diff options
| -rw-r--r-- | include/linux/tracehook.h | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/include/linux/tracehook.h b/include/linux/tracehook.h index 8b4c15e208fe..3548694a24db 100644 --- a/include/linux/tracehook.h +++ b/include/linux/tracehook.h @@ -66,6 +66,76 @@ 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) +{ + int ptrace = task_ptrace(current); + + if (!(ptrace & PT_PTRACED)) + return; + + 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; + } +} + +/** + * tracehook_report_syscall_entry - task is about to attempt a system call + * @regs: user register state of current task + * + * This will be called if %TIF_SYSCALL_TRACE has 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. + * + * Called without locks, just after entering kernel mode. + */ +static inline __must_check int tracehook_report_syscall_entry( + struct pt_regs *regs) +{ + ptrace_report_syscall(regs); + return 0; +} + +/** + * 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 %TIF_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, %TIF_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) +{ + ptrace_report_syscall(regs); +} + /** * tracehook_unsafe_exec - check for exec declared unsafe due to tracing * @task: current task doing exec |