1#ifndef _LINUX_PTRACE_H 2#define _LINUX_PTRACE_H 3 4#include <linux/compiler.h> /* For unlikely. */ 5#include <linux/sched.h> /* For struct task_struct. */ 6#include <linux/err.h> /* for IS_ERR_VALUE */ 7#include <linux/bug.h> /* For BUG_ON. */ 8#include <uapi/linux/ptrace.h> 9 10/* 11 * Ptrace flags 12 * 13 * The owner ship rules for task->ptrace which holds the ptrace 14 * flags is simple. When a task is running it owns it's task->ptrace 15 * flags. When the a task is stopped the ptracer owns task->ptrace. 16 */ 17 18#define PT_SEIZED 0x00010000 /* SEIZE used, enable new behavior */ 19#define PT_PTRACED 0x00000001 20#define PT_DTRACE 0x00000002 /* delayed trace (used on m68k, i386) */ 21#define PT_PTRACE_CAP 0x00000004 /* ptracer can follow suid-exec */ 22 23#define PT_OPT_FLAG_SHIFT 3 24/* PT_TRACE_* event enable flags */ 25#define PT_EVENT_FLAG(event) (1 << (PT_OPT_FLAG_SHIFT + (event))) 26#define PT_TRACESYSGOOD PT_EVENT_FLAG(0) 27#define PT_TRACE_FORK PT_EVENT_FLAG(PTRACE_EVENT_FORK) 28#define PT_TRACE_VFORK PT_EVENT_FLAG(PTRACE_EVENT_VFORK) 29#define PT_TRACE_CLONE PT_EVENT_FLAG(PTRACE_EVENT_CLONE) 30#define PT_TRACE_EXEC PT_EVENT_FLAG(PTRACE_EVENT_EXEC) 31#define PT_TRACE_VFORK_DONE PT_EVENT_FLAG(PTRACE_EVENT_VFORK_DONE) 32#define PT_TRACE_EXIT PT_EVENT_FLAG(PTRACE_EVENT_EXIT) 33#define PT_TRACE_SECCOMP PT_EVENT_FLAG(PTRACE_EVENT_SECCOMP) 34 35#define PT_EXITKILL (PTRACE_O_EXITKILL << PT_OPT_FLAG_SHIFT) 36 37/* single stepping state bits (used on ARM and PA-RISC) */ 38#define PT_SINGLESTEP_BIT 31 39#define PT_SINGLESTEP (1<<PT_SINGLESTEP_BIT) 40#define PT_BLOCKSTEP_BIT 30 41#define PT_BLOCKSTEP (1<<PT_BLOCKSTEP_BIT) 42 43extern long arch_ptrace(struct task_struct *child, long request, 44 unsigned long addr, unsigned long data); 45extern int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len); 46extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len); 47extern void ptrace_disable(struct task_struct *); 48extern int ptrace_request(struct task_struct *child, long request, 49 unsigned long addr, unsigned long data); 50extern void ptrace_notify(int exit_code); 51extern void __ptrace_link(struct task_struct *child, 52 struct task_struct *new_parent); 53extern void __ptrace_unlink(struct task_struct *child); 54extern void exit_ptrace(struct task_struct *tracer); 55#define PTRACE_MODE_READ 0x01 56#define PTRACE_MODE_ATTACH 0x02 57#define PTRACE_MODE_NOAUDIT 0x04 58/* Returns true on success, false on denial. */ 59extern bool ptrace_may_access(struct task_struct *task, unsigned int mode); 60 61static inline int ptrace_reparented(struct task_struct *child) 62{ 63 return !same_thread_group(child->real_parent, child->parent); 64} 65 66static inline void ptrace_unlink(struct task_struct *child) 67{ 68 if (unlikely(child->ptrace)) 69 __ptrace_unlink(child); 70} 71 72int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, 73 unsigned long data); 74int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, 75 unsigned long data); 76 77/** 78 * ptrace_parent - return the task that is tracing the given task 79 * @task: task to consider 80 * 81 * Returns %NULL if no one is tracing @task, or the &struct task_struct 82 * pointer to its tracer. 83 * 84 * Must called under rcu_read_lock(). The pointer returned might be kept 85 * live only by RCU. During exec, this may be called with task_lock() held 86 * on @task, still held from when check_unsafe_exec() was called. 87 */ 88static inline struct task_struct *ptrace_parent(struct task_struct *task) 89{ 90 if (unlikely(task->ptrace)) 91 return rcu_dereference(task->parent); 92 return NULL; 93} 94 95/** 96 * ptrace_event_enabled - test whether a ptrace event is enabled 97 * @task: ptracee of interest 98 * @event: %PTRACE_EVENT_* to test 99 * 100 * Test whether @event is enabled for ptracee @task. 101 * 102 * Returns %true if @event is enabled, %false otherwise. 103 */ 104static inline bool ptrace_event_enabled(struct task_struct *task, int event) 105{ 106 return task->ptrace & PT_EVENT_FLAG(event); 107} 108 109/** 110 * ptrace_event - possibly stop for a ptrace event notification 111 * @event: %PTRACE_EVENT_* value to report 112 * @message: value for %PTRACE_GETEVENTMSG to return 113 * 114 * Check whether @event is enabled and, if so, report @event and @message 115 * to the ptrace parent. 116 * 117 * Called without locks. 