diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/entry-common.h | 47 | ||||
| -rw-r--r-- | include/linux/entry-kvm.h | 2 | ||||
| -rw-r--r-- | include/linux/posix-timers.h | 1 | ||||
| -rw-r--r-- | include/linux/ptrace.h | 81 | ||||
| -rw-r--r-- | include/linux/resume_user_mode.h | 64 | ||||
| -rw-r--r-- | include/linux/sched/signal.h | 17 | ||||
| -rw-r--r-- | include/linux/task_work.h | 5 | ||||
| -rw-r--r-- | include/linux/tracehook.h | 226 |
8 files changed, 169 insertions, 274 deletions
diff --git a/include/linux/entry-common.h b/include/linux/entry-common.h index 141952f4fee8..ab78bd4c2eb0 100644 --- a/include/linux/entry-common.h +++ b/include/linux/entry-common.h @@ -3,7 +3,7 @@ #define __LINUX_ENTRYCOMMON_H #include <linux/static_call_types.h> -#include <linux/tracehook.h> +#include <linux/ptrace.h> #include <linux/syscalls.h> #include <linux/seccomp.h> #include <linux/sched.h> @@ -80,26 +80,6 @@ static __always_inline void arch_check_user_regs(struct pt_regs *regs) {} #endif /** - * arch_syscall_enter_tracehook - Wrapper around tracehook_report_syscall_entry() - * @regs: Pointer to currents pt_regs - * - * Returns: 0 on success or an error code to skip the syscall. - * - * Defaults to tracehook_report_syscall_entry(). Can be replaced by - * architecture specific code. - * - * Invoked from syscall_enter_from_user_mode() - */ -static inline __must_check int arch_syscall_enter_tracehook(struct pt_regs *regs); - -#ifndef arch_syscall_enter_tracehook -static inline __must_check int arch_syscall_enter_tracehook(struct pt_regs *regs) -{ - return tracehook_report_syscall_entry(regs); -} -#endif - -/** * enter_from_user_mode - Establish state when coming from user mode * * Syscall/interrupt entry disables interrupts, but user mode is traced as @@ -157,7 +137,7 @@ void syscall_enter_from_user_mode_prepare(struct pt_regs *regs); * It handles the following work items: * * 1) syscall_work flag dependent invocations of - * arch_syscall_enter_tracehook(), __secure_computing(), trace_sys_enter() + * ptrace_report_syscall_entry(), __secure_computing(), trace_sys_enter() * 2) Invocation of audit_syscall_entry() */ long syscall_enter_from_user_mode_work(struct pt_regs *regs, long syscall); @@ -277,26 +257,7 @@ static __always_inline void arch_exit_to_user_mode(void) { } * * Invoked from exit_to_user_mode_loop(). */ -void arch_do_signal_or_restart(struct pt_regs *regs, bool has_signal); - -/** - * arch_syscall_exit_tracehook - Wrapper around tracehook_report_syscall_exit() - * @regs: Pointer to currents pt_regs - * @step: Indicator for single step - * - * Defaults to tracehook_report_syscall_exit(). Can be replaced by - * architecture specific code. - * - * Invoked from syscall_exit_to_user_mode() - */ -static inline void arch_syscall_exit_tracehook(struct pt_regs *regs, bool step); - -#ifndef arch_syscall_exit_tracehook -static inline void arch_syscall_exit_tracehook(struct pt_regs *regs, bool step) -{ - tracehook_report_syscall_exit(regs, step); -} -#endif +void arch_do_signal_or_restart(struct pt_regs *regs); /** * exit_to_user_mode - Fixup state when exiting to user mode @@ -347,7 +308,7 @@ void syscall_exit_to_user_mode_work(struct pt_regs *regs); * - rseq syscall exit * - audit * - syscall tracing - * - tracehook (single stepping) + * - ptrace (single stepping) * * 2) Preparatory work * - Exit to user mode loop (common TIF handling). Invokes diff --git a/include/linux/entry-kvm.h b/include/linux/entry-kvm.h index 07c878d6e323..6813171afccb 100644 --- a/include/linux/entry-kvm.h +++ b/include/linux/entry-kvm.h @@ -3,7 +3,7 @@ #define __LINUX_ENTRYKVM_H #include <linux/static_call_types.h> -#include <linux/tracehook.h> +#include <linux/resume_user_mode.h> #include <linux/syscalls.h> #include <linux/seccomp.h> #include <linux/sched.h> diff --git a/include/linux/posix-timers.h