OSCL-LXR linux-6.0.1/​include/​linux/​ptrace.h	Source navigation Diff markup Identifier search General search
	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LINUX_PTRACE_H
 #define _LINUX_PTRACE_H
 
 #include <linux/compiler.h>     /* For unlikely.  */
 #include <linux/sched.h>        /* For struct task_struct.  */
 #include <linux/sched/signal.h>     /* For send_sig(), same_thread_group(), etc. */
 #include <linux/err.h>          /* for IS_ERR_VALUE */
 #include <linux/bug.h>          /* For BUG_ON.  */
 #include <linux/pid_namespace.h>    /* For task_active_pid_ns.  */
 #include <uapi/linux/ptrace.h>
 #include <linux/seccomp.h>
 
 /* Add sp to seccomp_data, as seccomp is user API, we don't want to modify it */
 struct syscall_info {
     __u64           sp;
     struct seccomp_data data;
 };
 
 extern int ptrace_access_vm(struct task_struct *tsk, unsigned long addr,
                 void *buf, int len, unsigned int gup_flags);
 
 /*
  * 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_OPT_FLAG_SHIFT   3
 /* PT_TRACE_* event enable flags */
 #define PT_EVENT_FLAG(event)    (1 << (PT_OPT_FLAG_SHIFT + (event)))
 #define PT_TRACESYSGOOD     PT_EVENT_FLAG(0)
 #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_SECCOMP    PT_EVENT_FLAG(PTRACE_EVENT_SECCOMP)
 
 #define PT_EXITKILL     (PTRACE_O_EXITKILL << PT_OPT_FLAG_SHIFT)
 #define PT_SUSPEND_SECCOMP  (PTRACE_O_SUSPEND_SECCOMP << PT_OPT_FLAG_SHIFT)
 
 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_request(struct task_struct *child, long request,
               unsigned long addr, unsigned long data);
 extern int ptrace_notify(int exit_code, unsigned long message);
 extern void __ptrace_link(struct task_struct *child,
               struct task_struct *new_parent,
               const struct cred *ptracer_cred);
 extern void __ptrace_unlink(struct task_struct *child);
 extern void exit_ptrace(struct task_struct *tracer, struct list_head *dead);
 #define PTRACE_MODE_READ    0x01
 #define PTRACE_MODE_ATTACH  0x02
 #define PTRACE_MODE_NOAUDIT 0x04
 #define PTRACE_MODE_FSCREDS 0x08
 #define PTRACE_MODE_REALCREDS   0x10
 
 /* shorthands for READ/ATTACH and FSCREDS/REALCREDS combinations */
 #define PTRACE_MODE_READ_FSCREDS (PTRACE_MODE_READ | PTRACE_MODE_FSCREDS)
 #define PTRACE_MODE_READ_REALCREDS (PTRACE_MODE_READ | PTRACE_MODE_REALCREDS)
 #define PTRACE_MODE_ATTACH_FSCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_FSCREDS)
 #define PTRACE_MODE_ATTACH_REALCREDS (PTRACE_MODE_ATTACH | PTRACE_MODE_REALCREDS)
 
 /**
  * ptrace_may_access - check whether the caller is permitted to access
  * a target task.
  * @task: target task
  * @mode: selects type of access and caller credentials
  *
  * Returns true on success, false on denial.
  *
  * One of the flags PTRACE_MODE_FSCREDS and PTRACE_MODE_REALCREDS must
  * be set in @mode to specify whether the access was requested through
  * a filesystem syscall (should use effective capabilities and fsuid
  * of the caller) or through an explicit syscall such as
  * process_vm_writev or ptrace (and should use the real credentials).
  */
 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))) {
         ptrace_notify((event << 8) | SIGTRAP, message);
     } else if (event == PTRACE_EVENT_EXEC) {
         /* legacy EXEC report via SIGTRAP */
         if ((current->ptrace & (PT_PTRACED|PT_SEIZED)) == PT_PTRACED)
             send_sig(SIGTRAP, current, 0);
     }
 }
 
 /**
  * ptrace_event_pid - possibly stop for a ptrace event notification
  * @event:  %PTRACE_EVENT_* value to report
  * @pid:    process identifier for %PTRACE_GETEVENTMSG to return
  *
  * Check whether @event is enabled and, if so, report @event and @pid
  * to the ptrace parent.  @pid is reported as the pid_t seen from the
  * ptrace parent's pid namespace.
  *
  * Called without locks.
  */
 static inline void ptrace_event_pid(int event, struct pid *pid)
 {
     /*
      * FIXME: There's a potential race if a ptracer in a different pid
      * namespace than parent attaches between computing message below and
      * when we acquire tasklist_lock in ptrace_stop().  If this happens,
      * the ptracer will get a bogus pid from PTRACE_GETEVENTMSG.
      */
     unsigned long message = 0;
     struct pid_namespace *ns;
 
     rcu_read_lock();
     ns = task_active_pid_ns(rcu_dereference(current->parent));
     if (ns)
         message = pid_nr_ns(pid, ns);
     rcu_read_unlock();
 
     ptrace_event(event, message);
 }
 
 /**
  * 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);
     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, current->ptracer_cred);
 
         if (child->ptrace & PT_SEIZED)
             task_set_jobctl_pending(child, JOBCTL_TRAP_STOP);
         else
             sigaddset(&child->pending.signal, SIGSTOP);
     }
     else
         child->ptracer_cred = NULL;
 }
 
