ptrace: implement PTRACE_SEIZE
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / include / linux / ptrace.h
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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
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19#define PTRACE_ATTACH 16
20#define PTRACE_DETACH 17
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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
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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).
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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.
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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
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50#define PTRACE_SEIZE 0x4206
51
52/* flags in @data for PTRACE_SEIZE */
53#define PTRACE_SEIZE_DEVEL 0x80000000 /* temp flag for development */
54
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55/* options set using PTRACE_SETOPTIONS */
56#define PTRACE_O_TRACESYSGOOD 0x00000001
57#define PTRACE_O_TRACEFORK 0x00000002
58#define PTRACE_O_TRACEVFORK 0x00000004
59#define PTRACE_O_TRACECLONE 0x00000008
60#define PTRACE_O_TRACEEXEC 0x00000010
61#define PTRACE_O_TRACEVFORKDONE 0x00000020
62#define PTRACE_O_TRACEEXIT 0x00000040
63
64#define PTRACE_O_MASK 0x0000007f
65
66/* Wait extended result codes for the above trace options. */
67#define PTRACE_EVENT_FORK 1
68#define PTRACE_EVENT_VFORK 2
69#define PTRACE_EVENT_CLONE 3
70#define PTRACE_EVENT_EXEC 4
71#define PTRACE_EVENT_VFORK_DONE 5
72#define PTRACE_EVENT_EXIT 6
3544d72a 73#define PTRACE_EVENT_STOP 7
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74
75#include <asm/ptrace.h>
76
77#ifdef __KERNEL__
78/*
79 * Ptrace flags
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80 *
81 * The owner ship rules for task->ptrace which holds the ptrace
82 * flags is simple. When a task is running it owns it's task->ptrace
83 * flags. When the a task is stopped the ptracer owns task->ptrace.
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84 */
85
3544d72a 86#define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */
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87#define PT_PTRACED 0x00000001
88#define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */
89#define PT_TRACESYSGOOD 0x00000004
90#define PT_PTRACE_CAP 0x00000008 /* ptracer can follow suid-exec */
91#define PT_TRACE_FORK 0x00000010
92#define PT_TRACE_VFORK 0x00000020
93#define PT_TRACE_CLONE 0x00000040
94#define PT_TRACE_EXEC 0x00000080
95#define PT_TRACE_VFORK_DONE 0x00000100
96#define PT_TRACE_EXIT 0x00000200
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97
98#define PT_TRACE_MASK 0x000003f4
99
100/* single stepping state bits (used on ARM and PA-RISC) */
101#define PT_SINGLESTEP_BIT 31
102#define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT)
103#define PT_BLOCKSTEP_BIT 30
104#define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT)
105
106#include <linux/compiler.h> /* For unlikely. */
107#include <linux/sched.h> /* For struct task_struct. */
108
481bed45 109
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110extern long arch_ptrace(struct task_struct *child, long request,
111 unsigned long addr, unsigned long data);
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112extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len);
113extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len);
1da177e4 114extern void ptrace_disable(struct task_struct *);
755e276b 115extern int ptrace_check_attach(struct task_struct *task, bool ignore_state);
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116extern int ptrace_request(struct task_struct *child, long request,
117 unsigned long addr, unsigned long data);
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118extern void ptrace_notify(int exit_code);
119extern void __ptrace_link(struct task_struct *child,
120 struct task_struct *new_parent);
121extern void __ptrace_unlink(struct task_struct *child);
39c626ae 122extern void exit_ptrace(struct task_struct *tracer);
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123#define PTRACE_MODE_READ 1
124#define PTRACE_MODE_ATTACH 2
125/* Returns 0 on success, -errno on denial. */
126extern int __ptrace_may_access(struct task_struct *task, unsigned int mode);
127/* Returns true on success, false on denial. */
128extern bool ptrace_may_access(struct task_struct *task, unsigned int mode);
1da177e4 129
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130static inline int ptrace_reparented(struct task_struct *child)
131{
132 return child->real_parent != child->parent;
133}
c6a47cc2 134
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135static inline void ptrace_unlink(struct task_struct *child)
136{
137 if (unlikely(child->ptrace))
138 __ptrace_unlink(child);
139}
140
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141int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
142 unsigned long data);
143int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
144 unsigned long data);
1da177e4 145
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146/**
147 * task_ptrace - return %PT_* flags that apply to a task
148 * @task: pointer to &task_struct in question
149 *
150 * Returns the %PT_* flags that apply to @task.
