Tools: hv: use single send+recv buffer
send_buffer is used only once during registration. To reduce runtime
memory usage reuse the recv_buffer for registration. Also use
NLMSG_LENGTH instead of NLMSG_HDRLEN to take alignment into account.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/tools/hv/hv_vss_daemon.c b/tools/hv/hv_vss_daemon.c
index 8611962..8bcb040 100644
--- a/tools/hv/hv_vss_daemon.c
+++ b/tools/hv/hv_vss_daemon.c
@@ -140,7 +140,6 @@
struct cn_msg *incoming_cn_msg;
int op;
struct hv_vss_msg *vss_msg;
- char *vss_send_buffer;
char *vss_recv_buffer;
size_t vss_recv_buffer_len;
@@ -150,10 +149,9 @@
openlog("Hyper-V VSS", 0, LOG_USER);
syslog(LOG_INFO, "VSS starting; pid is:%d", getpid());
- vss_recv_buffer_len = NLMSG_HDRLEN + sizeof(struct cn_msg) + sizeof(struct hv_vss_msg);
- vss_send_buffer = calloc(1, vss_recv_buffer_len);
+ vss_recv_buffer_len = NLMSG_LENGTH(0) + sizeof(struct cn_msg) + sizeof(struct hv_vss_msg);
vss_recv_buffer = calloc(1, vss_recv_buffer_len);
- if (!(vss_send_buffer && vss_recv_buffer)) {
+ if (!vss_recv_buffer) {
syslog(LOG_ERR, "Failed to allocate netlink buffers");
exit(EXIT_FAILURE);
}
@@ -185,7 +183,7 @@
/*
* Register ourselves with the kernel.
*/
- message = (struct cn_msg *)vss_send_buffer;
+ message = (struct cn_msg *)vss_recv_buffer;
message->id.idx = CN_VSS_IDX;
message->id.val = CN_VSS_VAL;
message->ack = 0;