[deliverable/linux.git] / include / linux / ptrace.h

#ifndef _LINUX_PTRACE_H
#define _LINUX_PTRACE_H
/* ptrace.h */
/* structs and defines to help the user use the ptrace system call. */

/* has the defines to get at the registers. */

#define PTRACE_TRACEME		   0
#define PTRACE_PEEKTEXT		   1
#define PTRACE_PEEKDATA		   2
#define PTRACE_PEEKUSR		   3
#define PTRACE_POKETEXT		   4
#define PTRACE_POKEDATA		   5
#define PTRACE_POKEUSR		   6
#define PTRACE_CONT		   7
#define PTRACE_KILL		   8
#define PTRACE_SINGLESTEP	   9

#define PTRACE_ATTACH		  16
#define PTRACE_DETACH		  17

#define PTRACE_SYSCALL		  24

/* 0x4200-0x4300 are reserved for architecture-independent additions.  */
#define PTRACE_SETOPTIONS	0x4200
#define PTRACE_GETEVENTMSG	0x4201
#define PTRACE_GETSIGINFO	0x4202
#define PTRACE_SETSIGINFO	0x4203

/* options set using PTRACE_SETOPTIONS */
#define PTRACE_O_TRACESYSGOOD	0x00000001
#define PTRACE_O_TRACEFORK	0x00000002
#define PTRACE_O_TRACEVFORK	0x00000004
#define PTRACE_O_TRACECLONE	0x00000008
#define PTRACE_O_TRACEEXEC	0x00000010
#define PTRACE_O_TRACEVFORKDONE	0x00000020
#define PTRACE_O_TRACEEXIT	0x00000040

#define PTRACE_O_MASK		0x0000007f

/* Wait extended result codes for the above trace options.  */
#define PTRACE_EVENT_FORK	1
#define PTRACE_EVENT_VFORK	2
#define PTRACE_EVENT_CLONE	3
#define PTRACE_EVENT_EXEC	4
#define PTRACE_EVENT_VFORK_DONE	5
#define PTRACE_EVENT_EXIT	6

#include <asm/ptrace.h>

#ifdef __KERNEL__
/*
 * Ptrace flags
 *
 * The owner ship rules for task->ptrace which holds the ptrace
 * flags is simple.  When a task is running it owns it's task->ptrace
 * flags.  When the a task is stopped the ptracer owns task->ptrace.
 */

#define PT_PTRACED	0x00000001
#define PT_DTRACE	0x00000002	/* delayed trace (used on m68k, i386) */
#define PT_TRACESYSGOOD	0x00000004
#define PT_PTRACE_CAP	0x00000008	/* ptracer can follow suid-exec */
#define PT_TRACE_FORK	0x00000010
#define PT_TRACE_VFORK	0x00000020
#define PT_TRACE_CLONE	0x00000040
#define PT_TRACE_EXEC	0x00000080
#define PT_TRACE_VFORK_DONE	0x00000100
#define PT_TRACE_EXIT	0x00000200

#define PT_TRACE_MASK	0x000003f4

/* single stepping state bits (used on ARM and PA-RISC) */
#define PT_SINGLESTEP_BIT	31
#define PT_SINGLESTEP		(1<<PT_SINGLESTEP_BIT)
#define PT_BLOCKSTEP_BIT	30
#define PT_BLOCKSTEP		(1<<PT_BLOCKSTEP_BIT)

#include <linux/compiler.h>		/* For unlikely.  */
#include <linux/sched.h>		/* For struct task_struct.  */


extern long arch_ptrace(struct task_struct *child, long request, long addr, long data);
extern struct task_struct *ptrace_get_task_struct(pid_t pid);
extern int ptrace_traceme(void);
extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
extern int ptrace_attach(struct task_struct *tsk);
extern int ptrace_detach(struct task_struct *, unsigned int);
extern void ptrace_disable(struct task_struct *);
extern int ptrace_check_attach(struct task_struct *task, int kill);
extern int ptrace_request(struct task_struct *child, long request, long addr, long data);
extern void ptrace_notify(int exit_code);
extern void __ptrace_link(struct task_struct *child,
			  struct task_struct *new_parent);
extern void __ptrace_unlink(struct task_struct *child);
#define PTRACE_MODE_READ   1
#define PTRACE_MODE_ATTACH 2
/* Returns 0 on success, -errno on denial. */
extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
/* Returns true on success, false on denial. */
extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);