151 */
152static inline int task_ptrace(struct task_struct *task)
153{
154 return task->ptrace;
155}
156
157/**
158 * ptrace_event - possibly stop for a ptrace event notification
159 * @mask: %PT_* bit to check in @current->ptrace
160 * @event: %PTRACE_EVENT_* value to report if @mask is set
161 * @message: value for %PTRACE_GETEVENTMSG to return
162 *
163 * This checks the @mask bit to see if ptrace wants stops for this event.
164 * If so we stop, reporting @event and @message to the ptrace parent.
165 *
166 * Returns nonzero if we did a ptrace notification, zero if not.
167 *
168 * Called without locks.
169 */
170static inline int ptrace_event(int mask, int event, unsigned long message)
171{
172 if (mask && likely(!(current->ptrace & mask)))
173 return 0;
174 current->ptrace_message = message;
175 ptrace_notify((event << 8) | SIGTRAP);
176 return 1;
177}
178
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179/**
180 * ptrace_init_task - initialize ptrace state for a new child
181 * @child: new child task
182 * @ptrace: true if child should be ptrace'd by parent's tracer
183 *
184 * This is called immediately after adding @child to its parent's children
185 * list. @ptrace is false in the normal case, and true to ptrace @child.
186 *
187 * Called with current's siglock and write_lock_irq(&tasklist_lock) held.
188 */
189static inline void ptrace_init_task(struct task_struct *child, bool ptrace)
190{
191 INIT_LIST_HEAD(&child->ptrace_entry);
192 INIT_LIST_HEAD(&child->ptraced);
193 child->parent = child->real_parent;
194 child->ptrace = 0;
c6a47cc2 195 if (unlikely(ptrace) && (current->ptrace & PT_PTRACED)) {
09a05394 196 child->ptrace = current->ptrace;
c6a47cc2 197 __ptrace_link(child, current->parent);
09a05394 198 }
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199
200#ifdef CONFIG_HAVE_HW_BREAKPOINT
201 atomic_set(&child->ptrace_bp_refcnt, 1);
202#endif
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203}
204
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205/**
206 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped
207 * @task: task in %EXIT_DEAD state
208 *
209 * Called with write_lock(&tasklist_lock) held.
210 */
211static inline void ptrace_release_task(struct task_struct *task)
212{
213 BUG_ON(!list_empty(&task->ptraced));
214 ptrace_unlink(task);
215 BUG_ON(!list_empty(&task->ptrace_entry));
216}
217
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218#ifndef force_successful_syscall_return
219/*
220 * System call handlers that, upon successful completion, need to return a
221 * negative value should call force_successful_syscall_return() right before
222 * returning. On architectures where the syscall convention provides for a
223 * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly
224 * others), this macro can be used to ensure that the error flag will not get
225 * set. On architectures which do not support a separate error flag, the macro
226 * is a no-op and the spurious error condition needs to be filtered out by some
227 * other means (e.g., in user-level, by passing an extra argument to the
228 * syscall handler, or something along those lines).
229 */
230#define force_successful_syscall_return() do { } while (0)
231#endif
232
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233/*
234 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__.
235 *
236 * These do-nothing inlines are used when the arch does not
237 * implement single-step. The kerneldoc comments are here
238 * to document the interface for all arch definitions.
239 */
240
241#ifndef arch_has_single_step
242/**
243 * arch_has_single_step - does this CPU support user-mode single-step?
244 *
245 * If this is defined, then there must be function declarations or
246 * inlines for user_enable_single_step() and user_disable_single_step().
247 * arch_has_single_step() should evaluate to nonzero iff the machine
248 * supports instruction single-step for user mode.
249 * It can be a constant or it can test a CPU feature bit.
250 */
251#define arch_has_single_step() (0)
252
253/**
254 * user_enable_single_step - single-step in user-mode task
255 * @task: either current or a task stopped in %TASK_TRACED
256 *
257 * This can only be called when arch_has_single_step() has returned nonzero.
258 * Set @task so that when it returns to user mode, it will trap after the
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259 * next single instruction executes. If arch_has_block_step() is defined,
260 * this must clear the effects of user_enable_block_step() too.
