[src/trunk]: src/sys Make mqueue_get public, rearrange mq_open into a helper ...

[martin <martin%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/9fe9bd8b0c1e
branches:  trunk
changeset: 809110:9fe9bd8b0c1e
user:      martin <martin%NetBSD.org@localhost>
date:      Sat Jun 20 14:41:54 2015 +0000

description:
Make mqueue_get public, rearrange mq_open into a helper function that can
be called from compat code, adapt mqueue_create accordingly.

diffstat:

 sys/kern/sys_mqueue.c |  85 ++++++++++++++++++++++++++++++--------------------
 sys/sys/mqueue.h      |   5 ++-
 2 files changed, 55 insertions(+), 35 deletions(-)

diffs (184 lines):

diff -r 0a0e086dc2d3 -r 9fe9bd8b0c1e sys/kern/sys_mqueue.c
--- a/sys/kern/sys_mqueue.c     Sat Jun 20 07:13:25 2015 +0000
+++ b/sys/kern/sys_mqueue.c     Sat Jun 20 14:41:54 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: sys_mqueue.c,v 1.37 2014/09/05 09:20:59 matt Exp $     */
+/*     $NetBSD: sys_mqueue.c,v 1.38 2015/06/20 14:41:54 martin Exp $   */
 
 /*
  * Copyright (c) 2007-2011 Mindaugas Rasiukevicius <rmind at NetBSD org>
@@ -43,7 +43,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_mqueue.c,v 1.37 2014/09/05 09:20:59 matt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_mqueue.c,v 1.38 2015/06/20 14:41:54 martin Exp $");
 
 #include <sys/param.h>
 #include <sys/types.h>
@@ -284,7 +284,7 @@
  * => locks the message queue, if found.
  * => holds a reference on the file descriptor.
  */
-static int
+int
 mqueue_get(mqd_t mqd, int fflag, mqueue_t **mqret)
 {
        const int fd = (int)mqd;
@@ -422,13 +422,12 @@
 }
 
 static int
-mqueue_create(lwp_t *l, char *name, struct mq_attr *uattr, mode_t mode,
+mqueue_create(lwp_t *l, char *name, struct mq_attr *attr, mode_t mode,
     int oflag, mqueue_t **mqret)
 {
        proc_t *p = l->l_proc;
        struct cwdinfo *cwdi = p->p_cwdi;
        mqueue_t *mq;
-       struct mq_attr attr;
        u_int i;
 
        /* Pre-check the limit. */
@@ -442,22 +441,13 @@
        }
 
        /* Check for mqueue attributes. */
-       if (uattr) {
-               int error;
-
-               error = copyin(uattr, &attr, sizeof(struct mq_attr));
-               if (error) {
-                       return error;
-               }
-               if (attr.mq_maxmsg <= 0 || attr.mq_maxmsg > mq_max_maxmsg ||
-                   attr.mq_msgsize <= 0 || attr.mq_msgsize > mq_max_msgsize) {
+       if (attr) {
+               if (attr->mq_maxmsg <= 0 || attr->mq_maxmsg > mq_max_maxmsg ||
+                   attr->mq_msgsize <= 0 ||
+                   attr->mq_msgsize > mq_max_msgsize) {
                        return EINVAL;
                }
-               attr.mq_curmsgs = 0;
-       } else {
-               memset(&attr, 0, sizeof(struct mq_attr));
-               attr.mq_maxmsg = mq_def_maxmsg;
-               attr.mq_msgsize = MQ_DEF_MSGSIZE - sizeof(struct mq_msg);
+               attr->mq_curmsgs = 0;
        }
 
        /*
@@ -477,7 +467,13 @@
        mq->mq_name = name;
        mq->mq_refcnt = 1;
 
-       memcpy(&mq->mq_attrib, &attr, sizeof(struct mq_attr));
+       if (attr != NULL) {
+               memcpy(&mq->mq_attrib, attr, sizeof(struct mq_attr));
+       } else {
+               memset(&mq->mq_attrib, 0, sizeof(struct mq_attr));
+               mq->mq_attrib.mq_maxmsg = mq_def_maxmsg;
+               mq->mq_attrib.mq_msgsize = MQ_DEF_MSGSIZE - sizeof(struct mq_msg);
+       }
 