static inline int ptrace_reparented(struct task_struct *child)
{
	return child->real_parent != child->parent;
}
static inline void ptrace_link(struct task_struct *child,
			       struct task_struct *new_parent)
{
	if (unlikely(child->ptrace))
		__ptrace_link(child, new_parent);
}
static inline void ptrace_unlink(struct task_struct *child)
{
	if (unlikely(child->ptrace))
		__ptrace_unlink(child);
}

int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data);
int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data);

/**
 * task_ptrace - return %PT_* flags that apply to a task
 * @task:	pointer to &task_struct in question
 *
 * Returns the %PT_* flags that apply to @task.
 */
static inline int task_ptrace(struct task_struct *task)
{
	return task->ptrace;
}

/**
 * ptrace_event - possibly stop for a ptrace event notification
 * @mask:	%PT_* bit to check in @current->ptrace
 * @event:	%PTRACE_EVENT_* value to report if @mask is set
 * @message:	value for %PTRACE_GETEVENTMSG to return
 *
 * This checks the @mask bit to see if ptrace wants stops for this event.
 * If so we stop, reporting @event and @message to the ptrace parent.
 *
 * Returns nonzero if we did a ptrace notification, zero if not.
 *
 * Called without locks.
 */
static inline int ptrace_event(int mask, int event, unsigned long message)
{
	if (mask && likely(!(current->ptrace & mask)))
		return 0;
	current->ptrace_message = message;
	ptrace_notify((event << 8) | SIGTRAP);
	return 1;
}

/**
 * ptrace_init_task - initialize ptrace state for a new child
 * @child:		new child task
 * @ptrace:		true if child should be ptrace'd by parent's tracer
 *
 * This is called immediately after adding @child to its parent's children
 * list.  @ptrace is false in the normal case, and true to ptrace @child.
 *
 * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
 */
static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
{
	INIT_LIST_HEAD(&child->ptrace_entry);
	INIT_LIST_HEAD(&child->ptraced);
	child->parent = child->real_parent;
	child->ptrace = 0;
	if (unlikely(ptrace)) {
		child->ptrace = current->ptrace;
		ptrace_link(child, current->parent);
	}
}

/**
 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
 * @task:	task in %EXIT_DEAD state
 *
 * Called with write_lock(&tasklist_lock) held.
 */
static inline void ptrace_release_task(struct task_struct *task)
{
	BUG_ON(!list_empty(&task->ptraced));
	ptrace_unlink(task);
	BUG_ON(!list_empty(&task->ptrace_entry));
}

#ifndef force_successful_syscall_return
/*
 * System call handlers that, upon successful completion, need to return a
 * negative value should call force_successful_syscall_return() right before
 * returning.  On architectures where the syscall convention provides for a
 * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
 * others), this macro can be used to ensure that the error flag will not get
 * set.  On architectures which do not support a separate error flag, the macro
 * is a no-op and the spurious error condition needs to be filtered out by some
 * other means (e.g., in user-level, by passing an extra argument to the
 * syscall handler, or something along those lines).
 */
#define force_successful_syscall_return() do { } while (0)
#endif

/*
 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
 *
 * These do-nothing inlines are used when the arch does not
 * implement single-step.  The kerneldoc comments are here
 * to document the interface for all arch definitions.
 */

#ifndef arch_has_single_step
/**
 * arch_has_single_step - does this CPU support user-mode single-step?
 *
 * If this is defined, then there must be function declarations or
 * inlines for user_enable_single_step() and user_disable_single_step().
 * arch_has_single_step() should evaluate to nonzero iff the machine
 * supports instruction single-step for user mode.
 * It can be a constant or it can test a CPU feature bit.
 */
#define arch_has_single_step()		(0)

/**
 * user_enable_single_step - single-step in user-mode task
 * @task: either current or a task stopped in %TASK_TRACED
 *
 * This can only be called when arch_has_single_step() has returned nonzero.
 * Set @task so that when it returns to user mode, it will trap after the
 * next single instruction executes.  If arch_has_block_step() is defined,
 * this must clear the effects of user_enable_block_step() too.
 */
static inline void user_enable_single_step(struct task_struct *task)
{
	BUG();			/* This can never be called.  */
}

