On Mon, 2018-01-22 at 13:00 +0000, kbuild test robot wrote: > tree: https://git.kernel.org/pub/scm/linux/kernel/git/jberg/mac80211-next.gi > t master > head: 076dc671ee9fa374e77c3d05925dafb75b23a74c > commit: c179e91512cab01e83be35a60eaeda0f170a9101 [3/5] cfg80211: wext: don't > use static struct > config: x86_64-randconfig-x016-01221834 (attached as .config) > compiler: gcc-7 (Debian 7.2.0-12) 7.2.1 20171025 > reproduce: > git checkout c179e91512cab01e83be35a60eaeda0f170a9101 > # save the attached .config to linux build tree > make ARCH=x86_64 > > All warnings (new ones prefixed by >>): > > net//wireless/wext-compat.c: In function 'cfg80211_wireless_stats': > >> net//wireless/wext-compat.c:1351:9: warning: function returns address of > local variable [-Wreturn-local-addr] > return &wstats; > ^~~~~~~ > Hi Johannes, In commit c179e9151, you remove 'static' from struct, but function return the address of local variable as kbuild robot mentioned. It is a problem, but my prior experiment looks fine. Hence, I check the callers of get_wireless_stats(), and found they use the address that points to stack immediately, so content of stack wasn't broken luckily. So, please recall the 'static' of 'struct iw_statistics wstats'. Thanks PK
