From d6329667781749eaa6e86d5b5508633ce0aa8a25 Mon Sep 17 00:00:00 2001 From: Bahadir Balban Date: Fri, 22 May 2009 23:02:40 +0300 Subject: [PATCH] Comment fix to utcb lazy mapping --- src/generic/tcb.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/src/generic/tcb.c b/src/generic/tcb.c index 67d18e1..dbee4b7 100644 --- a/src/generic/tcb.c +++ b/src/generic/tcb.c @@ -166,9 +166,14 @@ void task_update_utcb(struct ktcb *cur, struct ktcb *next) } /* - * Checks whether a task's utcb is currently accessible by the kernel - * It returns an error if its not paged in yet, and also maps a non-current - * task's utcb to current task with kernel-access privileges. + * Checks whether a task's utcb is currently accessible by the kernel. + * Returns an error if its not paged in yet, maps a non-current task's + * utcb to current task for kernel-only access if it is unmapped. + * + * UTCB Mappings: The design is that each task maps its utcb with user + * access, and any other utcb is mapped with kernel-only access privileges + * upon an ipc that requires the kernel to access that utcb, in other + * words foreign utcbs are mapped lazily. */ int tcb_check_and_lazy_map_utcb(struct ktcb *task) {