[net-next-2.6.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

/*
 * Generic ptrace interface that exports the architecture specific regsets
 * using the corresponding NT_* types (which are also used in the core dump).
 * Please note that the NT_PRSTATUS note type in a core dump contains a full
 * 'struct elf_prstatus'. But the user_regset for NT_PRSTATUS contains just the
 * elf_gregset_t that is the pr_reg field of 'struct elf_prstatus'. For all the
 * other user_regset flavors, the user_regset layout and the ELF core dump note
 * payload are exactly the same layout.
 *
 * This interface usage is as follows:
 *	struct iovec iov = { buf, len};
 *
 *	ret = ptrace(PTRACE_GETREGSET/PTRACE_SETREGSET, pid, NT_XXX_TYPE, &iov);
 *
 * On the successful completion, iov.len will be updated by the kernel,
 * specifying how much the kernel has written/read to/from the user's iov.buf.
 */
#define PTRACE_GETREGSET	0x4204
#define PTRACE_SETREGSET	0x4205

/* 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,
			unsigned long addr, unsigned long data);
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,
			  unsigned long addr, unsigned 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);
extern void exit_ptrace(struct task_struct *tracer);
#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_unlink(struct task_struct *child)
{
	if (unlikely(child->ptrace))
		__ptrace_unlink(child);
}

int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
			    unsigned long data);
int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
			    unsigned 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) && (current->ptrace & PT_PTRACED)) {
		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)
{
}
#else
extern void user_enable_single_step(struct task_struct *);
extern void user_disable_single_step(struct task_struct *);
#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.  */
}
#else
extern void user_enable_block_step(struct task_struct *);
#endif	/* arch_has_block_step */

#ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
extern void user_single_step_siginfo(struct task_struct *tsk,
				struct pt_regs *regs, siginfo_t *info);
#else
static inline void user_single_step_siginfo(struct task_struct *tsk,
				struct pt_regs *regs, siginfo_t *info)
{
	memset(info, 0, sizeof(*info));
	info->si_signo = SIGTRAP;
}
#endif

#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
2225a122 SS	30	/*
	31	* Generic ptrace interface that exports the architecture specific regsets
	32	* using the corresponding NT_* types (which are also used in the core dump).
c6a0dd7e SS	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.
2225a122 SS	38	*
	39	* This interface usage is as follows:
	40	* struct iovec iov = { buf, len};
	41	*
	42	* ret = ptrace(PTRACE_GETREGSET/PTRACE_SETREGSET, pid, NT_XXX_TYPE, &iov);
	43	*
	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.
	46	*/
	47	#define PTRACE_GETREGSET 0x4204
	48	#define PTRACE_SETREGSET 0x4205
	49
1da177e4 LT	50	/* options set using PTRACE_SETOPTIONS */
	51	#define PTRACE_O_TRACESYSGOOD 0x00000001
	52	#define PTRACE_O_TRACEFORK 0x00000002
	53	#define PTRACE_O_TRACEVFORK 0x00000004
	54	#define PTRACE_O_TRACECLONE 0x00000008
	55	#define PTRACE_O_TRACEEXEC 0x00000010
	56	#define PTRACE_O_TRACEVFORKDONE 0x00000020
	57	#define PTRACE_O_TRACEEXIT 0x00000040
	58
	59	#define PTRACE_O_MASK 0x0000007f
	60
	61	/* Wait extended result codes for the above trace options. */
	62	#define PTRACE_EVENT_FORK 1
	63	#define PTRACE_EVENT_VFORK 2
	64	#define PTRACE_EVENT_CLONE 3
	65	#define PTRACE_EVENT_EXEC 4
	66	#define PTRACE_EVENT_VFORK_DONE 5
	67	#define PTRACE_EVENT_EXIT 6
	68
	69	#include <asm/ptrace.h>
	70
	71	#ifdef __KERNEL__
	72	/*
	73	* Ptrace flags
260ea101 EB	74	*
	75	* The owner ship rules for task->ptrace which holds the ptrace
	76	* flags is simple. When a task is running it owns it's task->ptrace
	77	* flags. When the a task is stopped the ptracer owns task->ptrace.