b/include/linux/posix-timers.h index 9cf126c3b27f..2c6e99ca48af 100644 --- a/include/linux/posix-timers.h +++ b/include/linux/posix-timers.h @@ -6,7 +6,6 @@ #include <linux/list.h> #include <linux/alarmtimer.h> #include <linux/timerqueue.h> -#include <linux/task_work.h> struct kernel_siginfo; struct task_struct; diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index 8aee2945ff08..15b3d176b6b4 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -60,7 +60,7 @@ extern int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned extern void ptrace_disable(struct task_struct *); extern int ptrace_request(struct task_struct *child, long request, unsigned long addr, unsigned long data); -extern void ptrace_notify(int exit_code); +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); @@ -155,8 +155,7 @@ static inline bool ptrace_event_enabled(struct task_struct *task, int event) static inline void ptrace_event(int event, unsigned long message) { if (unlikely(ptrace_event_enabled(current, event))) { - current->ptrace_message = message; - ptrace_notify((event << 8) | SIGTRAP); + 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) @@ -413,4 +412,80 @@ static inline void user_single_step_report(struct pt_regs *regs) 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 diff --git a/include/linux/resume_user_mode.h b/include/linux/resume_user_mode.h new file mode 100644 index 000000000000..285189454449 --- /dev/null +++ b/include/linux/resume_user_mode.h @@ -0,0 +1,64 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ + +#ifndef LINUX_RESUME_USER_MODE_H +#define LINUX_RESUME_USER_MODE_H + +#include <linux/sched.h> +#include <linux/task_work.h> +#include <linux/memcontrol.h> +#include <linux/blk-cgroup.h> + +/** + * set_notify_resume - cause resume_user_mode_work() to be called + * @task: task that will call resume_user_mode_work() + * + * Calling this arranges that @task will call resume_user_mode_work() + * before returning to user mode. If it's already running in user mode, + * it will enter the kernel and call resume_user_mode_work() soon. + * If it's blocked, it will not be woken. + */ +static inline void set_notify_resume(struct task_struct *task) +{ + if (!test_and_set_tsk_thread_flag(task, TIF_NOTIFY_RESUME)) + kick_process(task); +} + + +/** + * resume_user_mode_work - Perform work before returning 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 resume_user_mode_work(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(task_work_pending(current))) + 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); +} + +#endif /* LINUX_RESUME_USER_MODE_H */ diff --git a/include/linux/sched/signal.h b/include/linux/sched/signal.h index b6ecb9fc4cd2..3c8b34876744 100644 --- a/include/linux/sched/signal.h +++ b/include/linux/sched/signal.h @@ -349,6 +349,23 @@ extern void sigqueue_free(struct sigqueue *); extern int send_sigqueue(struct sigqueue *, struct pid *, enum pid_type); extern int do_sigaction(int, struct k_sigaction *, struct k_sigaction *); +static inline void clear_notify_signal(void) +{ + clear_thread_flag(TIF_NOTIFY_SIGNAL); + smp_mb__after_atomic(); +} + +/* + * Called to break out of interruptible wait loops, and enter the + * 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); +} + static inline int restart_syscall(void) { set_tsk_thread_flag(current, TIF_SIGPENDING); diff --git a/include/linux/task_work.h b/include/linux/task_work.h index 5b8a93f288bb..897494b597ba 100644 --- a/include/linux/task_work.h +++ b/include/linux/task_work.h @@ -19,6 +19,11 @@ enum task_work_notify_mode { TWA_SIGNAL, }; +static inline bool task_work_pending(struct task_struct *task) +{ + return READ_ONCE(task->task_works); +} + int task_work_add(struct task_struct *task, struct callback_head *twork, enum task_work_notify_mode mode); 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> */ |