[PATCH] posix message queues: code move

From: Manfred Spraul <manfred@colorfullife.com>

cleanup of sysv ipc as a preparation for posix message queues:

- replace !CONFIG_SYSVIPC wrappers for copy_semundo and exit_sem with
  static inline wrappers.  Now the whole ipc/util.c file is only used if
  CONFIG_SYSVIPC is set, use makefile magic instead of #ifdef.

- remove the prototypes for copy_semundo and exit_sem from kernel/fork.c

- they belong into a header file.

- create a new msgutil.c with the helper functions for message queues.

- cleanup the helper functions: run Lindent, add __user tags.

include/linux/msg.h

@@ -74,9 +74,6 @@ struct msg_msg {
 	/* the actual message follows immediately */
 };
 
-#define DATALEN_MSG	(PAGE_SIZE-sizeof(struct msg_msg))
-#define DATALEN_SEG	(PAGE_SIZE-sizeof(struct msg_msgseg))
-
 /* one msq_queue structure for each present queue on the system */
 struct msg_queue {
 	struct kern_ipc_perm q_perm;

include/linux/sem.h

@@ -134,7 +134,22 @@ struct sysv_sem {
 	struct sem_undo_list *undo_list;
 };
 
-void exit_sem(struct task_struct *p);
+#ifdef CONFIG_SYSVIPC
+
+extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
+extern void exit_sem(struct task_struct *tsk);
+
+#else
+static inline int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
+{
+	return 0;
+}
+
+static inline void exit_sem(struct task_struct *tsk)
+{
+	return;
+}
+#endif
 
 #endif /* __KERNEL__ */
 

ipc/Makefile

@@ -2,7 +2,5 @@
 # Makefile for the linux ipc.
 #
 
-obj-y   := util.o
-
 obj-$(CONFIG_SYSVIPC_COMPAT) += compat.o
-obj-$(CONFIG_SYSVIPC) += msg.o sem.o shm.o
+obj-$(CONFIG_SYSVIPC) += util.o msgutil.o msg.o sem.o shm.o

ipc/msg.c

@@ -51,11 +51,6 @@ struct msg_sender {
 	struct task_struct* tsk;
 };
 
-struct msg_msgseg {
-	struct msg_msgseg* next;
-	/* the next part of the message follows immediately */
-};
-
 #define SEARCH_ANY		1
 #define SEARCH_EQUAL		2
 #define SEARCH_NOTEQUAL		3
@@ -129,106 +124,6 @@ static int newque (key_t key, int msgflg)
 	return msg_buildid(id,msq->q_perm.seq);
 }
 
-static void free_msg(struct msg_msg* msg)
-{
-	struct msg_msgseg* seg;
-
-	security_msg_msg_free(msg);
-
-	seg = msg->next;
-	kfree(msg);
-	while(seg != NULL) {
-		struct msg_msgseg* tmp = seg->next;
-		kfree(seg);
-		seg = tmp;
-	}
-}
-
-static struct msg_msg* load_msg(void* src, int len)
-{
-	struct msg_msg* msg;
-	struct msg_msgseg** pseg;
-	int err;
-	int alen;
-
-	alen = len;
-	if(alen > DATALEN_MSG)
-		alen = DATALEN_MSG;
-
-	msg = (struct msg_msg *) kmalloc (sizeof(*msg) + alen, GFP_KERNEL);
-	if(msg==NULL)
-		return ERR_PTR(-ENOMEM);
-
-	msg->next = NULL;
-	msg->security = NULL;
-
-	if (copy_from_user(msg+1, src, alen)) {
-		err = -EFAULT;
-		goto out_err;
-	}
-
-	len -= alen;
-	src = ((char*)src)+alen;
-	pseg = &msg->next;
-	while(len > 0) {
-		struct msg_msgseg* seg;
-		alen = len;
-		if(alen > DATALEN_SEG)
-			alen = DATALEN_SEG;
-		seg = (struct msg_msgseg *) kmalloc (sizeof(*seg) + alen, GFP_KERNEL);
-		if(seg==NULL) {
-			err=-ENOMEM;
-			goto out_err;
-		}
-		*pseg = seg;
-		seg->next = NULL;
-		if(copy_from_user (seg+1, src, alen)) {
-			err = -EFAULT;
-			goto out_err;
-		}
-		pseg = &seg->next;
-		len -= alen;
-		src = ((char*)src)+alen;
-	}
-	
-	err = security_msg_msg_alloc(msg);
-	if (err)
-		goto out_err;
-
-	return msg;
-
-out_err:
-	free_msg(msg);
-	return ERR_PTR(err);
-}
-
-static int store_msg(void* dest, struct msg_msg* msg, int len)
-{
-	int alen;
-	struct msg_msgseg *seg;
-
-	alen = len;
-	if(alen > DATALEN_MSG)
-		alen = DATALEN_MSG;
-	if(copy_to_user (dest, msg+1, alen))
-		return -1;
-
-	len -= alen;
-	dest = ((char*)dest)+alen;
-	seg = msg->next;
-	while(len > 0) {
-		alen = len;
-		if(alen > DATALEN_SEG)
-			alen = DATALEN_SEG;
-		if(copy_to_user (dest, seg+1, alen))
-			return -1;
-		len -= alen;
-		dest = ((char*)dest)+alen;
-		seg=seg->next;
-	}
-	return 0;
-}
-
 static inline void ss_add(struct msg_queue* msq, struct msg_sender* mss)
 {
 	mss->tsk=current;

