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Diffstat (limited to 'include/linux/tracehook.h')
| -rw-r--r-- | include/linux/tracehook.h | 226 |
1 files changed, 0 insertions, 226 deletions
diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h deleted file mode 100644 index 88c007ab5ebc..000000000000 --- a/include/linux/tracehook.h +++ /dev/null @@ -1,226 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -/* - * Tracing hooks - * - * Copyright (C) 2008-2009 Red Hat, Inc. All rights reserved. - * - * This file defines hook entry points called by core code where - * user tracing/debugging support might need to do something. These - * entry points are called tracehook_*(). Each hook declared below - * has a detailed kerneldoc comment giving the context (locking et - * al) from which it is called, and the meaning of its return value. - * - * Each function here typically has only one call site, so it is ok - * to have some nontrivial tracehook_*() inlines. In all cases, the - * fast path when no tracing is enabled should be very short. - * - * The purpose of this file and the tracehook_* layer is to consolidate - * the interface that the kernel core and arch code uses to enable any - * user debugging or tracing facility (such as ptrace). The interfaces - * here are carefully documented so that maintainers of core and arch - * code do not need to think about the implementation details of the - * tracing facilities. Likewise, maintainers of the tracing code do not - * need to understand all the calling core or arch code in detail, just - * documented circumstances of each call, such as locking conditions. - * - * If the calling core code changes so that locking is different, then - * it is ok to change the interface documented here. The maintainer of - * core code changing should notify the maintainers of the tracing code - * that they need to work out the change. - * - * Some tracehook_*() inlines take arguments that the current tracing - * implementations might not necessarily use. These function signatures - * are chosen to pass in all the information that is on hand in the - * caller and might conceivably be relevant to a tracer, so that the - * core code won't have to be updated when tracing adds more features. - * If a call site changes so that some of those parameters are no longer - * already on hand without extra work, then the tracehook_* interface - * can change so there is no make-work burden on the core code. The - * maintainer of core code changing should notify the maintainers of the - * tracing code that they need to work out the change. - */ - -#ifndef _LINUX_TRACEHOOK_H -#define _LINUX_TRACEHOOK_H 1 - -#include <linux/sched.h> -#include <linux/ptrace.h> -#include <linux/security.h> -#include <linux/task_work.h> -#include <linux/memcontrol.h> -#include <linux/blk-cgroup.h> -struct linux_binprm; - -/* - * ptrace report for syscall entry and exit looks identical. - */ -static inline int ptrace_report_syscall(unsigned long message) -{ - int ptrace = current->ptrace; - - if (!(ptrace & PT_PTRACED)) - return 0; - - current->ptrace_message = message; - ptrace_notify(SIGTRAP | ((ptrace & PT_TRACESYSGOOD) ? 0x80 : 0)); - - /* - * 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 (current->exit_code) { - send_sig(current->exit_code, current, 1); - current->exit_code = 0; - } - - current->ptrace_message = 0; - return fatal_signal_pending(current); -} - -/** - * tracehook_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 tracehook_report_syscall_entry( - struct pt_regs *regs) -{ - return ptrace_report_syscall(PTRACE_EVENTMSG_SYSCALL_ENTRY); -} - -/** - * tracehook_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 tracehook_report_syscall_exit(struct pt_regs *regs, int step) -{ - if (step) - user_single_step_report(regs); - else - ptrace_report_syscall(PTRACE_EVENTMSG_SYSCALL_EXIT); -} - -/** - * tracehook_signal_handler - signal handler setup is complete - * @stepping: nonzero if debugger single-step or block-step in use - * - * Called by the arch code after a signal handler has been set up. - * Register and stack state reflects the user handler about to run. - * Signal mask changes have already been made. - * - * Called without locks, shortly before returning to user mode - * (or handling more signals). - */ -static inline void tracehook_signal_handler(int stepping) -{ - if (stepping) - ptrace_notify(SIGTRAP); -} - -/** - * set_notify_resume - cause tracehook_notify_resume() to be called - * @task: task that will call tracehook_notify_resume() - * - * Calling this arranges that @task will call tracehook_notify_resume() - * before returning to user mode. If it's already running in user mode, - * it will enter the kernel and call tracehook_notify_resume() soon. - * If it's blocked, it will not be woken. - */ -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 -} - -/** - * tracehook_notify_resume - report when about to return to user mode - * @regs: user-mode registers of @current task - * - * This is called when %TIF_NOTIFY_RESUME has been set. Now we are - * about to return to user mode, and the user state in @regs can be - * inspected or adjusted. The caller in arch code has cleared - * %TIF_NOTIFY_RESUME before the call. If the flag gets set again - * asynchronously, this will be called again before we return to - * user mode. - * - * Called without locks. - */ -static inline void tracehook_notify_resume(struct pt_regs *regs) -{ - clear_thread_flag(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(); - -#ifdef CONFIG_KEYS_REQUEST_CACHE - if (unlikely(current->cached_requested_key)) { - key_put(current->cached_requested_key); - current->cached_requested_key = NULL; - } -#endif - - mem_cgroup_handle_over_high(); - blkcg_maybe_throttle_current(); - - rseq_handle_notify_resume(NULL, regs); -} - -/* - * called by exit_to_user_mode_loop() if ti_work & _TIF_NOTIFY_SIGNAL. This - * is currently used by TWA_SIGNAL based task_work, which requires breaking - * wait loops to ensure that task_work is noticed and run. - */ -static inline void tracehook_notify_signal(void) -{ - clear_thread_flag(TIF_NOTIFY_SIGNAL); - smp_mb__after_atomic(); - if (current->task_works) - task_work_run(); -} - -/* - * Called when we have work to process from exit_to_user_mode_loop() - */ -static inline void set_notify_signal(struct task_struct *task) -{ - if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_SIGNAL) && - !wake_up_state(task, TASK_INTERRUPTIBLE)) - kick_process(task); -} - -#endif /* <linux/tracehook.h> */ |