| Message ID | 20190506062358.8288-1-sgruszka@redhat.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | [5.1] rtw88: fix subscript above array bounds compiler warning | expand |
> 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@redhat.com> > --- > 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. > + > /* 1dB ~ 96dB */ > i = (power_db - 1) >> 3; > j = (power_db - 1) - (i << 3); > -- Yan-Hsuan
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@redhat.com> > > --- > > 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. Stanislaw
> 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@redhat.com> > > > --- > > > 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
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; + /* 1dB ~ 96dB */ i = (power_db - 1) >> 3; j = (power_db - 1) - (i << 3);
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@redhat.com> --- 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(+)