/**
 * user_disable_single_step - cancel user-mode single-step
 * @task: either current or a task stopped in %TASK_TRACED
 *
 * Clear @task of the effects of user_enable_single_step() and
 * user_enable_block_step().  This can be called whether or not either
 * of those was ever called on @task, and even if arch_has_single_step()
 * returned zero.
 */
static inline void user_disable_single_step(struct task_struct *task)
{
}
#endif	/* arch_has_single_step */

#ifndef arch_has_block_step
/**
 * arch_has_block_step - does this CPU support user-mode block-step?
 *
 * If this is defined, then there must be a function declaration or inline
 * for user_enable_block_step(), and arch_has_single_step() must be defined
 * too.  arch_has_block_step() should evaluate to nonzero iff the machine
 * supports step-until-branch for user mode.  It can be a constant or it
 * can test a CPU feature bit.
 */
#define arch_has_block_step()		(0)

/**
 * user_enable_block_step - step until branch in user-mode task
 * @task: either current or a task stopped in %TASK_TRACED
 *
 * This can only be called when arch_has_block_step() has returned nonzero,
 * and will never be called when single-instruction stepping is being used.
 * Set @task so that when it returns to user mode, it will trap after the
 * next branch or trap taken.
 */
static inline void user_enable_block_step(struct task_struct *task)
{
	BUG();			/* This can never be called.  */
}
#endif	/* arch_has_block_step */

#ifndef arch_ptrace_stop_needed
/**
 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
 * @code:	current->exit_code value ptrace will stop with
 * @info:	siginfo_t pointer (or %NULL) for signal ptrace will stop with
 *
 * This is called with the siglock held, to decide whether or not it's
 * necessary to release the siglock and call arch_ptrace_stop() with the
 * same @code and @info arguments.  It can be defined to a constant if
 * arch_ptrace_stop() is never required, or always is.  On machines where
 * this makes sense, it should be defined to a quick test to optimize out
 * calling arch_ptrace_stop() when it would be superfluous.  For example,
 * if the thread has not been back to user mode since the last stop, the
 * thread state might indicate that nothing needs to be done.
 */
#define arch_ptrace_stop_needed(code, info)	(0)
#endif

#ifndef arch_ptrace_stop
/**
 * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
 * @code:	current->exit_code value ptrace will stop with
 * @info:	siginfo_t pointer (or %NULL) for signal ptrace will stop with
 *
 * This is called with no locks held when arch_ptrace_stop_needed() has
 * just returned nonzero.  It is allowed to block, e.g. for user memory
 * access.  The arch can have machine-specific work to be done before
 * ptrace stops.  On ia64, register backing store gets written back to user
 * memory here.  Since this can be costly (requires dropping the siglock),
 * we only do it when the arch requires it for this particular stop, as
 * indicated by arch_ptrace_stop_needed().
 */
#define arch_ptrace_stop(code, info)		do { } while (0)
#endif

extern int task_current_syscall(struct task_struct *target, long *callno,
				unsigned long args[6], unsigned int maxargs,
				unsigned long *sp, unsigned long *pc);

