include/linux/ptrace.h

   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
  19 #define PTRACE_ATTACH             16
  20 #define PTRACE_DETACH             17
  21
  22 #define PTRACE_SYSCALL            24
  23
  24 /* 0x4200-0x4300 are reserved for architecture-independent additions.  */
  25 #define PTRACE_SETOPTIONS       0x4200
  26 #define PTRACE_GETEVENTMSG      0x4201
  27 #define PTRACE_GETSIGINFO       0x4202
  28 #define PTRACE_SETSIGINFO       0x4203
  29
  30 /* options set using PTRACE_SETOPTIONS */
  31 #define PTRACE_O_TRACESYSGOOD   0x00000001
  32 #define PTRACE_O_TRACEFORK      0x00000002
  33 #define PTRACE_O_TRACEVFORK     0x00000004
  34 #define PTRACE_O_TRACECLONE     0x00000008
  35 #define PTRACE_O_TRACEEXEC      0x00000010
  36 #define PTRACE_O_TRACEVFORKDONE 0x00000020
  37 #define PTRACE_O_TRACEEXIT      0x00000040
  38
  39 #define PTRACE_O_MASK           0x0000007f
  40
  41 /* Wait extended result codes for the above trace options.  */
  42 #define PTRACE_EVENT_FORK       1
  43 #define PTRACE_EVENT_VFORK      2
  44 #define PTRACE_EVENT_CLONE      3
  45 #define PTRACE_EVENT_EXEC       4
  46 #define PTRACE_EVENT_VFORK_DONE 5
  47 #define PTRACE_EVENT_EXIT       6
  48
  49 #include <asm/ptrace.h>
  50
  51 #ifdef __KERNEL__
  52 /*
  53  * Ptrace flags
  54  *
  55  * The owner ship rules for task->ptrace which holds the ptrace
  56  * flags is simple.  When a task is running it owns it's task->ptrace
  57  * flags.  When the a task is stopped the ptracer owns task->ptrace.
  58  */
  59
  60 #define PT_PTRACED      0x00000001
  61 #define PT_DTRACE       0x00000002      /* delayed trace (used on m68k, i386) */
  62 #define PT_TRACESYSGOOD 0x00000004
  63 #define PT_PTRACE_CAP   0x00000008      /* ptracer can follow suid-exec */
  64 #define PT_TRACE_FORK   0x00000010
  65 #define PT_TRACE_VFORK  0x00000020
  66 #define PT_TRACE_CLONE  0x00000040
  67 #define PT_TRACE_EXEC   0x00000080
  68 #define PT_TRACE_VFORK_DONE     0x00000100
  69 #define PT_TRACE_EXIT   0x00000200
  70
  71 #define PT_TRACE_MASK   0x000003f4
  72
  73 /* single stepping state bits (used on ARM and PA-RISC) */
  74 #define PT_SINGLESTEP_BIT       31
  75 #define PT_SINGLESTEP           (1<<PT_SINGLESTEP_BIT)
  76 #define PT_BLOCKSTEP_BIT        30
  77 #define PT_BLOCKSTEP            (1<<PT_BLOCKSTEP_BIT)
  78
  79 #include <linux/compiler.h>             /* For unlikely.  */
  80 #include <linux/sched.h>                /* For struct task_struct.  */
  81
  82
  83 extern long arch_ptrace(struct task_struct *child, long request, long addr, long data);
  84 extern struct task_struct *ptrace_get_task_struct(pid_t pid);
  85 extern int ptrace_traceme(void);
  86 extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
  87 extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
  88 extern int ptrace_attach(struct task_struct *tsk);
  89 extern int ptrace_detach(struct task_struct *, unsigned int);
  90 extern void ptrace_disable(struct task_struct *);
  91 extern int ptrace_check_attach(struct task_struct *task, int kill);
  92 extern int ptrace_request(struct task_struct *child, long request, long addr, long data);
  93 extern void ptrace_notify(int exit_code);
  94 extern void __ptrace_link(struct task_struct *child,
  95                           struct task_struct *new_parent);
  96 extern void __ptrace_unlink(struct task_struct *child);
  97 extern void ptrace_untrace(struct task_struct *child);
  98 #define PTRACE_MODE_READ   1
  99 #define PTRACE_MODE_ATTACH 2
 100 /* Returns 0 on success, -errno on denial. */
 101 extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
 102 /* Returns true on success, false on denial. */
 103 extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
 104
 105 static inline int ptrace_reparented(struct task_struct *child)
 106 {
 107         return child->real_parent != child->parent;
 108 }
 109 static inline void ptrace_link(struct task_struct *child,
 110                                struct task_struct *new_parent)
 111 {
 112         if (unlikely(child->ptrace))
 113                 __ptrace_link(child, new_parent);
 114 }
 115 static inline void ptrace_unlink(struct task_struct *child)
 116 {
 117         if (unlikely(child->ptrace))
 118                 __ptrace_unlink(child);
 119 }
 120
 121 int generic_ptrace_peekdata(struct task_struct *tsk, long addr, long data);
 122 int generic_ptrace_pokedata(struct task_struct *tsk, long addr, long data);
 123
 124 #ifndef force_successful_syscall_return
 125 /*
 126  * System call handlers that, upon successful completion, need to return a
 127  * negative value should call force_successful_syscall_return() right before
 128  * returning.  On architectures where the syscall convention provides for a
 129  * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
 130  * others), this macro can be used to ensure that the error flag will not get
 131  * set.  On architectures which do not support a separate error flag, the macro
 132  * is a no-op and the spurious error condition needs to be filtered out by some
 133  * other means (e.g., in user-level, by passing an extra argument to the
 134  * syscall handler, or something along those lines).
