |
1da177e4 LT |
95 | static inline void ptrace_unlink(struct task_struct *child) |
96 | { | |
97 | if (unlikely(child->ptrace)) | |
98 | __ptrace_unlink(child); | |
99 | } | |
100 | ||
4abf9869 NK |
101 | int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, |
102 | unsigned long data); | |
103 | int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, | |
104 | unsigned long data); | |
1da177e4 | 105 | |
06d98473 TH |
106 | /** |
107 | * ptrace_parent - return the task that is tracing the given task | |
108 | * @task: task to consider | |
109 | * | |
110 | * Returns %NULL if no one is tracing @task, or the &struct task_struct | |
111 | * pointer to its tracer. | |
112 | * | |
113 | * Must called under rcu_read_lock(). The pointer returned might be kept | |
114 | * live only by RCU. During exec, this may be called with task_lock() held | |
115 | * on @task, still held from when check_unsafe_exec() was called. | |
116 | */ | |
117 | static inline struct task_struct *ptrace_parent(struct task_struct *task) | |
118 | { | |
119 | if (unlikely(task->ptrace)) | |
120 | return rcu_dereference(task->parent); | |
121 | return NULL; | |
122 | } | |
123 | ||
643ad838 TH |
124 | /** |
125 | * ptrace_event_enabled - test whether a ptrace event is enabled | |
126 | * @task: ptracee of interest | |
127 | * @event: %PTRACE_EVENT_* to test | |
128 | * | |
129 | * Test whether @event is enabled for ptracee @task. | |
130 | * | |
131 | * Returns %true if @event is enabled, %false otherwise. | |
132 | */ | |
133 | static inline bool ptrace_event_enabled(struct task_struct *task, int event) | |
134 | { | |
135 | return task->ptrace & PT_EVENT_FLAG(event); | |
136 | } | |
137 | ||
88ac2921 RM |
138 | /** |
139 | * ptrace_event - possibly stop for a ptrace event notification | |
643ad838 | 140 | * @event: %PTRACE_EVENT_* value to report |
88ac2921 RM |
141 | * @message: value for %PTRACE_GETEVENTMSG to return |
142 | * | |
643ad838 TH |
143 | * Check whether @event is enabled and, if so, report @event and @message |
144 | * to the ptrace parent. | |
88ac2921 | 145 | * |
88ac2921 RM |
146 | * Called without locks. |
147 | */ | |
f3c04b93 | 148 | static inline void ptrace_event(int event, unsigned long message) |
88ac2921 | 149 | { |
f3c04b93 TH |
150 | if (unlikely(ptrace_event_enabled(current, event))) { |
151 | current->ptrace_message = message; | |
152 | ptrace_notify((event << 8) | SIGTRAP); | |
b1845ff5 | 153 | } else if (event == PTRACE_EVENT_EXEC) { |
f3c04b93 | 154 | /* legacy EXEC report via SIGTRAP */ |
b1845ff5 ON |
155 | if ((current->ptrace & (PT_PTRACED|PT_SEIZED)) == PT_PTRACED) |
156 | send_sig(SIGTRAP, current, 0); | |
f3c04b93 | 157 | } |
88ac2921 RM |
158 | } |
159 | ||
4e52365f MD |
160 | /** |
161 | * ptrace_event_pid - possibly stop for a ptrace event notification | |
162 | * @event: %PTRACE_EVENT_* value to report | |
163 | * @pid: process identifier for %PTRACE_GETEVENTMSG to return | |
164 | * | |
165 | * Check whether @event is enabled and, if so, report @event and @pid | |
166 | * to the ptrace parent. @pid is reported as the pid_t seen from the | |
167 | * the ptrace parent's pid namespace. | |
168 | * | |
169 | * Called without locks. | |
170 | */ | |
171 | static inline void ptrace_event_pid(int event, struct pid *pid) | |
172 | { | |
173 | /* | |
174 | * FIXME: There's a potential race if a ptracer in a different pid | |
175 | * namespace than parent attaches between computing message below and | |
176 | * when we acquire tasklist_lock in ptrace_stop(). If this happens, | |
177 | * the ptracer will get a bogus pid from PTRACE_GETEVENTMSG. | |
