blob: 092a04f874a850ad66537aca4a2bfa7b7e973606 [file] [log] [blame]
/* ptrace.h */
/* structs and defines to help the user use the ptrace system call. */
/* has the defines to get at the registers. */
#define PTRACE_CONT 7
#define PTRACE_KILL 8
#define PTRACE_ATTACH 16
#define PTRACE_DETACH 17
/* 0x4200-0x4300 are reserved for architecture-independent additions. */
#define PTRACE_SETOPTIONS 0x4200
#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};
* 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. */
#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) */
#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);
/* 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))
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)
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)
#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)
* <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)
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. */
extern void user_enable_block_step(struct task_struct *);
#endif /* arch_has_block_step */
extern void user_single_step_siginfo(struct task_struct *tsk,
struct pt_regs *regs, siginfo_t *info);
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;
#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)
#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)
extern int task_current_syscall(struct task_struct *target, long *callno,
unsigned long args[6], unsigned int maxargs,
unsigned long *sp, unsigned long *pc);