1 #ifndef _LINUX_PTRACE_H
2 #define _LINUX_PTRACE_H
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>
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.
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 */
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)
35 #define PT_EXITKILL (PTRACE_O_EXITKILL << PT_OPT_FLAG_SHIFT)
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)
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
);
61 static inline int ptrace_reparented(struct task_struct
*child
)
63 return !same_thread_group(child
->real_parent
, child
->parent
);
66 static inline void ptrace_unlink(struct task_struct
*child
)
68 if (unlikely(child
->ptrace
))
69 __ptrace_unlink(child
);
72 int generic_ptrace_peekdata(struct task_struct
*tsk
, unsigned long addr
,
74 int generic_ptrace_pokedata(struct task_struct
*tsk
, unsigned long addr
,
78 * ptrace_parent - return the task that is tracing the given task
79 * @task: task to consider
81 * Returns %NULL if no one is tracing @task, or the &struct task_struct
82 * pointer to its tracer.
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.
88 static inline struct task_struct
*ptrace_parent(struct task_struct
*task
)
90 if (unlikely(task
->ptrace
))
91 return rcu_dereference(task
->parent
);
96 * ptrace_event_enabled - test whether a ptrace event is enabled
97 * @task: ptracee of interest
98 * @event: %PTRACE_EVENT_* to test
100 * Test whether @event is enabled for ptracee @task.
102 * Returns %true if @event is enabled, %false otherwise.
104 static inline bool ptrace_event_enabled(struct task_struct
*task
, int event
)
106 return task
->ptrace
& PT_EVENT_FLAG(event
);
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
114 * Check whether @event is enabled and, if so, report @event and @message
115 * to the ptrace parent.
117 * Called without locks.
119 static inline void ptrace_event(int event
, unsigned long message
)
121 if (unlikely(ptrace_event_enabled(current
, event
))) {
122 current
->ptrace_message
= message
;
123 ptrace_notify((event
<< 8) | SIGTRAP
);
124 } else if (event
== PTRACE_EVENT_EXEC
) {
125 /* legacy EXEC report via SIGTRAP */
126 if ((current
->ptrace
& (PT_PTRACED
|PT_SEIZED
)) == PT_PTRACED
)
127 send_sig(SIGTRAP
, current
, 0);
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
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.
139 * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
141 static inline void ptrace_init_task(struct task_struct
*child
, bool ptrace
)
143 INIT_LIST_HEAD(&child
->ptrace_entry
);
144 INIT_LIST_HEAD(&child
->ptraced
);
147 child
->parent
= child
->real_parent
;
149 if (unlikely(ptrace
) && current
->ptrace
) {
150 child
->ptrace
= current
->ptrace
;
151 __ptrace_link(child
, current
->parent
);
153 if (child
->ptrace
& PT_SEIZED
)
154 task_set_jobctl_pending(child
, JOBCTL_TRAP_STOP
);
156 sigaddset(&child
->pending
.signal
, SIGSTOP
);
158 set_tsk_thread_flag(child
, TIF_SIGPENDING
);
163 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
164 * @task: task in %EXIT_DEAD state
166 * Called with write_lock(&tasklist_lock) held.
168 static inline void ptrace_release_task(struct task_struct
*task
)
170 BUG_ON(!list_empty(&task
->ptraced
));
172 BUG_ON(!list_empty(&task
->ptrace_entry
));
175 #ifndef force_successful_syscall_return
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).
187 #define force_successful_syscall_return() do { } while (0)
190 #ifndef is_syscall_success
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.
196 #define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs))))
200 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
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.
207 #ifndef arch_has_single_step
209 * arch_has_single_step - does this CPU support user-mode single-step?
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.
217 #define arch_has_single_step() (0)
220 * user_enable_single_step - single-step in user-mode task
221 * @task: either current or a task stopped in %TASK_TRACED
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.
228 static inline void user_enable_single_step(struct task_struct
*task
)
230 BUG(); /* This can never be called. */
234 * user_disable_single_step - cancel user-mode single-step
235 * @task: either current or a task stopped in %TASK_TRACED
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()
242 static inline void user_disable_single_step(struct task_struct
*task
)
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 */
250 #ifndef arch_has_block_step
252 * arch_has_block_step - does this CPU support user-mode block-step?
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.
260 #define arch_has_block_step() (0)
263 * user_enable_block_step - step until branch in user-mode task
264 * @task: either current or a task stopped in %TASK_TRACED
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.
271 static inline void user_enable_block_step(struct task_struct
*task
)
273 BUG(); /* This can never be called. */
276 extern void user_enable_block_step(struct task_struct
*);
277 #endif /* arch_has_block_step */
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
);
283 static inline void user_single_step_siginfo(struct task_struct
*tsk
,
284 struct pt_regs
*regs
, siginfo_t
*info
)
286 memset(info
, 0, sizeof(*info
));
287 info
->si_signo
= SIGTRAP
;
291 #ifndef arch_ptrace_stop_needed
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
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.
306 #define arch_ptrace_stop_needed(code, info) (0)
309 #ifndef arch_ptrace_stop
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
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().
323 #define arch_ptrace_stop(code, info) do { } while (0)
326 #ifndef current_pt_regs
327 #define current_pt_regs() task_pt_regs(current)
330 #ifndef ptrace_signal_deliver
331 #define ptrace_signal_deliver() ((void)0)
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
339 #ifndef signal_pt_regs
340 #define signal_pt_regs() task_pt_regs(current)
343 #ifndef current_user_stack_pointer
344 #define current_user_stack_pointer() user_stack_pointer(current_pt_regs())
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
);
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