[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

/*
 * 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

#define PTRACE_SEIZE		0x4206
#define PTRACE_INTERRUPT	0x4207
#define PTRACE_LISTEN		0x4208

/* flags in @data for PTRACE_SEIZE */
#define PTRACE_SEIZE_DEVEL	0x80000000 /* temp flag for development */

/* 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
#define PTRACE_EVENT_STOP	7

#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_SEIZED	0x00010000	/* SEIZE used, enable new behavior */
#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 */

/* PT_TRACE_* event enable flags */
#define PT_EVENT_FLAG_SHIFT	4
#define PT_EVENT_FLAG(event)	(1 << (PT_EVENT_FLAG_SHIFT + (event) - 1))

#define PT_TRACE_FORK		PT_EVENT_FLAG(PTRACE_EVENT_FORK)
#define PT_TRACE_VFORK		PT_EVENT_FLAG(PTRACE_EVENT_VFORK)
#define PT_TRACE_CLONE		PT_EVENT_FLAG(PTRACE_EVENT_CLONE)
#define PT_TRACE_EXEC		PT_EVENT_FLAG(PTRACE_EVENT_EXEC)
#define PT_TRACE_VFORK_DONE	PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE)
#define PT_TRACE_EXIT		PT_EVENT_FLAG(PTRACE_EVENT_EXIT)

#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.  */
#include <linux/err.h>			/* for IS_ERR_VALUE */
#include <linux/bug.h>			/* For BUG_ON.  */


extern long arch_ptrace(struct task_struct *child, long request,
			unsigned long addr, unsigned long data);
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 void ptrace_disable(struct task_struct *);
extern int ptrace_check_attach(struct task_struct *task, bool ignore_state);
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	0x01
#define PTRACE_MODE_ATTACH	0x02
#define PTRACE_MODE_NOAUDIT	0x04
/* 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 !same_thread_group(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);

/**
 * ptrace_parent - return the task that is tracing the given task
 * @task: task to consider
 *
 * Returns %NULL if no one is tracing @task, or the &struct task_struct
 * pointer to its tracer.
 *
 * Must called under rcu_read_lock().  The pointer returned might be kept
 * live only by RCU.  During exec, this may be called with task_lock() held
 * on @task, still held from when check_unsafe_exec() was called.
 */
static inline struct task_struct *ptrace_parent(struct task_struct *task)
{
	if (unlikely(task->ptrace))
		return rcu_dereference(task->parent);
	return NULL;
}

/**
 * ptrace_event_enabled - test whether a ptrace event is enabled
 * @task: ptracee of interest
 * @event: %PTRACE_EVENT_* to test
 *
 * Test whether @event is enabled for ptracee @task.
 *
 * Returns %true if @event is enabled, %false otherwise.
 */
static inline bool ptrace_event_enabled(struct task_struct *task, int event)
{
	return task->ptrace & PT_EVENT_FLAG(event);
}

/**
 * ptrace_event - possibly stop for a ptrace event notification
 * @event:	%PTRACE_EVENT_* value to report
 * @message:	value for %PTRACE_GETEVENTMSG to return
 *
 * Check whether @event is enabled and, if so, report @event and @message
 * to the ptrace parent.
 *
 * Called without locks.
 */
static inline void ptrace_event(int event, unsigned long message)
{
	if (unlikely(ptrace_event_enabled(current, event))) {
		current->ptrace_message = message;
		ptrace_notify((event << 8) | SIGTRAP);
	} else if (event == PTRACE_EVENT_EXEC && unlikely(current->ptrace)) {
		/* legacy EXEC report via SIGTRAP */
		send_sig(SIGTRAP, current, 0);
	}
}

/**
 * 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);
#ifdef CONFIG_HAVE_HW_BREAKPOINT
	atomic_set(&child->ptrace_bp_refcnt, 1);
#endif
	child->jobctl = 0;
	child->ptrace = 0;
	child->parent = child->real_parent;

	if (unlikely(ptrace) && current->ptrace) {
		child->ptrace = current->ptrace;
		__ptrace_link(child, current->parent);

		if (child->ptrace & PT_SEIZED)
			task_set_jobctl_pending(child, JOBCTL_TRAP_STOP);
		else
			sigaddset(&child->pending.signal, SIGSTOP);

		set_tsk_thread_flag(child, TIF_SIGPENDING);
	}
}

/**
 * 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

#ifndef is_syscall_success
/*
 * On most systems we can tell if a syscall is a success based on if the retval
 * is an error value.  On some systems like ia64 and powerpc they have different
 * indicators of success/failure and must define their own.
 */
#define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs))))
#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);