178 | */ | |
179 | unsigned long message = 0; | |
180 | struct pid_namespace *ns; | |
181 | ||
182 | rcu_read_lock(); | |
183 | ns = task_active_pid_ns(rcu_dereference(current->parent)); | |
184 | if (ns) | |
185 | message = pid_nr_ns(pid, ns); | |
186 | rcu_read_unlock(); | |
187 | ||
188 | ptrace_event(event, message); | |
189 | } | |
190 | ||
09a05394 RM |
191 | /** |
192 | * ptrace_init_task - initialize ptrace state for a new child | |
193 | * @child: new child task | |
194 | * @ptrace: true if child should be ptrace'd by parent's tracer | |
195 | * | |
196 | * This is called immediately after adding @child to its parent's children | |
197 | * list. @ptrace is false in the normal case, and true to ptrace @child. | |
198 | * | |
199 | * Called with current's siglock and write_lock_irq(&tasklist_lock) held. | |
200 | */ | |
201 | static inline void ptrace_init_task(struct task_struct *child, bool ptrace) | |
202 | { | |
203 | INIT_LIST_HEAD(&child->ptrace_entry); | |
204 | INIT_LIST_HEAD(&child->ptraced); | |
6634ae10 | 205 | child->jobctl = 0; |
09a05394 | 206 | child->ptrace = 0; |
6634ae10 ON |
207 | child->parent = child->real_parent; |
208 | ||
209 | if (unlikely(ptrace) && current->ptrace) { | |
09a05394 | 210 | child->ptrace = current->ptrace; |
c70d9d80 | 211 | __ptrace_link(child, current->parent, current->ptracer_cred); |
dcace06c | 212 | |
d184d6eb ON |
213 | if (child->ptrace & PT_SEIZED) |
214 | task_set_jobctl_pending(child, JOBCTL_TRAP_STOP); | |
215 | else | |
216 | sigaddset(&child->pending.signal, SIGSTOP); | |
09a05394 | 217 | } |
c70d9d80 EB |
218 | else |
219 | child->ptracer_cred = NULL; | |
09a05394 RM |
220 | } |
221 | ||
dae33574 RM |
222 | /** |
223 | * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped | |
224 | * @task: task in %EXIT_DEAD state | |
225 | * | |
226 | * Called with write_lock(&tasklist_lock) held. | |
227 | */ | |
228 | static inline void ptrace_release_task(struct task_struct *task) | |
229 | { | |
230 | BUG_ON(!list_empty(&task->ptraced)); | |
231 | ptrace_unlink(task); | |
232 | BUG_ON(!list_empty(&task->ptrace_entry)); | |
233 | } | |
234 | ||
1da177e4 LT |
235 | #ifndef force_successful_syscall_return |
236 | /* | |
237 | * System call handlers that, upon successful completion, need to return a | |
238 | * negative value should call force_successful_syscall_return() right before | |
239 | * returning. On architectures where the syscall convention provides for a | |
240 | * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly | |
241 | * others), this macro can be used to ensure that the error flag will not get | |
242 | * set. On architectures which do not support a separate error flag, the macro | |
243 | * is a no-op and the spurious error condition needs to be filtered out by some | |
244 | * other means (e.g., in user-level, by passing an extra argument to the | |
245 | * syscall handler, or something along those lines). | |
246 | */ | |
247 | #define force_successful_syscall_return() do { } while (0) | |
248 | #endif | |
249 | ||
d7e7528b EP |
250 | #ifndef is_syscall_success |
251 | /* | |
252 | * On most systems we can tell if a syscall is a success based on if the retval | |
253 | * is an error value. On some systems like ia64 and powerpc they have different | |
254 | * indicators of success/failure and must define their own. | |
255 | */ | |
256 | #define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs)))) | |
257 | #endif | |
258 | ||
fb7fa8f1 RM |
259 | /* |
260 | * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__. | |
261 | * | |
262 | * These do-nothing inlines are used when the arch does not | |