118 */ 119static inline void ptrace_event(int event, unsigned long message) 120{ 121 if (unlikely(ptrace_event_enabled(current, event))) { 122 current->ptrace_message = message; 123 ptrace_notify((event << 8) | SIGTRAP); 124 } else if (event == PTRACE_EVENT_EXEC) { 125 /* legacy EXEC report via SIGTRAP */ 126 if ((current->ptrace & (PT_PTRACED|PT_SEIZED)) == PT_PTRACED) 127 send_sig(SIGTRAP, current, 0); 128 } 129} 130 131/** 132 * ptrace_init_task - initialize ptrace state for a new child 133 * @child: new child task 134 * @ptrace: true if child should be ptrace'd by parent's tracer 135 * 136 * This is called immediately after adding @child to its parent's children 137 * list. @ptrace is false in the normal case, and true to ptrace @child. 138 * 139 * Called with current's siglock and write_lock_irq(&tasklist_lock) held. 140 */ 141static inline void ptrace_init_task(struct task_struct *child, bool ptrace) 142{ 143 INIT_LIST_HEAD(&child->ptrace_entry); 144 INIT_LIST_HEAD(&child->ptraced); 145 child->jobctl = 0; 146 child->ptrace = 0; 147 child->parent = child->real_parent; 148 149 if (unlikely(ptrace) && current->ptrace) { 150 child->ptrace = current->ptrace; 151 __ptrace_link(child, current->parent); 152 153 if (child->ptrace & PT_SEIZED) 154 task_set_jobctl_pending(child, JOBCTL_TRAP_STOP); 155 else 156 sigaddset(&child->pending.signal, SIGSTOP); 157 158 set_tsk_thread_flag(child, TIF_SIGPENDING); 159 } 160} 161 162/** 163 * ptrace_release_task - final ptrace-related cleanup of a zombie being reaped 164 * @task: task in %EXIT_DEAD state 165 * 166 * Called with write_lock(&tasklist_lock) held. 167 */ 168static inline void ptrace_release_task(struct task_struct *task) 169{ 170 BUG_ON(!list_empty(&task->ptraced)); 171 ptrace_unlink(task); 172 BUG_ON(!list_empty(&task->ptrace_entry)); 173} 174 175#ifndef force_successful_syscall_return 176/* 177 * System call handlers that, upon successful completion, need to return a 178 * negative value should call force_successful_syscall_return() right before 179 * returning. On architectures where the syscall convention provides for a 180 * separate error flag (e.g., alpha, ia64, ppc{,64}, sparc{,64}, possibly 181 * others), this macro can be used to ensure that the error flag will not get 182 * set. On architectures which do not support a separate error flag, the macro 183 * is a no-op and the spurious error condition needs to be filtered out by some 184 * other means (e.g., in user-level, by passing an extra argument to the 185 * syscall handler, or something along those lines). 186 */ 187#define force_successful_syscall_return() do { } while (0) 188#endif 189 190#ifndef is_syscall_success 191/* 192 * On most systems we can tell if a syscall is a success based on if the retval 193 * is an error value. On some systems like ia64 and powerpc they have different 194 * indicators of success/failure and must define their own. 195 */ 196#define is_syscall_success(regs) (!IS_ERR_VALUE((unsigned long)(regs_return_value(regs)))) 197#endif 198 199/* 200 * <asm/ptrace.h> should define the following things inside #ifdef __KERNEL__. 201 * 202 * These do-nothing inlines are used when the arch does not 203 * implement single-step. The kerneldoc comments are here 204 * to document the interface for all arch definitions. 205 */ 206 207#ifndef arch_has_single_step 208/** 209 * arch_has_single_step - does this CPU support user-mode single-step? 210 * 211 * If this is defined, then there must be function declarations or 212 * inlines for user_enable_single_step() and user_disable_single_step(). 213 * arch_has_single_step() should evaluate to nonzero iff the machine 214 * supports instruction single-step for user mode. 215 * It can be a constant or it can test a CPU feature bit. 216 */ 217#define arch_has_single_step() (0) 218 219/** 220 * user_enable_single_step - single-step in user-mode task 221 * @task: either current or a task stopped in %TASK_TRACED 222 * 223 * This can only be called when arch_has_single_step() has returned nonzero. 