#ifdef CONFIG_HAVE_HW_BREAKPOINT
extern int ptrace_get_breakpoints(struct task_struct *tsk);
extern void ptrace_put_breakpoints(struct task_struct *tsk);
#else
static inline void ptrace_put_breakpoints(struct task_struct *tsk) { }
#endif /* CONFIG_HAVE_HW_BREAKPOINT */

#endif /* __KERNEL */

#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
3544d72a	50	#define PTRACE_SEIZE 0x4206
fca26f26	51	#define PTRACE_INTERRUPT 0x4207
544b2c91	52	#define PTRACE_LISTEN 0x4208
3544d72a TH	53
	54	/* flags in @data for PTRACE_SEIZE */
	55	#define PTRACE_SEIZE_DEVEL 0x80000000 /* temp flag for development */
	56
1da177e4 LT	57	/* options set using PTRACE_SETOPTIONS */
	58	#define PTRACE_O_TRACESYSGOOD 0x00000001
	59	#define PTRACE_O_TRACEFORK 0x00000002
	60	#define PTRACE_O_TRACEVFORK 0x00000004
	61	#define PTRACE_O_TRACECLONE 0x00000008
	62	#define PTRACE_O_TRACEEXEC 0x00000010
	63	#define PTRACE_O_TRACEVFORKDONE 0x00000020
	64	#define PTRACE_O_TRACEEXIT 0x00000040
	65
	66	#define PTRACE_O_MASK 0x0000007f
	67
	68	/* Wait extended result codes for the above trace options. */
	69	#define PTRACE_EVENT_FORK 1
	70	#define PTRACE_EVENT_VFORK 2
	71	#define PTRACE_EVENT_CLONE 3
	72	#define PTRACE_EVENT_EXEC 4
	73	#define PTRACE_EVENT_VFORK_DONE 5
	74	#define PTRACE_EVENT_EXIT 6
3544d72a	75	#define PTRACE_EVENT_STOP 7
1da177e4 LT	76
	77	#include <asm/ptrace.h>
	78
	79	#ifdef __KERNEL__
	80	/*
	81	* Ptrace flags
260ea101 EB	82	*
	83	* The owner ship rules for task->ptrace which holds the ptrace
	84	* flags is simple. When a task is running it owns it's task->ptrace
	85	* flags. When the a task is stopped the ptracer owns task->ptrace.
1da177e4 LT	86	*/
1da177e4 LT	87
3544d72a	88	#define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */
1da177e4 LT	89	#define PT_PTRACED 0x00000001
	90	#define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
	91	#define PT_TRACESYSGOOD 0x00000004
	92	#define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */
643ad838 TH	93
	94	/* PT_TRACE_* event enable flags */
	95	#define PT_EVENT_FLAG_SHIFT 4
	96	#define PT_EVENT_FLAG(event) (1 << (PT_EVENT_FLAG_SHIFT + (event) - 1))
	97
	98	#define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK)
	99	#define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK)
	100	#define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE)
	101	#define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC)
	102	#define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE)
	103	#define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT)
1da177e4 LT	104
	105	#define PT_TRACE_MASK 0x000003f4
	106
	107	/* single stepping state bits (used on ARM and PA-RISC) */
	108	#define PT_SINGLESTEP_BIT 31
	109	#define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT)
	110	#define PT_BLOCKSTEP_BIT 30
	111	#define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT)
	112
	113	#include <linux/compiler.h> /* For unlikely. */
	114	#include <linux/sched.h> /* For struct task_struct. */
d7e7528b	115	#include <linux/err.h> /* for IS_ERR_VALUE */
187f1882	116	#include <linux/bug.h> /* For BUG_ON. */
1da177e4	117
481bed45	118
9b05a69e NK	119	extern long arch_ptrace(struct task_struct *child, long request,
9b05a69e NK	120	unsigned long addr, unsigned long data);
1da177e4 LT	121	extern int ptrace_readdata(struct task_struct tsk, unsigned long src, char __user dst, int len);
1da177e4 LT	122	extern int ptrace_writedata(struct task_struct tsk, char __user src, unsigned long dst, int len);
1da177e4	123	extern void ptrace_disable(struct task_struct *);
755e276b	124	extern int ptrace_check_attach(struct task_struct *task, bool ignore_state);
4abf9869 NK	125	extern int ptrace_request(struct task_struct *child, long request,
4abf9869 NK	126	unsigned long addr, unsigned long data);
1da177e4 LT	127	extern void ptrace_notify(int exit_code);
	128	extern void __ptrace_link(struct task_struct *child,
	129	struct task_struct *new_parent);
	130	extern void __ptrace_unlink(struct task_struct *child);