#endif

#endif
Commit	Line	Data
1da177e4 LT	1	#ifndef _LINUX_PTRACE_H
	2	#define _LINUX_PTRACE_H
	3	/* ptrace.h */
	4	/* structs and defines to help the user use the ptrace system call. */
	5
	6	/* has the defines to get at the registers. */
	7
	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
	15	#define PTRACE_CONT 7
	16	#define PTRACE_KILL 8
	17	#define PTRACE_SINGLESTEP 9
	18
416bc512 RM	19	#define PTRACE_ATTACH 16
416bc512 RM	20	#define PTRACE_DETACH 17
1da177e4 LT	21
	22	#define PTRACE_SYSCALL 24
	23
	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
	29
	30	/* options set using PTRACE_SETOPTIONS */
	31	#define PTRACE_O_TRACESYSGOOD 0x00000001
	32	#define PTRACE_O_TRACEFORK 0x00000002
	33	#define PTRACE_O_TRACEVFORK 0x00000004
	34	#define PTRACE_O_TRACECLONE 0x00000008
	35	#define PTRACE_O_TRACEEXEC 0x00000010
	36	#define PTRACE_O_TRACEVFORKDONE 0x00000020
	37	#define PTRACE_O_TRACEEXIT 0x00000040
	38
	39	#define PTRACE_O_MASK 0x0000007f
	40
	41	/* Wait extended result codes for the above trace options. */
	42	#define PTRACE_EVENT_FORK 1
	43	#define PTRACE_EVENT_VFORK 2
	44	#define PTRACE_EVENT_CLONE 3
	45	#define PTRACE_EVENT_EXEC 4
	46	#define PTRACE_EVENT_VFORK_DONE 5
	47	#define PTRACE_EVENT_EXIT 6
	48
	49	#include <asm/ptrace.h>
	50
	51	#ifdef __KERNEL__
	52	/*
	53	* Ptrace flags
260ea101 EB	54	*
	55	* The owner ship rules for task->ptrace which holds the ptrace
	56	* flags is simple. When a task is running it owns it's task->ptrace
	57	* flags. When the a task is stopped the ptracer owns task->ptrace.
1da177e4 LT	58	*/
	59
	60	#define PT_PTRACED 0x00000001
	61	#define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
	62	#define PT_TRACESYSGOOD 0x00000004
	63	#define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */
	64	#define PT_TRACE_FORK 0x00000010
	65	#define PT_TRACE_VFORK 0x00000020
	66	#define PT_TRACE_CLONE 0x00000040
	67	#define PT_TRACE_EXEC 0x00000080
	68	#define PT_TRACE_VFORK_DONE 0x00000100
	69	#define PT_TRACE_EXIT 0x00000200
1da177e4 LT	70
	71	#define PT_TRACE_MASK 0x000003f4
	72
	73	/* single stepping state bits (used on ARM and PA-RISC) */
	74	#define PT_SINGLESTEP_BIT 31
	75	#define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT)
	76	#define PT_BLOCKSTEP_BIT 30
	77	#define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT)
	78
	79	#include <linux/compiler.h> /* For unlikely. */
	80	#include <linux/sched.h> /* For struct task_struct. */
	81
481bed45 CH	82
481bed45 CH	83	extern long arch_ptrace(struct task_struct *child, long request, long addr, long data);
6b9c7ed8 CH	84	extern struct task_struct *ptrace_get_task_struct(pid_t pid);
6b9c7ed8 CH	85	extern int ptrace_traceme(void);
1da177e4 LT	86	extern int ptrace_readdata(struct task_struct tsk, unsigned long src, char __user dst, int len);
	87	extern int ptrace_writedata(struct task_struct tsk, char __user src, unsigned long dst, int len);
	88	extern int ptrace_attach(struct task_struct *tsk);
	89	extern int ptrace_detach(struct task_struct *, unsigned int);
	90	extern void ptrace_disable(struct task_struct *);
	91	extern int ptrace_check_attach(struct task_struct *task, int kill);
	92	extern int ptrace_request(struct task_struct *child, long request, long addr, long data);
	93	extern void ptrace_notify(int exit_code);
	94	extern void __ptrace_link(struct task_struct *child,
	95	struct task_struct *new_parent);
	96	extern void __ptrace_unlink(struct task_struct *child);
006ebb40 SS	97	#define PTRACE_MODE_READ 1
	98	#define PTRACE_MODE_ATTACH 2
	99	/* Returns 0 on success, -errno on denial. */
	100	extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
	101	/* Returns true on success, false on denial. */
	102	extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
1da177e4	103
53b6f9fb ON	104	static inline int ptrace_reparented(struct task_struct *child)
	105	{
	106	return child->real_parent != child->parent;
	107	}
1da177e4 LT	108	static inline void ptrace_link(struct task_struct *child,
	109	struct task_struct *new_parent)
	110	{
	111	if (unlikely(child->ptrace))
	112	__ptrace_link(child, new_parent);
	113	}
	114	static inline void ptrace_unlink(struct task_struct *child)
	115	{
	116	if (unlikely(child->ptrace))
	117	__ptrace_unlink(child);
