diff options
Diffstat (limited to 'include/linux/tracehook.h')
| -rw-r--r-- | include/linux/tracehook.h | 434 |
1 files changed, 17 insertions, 417 deletions
diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h index 3a2e66d88a3..6f8ab7da27c 100644 --- a/include/linux/tracehook.h +++ b/include/linux/tracehook.h @@ -49,32 +49,18 @@ #include <linux/sched.h> #include <linux/ptrace.h> #include <linux/security.h> +#include <linux/task_work.h> struct linux_binprm; -/** - * tracehook_expect_breakpoints - guess if task memory might be touched - * @task: current task, making a new mapping - * - * Return nonzero if @task is expected to want breakpoint insertion in - * its memory at some point. A zero return is no guarantee it won't - * be done, but this is a hint that it's known to be likely. - * - * May be called with @task->mm->mmap_sem held for writing. - */ -static inline int tracehook_expect_breakpoints(struct task_struct *task) -{ - return (task_ptrace(task) & PT_PTRACED) != 0; -} - /* * ptrace report for syscall entry and exit looks identical. */ -static inline void ptrace_report_syscall(struct pt_regs *regs) +static inline int ptrace_report_syscall(struct pt_regs *regs) { - int ptrace = task_ptrace(current); + int ptrace = current->ptrace; if (!(ptrace & PT_PTRACED)) - return; + return 0; ptrace_notify(SIGTRAP | ((ptrace & PT_TRACESYSGOOD) ? 0x80 : 0)); @@ -87,6 +73,8 @@ static inline void ptrace_report_syscall(struct pt_regs *regs) send_sig(current->exit_code, current, 1); current->exit_code = 0; } + + return fatal_signal_pending(current); } /** @@ -111,8 +99,7 @@ static inline void ptrace_report_syscall(struct pt_regs *regs) static inline __must_check int tracehook_report_syscall_entry( struct pt_regs *regs) { - ptrace_report_syscall(regs); - return 0; + return ptrace_report_syscall(regs); } /** @@ -145,229 +132,6 @@ static inline void tracehook_report_syscall_exit(struct pt_regs *regs, int step) } /** - * tracehook_unsafe_exec - check for exec declared unsafe due to tracing - * @task: current task doing exec - * - * Return %LSM_UNSAFE_* bits applied to an exec because of tracing. - * - * @task->signal->cred_guard_mutex is held by the caller through the do_execve(). - */ -static inline int tracehook_unsafe_exec(struct task_struct *task) -{ - int unsafe = 0; - int ptrace = task_ptrace(task); - if (ptrace & PT_PTRACED) { - if (ptrace & PT_PTRACE_CAP) - unsafe |= LSM_UNSAFE_PTRACE_CAP; - else - unsafe |= LSM_UNSAFE_PTRACE; - } - return unsafe; -} - -/** - * tracehook_tracer_task - return the task that is tracing the given task - * @tsk: task to consider - * - * Returns NULL if noone 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 tracehook_unsafe_exec() was called. - */ -static inline struct task_struct *tracehook_tracer_task(struct task_struct *tsk) -{ - if (task_ptrace(tsk) & PT_PTRACED) - return rcu_dereference(tsk->parent); - return NULL; -} - -/** - * tracehook_report_exec - a successful exec was completed - * @fmt: &struct linux_binfmt that performed the exec - * @bprm: &struct linux_binprm containing exec details - * @regs: user-mode register state - * - * An exec just completed, we are shortly going to return to user mode. - * The freshly initialized register state can be seen and changed in @regs. - * The name, file and other pointers in @bprm are still on hand to be - * inspected, but will be freed as soon as this returns. - * - * Called with no locks, but with some kernel resources held live - * and a reference on @fmt->module. - */ -static inline void tracehook_report_exec(struct linux_binfmt *fmt, - struct linux_binprm *bprm, - struct pt_regs *regs) -{ - if (!ptrace_event(PT_TRACE_EXEC, PTRACE_EVENT_EXEC, 0) && - unlikely(task_ptrace(current) & PT_PTRACED)) - send_sig(SIGTRAP, current, 0); -} - -/** - * tracehook_report_exit - task has begun to exit - * @exit_code: pointer to value destined for @current->exit_code - * - * @exit_code points to the value passed to do_exit(), which tracing - * might change here. This is almost the first thing in do_exit(), - * before freeing any resources or setting the %PF_EXITING flag. - * - * Called with no locks held. - */ -static