263 | * implement single-step. The kerneldoc comments are here | |
264 | * to document the interface for all arch definitions. | |
265 | */ | |
266 | ||
267 | #ifndef arch_has_single_step | |
268 | /** | |
269 | * arch_has_single_step - does this CPU support user-mode single-step? | |
270 | * | |
271 | * If this is defined, then there must be function declarations or | |
272 | * inlines for user_enable_single_step() and user_disable_single_step(). | |
273 | * arch_has_single_step() should evaluate to nonzero iff the machine | |
274 | * supports instruction single-step for user mode. | |
275 | * It can be a constant or it can test a CPU feature bit. | |
276 | */ | |
277 | #define arch_has_single_step() (0) | |
278 | ||
279 | /** | |
280 | * user_enable_single_step - single-step in user-mode task | |
281 | * @task: either current or a task stopped in %TASK_TRACED | |
282 | * | |
283 | * This can only be called when arch_has_single_step() has returned nonzero. | |
284 | * Set @task so that when it returns to user mode, it will trap after the | |
dc802c2d RM |
285 | * next single instruction executes. If arch_has_block_step() is defined, |
286 | * this must clear the effects of user_enable_block_step() too. | |
fb7fa8f1 RM |
287 | */ |
288 | static inline void user_enable_single_step(struct task_struct *task) | |
289 | { | |
290 | BUG(); /* This can never be called. */ | |
291 | } | |
292 | ||
293 | /** | |
294 | * user_disable_single_step - cancel user-mode single-step | |
295 | * @task: either current or a task stopped in %TASK_TRACED | |
296 | * | |
dc802c2d RM |
297 | * Clear @task of the effects of user_enable_single_step() and |
298 | * user_enable_block_step(). This can be called whether or not either | |
299 | * of those was ever called on @task, and even if arch_has_single_step() | |
300 | * returned zero. | |
fb7fa8f1 RM |
301 | */ |
302 | static inline void user_disable_single_step(struct task_struct *task) | |
303 | { | |
304 | } | |
dacbe41f CH |
305 | #else |
306 | extern void user_enable_single_step(struct task_struct *); | |
307 | extern void user_disable_single_step(struct task_struct *); | |
fb7fa8f1 RM |
308 | #endif /* arch_has_single_step */ |
309 | ||
dc802c2d RM |
310 | #ifndef arch_has_block_step |
311 | /** | |
312 | * arch_has_block_step - does this CPU support user-mode block-step? | |
313 | * | |
314 | * If this is defined, then there must be a function declaration or inline | |
315 | * for user_enable_block_step(), and arch_has_single_step() must be defined | |
316 | * too. arch_has_block_step() should evaluate to nonzero iff the machine | |
317 | * supports step-until-branch for user mode. It can be a constant or it | |
318 | * can test a CPU feature bit. | |
319 | */ | |
5b88abbf | 320 | #define arch_has_block_step() (0) |
dc802c2d RM |
321 | |
322 | /** | |
323 | * user_enable_block_step - step until branch in user-mode task | |
324 | * @task: either current or a task stopped in %TASK_TRACED | |
325 | * | |
326 | * This can only be called when arch_has_block_step() has returned nonzero, | |
327 | * and will never be called when single-instruction stepping is being used. | |
328 | * Set @task so that when it returns to user mode, it will trap after the | |
329 | * next branch or trap taken. | |
330 | */ | |
331 | static inline void user_enable_block_step(struct task_struct *task) | |
332 | { | |
333 | BUG(); /* This can never be called. */ | |
334 | } | |
dacbe41f CH |
335 | #else |
336 | extern void user_enable_block_step(struct task_struct *); | |
dc802c2d RM |
337 | #endif /* arch_has_block_step */ |
338 | ||