39c626ae	131	extern void exit_ptrace(struct task_struct *tracer);
69f594a3 EP	132	#define PTRACE_MODE_READ 0x01
	133	#define PTRACE_MODE_ATTACH 0x02
	134	#define PTRACE_MODE_NOAUDIT 0x04
006ebb40 SS	135	/* Returns 0 on success, -errno on denial. */
	136	extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
	137	/* Returns true on success, false on denial. */
	138	extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
1da177e4	139
53b6f9fb ON	140	static inline int ptrace_reparented(struct task_struct *child)
53b6f9fb ON	141	{
0347e177	142	return !same_thread_group(child->real_parent, child->parent);
53b6f9fb	143	}
c6a47cc2	144
1da177e4 LT	145	static inline void ptrace_unlink(struct task_struct *child)
	146	{
	147	if (unlikely(child->ptrace))
	148	__ptrace_unlink(child);
	149	}
	150
4abf9869 NK	151	int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
	152	unsigned long data);
	153	int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
	154	unsigned long data);
1da177e4	155
06d98473 TH	156	/**
	157	* ptrace_parent - return the task that is tracing the given task
	158	* @task: task to consider
	159	*
	160	* Returns %NULL if no one is tracing @task, or the &struct task_struct
	161	* pointer to its tracer.
	162	*
	163	* Must called under rcu_read_lock(). The pointer returned might be kept
	164	* live only by RCU. During exec, this may be called with task_lock() held
	165	* on @task, still held from when check_unsafe_exec() was called.
	166	*/
	167	static inline struct task_struct ptrace_parent(struct task_struct task)
	168	{
	169	if (unlikely(task->ptrace))
	170	return rcu_dereference(task->parent);
	171	return NULL;
	172	}
	173
643ad838 TH	174	/**
	175	* ptrace_event_enabled - test whether a ptrace event is enabled
	176	* @task: ptracee of interest
	177	* @event: %PTRACE_EVENT_* to test
	178	*
	179	* Test whether @event is enabled for ptracee @task.
	180	*
	181	* Returns %true if @event is enabled, %false otherwise.
	182	*/
	183	static inline bool ptrace_event_enabled(struct task_struct *task, int event)
	184	{
	185	return task->ptrace & PT_EVENT_FLAG(event);
	186	}
	187
88ac2921 RM	188	/**
88ac2921 RM	189	* ptrace_event - possibly stop for a ptrace event notification
643ad838	190	* @event: %PTRACE_EVENT_* value to report
88ac2921 RM	191	* @message: value for %PTRACE_GETEVENTMSG to return
88ac2921 RM	192	*
643ad838 TH	193	* Check whether @event is enabled and, if so, report @event and @message
643ad838 TH	194	* to the ptrace parent.
88ac2921	195	*
88ac2921 RM	196	* Called without locks.
88ac2921 RM	197	*/
f3c04b93	198	static inline void ptrace_event(int event, unsigned long message)
88ac2921	199	{
f3c04b93 TH	200	if (unlikely(ptrace_event_enabled(current, event))) {
	201	current->ptrace_message = message;
	202	ptrace_notify((event << 8) \| SIGTRAP);
	203	} else if (event == PTRACE_EVENT_EXEC && unlikely(current->ptrace)) {
	204	/* legacy EXEC report via SIGTRAP */
	205	send_sig(SIGTRAP, current, 0);
	206	}
88ac2921 RM	207	}
88ac2921 RM	208
09a05394 RM	209	/**
	210	* ptrace_init_task - initialize ptrace state for a new child
	211	* @child: new child task
	212	* @ptrace: true if child should be ptrace'd by parent's tracer
	213	*
	214	* This is called immediately after adding @child to its parent's children
	215	* list. @ptrace is false in the normal case, and true to ptrace @child.
	216	*
	217	* Called with current's siglock and write_lock_irq(&tasklist_lock) held.
	218	*/
	219	static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
	220	{
	221	INIT_LIST_HEAD(&child->ptrace_entry);
	222	INIT_LIST_HEAD(&child->ptraced);
6634ae10 ON	223	#ifdef CONFIG_HAVE_HW_BREAKPOINT
	224	atomic_set(&child->ptrace_bp_refcnt, 1);
	225	#endif
	226	child->jobctl = 0;
09a05394	227	child->ptrace = 0;
6634ae10 ON	228	child->parent = child->real_parent;
	229
	230	if (unlikely(ptrace) && current->ptrace) {
09a05394	231	child->ptrace = current->ptrace;
c6a47cc2	232	__ptrace_link(child, current->parent);
dcace06c	233