inline void tracehook_report_exit(long *exit_code) -{ - ptrace_event(PT_TRACE_EXIT, PTRACE_EVENT_EXIT, *exit_code); -} - -/** - * tracehook_prepare_clone - prepare for new child to be cloned - * @clone_flags: %CLONE_* flags from clone/fork/vfork system call - * - * This is called before a new user task is to be cloned. - * Its return value will be passed to tracehook_finish_clone(). - * - * Called with no locks held. - */ -static inline int tracehook_prepare_clone(unsigned clone_flags) -{ - if (clone_flags & CLONE_UNTRACED) - return 0; - - if (clone_flags & CLONE_VFORK) { - if (current->ptrace & PT_TRACE_VFORK) - return PTRACE_EVENT_VFORK; - } else if ((clone_flags & CSIGNAL) != SIGCHLD) { - if (current->ptrace & PT_TRACE_CLONE) - return PTRACE_EVENT_CLONE; - } else if (current->ptrace & PT_TRACE_FORK) - return PTRACE_EVENT_FORK; - - return 0; -} - -/** - * tracehook_finish_clone - new child created and being attached - * @child: new child task - * @clone_flags: %CLONE_* flags from clone/fork/vfork system call - * @trace: return value from tracehook_prepare_clone() - * - * This is called immediately after adding @child to its parent's children list. - * The @trace value is that returned by tracehook_prepare_clone(). - * - * Called with current's siglock and write_lock_irq(&tasklist_lock) held. - */ -static inline void tracehook_finish_clone(struct task_struct *child, - unsigned long clone_flags, int trace) -{ - ptrace_init_task(child, (clone_flags & CLONE_PTRACE) || trace); -} - -/** - * tracehook_report_clone - in parent, new child is about to start running - * @regs: parent's user register state - * @clone_flags: flags from parent's system call - * @pid: new child's PID in the parent's namespace - * @child: new child task - * - * Called after a child is set up, but before it has been started running. - * This is not a good place to block, because the child has not started - * yet. Suspend the child here if desired, and then block in - * tracehook_report_clone_complete(). This must prevent the child from - * self-reaping if tracehook_report_clone_complete() uses the @child - * pointer; otherwise it might have died and been released by the time - * tracehook_report_clone_complete() is called. - * - * Called with no locks held, but the child cannot run until this returns. - */ -static inline void tracehook_report_clone(struct pt_regs *regs, - unsigned long clone_flags, - pid_t pid, struct task_struct *child) -{ - if (unlikely(task_ptrace(child))) { - /* - * It doesn't matter who attached/attaching to this - * task, the pending SIGSTOP is right in any case. - */ - sigaddset(&child->pending.signal, SIGSTOP); - set_tsk_thread_flag(child, TIF_SIGPENDING); - } -} - -/** - * tracehook_report_clone_complete - new child is running - * @trace: return value from tracehook_prepare_clone() - * @regs: parent's user register state - * @clone_flags: flags from parent's system call - * @pid: new child's PID in the parent's namespace - * @child: child task, already running - * - * This is called just after the child has started running. This is - * just before the clone/fork syscall returns, or blocks for vfork - * child completion if @clone_flags has the %CLONE_VFORK bit set. - * The @child pointer may be invalid if a self-reaping child died and - * tracehook_report_clone() took no action to prevent it from self-reaping. - * - * Called with no locks held. - */ -static inline void tracehook_report_clone_complete(int trace, - struct pt_regs *regs, - unsigned long clone_flags, - pid_t pid, - struct task_struct *child) -{ - if (unlikely(trace)) - ptrace_event(0, trace, pid); -} - -/** - * tracehook_report_vfork_done - vfork parent's child has exited or exec'd - * @child: child task, already running - * @pid: new child's PID in the parent's namespace - * - * Called after a %CLONE_VFORK parent has waited for the child to complete. - * The clone/vfork system call will return immediately after this. - * The @child pointer may be invalid if a self-reaping child died and - * tracehook_report_clone() took no action to prevent it from self-reaping. - * - * Called with no locks held. - */ -static inline void