cobalt/posix/mq, lib/cobalt: alloc file descriptors on the anon inode

kernel/cobalt/posix/mqueue.c

@@ -18,6 +18,8 @@
 
 #include <stdarg.h>
 #include <linux/fs.h>
+#include <linux/fdtable.h>
+#include <linux/anon_inodes.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <cobalt/kernel/select.h>
@@ -284,13 +286,11 @@ static inline int mqd_create(struct cobalt_mq *mq, unsigned long flags, int ufd)
 	return rtdm_fd_enter(p, &mqd->fd, ufd, COBALT_MQD_MAGIC, &mqd_ops);
 }
 
-static int mq_open(int uqd, const char *name, int oflags, ...)
+static int mq_open(int uqd, const char *name, int oflags,
+		   int mode, struct mq_attr *attr)
 {
 	struct cobalt_mq *mq;
-	struct mq_attr *attr;
 	xnhandle_t handle;
-	mode_t mode;
-	va_list ap;
 	spl_t s;
 	int err;
 
@@ -337,11 +337,6 @@ static int mq_open(int uqd, const char *name, int oflags, ...)
 		if (mq == NULL)
 			return -ENOSPC;
 
-		va_start(ap, oflags);
-		mode = va_arg(ap, int);	/* unused */
-		attr = va_arg(ap, struct mq_attr *);
-		va_end(ap);
-
 		err = mq_init(mq, attr);
 		if (err) {
 			xnfree(mq);
@@ -792,11 +787,14 @@ COBALT_SYSCALL(mq_notify, primary,
 
 COBALT_SYSCALL(mq_open, lostage,
 	       int, (const char __user *u_name, int oflags,
-		     mode_t mode, struct mq_attr __user *u_attr, mqd_t uqd))
+		     mode_t mode, struct mq_attr __user *u_attr))
 {
 	struct mq_attr locattr, *attr;
 	char name[COBALT_MAXNAME];
-	unsigned len;
+	struct xnsys_ppd *ppd;
+	unsigned int len;
+	mqd_t uqd;
+	int ret;
 
 	len = __xn_safe_strncpy_from_user(name, u_name, sizeof(name));
 	if (len < 0)
@@ -816,9 +814,20 @@ COBALT_SYSCALL(mq_open, lostage,
 	} else
 		attr = NULL;
 
-	trace_cobalt_mq_open(name, oflags, mode, uqd);
+	trace_cobalt_mq_open(name, oflags, mode);
+
+	ppd = cobalt_ppd_get(0);
+	uqd = anon_inode_getfd("[cobalt-mq]", &rtdm_dumb_fops, ppd, oflags);
+	if (uqd < 0)
+		return uqd;
+
+	ret = mq_open(uqd, name, oflags, mode, attr);
+	if (ret < 0) {
+		__close_fd(current->files, uqd);
+		return ret;
+	}
 
-	return mq_open(uqd, name, oflags, mode, attr);
+	return uqd;
 }
 
 COBALT_SYSCALL(mq_close, lostage, int, (mqd_t uqd))

kernel/cobalt/posix/mqueue.h

@@ -32,8 +32,7 @@ struct mq_attr {
 
 COBALT_SYSCALL_DECL(mq_open,
 		    int, (const char __user *u_name, int oflags,
-			  mode_t mode, struct mq_attr __user *u_attr,
-			  mqd_t uqd));
+			  mode_t mode, struct mq_attr __user *u_attr));
 
 COBALT_SYSCALL_DECL(mq_close, int, (mqd_t uqd));
 

kernel/cobalt/trace/cobalt-posix.h

@@ -739,28 +739,25 @@ TRACE_EVENT(cobalt_cond_wait,
 );
 
 TRACE_EVENT(cobalt_mq_open,
-	TP_PROTO(const char *name, int oflags, mode_t mode, mqd_t mqd),
-	TP_ARGS(name, oflags, mode, mqd),
+	TP_PROTO(const char *name, int oflags, mode_t mode),
+	TP_ARGS(name, oflags, mode),
 
 	TP_STRUCT__entry(
 		__string(name, name)
 		__field(int, oflags)
 		__field(mode_t, mode)
-		__field(mqd_t, mqd)
 	),
 
 	TP_fast_assign(
 		__assign_str(name, name);
 		__entry->oflags = oflags;
 		__entry->mode = (oflags & O_CREAT) ? mode : 0;
-		__entry->mqd = mqd;
 	),
 
-	TP_printk("name=%s oflags=%#x(%s) mode=%o mqd=%d",
+	TP_printk("name=%s oflags=%#x(%s) mode=%o",
 		  __get_str(name),
 		  __entry->oflags, cobalt_print_oflags(__entry->oflags),
-		  __entry->mode,
-		  __entry->mqd)
+		  __entry->mode)
 );
 
 TRACE_EVENT(cobalt_mq_notify,

lib/cobalt/mq.c

@@ -104,7 +104,7 @@ COBALT_IMPL(mqd_t, mq_open, (const char *name, int oflags, ...))
 	struct mq_attr *attr = NULL;
 	mode_t mode = 0;
 	va_list ap;
-	int q, err;
+	int fd;
 
 	if ((oflags & O_CREAT) != 0) {
 		va_start(ap, oflags);
@@ -113,17 +113,13 @@ COBALT_IMPL(mqd_t, mq_open, (const char *name, int oflags, ...))
 		va_end(ap);
 	}
 
-	q = __STD(open("/dev/null", O_RDWR, 0));
-	if (q == -1)
-		return (mqd_t) - 1;
-
-	err = -XENOMAI_SYSCALL5(sc_cobalt_mq_open, name, oflags, mode, attr, q);
-
-	if (!err)
-		return (mqd_t) q;
+	fd = XENOMAI_SYSCALL4(sc_cobalt_mq_open, name, oflags, mode, attr);
+	if (fd < 0) {
+		errno = -fd;
+		return (mqd_t)-1;
+	}
 
-	errno = err;
-	return (mqd_t) - 1;
+	return (mqd_t)fd;
 }
 
 /**