d184d6eb ON	234	if (child->ptrace & PT_SEIZED)
	235	task_set_jobctl_pending(child, JOBCTL_TRAP_STOP);
	236	else
	237	sigaddset(&child->pending.signal, SIGSTOP);
	238
dcace06c	239	set_tsk_thread_flag(child, TIF_SIGPENDING);
09a05394 RM	240	}
	241	}
	242
dae33574 RM	243	/**
	244	* ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
	245	* @task: task in %EXIT_DEAD state
	246	*
	247	* Called with write_lock(&tasklist_lock) held.
	248	*/
	249	static inline void ptrace_release_task(struct task_struct *task)
	250	{
	251	BUG_ON(!list_empty(&task->ptraced));
	252	ptrace_unlink(task);
	253	BUG_ON(!list_empty(&task->ptrace_entry));
	254	}
	255
1da177e4 LT	256	#ifndef force_successful_syscall_return
	257	/*
	258	* System call handlers that, upon successful completion, need to return a
	259	* negative value should call force_successful_syscall_return() right before
	260	* returning. On architectures where the syscall convention provides for a
	261	* separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
	262	* others), this macro can be used to ensure that the error flag will not get
	263	* set. On architectures which do not support a separate error flag, the macro
	264	* is a no-op and the spurious error condition needs to be filtered out by some
	265	* other means (e.g., in user-level, by passing an extra argument to the
	266	* syscall handler, or something along those lines).
	267	*/
	268	#define force_successful_syscall_return() do { } while (0)
	269	#endif
	270
d7e7528b EP	271	#ifndef is_syscall_success
	272	/*
	273	* On most systems we can tell if a syscall is a success based on if the retval
	274	* is an error value. On some systems like ia64 and powerpc they have different
	275	* indicators of success/failure and must define their own.
	276	*/
	277	#define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs))))
	278	#endif
	279
fb7fa8f1 RM	280	/*
	281	* <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
	282	*
	283	* These do-nothing inlines are used when the arch does not
	284	* implement single-step. The kerneldoc comments are here
	285	* to document the interface for all arch definitions.
	286	*/
	287
	288	#ifndef arch_has_single_step
	289	/**
	290	* arch_has_single_step - does this CPU support user-mode single-step?
	291	*
	292	* If this is defined, then there must be function declarations or
	293	* inlines for user_enable_single_step() and user_disable_single_step().
	294	* arch_has_single_step() should evaluate to nonzero iff the machine
	295	* supports instruction single-step for user mode.
	296	* It can be a constant or it can test a CPU feature bit.
	297	*/
	298	#define arch_has_single_step() (0)
	299
	300	/**
	301	* user_enable_single_step - single-step in user-mode task
	302	* @task: either current or a task stopped in %TASK_TRACED
	303	*
	304	* This can only be called when arch_has_single_step() has returned nonzero.
	305	* Set @task so that when it returns to user mode, it will trap after the
dc802c2d RM	306	* next single instruction executes. If arch_has_block_step() is defined,
dc802c2d RM	307	* this must clear the effects of user_enable_block_step() too.
fb7fa8f1 RM	308	*/
	309	static inline void user_enable_single_step(struct task_struct *task)
	310	{
	311	BUG(); /* This can never be called. */
	312	}
	313
	314	/**
	315	* user_disable_single_step - cancel user-mode single-step
	316	* @task: either current or a task stopped in %TASK_TRACED
	317	*
dc802c2d RM	318	* Clear @task of the effects of user_enable_single_step() and
	319	* user_enable_block_step(). This can be called whether or not either
	320	* of those was ever called on @task, and even if arch_has_single_step()
	321	* returned zero.
fb7fa8f1 RM	322	*/
	323	static inline void user_disable_single_step(struct task_struct *task)
	324	{
	325	}
dacbe41f CH	326	#else
	327	extern void user_enable_single_step(struct task_struct *);
	328	extern void user_disable_single_step(struct task_struct *);
fb7fa8f1 RM	329	#endif /* arch_has_single_step */
fb7fa8f1 RM	330
