1 #ifndef _LINUX_PTRACE_H
2 #define _LINUX_PTRACE_H
4 /* structs and defines to help the user use the ptrace system call. */
6 /* has the defines to get at the registers. */
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
17 #define PTRACE_SINGLESTEP 9
19 #define PTRACE_ATTACH 16
20 #define PTRACE_DETACH 17
22 #define PTRACE_SYSCALL 24
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
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.
39 * This interface usage is as follows:
40 * struct iovec iov = { buf, len};
42 * ret = ptrace(PTRACE_GETREGSET/PTRACE_SETREGSET, pid, NT_XXX_TYPE, &iov);
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.
47 #define PTRACE_GETREGSET 0x4204
48 #define PTRACE_SETREGSET 0x4205
50 #define PTRACE_SEIZE 0x4206
51 #define PTRACE_INTERRUPT 0x4207
52 #define PTRACE_LISTEN 0x4208
54 /* flags in @data for PTRACE_SEIZE */
55 #define PTRACE_SEIZE_DEVEL 0x80000000 /* temp flag for development */
57 /* options set using PTRACE_SETOPTIONS */
58 #define PTRACE_O_TRACESYSGOOD 0x00000001
59 #define PTRACE_O_TRACEFORK 0x00000002
60 #define PTRACE_O_TRACEVFORK 0x00000004
61 #define PTRACE_O_TRACECLONE 0x00000008
62 #define PTRACE_O_TRACEEXEC 0x00000010
63 #define PTRACE_O_TRACEVFORKDONE 0x00000020
64 #define PTRACE_O_TRACEEXIT 0x00000040
66 #define PTRACE_O_MASK 0x0000007f
68 /* Wait extended result codes for the above trace options. */
69 #define PTRACE_EVENT_FORK 1
70 #define PTRACE_EVENT_VFORK 2
71 #define PTRACE_EVENT_CLONE 3
72 #define PTRACE_EVENT_EXEC 4
73 #define PTRACE_EVENT_VFORK_DONE 5
74 #define PTRACE_EVENT_EXIT 6
75 #define PTRACE_EVENT_STOP 7
77 #include <asm/ptrace.h>
83 * The owner ship rules for task->ptrace which holds the ptrace
84 * flags is simple. When a task is running it owns it's task->ptrace
85 * flags. When the a task is stopped the ptracer owns task->ptrace.
88 #define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */
89 #define PT_PTRACED 0x00000001
90 #define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
91 #define PT_TRACESYSGOOD 0x00000004
92 #define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */
94 /* PT_TRACE_* event enable flags */
95 #define PT_EVENT_FLAG_SHIFT 4
96 #define PT_EVENT_FLAG(event) (1 << (PT_EVENT_FLAG_SHIFT + (event) - 1))
98 #define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK)
99 #define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK)
100 #define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE)
101 #define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC)
102 #define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE)
103 #define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT)
105 #define PT_TRACE_MASK 0x000003f4
107 /* single stepping state bits (used on ARM and PA-RISC) */
108 #define PT_SINGLESTEP_BIT 31
109 #define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT)
110 #define PT_BLOCKSTEP_BIT 30
111 #define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT)
113 #include <linux/compiler.h> /* For unlikely. */
114 #include <linux/sched.h> /* For struct task_struct. */
115 #include <linux/pid_namespace.h> /* For task_active_pid_ns. */
118 extern long arch_ptrace(struct task_struct *child, long request,
119 unsigned long addr, unsigned long data);
120 extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
121 extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
122 extern void ptrace_disable(struct task_struct *);
123 extern int ptrace_check_attach(struct task_struct *task, bool ignore_state);
124 extern int ptrace_request(struct task_struct *child, long request,
125 unsigned long addr, unsigned long data);
126 extern void ptrace_notify(int exit_code);
127 extern void __ptrace_link(struct task_struct *child,
128 struct task_struct *new_parent);
129 extern void __ptrace_unlink(struct task_struct *child);
130 extern void exit_ptrace(struct task_struct *tracer);
131 #define PTRACE_MODE_READ 1
132 #define PTRACE_MODE_ATTACH 2
133 #define PTRACE_MODE_FSCREDS 0x08
134 #define PTRACE_MODE_REALCREDS 0x10
136 /* shorthands for READ/ATTACH and FSCREDS/REALCREDS combinations */
137 #define PTRACE_MODE_READ_FSCREDS (PTRACE_MODE_READ | PTRACE_MODE_FSCREDS)
138 #define PTRACE_MODE_READ_REALCREDS (PTRACE_MODE_READ | PTRACE_MODE_REALCREDS)
139 #define PTRACE_MODE_ATTACH_FSCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_FSCREDS)
140 #define PTRACE_MODE_ATTACH_REALCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_REALCREDS)
142 /* Returns 0 on success, -errno on denial. */
143 extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
145 * ptrace_may_access - check whether the caller is permitted to access
148 * @mode: selects type of access and caller credentials
150 * Returns true on success, false on denial.