	118	}
	119
76647323	120	int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data);
f284ce72	121	int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data);
1da177e4	122
88ac2921 RM	123	/**
	124	* task_ptrace - return %PT_* flags that apply to a task
	125	* @task: pointer to &task_struct in question
	126	*
	127	* Returns the %PT_* flags that apply to @task.
	128	*/
	129	static inline int task_ptrace(struct task_struct *task)
	130	{
	131	return task->ptrace;
	132	}
	133
	134	/**
	135	* ptrace_event - possibly stop for a ptrace event notification
	136	* @mask: %PT_* bit to check in @current->ptrace
	137	* @event: %PTRACE_EVENT_* value to report if @mask is set
	138	* @message: value for %PTRACE_GETEVENTMSG to return
	139	*
	140	* This checks the @mask bit to see if ptrace wants stops for this event.
	141	* If so we stop, reporting @event and @message to the ptrace parent.
	142	*
	143	* Returns nonzero if we did a ptrace notification, zero if not.
	144	*
	145	* Called without locks.
	146	*/
	147	static inline int ptrace_event(int mask, int event, unsigned long message)
	148	{
	149	if (mask && likely(!(current->ptrace & mask)))
	150	return 0;
	151	current->ptrace_message = message;
	152	ptrace_notify((event << 8) \| SIGTRAP);
	153	return 1;
	154	}
	155
09a05394 RM	156	/**
	157	* ptrace_init_task - initialize ptrace state for a new child
	158	* @child: new child task
	159	* @ptrace: true if child should be ptrace'd by parent's tracer
	160	*
	161	* This is called immediately after adding @child to its parent's children
	162	* list. @ptrace is false in the normal case, and true to ptrace @child.
	163	*
	164	* Called with current's siglock and write_lock_irq(&tasklist_lock) held.
	165	*/
	166	static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
	167	{
	168	INIT_LIST_HEAD(&child->ptrace_entry);
	169	INIT_LIST_HEAD(&child->ptraced);
	170	child->parent = child->real_parent;
	171	child->ptrace = 0;
	172	if (unlikely(ptrace)) {
	173	child->ptrace = current->ptrace;
5861bbfc	174	ptrace_link(child, current->parent);
09a05394 RM	175	}
	176	}
	177
dae33574 RM	178	/**
	179	* ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
	180	* @task: task in %EXIT_DEAD state
	181	*
	182	* Called with write_lock(&tasklist_lock) held.
	183	*/
	184	static inline void ptrace_release_task(struct task_struct *task)
	185	{
	186	BUG_ON(!list_empty(&task->ptraced));
	187	ptrace_unlink(task);
	188	BUG_ON(!list_empty(&task->ptrace_entry));
	189	}
	190
1da177e4 LT	191	#ifndef force_successful_syscall_return
	192	/*
	193	* System call handlers that, upon successful completion, need to return a
	194	* negative value should call force_successful_syscall_return() right before
	195	* returning. On architectures where the syscall convention provides for a
	196	* separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
	197	* others), this macro can be used to ensure that the error flag will not get
	198	* set. On architectures which do not support a separate error flag, the macro
	199	* is a no-op and the spurious error condition needs to be filtered out by some
	200	* other means (e.g., in user-level, by passing an extra argument to the
	201	* syscall handler, or something along those lines).
	202	*/
	203	#define force_successful_syscall_return() do { } while (0)
	204	#endif
	205
fb7fa8f1 RM	206	/*
	207	* <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
	208	*
	209	* These do-nothing inlines are used when the arch does not
	210	* implement single-step. The kerneldoc comments are here
	211	* to document the interface for all arch definitions.
	212	*/
	213
	214	#ifndef arch_has_single_step
	215	/**
	216	* arch_has_single_step - does this CPU support user-mode single-step?
	217	*
	218	* If this is defined, then there must be function declarations or
	219	* inlines for user_enable_single_step() and user_disable_single_step().
	220	* arch_has_single_step() should evaluate to nonzero iff the machine
	221	* supports instruction single-step for user mode.
	222	* It can be a constant or it can test a CPU feature bit.
	223	*/
	224	#define arch_has_single_step() (0)
	225
	226	/**
	227	* user_enable_single_step - single-step in user-mode task