        CTASSERT((O_MASK & (MQ_UNLINKED | MQ_RECEIVE)) == 0);
        mq->mq_attrib.mq_flags = (O_MASK & oflag);
@@ -492,28 +488,22 @@
 }
 
 /*
- * General mqueue system calls.
+ * Helper function for mq_open() - note that "u_name" is a userland pointer,
+ * while "attr" is a kernel pointer!
  */
-
 int
-sys_mq_open(struct lwp *l, const struct sys_mq_open_args *uap,
-    register_t *retval)
+mq_handle_open(struct lwp *l, const char *u_name, int oflag, mode_t mode,
+    struct mq_attr *attr, register_t *retval)
 {
-       /* {
-               syscallarg(const char *) name;
-               syscallarg(int) oflag;
-               syscallarg(mode_t) mode;
-               syscallarg(struct mq_attr) attr;
-       } */
        struct proc *p = l->l_proc;
        struct mqueue *mq, *mq_new = NULL;
-       int mqd, error, oflag = SCARG(uap, oflag);
+       int mqd, error;
        file_t *fp;
        char *name;
 
        /* Get the name from the user-space. */
        name = kmem_alloc(MQ_NAMELEN, KM_SLEEP);
-       error = copyinstr(SCARG(uap, name), name, MQ_NAMELEN - 1, NULL);
+       error = copyinstr(u_name, name, MQ_NAMELEN - 1, NULL);
        if (error) {
                kmem_free(name, MQ_NAMELEN);
                return error;
@@ -531,8 +521,7 @@
 
        if (oflag & O_CREAT) {
                /* Create a new message queue. */
-               error = mqueue_create(l, name, SCARG(uap, attr),
-                   SCARG(uap, mode), oflag, &mq_new);
+               error = mqueue_create(l, name, attr, mode, oflag, &mq_new);
                if (error) {
                        goto err;
                }
@@ -612,6 +601,34 @@
        return error;
 }
 
+/*
+ * General mqueue system calls.
+ */
+
+int
+sys_mq_open(struct lwp *l, const struct sys_mq_open_args *uap,
+    register_t *retval)
+{
+       /* {
+               syscallarg(const char *) name;
+               syscallarg(int) oflag;
+               syscallarg(mode_t) mode;
+               syscallarg(struct mq_attr) attr;
+       } */
+       struct mq_attr *attr = NULL, a;
+       int error;
+
+       if ((SCARG(uap, oflag) & O_CREAT) && (SCARG(uap,attr) != NULL)) {
+               error = copyin(&a, SCARG(uap,attr), sizeof(a));
+               if (error)
+                       return error;
+               attr = &a;
+       }
+
+       return mq_handle_open(l, SCARG(uap, name), SCARG(uap, oflag),
+           SCARG(uap, mode), attr, retval);
+}
+
 int
 sys_mq_close(struct lwp *l, const struct sys_mq_close_args *uap,
     register_t *retval)
diff -r 0a0e086dc2d3 -r 9fe9bd8b0c1e sys/sys/mqueue.h
--- a/sys/sys/mqueue.h  Sat Jun 20 07:13:25 2015 +0000
+++ b/sys/sys/mqueue.h  Sat Jun 20 14:41:54 2015 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: mqueue.h,v 1.16 2011/11/21 04:36:05 christos Exp $     */
+/*     $NetBSD: mqueue.h,v 1.17 2015/06/20 14:41:54 martin Exp $       */
 
 /*
  * Copyright (c) 2007-2009 Mindaugas Rasiukevicius <rmind at NetBSD org>
@@ -112,6 +112,9 @@
 void   mqueue_print_list(void (*pr)(const char *, ...) __printflike(1, 2));
 int    mq_send1(mqd_t, const char *, size_t, u_int, struct timespec *);
 int    mq_recv1(mqd_t, void *, size_t, u_int *, struct timespec *, ssize_t *);
+int    mqueue_get(mqd_t mqd, int fflag, mqueue_t **mqret);
+int    mq_handle_open(struct lwp *l, const char *, int, mode_t,
+           struct mq_attr*, register_t *retval);
 
 #endif /* _KERNEL */