 /**
  * 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_REPORT
 extern void user_single_step_report(struct pt_regs *regs);
 #else
 static inline void user_single_step_report(struct pt_regs *regs)
 {
     kernel_siginfo_t info;
     clear_siginfo(&info);
     info.si_signo = SIGTRAP;
     info.si_errno = 0;
     info.si_code = SI_USER;
     info.si_pid = 0;
     info.si_uid = 0;
     force_sig_info(&info);
 }
 #endif
 
 #ifndef arch_ptrace_stop_needed
 /**
  * arch_ptrace_stop_needed - Decide whether arch_ptrace_stop() should be called
  *
  * This is called with the siglock held, to decide whether or not it's
  * necessary to release the siglock and call arch_ptrace_stop().  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.
  *
  * This is guaranteed to be invoked once before a task stops for ptrace and
  * may include arch-specific operations necessary prior to a ptrace stop.
  */
 #define arch_ptrace_stop_needed()   (0)
 #endif
 
 #ifndef arch_ptrace_stop
 /**
  * arch_ptrace_stop - Do machine-specific work before stopping for ptrace
  *
  * 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()      do { } while (0)
 #endif
 
 #ifndef current_pt_regs
 #define current_pt_regs() task_pt_regs(current)
 #endif
 
 /*
  * unlike current_pt_regs(), this one is equal to task_pt_regs(current)
  * on *all* architectures; the only reason to have a per-arch definition
  * is optimisation.
  */
 #ifndef signal_pt_regs
 #define signal_pt_regs() task_pt_regs(current)
 #endif
 
 #ifndef current_user_stack_pointer
 #define current_user_stack_pointer() user_stack_pointer(current_pt_regs())
 #endif
 
 extern int task_current_syscall(struct task_struct *target, struct syscall_info *info);
 
 extern void sigaction_compat_abi(struct k_sigaction *act, struct k_sigaction *oact);
 
 /*
  * ptrace report for syscall entry and exit looks identical.
  */
 static inline int ptrace_report_syscall(unsigned long message)
 {
     int ptrace = current->ptrace;
     int signr;
 
     if (!(ptrace & PT_PTRACED))
         return 0;
 
     signr = ptrace_notify(SIGTRAP | ((ptrace & PT_TRACESYSGOOD) ? 0x80 : 0),
                   message);
 
     /*
      * this isn't the same as continuing with a signal, but it will do
      * for normal use.  strace only continues with a signal if the
      * stopping signal is not SIGTRAP.  -brl
      */
     if (signr)
         send_sig(signr, current, 1);
 
     return fatal_signal_pending(current);
 }
 
 /**
  * ptrace_report_syscall_entry - task is about to attempt a system call
  * @regs:       user register state of current task
  *
  * This will be called if %SYSCALL_WORK_SYSCALL_TRACE or
  * %SYSCALL_WORK_SYSCALL_EMU have been set, when the current task has just
  * entered the kernel for a system call.  Full user register state is
  * available here.  Changing the values in @regs can affect the system
  * call number and arguments to be tried.  It is safe to block here,
  * preventing the system call from beginning.
  *
  * Returns zero normally, or nonzero if the calling arch code should abort
  * the system call.  That must prevent normal entry so no system call is
  * made.  If @task ever returns to user mode after this, its register state
  * is unspecified, but should be something harmless like an %ENOSYS error
  * return.  It should preserve enough information so that syscall_rollback()
  * can work (see asm-generic/syscall.h).
  *
  * Called without locks, just after entering kernel mode.
  */
 static inline __must_check int ptrace_report_syscall_entry(
     struct pt_regs *regs)
 {
     return ptrace_report_syscall(PTRACE_EVENTMSG_SYSCALL_ENTRY);
 }
 
 /**
  * ptrace_report_syscall_exit - task has just finished a system call
  * @regs:       user register state of current task
  * @step:       nonzero if simulating single-step or block-step
  *
  * This will be called if %SYSCALL_WORK_SYSCALL_TRACE has been set, when
  * the current task has just finished an attempted system call.  Full
  * user register state is available here.  It is safe to block here,
  * preventing signals from being processed.
  *
  * If @step is nonzero, this report is also in lieu of the normal
  * trap that would follow the system call instruction because
  * user_enable_block_step() or user_enable_single_step() was used.
  * In this case, %SYSCALL_WORK_SYSCALL_TRACE might not be set.
  *
  * Called without locks, just before checking for pending signals.
  */
 static inline void ptrace_report_syscall_exit(struct pt_regs *regs, int step)
 {
     if (step)
         user_single_step_report(regs);
     else
         ptrace_report_syscall(PTRACE_EVENTMSG_SYSCALL_EXIT);
 }
 #endif

This page was automatically generated by the 2.1.0 LXR engine. The LXR team