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