152 * One of the flags PTRACE_MODE_FSCREDS and PTRACE_MODE_REALCREDS must
153 * be set in @mode to specify whether the access was requested through
154 * a filesystem syscall (should use effective capabilities and fsuid
155 * of the caller) or through an explicit syscall such as
156 * process_vm_writev or ptrace (and should use the real credentials).
158 extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
160 static inline int ptrace_reparented(struct task_struct *child)
162 return !same_thread_group(child->real_parent, child->parent);
165 static inline void ptrace_unlink(struct task_struct *child)
167 if (unlikely(child->ptrace))
168 __ptrace_unlink(child);
171 int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
173 int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
177 * ptrace_parent - return the task that is tracing the given task
178 * @task: task to consider
180 * Returns %NULL if no one is tracing @task, or the &struct task_struct
181 * pointer to its tracer.
183 * Must called under rcu_read_lock(). The pointer returned might be kept
184 * live only by RCU. During exec, this may be called with task_lock() held
185 * on @task, still held from when check_unsafe_exec() was called.
187 static inline struct task_struct *ptrace_parent(struct task_struct *task)
189 if (unlikely(task->ptrace))
190 return rcu_dereference(task->parent);
195 * ptrace_event_enabled - test whether a ptrace event is enabled
196 * @task: ptracee of interest
197 * @event: %PTRACE_EVENT_* to test
199 * Test whether @event is enabled for ptracee @task.
201 * Returns %true if @event is enabled, %false otherwise.
203 static inline bool ptrace_event_enabled(struct task_struct *task, int event)
205 return task->ptrace & PT_EVENT_FLAG(event);
209 * ptrace_event - possibly stop for a ptrace event notification
210 * @event: %PTRACE_EVENT_* value to report
211 * @message: value for %PTRACE_GETEVENTMSG to return
213 * Check whether @event is enabled and, if so, report @event and @message
214 * to the ptrace parent.
216 * Called without locks.
218 static inline void ptrace_event(int event, unsigned long message)
220 if (unlikely(ptrace_event_enabled(current, event))) {
221 current->ptrace_message = message;
222 ptrace_notify((event << 8) | SIGTRAP);
223 } else if (event == PTRACE_EVENT_EXEC && unlikely(current->ptrace)) {
224 /* legacy EXEC report via SIGTRAP */
225 send_sig(SIGTRAP, current, 0);
230 * ptrace_event_pid - possibly stop for a ptrace event notification
231 * @event: %PTRACE_EVENT_* value to report
232 * @pid: process identifier for %PTRACE_GETEVENTMSG to return
234 * Check whether @event is enabled and, if so, report @event and @pid
235 * to the ptrace parent. @pid is reported as the pid_t seen from the
236 * the ptrace parent's pid namespace.
238 * Called without locks.
240 static inline void ptrace_event_pid(int event, struct pid *pid)
243 * FIXME: There's a potential race if a ptracer in a different pid
244 * namespace than parent attaches between computing message below and
245 * when we acquire tasklist_lock in ptrace_stop(). If this happens,
246 * the ptracer will get a bogus pid from PTRACE_GETEVENTMSG.
248 unsigned long message = 0;
249 struct pid_namespace *ns;
252 ns = task_active_pid_ns(rcu_dereference(current->parent));
254 message = pid_nr_ns(pid, ns);
257 ptrace_event(event, message);
261 * ptrace_init_task - initialize ptrace state for a new child
262 * @child: new child task
263 * @ptrace: true if child should be ptrace'd by parent's tracer
265 * This is called immediately after adding @child to its parent's children
266 * list. @ptrace is false in the normal case, and true to ptrace @child.
268 * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
270 static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
272 INIT_LIST_HEAD(&child->ptrace_entry);
273 INIT_LIST_HEAD(&child->ptraced);
274 #ifdef CONFIG_HAVE_HW_BREAKPOINT
275 atomic_set(&child->ptrace_bp_refcnt, 1);
279 child->parent = child->real_parent;
281 if (unlikely(ptrace) && current->ptrace) {
282 child->ptrace = current->ptrace;
283 __ptrace_link(child, current->parent);
285 if (child->ptrace & PT_SEIZED)
286 task_set_jobctl_pending(child, JOBCTL_TRAP_STOP);
288 sigaddset(&child->pending.signal, SIGSTOP);
290 set_tsk_thread_flag(child, TIF_SIGPENDING);
295 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
296 * @task: task in %EXIT_DEAD state
298 * Called with write_lock(&tasklist_lock) held.
300 static inline void ptrace_release_task(struct task_struct *task)
302 BUG_ON(!list_empty(&task->ptraced));
304 BUG_ON(!list_empty(&task->ptrace_entry));
307 #ifndef force_successful_syscall_return
309 * System call handlers that, upon successful completion, need to return a
310 * negative value should call force_successful_syscall_return() right before
311 * returning. On architectures where the syscall convention provides for a
312 * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
313 * others), this macro can be used to ensure that the error flag will not get
314 * set. On architectures which do not support a separate error flag, the macro
315 * is a no-op and the spurious error condition needs to be filtered out by some
316 * other means (e.g., in user-level, by passing an extra argument to the
317 * syscall handler, or something along those lines).
