Arnd Bergmann <arnd@xxxxxxxxxx> writes: > From: Arnd Bergmann <arnd@xxxxxxxx> > > gcc-10 shows a false-positive warning with CONFIG_KASAN: > > drivers/net/wireless/ath/ath9k/dynack.c: In function 'ath_dynack_sample_tx_ts': > include/linux/etherdevice.h:290:14: warning: writing 4 bytes into a region of size 0 [-Wstringop-overflow=] > 290 | *(u32 *)dst = *(const u32 *)src; > | ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~ > > Until gcc is fixed, work around this by using memcpy() in place > of ether_addr_copy(). Hopefully gcc-11 will not have this problem. > > Link: https://godbolt.org/z/sab1MK > Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97490 > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> > --- > drivers/net/wireless/ath/ath9k/dynack.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/net/wireless/ath/ath9k/dynack.c b/drivers/net/wireless/ath/ath9k/dynack.c > index fbeb4a739d32..e4eb96b26ca4 100644 > --- a/drivers/net/wireless/ath/ath9k/dynack.c > +++ b/drivers/net/wireless/ath/ath9k/dynack.c > @@ -247,8 +247,14 @@ void ath_dynack_sample_tx_ts(struct ath_hw *ah, struct sk_buff *skb, > ridx = ts->ts_rateindex; > > da->st_rbf.ts[da->st_rbf.t_rb].tstamp = ts->ts_tstamp; > +#if defined(CONFIG_KASAN) && (CONFIG_GCC_VERSION >= 100000) && (CONFIG_GCC_VERSION < 110000) > + /* https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97490 */ > + memcpy(da->st_rbf.addr[da->st_rbf.t_rb].h_dest, hdr->addr1, ETH_ALEN); > + memcpy(da->st_rbf.addr[da->st_rbf.t_rb].h_src, hdr->addr2, ETH_ALEN); > +#else > ether_addr_copy(da->st_rbf.addr[da->st_rbf.t_rb].h_dest, hdr->addr1); > ether_addr_copy(da->st_rbf.addr[da->st_rbf.t_rb].h_src, hdr->addr2); > +#endif Isn't there a better way to handle this? I really would not want checking for GCC versions become a common approach in drivers. I even think that using memcpy() always is better than the ugly ifdef. -- https://patchwork.kernel.org/project/linux-wireless/list/ https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
