[PATCH][trivial] mISDN: l1oip - reduce stack memory footprint

Frank Seidel
2009-02-25T15:55:35Z

From: Frank Seidel <frank@f-seidel.de>

Applying kernel janitors todos (reduce stack
footprint where possible) to l1oip mISDN driver.
(Before 1656 bytes on i386, now 164)

Signed-off-by: Frank Seidel <frank@f-seidel.de>
---
drivers/isdn/mISDN/l1oip_core.c | 21 +++++++++++++++++----
1 file changed, 17 insertions(+), 4 deletions(-)

--- a/drivers/isdn/mISDN/l1oip_core.c
+++ b/drivers/isdn/mISDN/l1oip_core.c
@@ -663,18 +663,28 @@ l1oip_socket_thread(void *data)
struct iovec iov;
mm_segment_t oldfs;
struct sockaddr_in sin_rx;
- unsigned char recvbuf[1500];
+ unsigned char *recvbuf;
+ size_t recvbuf_size = 1500;
int recvlen;
struct socket *socket = NULL;
DECLARE_COMPLETION(wait);

+ /* allocate buffer memory */
+ recvbuf = kmalloc(recvbuf_size * sizeof(*recvbuf), GFP_KERNEL);
+ if (!recvbuf) {
+ printk(KERN_ERR "%s: Failed to allocate memory.\n", __func__);
+ ret = -ENOMEM;
+ goto out;
+ }
+
/* make daemon */
allow_signal(SIGTERM);

/* create socket */
if (sock_create(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &socket)) {
printk(KERN_ERR "%s: Failed to create socket.\n", __func__);
- return -EIO;
+ ret = -EIO;
+ goto out;
}

/* set incoming address */
@@ -730,10 +740,10 @@ l1oip_socket_thread(void *data)
__func__);
while (!signal_pending(current)) {
iov.iov_base = recvbuf;
- iov.iov_len = sizeof(recvbuf);
+ iov.iov_len = recvbuf_size;
oldfs = get_fs();
set_fs(KERNEL_DS);
- recvlen = sock_recvmsg(socket, &msg, sizeof(recvbuf), 0);
+ recvlen = sock_recvmsg(socket, &msg, recvbuf_size, 0);
set_fs(oldfs);
if (recvlen > 0) {
l1oip_socket_parse(hc, &sin_rx, recvbuf, recvlen);
@@ -771,6 +781,9 @@ fail:
if (debug & DEBUG_L1OIP_SOCKET)
printk(KERN_DEBUG "%s: socket thread terminated\n",
__func__);
+
+out:
+ kfree(recvbuf);
return ret;
}