dc802c2d RM	331	#ifndef arch_has_block_step
	332	/**
	333	* arch_has_block_step - does this CPU support user-mode block-step?
	334	*
	335	* If this is defined, then there must be a function declaration or inline
	336	* for user_enable_block_step(), and arch_has_single_step() must be defined
	337	* too. arch_has_block_step() should evaluate to nonzero iff the machine
	338	* supports step-until-branch for user mode. It can be a constant or it
	339	* can test a CPU feature bit.
	340	*/
5b88abbf	341	#define arch_has_block_step() (0)
dc802c2d RM	342
	343	/**
	344	* user_enable_block_step - step until branch in user-mode task
	345	* @task: either current or a task stopped in %TASK_TRACED
	346	*
	347	* This can only be called when arch_has_block_step() has returned nonzero,
	348	* and will never be called when single-instruction stepping is being used.
	349	* Set @task so that when it returns to user mode, it will trap after the
	350	* next branch or trap taken.
	351	*/
	352	static inline void user_enable_block_step(struct task_struct *task)
	353	{
	354	BUG(); /* This can never be called. */
	355	}
dacbe41f CH	356	#else
dacbe41f CH	357	extern void user_enable_block_step(struct task_struct *);
dc802c2d RM	358	#endif /* arch_has_block_step */
dc802c2d RM	359
85ec7fd9 ON	360	#ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
	361	extern void user_single_step_siginfo(struct task_struct *tsk,
	362	struct pt_regs regs, siginfo_t info);
	363	#else
	364	static inline void user_single_step_siginfo(struct task_struct *tsk,
	365	struct pt_regs regs, siginfo_t info)
	366	{
	367	memset(info, 0, sizeof(*info));
	368	info->si_signo = SIGTRAP;
	369	}
	370	#endif
	371
1a669c2f RM	372	#ifndef arch_ptrace_stop_needed
	373	/**
	374	* arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
	375	* @code: current->exit_code value ptrace will stop with
	376	* @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
	377	*
	378	* This is called with the siglock held, to decide whether or not it's
	379	* necessary to release the siglock and call arch_ptrace_stop() with the
	380	* same @code and @info arguments. It can be defined to a constant if
	381	* arch_ptrace_stop() is never required, or always is. On machines where
	382	* this makes sense, it should be defined to a quick test to optimize out
	383	* calling arch_ptrace_stop() when it would be superfluous. For example,
	384	* if the thread has not been back to user mode since the last stop, the
	385	* thread state might indicate that nothing needs to be done.
	386	*/
	387	#define arch_ptrace_stop_needed(code, info) (0)
	388	#endif
	389
	390	#ifndef arch_ptrace_stop
	391	/**
	392	* arch_ptrace_stop - Do machine-specific work before stopping for ptrace
	393	* @code: current->exit_code value ptrace will stop with
	394	* @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
	395	*
	396	* This is called with no locks held when arch_ptrace_stop_needed() has
	397	* just returned nonzero. It is allowed to block, e.g. for user memory
	398	* access. The arch can have machine-specific work to be done before
	399	* ptrace stops. On ia64, register backing store gets written back to user
	400	* memory here. Since this can be costly (requires dropping the siglock),
	401	* we only do it when the arch requires it for this particular stop, as
	402	* indicated by arch_ptrace_stop_needed().
	403	*/
	404	#define arch_ptrace_stop(code, info) do { } while (0)
	405	#endif
	406
bbc69863 RM	407	extern int task_current_syscall(struct task_struct target, long callno,
	408	unsigned long args[6], unsigned int maxargs,
	409	unsigned long sp, unsigned long pc);
	410
bf26c018 FW	411	#ifdef CONFIG_HAVE_HW_BREAKPOINT
	412	extern int ptrace_get_breakpoints(struct task_struct *tsk);
	413	extern void ptrace_put_breakpoints(struct task_struct *tsk);
	414	#else
	415	static inline void ptrace_put_breakpoints(struct task_struct *tsk) { }
	416	#endif /* CONFIG_HAVE_HW_BREAKPOINT */
	417
	418	#endif /* __KERNEL */
1da177e4 LT	419
1da177e4 LT	420	#endif