Branch data Line data Source code
1 : : #ifndef _LINUX_PTRACE_H
2 : : #define _LINUX_PTRACE_H
3 : :
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. */
8 : : #include <uapi/linux/ptrace.h>
9 : :
10 : : /*
11 : : * Ptrace flags
12 : : *
13 : : * The owner ship rules for task->ptrace which holds the ptrace
14 : : * flags is simple. When a task is running it owns it's task->ptrace
15 : : * flags. When the a task is stopped the ptracer owns task->ptrace.
16 : : */
17 : :
18 : : #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */
19 : : #define PT_PTRACED 0x00000001
20 : : #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
21 : : #define PT_PTRACE_CAP 0x00000004 /* ptracer can follow suid-exec */
22 : :
23 : : #define PT_OPT_FLAG_SHIFT 3
24 : : /* PT_TRACE_* event enable flags */
25 : : #define PT_EVENT_FLAG(event) (1 << (PT_OPT_FLAG_SHIFT + (event)))
26 : : #define PT_TRACESYSGOOD PT_EVENT_FLAG(0)
27 : : #define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK)
28 : : #define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK)
29 : : #define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE)
30 : : #define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC)
31 : : #define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE)
32 : : #define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT)
33 : : #define PT_TRACE_SECCOMP PT_EVENT_FLAG(PTRACE_EVENT_SECCOMP)
34 : :
35 : : #define PT_EXITKILL (PTRACE_O_EXITKILL << PT_OPT_FLAG_SHIFT)
36 : :
37 : : /* single stepping state bits (used on ARM and PA-RISC) */
38 : : #define PT_SINGLESTEP_BIT 31
39 : : #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT)
40 : : #define PT_BLOCKSTEP_BIT 30
41 : : #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT)
42 : :
43 : : extern long arch_ptrace(struct task_struct *child, long request,
44 : : unsigned long addr, unsigned long data);
45 : : extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
46 : : extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
47 : : extern void ptrace_disable(struct task_struct *);
48 : : extern int ptrace_request(struct task_struct *child, long request,
49 : : unsigned long addr, unsigned long data);
50 : : extern void ptrace_notify(int exit_code);
51 : : extern void __ptrace_link(struct task_struct *child,
52 : : struct task_struct *new_parent);
53 : : extern void __ptrace_unlink(struct task_struct *child);
54 : : extern void exit_ptrace(struct task_struct *tracer);
55 : : #define PTRACE_MODE_READ 0x01
56 : : #define PTRACE_MODE_ATTACH 0x02
57 : : #define PTRACE_MODE_NOAUDIT 0x04
58 : : /* Returns true on success, false on denial. */
59 : : extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
60 : :
61 : : static inline int ptrace_reparented(struct task_struct *child)
62 : : {
63 : 2203511 : return !same_thread_group(child->real_parent, child->parent);
64 : : }
65 : :
66 : : static inline void ptrace_unlink(struct task_struct *child)
67 : : {
68 [ # # ][ + + ]: 1104228 : if (unlikely(child->ptrace))
69 : 7 : __ptrace_unlink(child);
70 : : }
71 : :
72 : : int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
73 : : unsigned long data);
74 : : int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
75 : : unsigned long data);
76 : :
77 : : /**
78 : : * ptrace_parent - return the task that is tracing the given task
79 : : * @task: task to consider
80 : : *
81 : : * Returns %NULL if no one is tracing @task, or the &struct task_struct
82 : : * pointer to its tracer.
83 : : *
84 : : * Must called under rcu_read_lock(). The pointer returned might be kept
85 : : * live only by RCU. During exec, this may be called with task_lock() held
86 : : * on @task, still held from when check_unsafe_exec() was called.
87 : : */
88 : : static inline struct task_struct *ptrace_parent(struct task_struct *task)
89 : : {
90 [ - + ]: 24180 : if (unlikely(task->ptrace))
[ # # # # ]
91 : 0 : return rcu_dereference(task->parent);
92 : : return NULL;
93 : : }
94 : :
95 : : /**
96 : : * ptrace_event_enabled - test whether a ptrace event is enabled
97 : : * @task: ptracee of interest
98 : : * @event: %PTRACE_EVENT_* to test
99 : : *
100 : : * Test whether @event is enabled for ptracee @task.
101 : : *
102 : : * Returns %true if @event is enabled, %false otherwise.
103 : : */
104 : : static inline bool ptrace_event_enabled(struct task_struct *task, int event)
105 : : {
106 : 2235802 : return task->ptrace & PT_EVENT_FLAG(event);
107 : : }
108 : :
109 : : /**
110 : : * ptrace_event - possibly stop for a ptrace event notification
111 : : * @event: %PTRACE_EVENT_* value to report
112 : : * @message: value for %PTRACE_GETEVENTMSG to return
113 : : *
114 : : * Check whether @event is enabled and, if so, report @event and @message
115 : : * to the ptrace parent.
116 : : *
117 : : * Called without locks.
