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Commit be5f4b33 authored by Peter Hurley's avatar Peter Hurley Committed by Linus Torvalds
Browse files

ipc: separate msg allocation from userspace copy 



Separating msg allocation enables single-block vmalloc
allocation instead.

Signed-off-by: default avatarPeter Hurley <peter@hurleysoftware.com>
Acked-by: default avatarStanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3d8fa456

ipc/msgutil.c

+38 −14
Original line number Diff line number Diff line
@@ -44,21 +44,54 @@ struct msg_msgseg { 
#define DATALEN_MSG	(int)(PAGE_SIZE-sizeof(struct msg_msg))

#define DATALEN_SEG	(int)(PAGE_SIZE-sizeof(struct msg_msgseg))



struct msg_msg *load_msg(const void __user *src, int len)



static struct msg_msg *alloc_msg(int len)

{

	struct msg_msg *msg;

	struct msg_msgseg **pseg;

	int err;

	int alen;



	alen = min(len, DATALEN_MSG);

	msg = kmalloc(sizeof(*msg) + alen, GFP_KERNEL);

	if (msg == NULL)

		return ERR_PTR(-ENOMEM);

		return NULL;



	msg->next = NULL;

	msg->security = NULL;



	len -= alen;

	pseg = &msg->next;

	while (len > 0) {

		struct msg_msgseg *seg;

		alen = min(len, DATALEN_SEG);

		seg = kmalloc(sizeof(*seg) + alen, GFP_KERNEL);

		if (seg == NULL)

			goto out_err;

		*pseg = seg;

		seg->next = NULL;

		pseg = &seg->next;

		len -= alen;

	}



	return msg;



out_err:

	free_msg(msg);

	return NULL;

}



struct msg_msg *load_msg(const void __user *src, int len)

{

	struct msg_msg *msg;

	struct msg_msgseg *seg;

	int err;

	int alen;



	msg = alloc_msg(len);

	if (msg == NULL)

		return ERR_PTR(-ENOMEM);



	alen = min(len, DATALEN_MSG);

	if (copy_from_user(msg + 1, src, alen)) {

		err = -EFAULT;

		goto out_err;
@@ -66,23 +99,14 @@ struct msg_msg *load_msg(const void __user *src, int len) 


	len -= alen;

	src = ((char __user *)src) + alen;

	pseg = &msg->next;

	seg = msg->next;

	while (len > 0) {

		struct msg_msgseg *seg;

		alen = min(len, DATALEN_SEG);

		seg = 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;

		seg = seg->next;

		len -= alen;

		src = ((char __user *)src) + alen;

	}