1da177e4 LT	78	*/
	79
	80	#define PT_PTRACED 0x00000001
	81	#define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
	82	#define PT_TRACESYSGOOD 0x00000004
	83	#define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */
	84	#define PT_TRACE_FORK 0x00000010
	85	#define PT_TRACE_VFORK 0x00000020
	86	#define PT_TRACE_CLONE 0x00000040
	87	#define PT_TRACE_EXEC 0x00000080
	88	#define PT_TRACE_VFORK_DONE 0x00000100
	89	#define PT_TRACE_EXIT 0x00000200
1da177e4 LT	90
	91	#define PT_TRACE_MASK 0x000003f4
	92
	93	/* single stepping state bits (used on ARM and PA-RISC) */
	94	#define PT_SINGLESTEP_BIT 31
	95	#define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT)
	96	#define PT_BLOCKSTEP_BIT 30
	97	#define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT)
	98
	99	#include <linux/compiler.h> /* For unlikely. */
	100	#include <linux/sched.h> /* For struct task_struct. */
	101
481bed45	102
9b05a69e NK	103	extern long arch_ptrace(struct task_struct *child, long request,
9b05a69e NK	104	unsigned long addr, unsigned long data);
6b9c7ed8	105	extern int ptrace_traceme(void);
1da177e4 LT	106	extern int ptrace_readdata(struct task_struct tsk, unsigned long src, char __user dst, int len);
	107	extern int ptrace_writedata(struct task_struct tsk, char __user src, unsigned long dst, int len);
	108	extern int ptrace_attach(struct task_struct *tsk);
	109	extern int ptrace_detach(struct task_struct *, unsigned int);
	110	extern void ptrace_disable(struct task_struct *);
	111	extern int ptrace_check_attach(struct task_struct *task, int kill);
4abf9869 NK	112	extern int ptrace_request(struct task_struct *child, long request,
4abf9869 NK	113	unsigned long addr, unsigned long data);
1da177e4 LT	114	extern void ptrace_notify(int exit_code);
	115	extern void __ptrace_link(struct task_struct *child,
	116	struct task_struct *new_parent);
	117	extern void __ptrace_unlink(struct task_struct *child);
39c626ae	118	extern void exit_ptrace(struct task_struct *tracer);
006ebb40 SS	119	#define PTRACE_MODE_READ 1
	120	#define PTRACE_MODE_ATTACH 2
	121	/* Returns 0 on success, -errno on denial. */
	122	extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
	123	/* Returns true on success, false on denial. */
	124	extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
1da177e4	125
53b6f9fb ON	126	static inline int ptrace_reparented(struct task_struct *child)
	127	{
	128	return child->real_parent != child->parent;
	129	}
c6a47cc2	130
1da177e4 LT	131	static inline void ptrace_unlink(struct task_struct *child)
	132	{
	133	if (unlikely(child->ptrace))
	134	__ptrace_unlink(child);
	135	}
	136
4abf9869 NK	137	int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
	138	unsigned long data);
	139	int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
	140	unsigned long data);
1da177e4	141
88ac2921 RM	142	/**
	143	* task_ptrace - return %PT_* flags that apply to a task
	144	* @task: pointer to &task_struct in question
	145	*
	146	* Returns the %PT_* flags that apply to @task.
	147	*/
	148	static inline int task_ptrace(struct task_struct *task)
	149	{
	150	return task->ptrace;
	151	}
	152
	153	/**
	154	* ptrace_event - possibly stop for a ptrace event notification
	155	* @mask: %PT_* bit to check in @current->ptrace
	156	* @event: %PTRACE_EVENT_* value to report if @mask is set
	157	* @message: value for %PTRACE_GETEVENTMSG to return
	158	*
	159	* This checks the @mask bit to see if ptrace wants stops for this event.
	160	* If so we stop, reporting @event and @message to the ptrace parent.
	161	*
	162	* Returns nonzero if we did a ptrace notification, zero if not.
	163	*
	164	* Called without locks.