118 : : */
119 : : static inline void ptrace_event(int event, unsigned long message)
120 : : {
121 [ + + ][ - + ]: 1132024 : if (unlikely(ptrace_event_enabled(current, event))) {
122 : 63 : current->ptrace_message = message;
123 : 1104285 : ptrace_notify((event << 8) | SIGTRAP);
124 : : } else if (event == PTRACE_EVENT_EXEC) {
125 : : /* legacy EXEC report via SIGTRAP */
126 [ + + ]: 27215 : if ((current->ptrace & (PT_PTRACED|PT_SEIZED)) == PT_PTRACED)
127 : 32 : send_sig(SIGTRAP, current, 0);
128 : : }
129 : : }
130 : :
131 : : /**
132 : : * ptrace_init_task - initialize ptrace state for a new child
133 : : * @child: new child task
134 : : * @ptrace: true if child should be ptrace'd by parent's tracer
135 : : *
136 : : * This is called immediately after adding @child to its parent's children
137 : : * list. @ptrace is false in the normal case, and true to ptrace @child.
138 : : *
139 : : * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
140 : : */
141 : : static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
142 : : {
143 : 1104222 : INIT_LIST_HEAD(&child->ptrace_entry);
144 : 1104222 : INIT_LIST_HEAD(&child->ptraced);
145 : 1104222 : child->jobctl = 0;
146 : 1104222 : child->ptrace = 0;
147 : 1104222 : child->parent = child->real_parent;
148 : :
149 [ + + ][ + - ]: 1104222 : if (unlikely(ptrace) && current->ptrace) {
150 : 32 : child->ptrace = current->ptrace;
151 : 32 : __ptrace_link(child, current->parent);
152 : :
153 [ - + ]: 32 : if (child->ptrace & PT_SEIZED)
154 : 0 : task_set_jobctl_pending(child, JOBCTL_TRAP_STOP);
155 : : else
156 : : sigaddset(&child->pending.signal, SIGSTOP);
157 : :
158 : : set_tsk_thread_flag(child, TIF_SIGPENDING);
159 : : }
160 : : }
161 : :
162 : : /**
163 : : * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
164 : : * @task: task in %EXIT_DEAD state
165 : : *
166 : : * Called with write_lock(&tasklist_lock) held.
167 : : */
168 : : static inline void ptrace_release_task(struct task_struct *task)
169 : : {
170 [ - + ]: 1104228 : BUG_ON(!list_empty(&task->ptraced));
171 : : ptrace_unlink(task);
172 [ - + ]: 1104228 : BUG_ON(!list_empty(&task->ptrace_entry));
173 : : }
174 : :
175 : : #ifndef force_successful_syscall_return
176 : : /*
177 : : * System call handlers that, upon successful completion, need to return a
178 : : * negative value should call force_successful_syscall_return() right before
179 : : * returning. On architectures where the syscall convention provides for a
180 : : * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
181 : : * others), this macro can be used to ensure that the error flag will not get
182 : : * set. On architectures which do not support a separate error flag, the macro
183 : : * is a no-op and the spurious error condition needs to be filtered out by some
184 : : * other means (e.g., in user-level, by passing an extra argument to the
185 : : * syscall handler, or something along those lines).
186 : : */
187 : : #define force_successful_syscall_return() do { } while (0)
188 : : #endif
189 : :
190 : : #ifndef is_syscall_success
191 : : /*
192 : : * On most systems we can tell if a syscall is a success based on if the retval
193 : : * is an error value. On some systems like ia64 and powerpc they have different
194 : : * indicators of success/failure and must define their own.
195 : : */
196 : : #define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs))))
197 : : #endif
198 : :
199 : : /*
200 : : * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
201 : : *
202 : : * These do-nothing inlines are used when the arch does not
203 : : * implement single-step. The kerneldoc comments are here
204 : : * to document the interface for all arch definitions.
205 : : */
206 : :
207 : : #ifndef arch_has_single_step
208 : : /**
209 : : * arch_has_single_step - does this CPU support user-mode single-step?
210 : : *
211 : : * If this is defined, then there must be function declarations or
212 : : * inlines for user_enable_single_step() and user_disable_single_step().
213 : : * arch_has_single_step() should evaluate to nonzero iff the machine
214 : : * supports instruction single-step for user mode.
215 : : * It can be a constant or it can test a CPU feature bit.
216 : : */
217 : : #define arch_has_single_step() (0)
218 : :
219 : : /**
220 : : * user_enable_single_step - single-step in user-mode task
221 : : * @task: either current or a task stopped in %TASK_TRACED
222 : : *
223 : : * This can only be called when arch_has_single_step() has returned nonzero.
224 : : * Set @task so that when it returns to user mode, it will trap after the
225 : : * next single instruction executes. If arch_has_block_step() is defined,
226 : : * this must clear the effects of user_enable_block_step() too.
