Hi Michael et all,
I'm digging in the reason for a failure when building ethtool with
buildroot [1].
I see the following error:
---
data/buildroot/buildroot-test/instance-0/output/host/bin/i686-linux-gcc
-DHAVE_CONFIG_H -I. -I./uapi -D_LARGEFILE_SOURCE
-D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Wall -D_LARGEFILE_SOURCE
-D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -Os -static -c -o
netlink/desc-rtnl.o netlink/desc-rtnl.c
In file included from ./uapi/linux/ethtool_netlink.h:12,
from netlink/desc-ethtool.c:7:
./uapi/linux/ethtool.h:1294:19: warning: implicit declaration of
function '__KERNEL_DIV_ROUND_UP' [-Wimplicit-function-declaration]
__u32 queue_mask[__KERNEL_DIV_ROUND_UP(MAX_NUM_QUEUE, 32)];
^~~~~~~~~~~~~~~~~~~~~
./uapi/linux/ethtool.h:1294:8: error: variably modified 'queue_mask'
at file scope
__u32 queue_mask[__KERNEL_DIV_ROUND_UP(MAX_NUM_QUEUE, 32)];
^~~~~~~~~~
---
The problems seems to be injected by the "warning: implicit
declaration of function".
When I move the __KERNEL_DIV_ROUND_UP macro right beside usage in
"uapi/linux/ethtool.h" the failure is gone.
---
diff --git a/uapi/linux/ethtool.h b/uapi/linux/ethtool.h
index d3dcb45..6710fa0 100644
--- a/uapi/linux/ethtool.h
+++ b/uapi/linux/ethtool.h
@@ -1288,6 +1288,11 @@ enum ethtool_sfeatures_retval_bits {
* @queue_mask: Bitmap of the queues which sub command apply to
* @data: A complete command structure following for each of the
queues addressed
*/
+/* ethtool.h epxects __KERNEL_DIV_ROUND_UP to be defined by <linux/kernel.h> */
+#include <linux/kernel.h>
+#ifndef __KERNEL_DIV_ROUND_UP
+#define __KERNEL_DIV_ROUND_UP(n, d) (((n) + (d) - 1) / (d))
+#endif
struct ethtool_per_queue_op {
__u32 cmd;
__u32 sub_command;
---
Has anyone an idea what goes wrong?
[1]
http://autobuild.buildroot.net/results/23dffe2f9766c12badb6e42bf3f0356c6df0cbfb/build-end.log
--
Thanks,
Heiko