319 #define force_successful_syscall_return() do { } while (0)
323 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
325 * These do-nothing inlines are used when the arch does not
326 * implement single-step. The kerneldoc comments are here
327 * to document the interface for all arch definitions.
330 #ifndef arch_has_single_step
332 * arch_has_single_step - does this CPU support user-mode single-step?
334 * If this is defined, then there must be function declarations or
335 * inlines for user_enable_single_step() and user_disable_single_step().
336 * arch_has_single_step() should evaluate to nonzero iff the machine
337 * supports instruction single-step for user mode.
338 * It can be a constant or it can test a CPU feature bit.
340 #define arch_has_single_step() (0)
343 * user_enable_single_step - single-step in user-mode task
344 * @task: either current or a task stopped in %TASK_TRACED
346 * This can only be called when arch_has_single_step() has returned nonzero.
347 * Set @task so that when it returns to user mode, it will trap after the
348 * next single instruction executes. If arch_has_block_step() is defined,
349 * this must clear the effects of user_enable_block_step() too.
351 static inline void user_enable_single_step(struct task_struct *task)
353 BUG(); /* This can never be called. */
357 * user_disable_single_step - cancel user-mode single-step
358 * @task: either current or a task stopped in %TASK_TRACED
360 * Clear @task of the effects of user_enable_single_step() and
361 * user_enable_block_step(). This can be called whether or not either
362 * of those was ever called on @task, and even if arch_has_single_step()
365 static inline void user_disable_single_step(struct task_struct *task)
369 extern void user_enable_single_step(struct task_struct *);
370 extern void user_disable_single_step(struct task_struct *);
371 #endif /* arch_has_single_step */
373 #ifndef arch_has_block_step
375 * arch_has_block_step - does this CPU support user-mode block-step?
377 * If this is defined, then there must be a function declaration or inline
378 * for user_enable_block_step(), and arch_has_single_step() must be defined
379 * too. arch_has_block_step() should evaluate to nonzero iff the machine
380 * supports step-until-branch for user mode. It can be a constant or it
381 * can test a CPU feature bit.
383 #define arch_has_block_step() (0)
386 * user_enable_block_step - step until branch in user-mode task
387 * @task: either current or a task stopped in %TASK_TRACED
389 * This can only be called when arch_has_block_step() has returned nonzero,
390 * and will never be called when single-instruction stepping is being used.
391 * Set @task so that when it returns to user mode, it will trap after the
392 * next branch or trap taken.
394 static inline void user_enable_block_step(struct task_struct *task)
396 BUG(); /* This can never be called. */
399 extern void user_enable_block_step(struct task_struct *);
400 #endif /* arch_has_block_step */
402 #ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
403 extern void user_single_step_siginfo(struct task_struct *tsk,
404 struct pt_regs *regs, siginfo_t *info);
406 static inline void user_single_step_siginfo(struct task_struct *tsk,
407 struct pt_regs *regs, siginfo_t *info)
409 memset(info, 0, sizeof(*info));
410 info->si_signo = SIGTRAP;
414 #ifndef arch_ptrace_stop_needed
416 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
417 * @code: current->exit_code value ptrace will stop with
418 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
420 * This is called with the siglock held, to decide whether or not it's
421 * necessary to release the siglock and call arch_ptrace_stop() with the
422 * same @code and @info arguments. It can be defined to a constant if
423 * arch_ptrace_stop() is never required, or always is. On machines where
424 * this makes sense, it should be defined to a quick test to optimize out
425 * calling arch_ptrace_stop() when it would be superfluous. For example,
426 * if the thread has not been back to user mode since the last stop, the
427 * thread state might indicate that nothing needs to be done.
429 * This is guaranteed to be invoked once before a task stops for ptrace and
430 * may include arch-specific operations necessary prior to a ptrace stop.
432 #define arch_ptrace_stop_needed(code, info) (0)
435 #ifndef arch_ptrace_stop
437 * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
438 * @code: current->exit_code value ptrace will stop with
439 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
441 * This is called with no locks held when arch_ptrace_stop_needed() has
442 * just returned nonzero. It is allowed to block, e.g. for user memory
443 * access. The arch can have machine-specific work to be done before
444 * ptrace stops. On ia64, register backing store gets written back to user
445 * memory here. Since this can be costly (requires dropping the siglock),
446 * we only do it when the arch requires it for this particular stop, as
447 * indicated by arch_ptrace_stop_needed().
449 #define arch_ptrace_stop(code, info) do { } while (0)
452 extern int task_current_syscall(struct task_struct *target, long *callno,
453 unsigned long args[6], unsigned int maxargs,
454 unsigned long *sp, unsigned long *pc);
456 #ifdef CONFIG_HAVE_HW_BREAKPOINT
457 extern int ptrace_get_breakpoints(struct task_struct *tsk);
458 extern void ptrace_put_breakpoints(struct task_struct *tsk);
460 static inline void ptrace_put_breakpoints(struct task_struct *tsk) { }
461 #endif /* CONFIG_HAVE_HW_BREAKPOINT */
463 #endif /* __KERNEL */