/* Please note the differences between mmput and mm_release. * mmput is called whenever we stop holding onto a mm_struct, * error success whatever. * * mm_release is called after a mm_struct has been removed * from the current process. * * This difference is important for error handling, when we * only half set up a mm_struct for a new process and need to restore * the old one. Because we mmput the new mm_struct before * restoring the old one. . . * Eric Biederman 10 January 1998 */ void mm_release(struct task_struct *tsk, struct mm_struct *mm) { /* Get rid of any futexes when releasing the mm */ #ifdef CONFIG_FUTEX if (unlikely(tsk->robust_list)) { exit_robust_list(tsk); tsk->robust_list = NULL; } #ifdef CONFIG_COMPAT if (unlikely(tsk->compat_robust_list)) { compat_exit_robust_list(tsk); tsk->compat_robust_list = NULL; } #endif if (unlikely(!list_empty(&tsk->pi_state_list))) exit_pi_state_list(tsk); #endif uprobe_free_utask(tsk); /* Get rid of any cached register state */ deactivate_mm(tsk, mm); /* * If we're exiting normally, clear a user-space tid field if * requested. We leave this alone when dying by signal, to leave * the value intact in a core dump, and to save the unnecessary * trouble, say, a killed vfork parent shouldn't touch this mm. * Userland only wants this done for a sys_exit. */ if (tsk->clear_child_tid) { if (!(tsk->flags & PF_SIGNALED) && atomic_read(&mm->mm_users) > 1) { struct syscall_result* psr; /* REPLAY */ if (current->record_thrd) new_syscall_enter_external (TID_WAKE_CALL); /* REPLAY */ else if (current->replay_thrd) get_next_syscall_enter_external (TID_WAKE_CALL, NULL, &psr); /* REPLAY */ /* * We don't check the error code - if userspace has * not set up a proper pointer then tough luck. */ put_user(0, tsk->clear_child_tid); sys_futex(tsk->clear_child_tid, FUTEX_WAKE, 1, NULL, NULL, 0); if (current->record_thrd) new_syscall_exit_external (TID_WAKE_CALL, 0, NULL); /* REPLAY */ else if (current->replay_thrd && psr) get_next_syscall_exit_external (psr); /* REPLAY */ } tsk->clear_child_tid = NULL; } /* * All done, finally we can wake up parent and return this mm to him. * Also kthread_stop() uses this completion for synchronization. */ if (tsk->vfork_done) complete_vfork_done(tsk); }
/* Please note the differences between mmput and mm_release. * mmput is called whenever we stop holding onto a mm_struct, * error success whatever. * * mm_release is called after a mm_struct has been removed * from the current process. * * This difference is important for error handling, when we * only half set up a mm_struct for a new process and need to restore * the old one. Because we mmput the new mm_struct before * restoring the old one. . . * Eric Biederman 10 January 1998 */ void mm_release(struct task_struct *tsk, struct mm_struct *mm) { /* Get rid of any futexes when releasing the mm */ #ifdef CONFIG_FUTEX if (unlikely(tsk->robust_list)) { exit_robust_list(tsk); tsk->robust_list = NULL; } #ifdef CONFIG_COMPAT if (unlikely(tsk->compat_robust_list)) { compat_exit_robust_list(tsk); tsk->compat_robust_list = NULL; } #endif if (unlikely(!list_empty(&tsk->pi_state_list))) exit_pi_state_list(tsk); #endif uprobe_free_utask(tsk); /* Get rid of any cached register state */ deactivate_mm(tsk, mm); if (tsk->vfork_done) complete_vfork_done(tsk); /* * If we're exiting normally, clear a user-space tid field if * requested. We leave this alone when dying by signal, to leave * the value intact in a core dump, and to save the unnecessary * trouble, say, a killed vfork parent shouldn't touch this mm. * Userland only wants this done for a sys_exit. */ if (tsk->clear_child_tid) { if (!(tsk->flags & PF_SIGNALED) && atomic_read(&mm->mm_users) > 1) { /* * We don't check the error code - if userspace has * not set up a proper pointer then tough luck. */ put_user(0, tsk->clear_child_tid); sys_futex(tsk->clear_child_tid, FUTEX_WAKE, 1, NULL, NULL, 0); } tsk->clear_child_tid = NULL; } }