 135  */
 136 #define force_successful_syscall_return() do { } while (0)
 137 #endif
 138
 139 /*
 140  * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
 141  *
 142  * These do-nothing inlines are used when the arch does not
 143  * implement single-step.  The kerneldoc comments are here
 144  * to document the interface for all arch definitions.
 145  */
 146
 147 #ifndef arch_has_single_step
 148 /**
 149  * arch_has_single_step - does this CPU support user-mode single-step?
 150  *
 151  * If this is defined, then there must be function declarations or
 152  * inlines for user_enable_single_step() and user_disable_single_step().
 153  * arch_has_single_step() should evaluate to nonzero iff the machine
 154  * supports instruction single-step for user mode.
 155  * It can be a constant or it can test a CPU feature bit.
 156  */
 157 #define arch_has_single_step()          (0)
 158
 159 /**
 160  * user_enable_single_step - single-step in user-mode task
 161  * @task: either current or a task stopped in %TASK_TRACED
 162  *
 163  * This can only be called when arch_has_single_step() has returned nonzero.
 164  * Set @task so that when it returns to user mode, it will trap after the
 165  * next single instruction executes.  If arch_has_block_step() is defined,
 166  * this must clear the effects of user_enable_block_step() too.
 167  */
 168 static inline void user_enable_single_step(struct task_struct *task)
 169 {
 170         BUG();                  /* This can never be called.  */
 171 }
 172
 173 /**
 174  * user_disable_single_step - cancel user-mode single-step
 175  * @task: either current or a task stopped in %TASK_TRACED
 176  *
 177  * Clear @task of the effects of user_enable_single_step() and
 178  * user_enable_block_step().  This can be called whether or not either
 179  * of those was ever called on @task, and even if arch_has_single_step()
 180  * returned zero.
 181  */
 182 static inline void user_disable_single_step(struct task_struct *task)
 183 {
 184 }
 185 #endif  /* arch_has_single_step */
 186
 187 #ifndef arch_has_block_step
 188 /**
 189  * arch_has_block_step - does this CPU support user-mode block-step?
 190  *
 191  * If this is defined, then there must be a function declaration or inline
 192  * for user_enable_block_step(), and arch_has_single_step() must be defined
 193  * too.  arch_has_block_step() should evaluate to nonzero iff the machine
 194  * supports step-until-branch for user mode.  It can be a constant or it
 195  * can test a CPU feature bit.
 196  */
 197 #define arch_has_block_step()           (0)
 198
 199 /**
 200  * user_enable_block_step - step until branch in user-mode task
 201  * @task: either current or a task stopped in %TASK_TRACED
 202  *
 203  * This can only be called when arch_has_block_step() has returned nonzero,
 204  * and will never be called when single-instruction stepping is being used.
 205  * Set @task so that when it returns to user mode, it will trap after the
 206  * next branch or trap taken.
 207  */
 208 static inline void user_enable_block_step(struct task_struct *task)
 209 {
 210         BUG();                  /* This can never be called.  */
 211 }
 212 #endif  /* arch_has_block_step */
 213
 214 #ifndef arch_ptrace_stop_needed
 215 /**
 216  * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
 217  * @code:       current->exit_code value ptrace will stop with
 218  * @info:       siginfo_t pointer (or %NULL) for signal ptrace will stop with
 219  *
 220  * This is called with the siglock held, to decide whether or not it's
 221  * necessary to release the siglock and call arch_ptrace_stop() with the
 222  * same @code and @info arguments.  It can be defined to a constant if
 223  * arch_ptrace_stop() is never required, or always is.  On machines where
 224  * this makes sense, it should be defined to a quick test to optimize out
 225  * calling arch_ptrace_stop() when it would be superfluous.  For example,
 226  * if the thread has not been back to user mode since the last stop, the
 227  * thread state might indicate that nothing needs to be done.
 228  */
 229 #define arch_ptrace_stop_needed(code, info)     (0)
 230 #endif
 231
 232 #ifndef arch_ptrace_stop
 233 /**
 234  * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
 235  * @code:       current->exit_code value ptrace will stop with
 236  * @info:       siginfo_t pointer (or %NULL) for signal ptrace will stop with
 237  *
 238  * This is called with no locks held when arch_ptrace_stop_needed() has
 239  * just returned nonzero.  It is allowed to block, e.g. for user memory
 240  * access.  The arch can have machine-specific work to be done before
 241  * ptrace stops.  On ia64, register backing store gets written back to user
 242  * memory here.  Since this can be costly (requires dropping the siglock),
 243  * we only do it when the arch requires it for this particular stop, as
 244  * indicated by arch_ptrace_stop_needed().
 245  */
 246 #define arch_ptrace_stop(code, info)            do { } while (0)
 247 #endif
 248
 249 #endif
 250
 251 #endif