ipc/msgutil.c

+/*
+ * linux/ipc/util.c
+ * Copyright (C) 1999, 2004 Manfred Spraul
+ *
+ * This file is released under GNU General Public Licence version 2 or
+ * (at your option) any later version.
+ *
+ * See the file COPYING for more details.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/security.h>
+#include <linux/slab.h>
+#include <linux/ipc.h>
+#include <asm/uaccess.h>
+
+#include "util.h"
+
+struct msg_msgseg {
+	struct msg_msgseg* next;
+	/* the next part of the message follows immediately */
+};
+
+#define DATALEN_MSG	(PAGE_SIZE-sizeof(struct msg_msg))
+#define DATALEN_SEG	(PAGE_SIZE-sizeof(struct msg_msgseg))
+
+struct msg_msg *load_msg(void __user *src, int len)
+{
+	struct msg_msg *msg;
+	struct msg_msgseg **pseg;
+	int err;
+	int alen;
+
+	alen = len;
+	if (alen > DATALEN_MSG)
+		alen = DATALEN_MSG;
+
+	msg = (struct msg_msg *)kmalloc(sizeof(*msg) + alen, GFP_KERNEL);
+	if (msg == NULL)
+		return ERR_PTR(-ENOMEM);
+
+	msg->next = NULL;
+	msg->security = NULL;
+
+	if (copy_from_user(msg + 1, src, alen)) {
+		err = -EFAULT;
+		goto out_err;
+	}
+
+	len -= alen;
+	src = ((char *)src) + alen;
+	pseg = &msg->next;
+	while (len > 0) {
+		struct msg_msgseg *seg;
+		alen = len;
+		if (alen > DATALEN_SEG)
+			alen = DATALEN_SEG;
+		seg = (struct msg_msgseg *)kmalloc(sizeof(*seg) + alen,
+						 GFP_KERNEL);
+		if (seg == NULL) {
+			err = -ENOMEM;
+			goto out_err;
+		}
+		*pseg = seg;
+		seg->next = NULL;
+		if (copy_from_user(seg + 1, src, alen)) {
+			err = -EFAULT;
+			goto out_err;
+		}
+		pseg = &seg->next;
+		len -= alen;
+		src = ((char *)src) + alen;
+	}
+
+	err = security_msg_msg_alloc(msg);
+	if (err)
+		goto out_err;
+
+	return msg;
+
+out_err:
+	free_msg(msg);
+	return ERR_PTR(err);
+}
+
+int store_msg(void __user *dest, struct msg_msg *msg, int len)
+{
+	int alen;
+	struct msg_msgseg *seg;
+
+	alen = len;
+	if (alen > DATALEN_MSG)
+		alen = DATALEN_MSG;
+	if (copy_to_user(dest, msg + 1, alen))
+		return -1;
+
+	len -= alen;
+	dest = ((char *)dest) + alen;
+	seg = msg->next;
+	while (len > 0) {
+		alen = len;
+		if (alen > DATALEN_SEG)
+			alen = DATALEN_SEG;
+		if (copy_to_user(dest, seg + 1, alen))
+			return -1;
+		len -= alen;
+		dest = ((char *)dest) + alen;
+		seg = seg->next;
+	}
+	return 0;
+}
+
+void free_msg(struct msg_msg *msg)
+{
+	struct msg_msgseg *seg;
+
+	security_msg_msg_free(msg);
+
+	seg = msg->next;
+	kfree(msg);
+	while (seg != NULL) {
+		struct msg_msgseg *tmp = seg->next;
+		kfree(seg);
+		seg = tmp;
+	}
+}

ipc/util.c

@@ -25,8 +25,6 @@
 #include <linux/rcupdate.h>
 #include <linux/workqueue.h>
 
-#if defined(CONFIG_SYSVIPC)
-
 #include "util.h"
 
 /**
@@ -531,20 +529,3 @@ int ipc_parse_version (int *cmd)
 }
 
 #endif /* __ia64__ */
-
-#else
-/*
- * Dummy functions when SYSV IPC isn't configured
- */
-
-int copy_semundo(unsigned long clone_flags, struct task_struct *tsk)
-{
-	return 0;
-}
-
-void exit_sem(struct task_struct *tsk)
-{
-	return;
-}
-
-#endif /* CONFIG_SYSVIPC */

ipc/util.h

@@ -4,6 +4,10 @@
  *
  * ipc helper functions (c) 1999 Manfred Spraul <manfreds@colorfullife.com>
  */
+
+#ifndef _IPC_UTIL_H
+#define _IPC_UTIL_H
+
 #define USHRT_MAX 0xffff
 #define SEQ_MULTIPLIER	(IPCMNI)
 
@@ -62,3 +66,9 @@ void ipc64_perm_to_ipc_perm(struct ipc64_perm *in, struct ipc_perm *out);
 #else
 int ipc_parse_version (int *cmd);
 #endif
+
+extern void free_msg(struct msg_msg *msg);
+extern struct msg_msg *load_msg(void __user *src, int len);
+extern int store_msg(void __user *dest, struct msg_msg *msg, int len);
+
+#endif

kernel/fork.c

@@ -21,6 +21,7 @@
 #include <linux/completion.h>
 #include <linux/namespace.h>
 #include <linux/personality.h>
+#include <linux/sem.h>
 #include <linux/file.h>
 #include <linux/binfmts.h>
 #include <linux/mman.h>
@@ -39,9 +40,6 @@
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
 
-extern int copy_semundo(unsigned long clone_flags, struct task_struct *tsk);
-extern void exit_sem(struct task_struct *tsk);
-
 /* The idle threads do not count..
  * Protected by write_lock_irq(&tasklist_lock)
  */