227 : : */
228 : : static inline void user_enable_single_step(struct task_struct *task)
229 : : {
230 : : BUG(); /* This can never be called. */
231 : : }
232 : :
233 : : /**
234 : : * user_disable_single_step - cancel user-mode single-step
235 : : * @task: either current or a task stopped in %TASK_TRACED
236 : : *
237 : : * Clear @task of the effects of user_enable_single_step() and
238 : : * user_enable_block_step(). This can be called whether or not either
239 : : * of those was ever called on @task, and even if arch_has_single_step()
240 : : * returned zero.
241 : : */
242 : : static inline void user_disable_single_step(struct task_struct *task)
243 : : {
244 : : }
245 : : #else
246 : : extern void user_enable_single_step(struct task_struct *);
247 : : extern void user_disable_single_step(struct task_struct *);
248 : : #endif /* arch_has_single_step */
249 : :
250 : : #ifndef arch_has_block_step
251 : : /**
252 : : * arch_has_block_step - does this CPU support user-mode block-step?
253 : : *
254 : : * If this is defined, then there must be a function declaration or inline
255 : : * for user_enable_block_step(), and arch_has_single_step() must be defined
256 : : * too. arch_has_block_step() should evaluate to nonzero iff the machine
257 : : * supports step-until-branch for user mode. It can be a constant or it
258 : : * can test a CPU feature bit.
259 : : */
260 : : #define arch_has_block_step() (0)
261 : :
262 : : /**
263 : : * user_enable_block_step - step until branch in user-mode task
264 : : * @task: either current or a task stopped in %TASK_TRACED
265 : : *
266 : : * This can only be called when arch_has_block_step() has returned nonzero,
267 : : * and will never be called when single-instruction stepping is being used.
268 : : * Set @task so that when it returns to user mode, it will trap after the
269 : : * next branch or trap taken.
270 : : */
271 : : static inline void user_enable_block_step(struct task_struct *task)
272 : : {
273 : : BUG(); /* This can never be called. */
274 : : }
275 : : #else
276 : : extern void user_enable_block_step(struct task_struct *);
277 : : #endif /* arch_has_block_step */
278 : :
279 : : #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
280 : : extern void user_single_step_siginfo(struct task_struct *tsk,
281 : : struct pt_regs *regs, siginfo_t *info);
282 : : #else
283 : : static inline void user_single_step_siginfo(struct task_struct *tsk,
284 : : struct pt_regs *regs, siginfo_t *info)
285 : : {
286 : : memset(info, 0, sizeof(*info));
287 : : info->si_signo = SIGTRAP;
288 : : }
289 : : #endif
290 : :
291 : : #ifndef arch_ptrace_stop_needed
292 : : /**
293 : : * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
294 : : * @code: current->exit_code value ptrace will stop with
295 : : * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
296 : : *
297 : : * This is called with the siglock held, to decide whether or not it's
298 : : * necessary to release the siglock and call arch_ptrace_stop() with the
299 : : * same @code and @info arguments. It can be defined to a constant if
300 : : * arch_ptrace_stop() is never required, or always is. On machines where
301 : : * this makes sense, it should be defined to a quick test to optimize out
302 : : * calling arch_ptrace_stop() when it would be superfluous. For example,
303 : : * if the thread has not been back to user mode since the last stop, the
304 : : * thread state might indicate that nothing needs to be done.
305 : : */
306 : : #define arch_ptrace_stop_needed(code, info) (0)
307 : : #endif
308 : :
309 : : #ifndef arch_ptrace_stop
310 : : /**
311 : : * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
312 : : * @code: current->exit_code value ptrace will stop with
313 : : * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
314 : : *
315 : : * This is called with no locks held when arch_ptrace_stop_needed() has
316 : : * just returned nonzero. It is allowed to block, e.g. for user memory
317 : : * access. The arch can have machine-specific work to be done before
318 : : * ptrace stops. On ia64, register backing store gets written back to user
319 : : * memory here. Since this can be costly (requires dropping the siglock),
320 : : * we only do it when the arch requires it for this particular stop, as
321 : : * indicated by arch_ptrace_stop_needed().
322 : : */
323 : : #define arch_ptrace_stop(code, info) do { } while (0)
324 : : #endif
325 : :
326 : : #ifndef current_pt_regs
327 : : #define current_pt_regs() task_pt_regs(current)
328 : : #endif
329 : :
330 : : #ifndef ptrace_signal_deliver
331 : : #define ptrace_signal_deliver() ((void)0)
332 : : #endif
333 : :
334 : : /*
335 : : * unlike current_pt_regs(), this one is equal to task_pt_regs(current)
336 : : * on *all* architectures; the only reason to have a per-arch definition
337 : : * is optimisation.
338 : : */
339 : : #ifndef signal_pt_regs
340 : : #define signal_pt_regs() task_pt_regs(current)
341 : : #endif
342 : :
343 : : #ifndef current_user_stack_pointer
344 : : #define current_user_stack_pointer() user_stack_pointer(current_pt_regs())
345 : : #endif
346 : :
347 : : extern int task_current_syscall(struct task_struct *target, long *callno,
348 : : unsigned long args[6], unsigned int maxargs,
349 : : unsigned long *sp, unsigned long *pc);
350 : :
351 : : #endif
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