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261 */
262static inline void user_enable_single_step(struct task_struct *task)
263{
264 BUG(); /* This can never be called. */
265}
266
267/**
268 * user_disable_single_step - cancel user-mode single-step
269 * @task: either current or a task stopped in %TASK_TRACED
270 *
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271 * Clear @task of the effects of user_enable_single_step() and
272 * user_enable_block_step(). This can be called whether or not either
273 * of those was ever called on @task, and even if arch_has_single_step()
274 * returned zero.
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275 */
276static inline void user_disable_single_step(struct task_struct *task)
277{
278}
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279#else
280extern void user_enable_single_step(struct task_struct *);
281extern void user_disable_single_step(struct task_struct *);
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282#endif /* arch_has_single_step */
283
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284#ifndef arch_has_block_step
285/**
286 * arch_has_block_step - does this CPU support user-mode block-step?
287 *
288 * If this is defined, then there must be a function declaration or inline
289 * for user_enable_block_step(), and arch_has_single_step() must be defined
290 * too. arch_has_block_step() should evaluate to nonzero iff the machine
291 * supports step-until-branch for user mode. It can be a constant or it
292 * can test a CPU feature bit.
293 */
5b88abbf 294#define arch_has_block_step() (0)
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295
296/**
297 * user_enable_block_step - step until branch in user-mode task
298 * @task: either current or a task stopped in %TASK_TRACED
299 *
300 * This can only be called when arch_has_block_step() has returned nonzero,
301 * and will never be called when single-instruction stepping is being used.
302 * Set @task so that when it returns to user mode, it will trap after the
303 * next branch or trap taken.
304 */
305static inline void user_enable_block_step(struct task_struct *task)
306{
307 BUG(); /* This can never be called. */
308}
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309#else
310extern void user_enable_block_step(struct task_struct *);
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311#endif /* arch_has_block_step */
312
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313#ifdef ARCH_HAS_USER_SINGLE_STEP_INFO
314extern void user_single_step_siginfo(struct task_struct *tsk,
315 struct pt_regs *regs, siginfo_t *info);
316#else
317static inline void user_single_step_siginfo(struct task_struct *tsk,
318 struct pt_regs *regs, siginfo_t *info)
319{
320 memset(info, 0, sizeof(*info));
321 info->si_signo = SIGTRAP;
322}
323#endif
324
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325#ifndef arch_ptrace_stop_needed
326/**
327 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
328 * @code: current->exit_code value ptrace will stop with
329 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
330 *
331 * This is called with the siglock held, to decide whether or not it's
332 * necessary to release the siglock and call arch_ptrace_stop() with the
333 * same @code and @info arguments. It can be defined to a constant if
334 * arch_ptrace_stop() is never required, or always is. On machines where
335 * this makes sense, it should be defined to a quick test to optimize out
336 * calling arch_ptrace_stop() when it would be superfluous. For example,
337 * if the thread has not been back to user mode since the last stop, the
338 * thread state might indicate that nothing needs to be done.
339 */
340#define arch_ptrace_stop_needed(code, info) (0)
341#endif
342
343#ifndef arch_ptrace_stop
344/**
345 * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
346 * @code: current->exit_code value ptrace will stop with
347 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with
348 *
349 * This is called with no locks held when arch_ptrace_stop_needed() has
350 * just returned nonzero. It is allowed to block, e.g. for user memory
351 * access. The arch can have machine-specific work to be done before
352 * ptrace stops. On ia64, register backing store gets written back to user
353 * memory here. Since this can be costly (requires dropping the siglock),
354 * we only do it when the arch requires it for this particular stop, as
355 * indicated by arch_ptrace_stop_needed().
356 */
357#define arch_ptrace_stop(code, info) do { } while (0)
358#endif
359
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360extern int task_current_syscall(struct task_struct *target, long *callno,
361 unsigned long args[6], unsigned int maxargs,
362 unsigned long *sp, unsigned long *pc);
363
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364#ifdef CONFIG_HAVE_HW_BREAKPOINT
365extern int ptrace_get_breakpoints(struct task_struct *tsk);
366extern void ptrace_put_breakpoints(struct task_struct *tsk);
367#else
368static inline void ptrace_put_breakpoints(struct task_struct *tsk) { }
369#endif /* CONFIG_HAVE_HW_BREAKPOINT */
370
371#endif /* __KERNEL */
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372
373#endif