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authorPeter Hurley <peter@hurleysoftware.com>2013-04-30 19:14:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2013-05-01 08:12:57 -0700
commitbe5f4b335f6e05df1b5c24b7e7d79ff52d7b8dbc (patch)
tree5076680c91f139ba8908d7ecd51dd02206e57496 /ipc
parent3d8fa456d5ed22ce8db085a89a037b87568b2b64 (diff)
downloadkernel-be5f4b335f6e05df1b5c24b7e7d79ff52d7b8dbc.tar.gz
ipc: separate msg allocation from userspace copy
Separating msg allocation enables single-block vmalloc allocation instead. Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'ipc')
-rw-r--r--ipc/msgutil.c52
1 files changed, 38 insertions, 14 deletions
diff --git a/ipc/msgutil.c b/ipc/msgutil.c
index 98b1c2b476cc..0a5c8a95c257 100644
--- a/ipc/msgutil.c
+++ b/ipc/msgutil.c
@@ -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;
}