224 * Set @task so that when it returns to user mode, it will trap after the 225 * next single instruction executes. If arch_has_block_step() is defined, 226 * this must clear the effects of user_enable_block_step() too. 227 */ 228static inline void user_enable_single_step(struct task_struct *task) 229{ 230 BUG(); /* This can never be called. */ 231} 232 233/** 234 * user_disable_single_step - cancel user-mode single-step 235 * @task: either current or a task stopped in %TASK_TRACED 236 * 237 * Clear @task of the effects of user_enable_single_step() and 238 * user_enable_block_step(). This can be called whether or not either 239 * of those was ever called on @task, and even if arch_has_single_step() 240 * returned zero. 241 */ 242static inline void user_disable_single_step(struct task_struct *task) 243{ 244} 245#else 246extern void user_enable_single_step(struct task_struct *); 247extern void user_disable_single_step(struct task_struct *); 248#endif /* arch_has_single_step */ 249 250#ifndef arch_has_block_step 251/** 252 * arch_has_block_step - does this CPU support user-mode block-step? 253 * 254 * If this is defined, then there must be a function declaration or inline 255 * for user_enable_block_step(), and arch_has_single_step() must be defined 256 * too. arch_has_block_step() should evaluate to nonzero iff the machine 257 * supports step-until-branch for user mode. It can be a constant or it 258 * can test a CPU feature bit. 259 */ 260#define arch_has_block_step() (0) 261 262/** 263 * user_enable_block_step - step until branch in user-mode task 264 * @task: either current or a task stopped in %TASK_TRACED 265 * 266 * This can only be called when arch_has_block_step() has returned nonzero, 267 * and will never be called when single-instruction stepping is being used. 268 * Set @task so that when it returns to user mode, it will trap after the 269 * next branch or trap taken. 270 */ 271static inline void user_enable_block_step(struct task_struct *task) 272{ 273 BUG(); /* This can never be called. */ 274} 275#else 276extern void user_enable_block_step(struct task_struct *); 277#endif /* arch_has_block_step */ 278 279#ifdef ARCH_HAS_USER_SINGLE_STEP_INFO 280extern void user_single_step_siginfo(struct task_struct *tsk, 281 struct pt_regs *regs, siginfo_t *info); 282#else 283static inline void user_single_step_siginfo(struct task_struct *tsk, 284 struct pt_regs *regs, siginfo_t *info) 285{ 286 memset(info, 0, sizeof(*info)); 287 info->si_signo = SIGTRAP; 288} 289#endif 290 291#ifndef arch_ptrace_stop_needed 292/** 293 * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called 294 * @code: current->exit_code value ptrace will stop with 295 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with 296 * 297 * This is called with the siglock held, to decide whether or not it's 298 * necessary to release the siglock and call arch_ptrace_stop() with the 299 * same @code and @info arguments. It can be defined to a constant if 300 * arch_ptrace_stop() is never required, or always is. On machines where 301 * this makes sense, it should be defined to a quick test to optimize out 302 * calling arch_ptrace_stop() when it would be superfluous. For example, 303 * if the thread has not been back to user mode since the last stop, the 304 * thread state might indicate that nothing needs to be done. 305 */ 306#define arch_ptrace_stop_needed(code, info) (0) 307#endif 308 309#ifndef arch_ptrace_stop 310/** 311 * arch_ptrace_stop - Do machine-specific work before stopping for ptrace 312 * @code: current->exit_code value ptrace will stop with 313 * @info: siginfo_t pointer (or %NULL) for signal ptrace will stop with 314 * 315 * This is called with no locks held when arch_ptrace_stop_needed() has 316 * just returned nonzero. It is allowed to block, e.g. for user memory 317 * access. The arch can have machine-specific work to be done before 318 * ptrace stops. On ia64, register backing store gets written back to user 319 * memory here. Since this can be costly (requires dropping the siglock), 320 * we only do it when the arch requires it for this particular stop, as 321 * indicated by arch_ptrace_stop_needed(). 322 */ 323#define arch_ptrace_stop(code, info) do { } while (0) 324#endif 325 326#ifndef current_pt_regs 327#define current_pt_regs() task_pt_regs(current) 328#endif 329 330#ifndef ptrace_signal_deliver 331#define ptrace_signal_deliver() ((void)0) 332#endif 333 334/* 335 * unlike current_pt_regs(), this one is equal to task_pt_regs(current) 336 * on *all* architectures; the only reason to have a per-arch definition 337 * is optimisation. 338 */ 339#ifndef signal_pt_regs 340#define signal_pt_regs() task_pt_regs(current) 341#endif 342 343#ifndef current_user_stack_pointer 344#define current_user_stack_pointer() user_stack_pointer(current_pt_regs()) 345#endif 346 347extern int task_current_syscall(struct task_struct *target, long *callno, 348 unsigned long args[6], unsigned int maxargs, 349 unsigned long *sp, unsigned long *pc); 350 351#endif 352