> Subject: Re: [PATCH 5.1] rtw88: fix subscript above array bounds compiler > warning > > On Mon, May 06, 2019 at 06:32:01AM +0000, Tony Chuang wrote: > > > Subject: [PATCH 5.1] rtw88: fix subscript above array bounds compiler > warning > > > > > > My compiler complains about: > > > > > > drivers/net/wireless/realtek/rtw88/phy.c: In function > > > ‘rtw_phy_rf_power_2_rssi’: > > > drivers/net/wireless/realtek/rtw88/phy.c:430:26: warning: array subscript is > > > above array bounds [-Warray-bounds] > > > linear = db_invert_table[i][j]; > > > > > > According to comment power_db should be in range 1 ~ 96 . > > > To fix add check for boundaries before access the array. > > > > > > Signed-off-by: Stanislaw Gruszka <sgruszka@xxxxxxxxxx> > > > --- > > > RFC -> v1 > > > - add check before accessing the array insted of > > > rtw_phy_power_2_db() change. > > > > > > drivers/net/wireless/realtek/rtw88/phy.c | 5 +++++ > > > 1 file changed, 5 insertions(+) > > > > > > diff --git a/drivers/net/wireless/realtek/rtw88/phy.c > > > b/drivers/net/wireless/realtek/rtw88/phy.c > > > index 4381b360b5b5..9ca52a4d025a 100644 > > > --- a/drivers/net/wireless/realtek/rtw88/phy.c > > > +++ b/drivers/net/wireless/realtek/rtw88/phy.c > > > @@ -423,6 +423,11 @@ static u64 rtw_phy_db_2_linear(u8 power_db) > > > u8 i, j; > > > u64 linear; > > > > > > + if (power_db > 96) > > > + power_db = 96; > > > + else if (power_db < 1) > > > + power_db = 1; > > > > I think it's "return 1" here. > > Ehh, I missed that in your comment. However 'return 1' change > the output of rtw_phy_db_2_linear() quite substantially > as the smallest value (for power_db = 1) from db_invert_table[][] > is 10. I'll post v2 patch, but please double check it's indeed > correct logic. Thanks. > I think "return 1" is correct because 0 is not in domain 1~96. And indeed anything to the power of zero is 1. Thanks. Yan-Hsuan