	165	*/
	166	static inline int ptrace_event(int mask, int event, unsigned long message)
	167	{
	168	if (mask && likely(!(current->ptrace & mask)))
	169	return 0;
	170	current->ptrace_message = message;
	171	ptrace_notify((event << 8) \| SIGTRAP);
	172	return 1;
	173	}
	174
09a05394 RM	175	/**
	176	* ptrace_init_task - initialize ptrace state for a new child
	177	* @child: new child task
	178	* @ptrace: true if child should be ptrace'd by parent's tracer
	179	*
	180	* This is called immediately after adding @child to its parent's children
	181	* list. @ptrace is false in the normal case, and true to ptrace @child.
	182	*
	183	* Called with current's siglock and write_lock_irq(&tasklist_lock) held.
	184	*/
	185	static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
	186	{
	187	INIT_LIST_HEAD(&child->ptrace_entry);
	188	INIT_LIST_HEAD(&child->ptraced);
	189	child->parent = child->real_parent;
	190	child->ptrace = 0;
c6a47cc2	191	if (unlikely(ptrace) && (current->ptrace & PT_PTRACED)) {
09a05394	192	child->ptrace = current->ptrace;
c6a47cc2	193	__ptrace_link(child, current->parent);
09a05394 RM	194	}
	195	}
	196
dae33574 RM	197	/**
	198	* ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
	199	* @task: task in %EXIT_DEAD state
	200	*
	201	* Called with write_lock(&tasklist_lock) held.
	202	*/
	203	static inline void ptrace_release_task(struct task_struct *task)
	204	{
	205	BUG_ON(!list_empty(&task->ptraced));
	206	ptrace_unlink(task);
	207	BUG_ON(!list_empty(&task->ptrace_entry));
	208	}
	209
1da177e4 LT	210	#ifndef force_successful_syscall_return
	211	/*
	212	* System call handlers that, upon successful completion, need to return a
	213	* negative value should call force_successful_syscall_return() right before
	214	* returning. On architectures where the syscall convention provides for a
	215	* separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
	216	* others), this macro can be used to ensure that the error flag will not get
	217	* set. On architectures which do not support a separate error flag, the macro
	218	* is a no-op and the spurious error condition needs to be filtered out by some
	219	* other means (e.g., in user-level, by passing an extra argument to the
	220	* syscall handler, or something along those lines).
	221	*/
	222	#define force_successful_syscall_return() do { } while (0)
	223	#endif
	224
fb7fa8f1 RM	225	/*
	226	* <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
	227	*
	228	* These do-nothing inlines are used when the arch does not
	229	* implement single-step. The kerneldoc comments are here
	230	* to document the interface for all arch definitions.
	231	*/
	232
	233	#ifndef arch_has_single_step
	234	/**
	235	* arch_has_single_step - does this CPU support user-mode single-step?
	236	*
	237	* If this is defined, then there must be function declarations or
	238	* inlines for user_enable_single_step() and user_disable_single_step().
	239	* arch_has_single_step() should evaluate to nonzero iff the machine
	240	* supports instruction single-step for user mode.
	241	* It can be a constant or it can test a CPU feature bit.
	242	*/
	243	#define arch_has_single_step() (0)
	244
	245	/**
	246	* user_enable_single_step - single-step in user-mode task
	247	* @task: either current or a task stopped in %TASK_TRACED
	248	*
	249	* This can only be called when arch_has_single_step() has returned nonzero.
	250	* Set @task so that when it returns to user mode, it will trap after the
dc802c2d RM	251	* next single instruction executes. If arch_has_block_step() is defined,
dc802c2d RM	252	* this must clear the effects of user_enable_block_step() too.
fb7fa8f1 RM	253	*/
	254	static inline void user_enable_single_step(struct task_struct *task)
	255	{
	256	BUG(); /* This can never be called. */
	257	}
	258
	259	/**
	260	* user_disable_single_step - cancel user-mode single-step
	261	* @task: either current or a task stopped in %TASK_TRACED
	262	*
dc802c2d RM	263	* Clear @task of the effects of user_enable_single_step() and
	264	* user_enable_block_step(). This can be called whether or not either
	265	* of those was ever called on @task, and even if arch_has_single_step()
	266	* returned zero.
fb7fa8f1 RM	267	*/
	268	static inline void user_disable_single_step(struct task_struct *task)
	269	{
	270	}
dacbe41f CH	271	#else
	272	extern void user_enable_single_step(struct task_struct *);
	273	extern void user_disable_single_step(struct task_struct *);
fb7fa8f1 RM	274	#endif /* arch_has_single_step */
fb7fa8f1 RM	275
dc802c2d RM	276	#ifndef arch_has_block_step
	277	/**
	278	* arch_has_block_step - does this CPU support user-mode block-step?