efc463ad EB |
339 | #ifdef ARCH_HAS_USER_SINGLE_STEP_REPORT |
340 | extern void user_single_step_report(struct pt_regs *regs); | |
85ec7fd9 | 341 | #else |
efc463ad | 342 | static inline void user_single_step_report(struct pt_regs *regs) |
85ec7fd9 | 343 | { |
ae7795bc | 344 | kernel_siginfo_t info; |
efc463ad EB |
345 | clear_siginfo(&info); |
346 | info.si_signo = SIGTRAP; | |
347 | info.si_errno = 0; | |
348 | info.si_code = SI_USER; | |
349 | info.si_pid = 0; | |
350 | info.si_uid = 0; | |
351 | force_sig_info(info.si_signo, &info, current); | |
85ec7fd9 ON |
352 | } |
353 | #endif | |
354 | ||
1a669c2f RM |
355 | #ifndef arch_ptrace_stop_needed |
356 | /** | |
357 | * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called | |
358 | * @code: current->exit_code value ptrace will stop with | |
359 | * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with | |
360 | * | |
361 | * This is called with the siglock held, to decide whether or not it's | |
362 | * necessary to release the siglock and call arch_ptrace_stop() with the | |
363 | * same @code and @info arguments. It can be defined to a constant if | |
364 | * arch_ptrace_stop() is never required, or always is. On machines where | |
365 | * this makes sense, it should be defined to a quick test to optimize out | |
366 | * calling arch_ptrace_stop() when it would be superfluous. For example, | |
367 | * if the thread has not been back to user mode since the last stop, the | |
368 | * thread state might indicate that nothing needs to be done. | |
b9cd18de TH |
369 | * |
370 | * This is guaranteed to be invoked once before a task stops for ptrace and | |
371 | * may include arch-specific operations necessary prior to a ptrace stop. | |
1a669c2f RM |
372 | */ |
373 | #define arch_ptrace_stop_needed(code, info) (0) | |
374 | #endif | |
375 | ||
376 | #ifndef arch_ptrace_stop | |
377 | /** | |
378 | * arch_ptrace_stop - Do machine-specific work before stopping for ptrace | |
379 | * @code: current->exit_code value ptrace will stop with | |
380 | * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with | |
381 | * | |
382 | * This is called with no locks held when arch_ptrace_stop_needed() has | |
383 | * just returned nonzero. It is allowed to block, e.g. for user memory | |
384 | * access. The arch can have machine-specific work to be done before | |
385 | * ptrace stops. On ia64, register backing store gets written back to user | |
386 | * memory here. Since this can be costly (requires dropping the siglock), | |
387 | * we only do it when the arch requires it for this particular stop, as | |
388 | * indicated by arch_ptrace_stop_needed(). | |
389 | */ | |
390 | #define arch_ptrace_stop(code, info) do { } while (0) | |
391 | #endif | |
392 | ||
a3460a59 AV |
393 | #ifndef current_pt_regs |
394 | #define current_pt_regs() task_pt_regs(current) | |
395 | #endif | |
396 | ||
22062a96 AV |
397 | /* |
398 | * unlike current_pt_regs(), this one is equal to task_pt_regs(current) | |
399 | * on *all* architectures; the only reason to have a per-arch definition | |
400 | * is optimisation. | |
401 | */ | |
402 | #ifndef signal_pt_regs | |
403 | #define signal_pt_regs() task_pt_regs(current) | |
404 | #endif | |
405 | ||
1ca97bb5 AV |
406 | #ifndef current_user_stack_pointer |
407 | #define current_user_stack_pointer() user_stack_pointer(current_pt_regs()) | |
408 | #endif | |
409 | ||
bbc69863 RM |
410 | extern int task_current_syscall(struct task_struct *target, long *callno, |
411 | unsigned long args[6], unsigned int maxargs, | |
412 | unsigned long *sp, unsigned long *pc); | |
413 | ||
1da177e4 | 414 | #endif |