tracehook_report_vfork_done(struct task_struct *child, - pid_t pid) -{ - ptrace_event(PT_TRACE_VFORK_DONE, PTRACE_EVENT_VFORK_DONE, pid); -} - -/** - * tracehook_prepare_release_task - task is being reaped, clean up tracing - * @task: task in %EXIT_DEAD state - * - * This is called in release_task() just before @task gets finally reaped - * and freed. This would be the ideal place to remove and clean up any - * tracing-related state for @task. - * - * Called with no locks held. - */ -static inline void tracehook_prepare_release_task(struct task_struct *task) -{ -} - -/** - * tracehook_finish_release_task - final tracing clean-up - * @task: task in %EXIT_DEAD state - * - * This is called in release_task() when @task is being in the middle of - * being reaped. After this, there must be no tracing entanglements. - * - * Called with write_lock_irq(&tasklist_lock) held. - */ -static inline void tracehook_finish_release_task(struct task_struct *task) -{ - ptrace_release_task(task); -} - -/** * tracehook_signal_handler - signal handler setup is complete * @sig: number of signal being delivered * @info: siginfo_t of signal being delivered @@ -391,179 +155,6 @@ static inline void tracehook_signal_handler(int sig, siginfo_t *info, } /** - * tracehook_consider_ignored_signal - suppress short-circuit of ignored signal - * @task: task receiving the signal - * @sig: signal number being sent - * - * Return zero iff tracing doesn't care to examine this ignored signal, - * so it can short-circuit normal delivery and never even get queued. - * - * Called with @task->sighand->siglock held. - */ -static inline int tracehook_consider_ignored_signal(struct task_struct *task, - int sig) -{ - return (task_ptrace(task) & PT_PTRACED) != 0; -} - -/** - * tracehook_consider_fatal_signal - suppress special handling of fatal signal - * @task: task receiving the signal - * @sig: signal number being sent - * - * Return nonzero to prevent special handling of this termination signal. - * Normally handler for signal is %SIG_DFL. It can be %SIG_IGN if @sig is - * ignored, in which case force_sig() is about to reset it to %SIG_DFL. - * When this returns zero, this signal might cause a quick termination - * that does not give the debugger a chance to intercept the signal. - * - * Called with or without @task->sighand->siglock held. - */ -static inline int tracehook_consider_fatal_signal(struct task_struct *task, - int sig) -{ - return (task_ptrace(task) & PT_PTRACED) != 0; -} - -/** - * tracehook_force_sigpending - let tracing force signal_pending(current) on - * - * Called when recomputing our signal_pending() flag. Return nonzero - * to force the signal_pending() flag on, so that tracehook_get_signal() - * will be called before the next return to user mode. - * - * Called with @current->sighand->siglock held. - */ -static inline int tracehook_force_sigpending(void) -{ - return 0; -} - -/** - * tracehook_get_signal - deliver synthetic signal to traced task - * @task: @current - * @regs: task_pt_regs(@current) - * @info: details of synthetic signal - * @return_ka: sigaction for synthetic signal - * - * Return zero to check for a real pending signal normally. - * Return -1 after releasing the siglock to repeat the check. - * Return a signal number to induce an artifical signal delivery, - * setting *@info and *@return_ka to specify its details and behavior. - * - * The @return_ka->sa_handler value controls the disposition of the - * signal, no matter the signal number. For %SIG_DFL, the return value - * is a representative signal to indicate the behavior (e.g. %SIGTERM - * for death, %SIGQUIT for core dump, %SIGSTOP for job control stop, - * %SIGTSTP for stop unless in an orphaned pgrp), but the signal number - * reported will be @info->si_signo instead. - * - * Called with @task->sighand->siglock held, before dequeuing pending signals. - */ -static inline int tracehook_get_signal(struct task_struct *task, - struct pt_regs *regs, - siginfo_t *info, - struct k_sigaction *return_ka) -{ - return 0; -} - -/** - * tracehook_notify_jctl - report about job control stop/continue - * @notify: zero, %CLD_STOPPED or %CLD_CONTINUED - * @why: %CLD_STOPPED or %CLD_CONTINUED - * - * This is called when we might call do_notify_parent_cldstop(). - * - * @notify is zero if we would not ordinarily send a %SIGCHLD, - * or is the %CLD_STOPPED or %CLD_CONTINUED .si_code for %SIGCHLD. - * - * @why is %CLD_STOPPED when about to stop for job control; - * we are already in %TASK_STOPPED state, about to call schedule(). - * It might also be that we have just exited (check %PF_EXITING), - * but need to report that a group-wide stop is complete. - * - * @why is %CLD_CONTINUED when waking up after job control stop and - * ready to make a delayed @notify report. - * - * Return the %CLD_* value for %SIGCHLD, or zero to generate no signal. - * - * Called with the siglock held. - */ -static inline int tracehook_notify_jctl(int notify, int why) -{ - return notify ?: (current->ptrace & PT_PTRACED) ? why : 0; -} - -/** - * tracehook_finish_jctl - report about return from job control stop - * - * This is called by do_signal_stop() after wakeup. - */ -static inline void tracehook_finish_jctl(void) -{ -} - -#define DEATH_REAP -1 -#define DEATH_DELAYED_GROUP_LEADER -2 - -/** - * tracehook_notify_death - task is dead, ready to notify parent - * @task: @current task now exiting - * @death_cookie: value to pass to tracehook_report_death() - * @group_dead: nonzero if this was the last thread in the group to die - * - * A return value >= 0 means call do_notify_parent() with that signal - * number. Negative return value can be %DEATH_REAP to self-reap right - * now, or %DEATH_DELAYED_GROUP_LEADER to a zombie without notifying our - * parent. Note that a return value of 0 means a do_notify_parent() call - * that sends no signal, but still wakes up a parent blocked in wait*(). - * - * Called with write_lock_irq(&tasklist_lock) held. - */ -static inline int tracehook_notify_death(struct task_struct *task, - void **death_cookie, int group_dead) -{ - if (task_detached(task)) - return task->ptrace ? SIGCHLD : DEATH_REAP; - - /* - * If something other than our normal parent is ptracing us, then - * send it a SIGCHLD instead of honoring exit_signal. exit_signal - * only has special meaning to our real parent. - */ - if (thread_group_empty(task) && !ptrace_reparented(task)) - return task->exit_signal; - - return task->ptrace ? SIGCHLD : DEATH_DELAYED_GROUP_LEADER; -} - -/** - * tracehook_report_death - task is dead and ready to be reaped - * @task: @current task now exiting - * @signal: return value from tracheook_notify_death() - * @death_cookie: value passed back from tracehook_notify_death() - * @group_dead: nonzero if this was the last thread in the group to die - * - * Thread has just become a zombie or is about to self-reap. If positive, - * @signal is the signal number just sent to the parent (usually %SIGCHLD). - * If @signal is %DEATH_REAP, this thread will self-reap. If @signal is - * %DEATH_DELAYED_GROUP_LEADER, this is a delayed_group_leader() zombie. - * The @death_cookie was passed back by tracehook_notify_death(). - * - * If normal reaping is not inhibited, @task->exit_state might be changing - * in parallel. - * - * Called without locks. - */ -static inline void tracehook_report_death(struct task_struct *task, - int signal, void *death_cookie, - int group_dead) -{ -} - -#ifdef TIF_NOTIFY_RESUME -/** * set_notify_resume - cause tracehook_notify_resume() to be called * @task: task that will call tracehook_notify_resume() * @@ -574,8 +165,10 @@ static inline void tracehook_report_death(struct task_struct *task, */ static inline void set_notify_resume(struct task_struct *task) { +#ifdef TIF_NOTIFY_RESUME if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_RESUME)) kick_process(task); +#endif } /** @@ -593,7 +186,14 @@ static inline void set_notify_resume(struct task_struct *task) */ static inline void tracehook_notify_resume(struct pt_regs *regs) { + /* + * The caller just cleared TIF_NOTIFY_RESUME. This barrier + * pairs with task_work_add()->set_notify_resume() after + * hlist_add_head(task->task_works); + */ + smp_mb__after_atomic(); + if (unlikely(current->task_works)) + task_work_run(); } -#endif /* TIF_NOTIFY_RESUME */ #endif /* <linux/tracehook.h> */ |