On Tue, Apr 27, 2021 at 01:59:32PM +0200, Arnd Bergmann wrote: > On Tue, Apr 27, 2021 at 11:33 AM Greg Kroah-Hartman > <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > On Thu, Apr 22, 2021 at 05:26:19PM +0200, Arnd Bergmann wrote: > > > From: Arnd Bergmann <arnd@xxxxxxxx> > > > > > > gcc gets confused by some of the type casts and produces an > > > apparently senseless warning about an out-of-bound memcpy to > > > an unrelated array in the same structure: > > > > > > drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c: In function 'rtw_cfg80211_ap_set_encryption': > > > cc1: error: writing 8 bytes into a region of size 0 [-Werror=stringop-overflow=] > > > In file included from drivers/staging/rtl8723bs/include/drv_types.h:32, > > > from drivers/staging/rtl8723bs/os_dep/ioctl_cfg80211.c:10: > > > drivers/staging/rtl8723bs/include/rtw_security.h:98:15: note: at offset [184, 4264] into destination object 'dot11AuthAlgrthm' of size 4 > > > 98 | u32 dot11AuthAlgrthm; /* 802.11 auth, could be open, shared, 8021x and authswitch */ > > > | ^~~~~~~~~~~~~~~~ > > > cc1: error: writing 8 bytes into a region of size 0 [-Werror=stringop-overflow=] > > > drivers/staging/rtl8723bs/include/rtw_security.h:98:15: note: at offset [264, 4344] into destination object 'dot11AuthAlgrthm' of size 4 > > > > > > This is a known gcc bug, and the patch here is only a workaround, > > > but the approach of using a temporary variable to hold a pointer > > > to the key also improves readability in addition to avoiding the > > > warning, so overall this should still help. > > > > What version of gcc causes this? Should this go into 5.13-final and be > > backported? Or is this only showing up on "unreleased" versions of gcc > > and it is safe to wait until 5.14? > > As I understand, this is related to > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99673 > > gcc-11.1.0 has now been released and it produces this warning. What's the odds we can get gcc to fix their bug, as it's not a kernel issue? :) thanks, greg k-h