	279	*
	280	* If this is defined, then there must be a function declaration or inline
	281	* for user_enable_block_step(), and arch_has_single_step() must be defined
	282	* too. arch_has_block_step() should evaluate to nonzero iff the machine
	283	* supports step-until-branch for user mode. It can be a constant or it
	284	* can test a CPU feature bit.
	285	*/
5b88abbf	286	#define arch_has_block_step() (0)
dc802c2d RM	287
	288	/**
	289	* user_enable_block_step - step until branch in user-mode task
	290	* @task: either current or a task stopped in %TASK_TRACED
	291	*
	292	* This can only be called when arch_has_block_step() has returned nonzero,
	293	* and will never be called when single-instruction stepping is being used.
	294	* Set @task so that when it returns to user mode, it will trap after the
	295	* next branch or trap taken.
	296	*/
	297	static inline void user_enable_block_step(struct task_struct *task)
	298	{
	299	BUG(); /* This can never be called. */
	300	}
dacbe41f CH	301	#else
dacbe41f CH	302	extern void user_enable_block_step(struct task_struct *);
dc802c2d RM	303	#endif /* arch_has_block_step */
dc802c2d RM	304
85ec7fd9 ON	305	#ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
	306	extern void user_single_step_siginfo(struct task_struct *tsk,
	307	struct pt_regs regs, siginfo_t info);
	308	#else
	309	static inline void user_single_step_siginfo(struct task_struct *tsk,
	310	struct pt_regs regs, siginfo_t info)
	311	{
	312	memset(info, 0, sizeof(*info));
	313	info->si_signo = SIGTRAP;
	314	}
	315	#endif
	316
1a669c2f RM	317	#ifndef arch_ptrace_stop_needed
	318	/**
	319	* arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
	320	* @code: current->exit_code value ptrace will stop with
	321	* @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
	322	*
	323	* This is called with the siglock held, to decide whether or not it's
	324	* necessary to release the siglock and call arch_ptrace_stop() with the
	325	* same @code and @info arguments. It can be defined to a constant if
	326	* arch_ptrace_stop() is never required, or always is. On machines where
	327	* this makes sense, it should be defined to a quick test to optimize out
	328	* calling arch_ptrace_stop() when it would be superfluous. For example,
	329	* if the thread has not been back to user mode since the last stop, the
	330	* thread state might indicate that nothing needs to be done.
	331	*/
	332	#define arch_ptrace_stop_needed(code, info) (0)
	333	#endif
	334
	335	#ifndef arch_ptrace_stop
	336	/**
	337	* arch_ptrace_stop - Do machine-specific work before stopping for ptrace
	338	* @code: current->exit_code value ptrace will stop with
	339	* @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
	340	*
	341	* This is called with no locks held when arch_ptrace_stop_needed() has
	342	* just returned nonzero. It is allowed to block, e.g. for user memory
	343	* access. The arch can have machine-specific work to be done before
	344	* ptrace stops. On ia64, register backing store gets written back to user
	345	* memory here. Since this can be costly (requires dropping the siglock),
	346	* we only do it when the arch requires it for this particular stop, as
	347	* indicated by arch_ptrace_stop_needed().
	348	*/
	349	#define arch_ptrace_stop(code, info) do { } while (0)
	350	#endif
	351
bbc69863 RM	352	extern int task_current_syscall(struct task_struct target, long callno,
	353	unsigned long args[6], unsigned int maxargs,
	354	unsigned long sp, unsigned long pc);
	355
1da177e4 LT	356	#endif
	357
	358	#endif