	228	* @task: either current or a task stopped in %TASK_TRACED
	229	*
	230	* This can only be called when arch_has_single_step() has returned nonzero.
	231	* Set @task so that when it returns to user mode, it will trap after the
dc802c2d RM	232	* next single instruction executes. If arch_has_block_step() is defined,
dc802c2d RM	233	* this must clear the effects of user_enable_block_step() too.
fb7fa8f1 RM	234	*/
	235	static inline void user_enable_single_step(struct task_struct *task)
	236	{
	237	BUG(); /* This can never be called. */
	238	}
	239
	240	/**
	241	* user_disable_single_step - cancel user-mode single-step
	242	* @task: either current or a task stopped in %TASK_TRACED
	243	*
dc802c2d RM	244	* Clear @task of the effects of user_enable_single_step() and
	245	* user_enable_block_step(). This can be called whether or not either
	246	* of those was ever called on @task, and even if arch_has_single_step()
	247	* returned zero.
fb7fa8f1 RM	248	*/
	249	static inline void user_disable_single_step(struct task_struct *task)
	250	{
	251	}
	252	#endif /* arch_has_single_step */
	253
dc802c2d RM	254	#ifndef arch_has_block_step
	255	/**
	256	* arch_has_block_step - does this CPU support user-mode block-step?
	257	*
	258	* If this is defined, then there must be a function declaration or inline
	259	* for user_enable_block_step(), and arch_has_single_step() must be defined
	260	* too. arch_has_block_step() should evaluate to nonzero iff the machine
	261	* supports step-until-branch for user mode. It can be a constant or it
	262	* can test a CPU feature bit.
	263	*/
5b88abbf	264	#define arch_has_block_step() (0)
dc802c2d RM	265
	266	/**
	267	* user_enable_block_step - step until branch in user-mode task
	268	* @task: either current or a task stopped in %TASK_TRACED
	269	*
	270	* This can only be called when arch_has_block_step() has returned nonzero,
	271	* and will never be called when single-instruction stepping is being used.
	272	* Set @task so that when it returns to user mode, it will trap after the
	273	* next branch or trap taken.
	274	*/
	275	static inline void user_enable_block_step(struct task_struct *task)
	276	{
	277	BUG(); /* This can never be called. */
	278	}
	279	#endif /* arch_has_block_step */
	280
1a669c2f RM	281	#ifndef arch_ptrace_stop_needed
	282	/**
	283	* arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
	284	* @code: current->exit_code value ptrace will stop with
	285	* @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
	286	*
	287	* This is called with the siglock held, to decide whether or not it's
	288	* necessary to release the siglock and call arch_ptrace_stop() with the
	289	* same @code and @info arguments. It can be defined to a constant if
	290	* arch_ptrace_stop() is never required, or always is. On machines where
	291	* this makes sense, it should be defined to a quick test to optimize out
	292	* calling arch_ptrace_stop() when it would be superfluous. For example,
	293	* if the thread has not been back to user mode since the last stop, the
	294	* thread state might indicate that nothing needs to be done.
	295	*/
	296	#define arch_ptrace_stop_needed(code, info) (0)
	297	#endif
	298
	299	#ifndef arch_ptrace_stop
	300	/**
	301	* arch_ptrace_stop - Do machine-specific work before stopping for ptrace
	302	* @code: current->exit_code value ptrace will stop with
	303	* @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
	304	*
	305	* This is called with no locks held when arch_ptrace_stop_needed() has
	306	* just returned nonzero. It is allowed to block, e.g. for user memory
	307	* access. The arch can have machine-specific work to be done before
	308	* ptrace stops. On ia64, register backing store gets written back to user
	309	* memory here. Since this can be costly (requires dropping the siglock),
	310	* we only do it when the arch requires it for this particular stop, as
	311	* indicated by arch_ptrace_stop_needed().
	312	*/
	313	#define arch_ptrace_stop(code, info) do { } while (0)
	314	#endif
	315
bbc69863 RM	316	extern int task_current_syscall(struct task_struct target, long callno,
	317	unsigned long args[6], unsigned int maxargs,
	318	unsigned long sp, unsigned long pc);
	319
1da177e4 LT	320	#endif
	321
	322	#endif