| Message ID | 20200603233203.1695403-5-keescook@chromium.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Kalle Valo |
| Headers | show |
| Series | Remove uninitialized_var() macro | expand |
On Wed, Jun 3, 2020 at 4:32 PM Kees Cook <keescook@chromium.org> wrote: > > Using uninitialized_var() is dangerous as it papers over real bugs[1] > (or can in the future), and suppresses unrelated compiler warnings (e.g. > "unused variable"). If the compiler thinks it is uninitialized, either > simply initialize the variable or make compiler changes. As a precursor > to removing[2] this[3] macro[4], just initialize this variable to NULL, > and avoid sending garbage by returning. > > [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ > [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ > [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ > [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ > > Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Fixes: dc0313f46664 ("rtlwifi: rtl8192cu: Add routine hw") > --- > drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c > index f070f25bb735..5b071b70bc08 100644 > --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c > +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c > @@ -592,7 +592,7 @@ static void _rtl92cu_init_chipn_one_out_ep_priority(struct ieee80211_hw *hw, > bool wmm_enable, > u8 queue_sel) > { > - u16 uninitialized_var(value); > + u16 value; > > switch (queue_sel) { > case TX_SELE_HQ: > @@ -606,7 +606,7 @@ static void _rtl92cu_init_chipn_one_out_ep_priority(struct ieee80211_hw *hw, > break; > default: > WARN_ON(1); /* Shall not reach here! */ > - break; > + return; > } > _rtl92c_init_chipn_reg_priority(hw, value, value, value, value, > value, value); Whew! Nothing like passing the same value 6 times! (Other callers do use distinct values though, just curious seeing this instance.)
Kees Cook <keescook@chromium.org> writes: > Using uninitialized_var() is dangerous as it papers over real bugs[1] > (or can in the future), and suppresses unrelated compiler warnings (e.g. > "unused variable"). If the compiler thinks it is uninitialized, either > simply initialize the variable or make compiler changes. As a precursor > to removing[2] this[3] macro[4], just initialize this variable to NULL, > and avoid sending garbage by returning. > > [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ > [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ > [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ > [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ > > Signed-off-by: Kees Cook <keescook@chromium.org> To which tree should this go? If something else than wireless-drivers tree: Acked-by: Kalle Valo <kvalo@codeaurora.org> But let me know if you want me to take this.
diff --git a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c index f070f25bb735..5b071b70bc08 100644 --- a/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c +++ b/drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c @@ -592,7 +592,7 @@ static void _rtl92cu_init_chipn_one_out_ep_priority(struct ieee80211_hw *hw, bool wmm_enable, u8 queue_sel) { - u16 uninitialized_var(value); + u16 value; switch (queue_sel) { case TX_SELE_HQ: @@ -606,7 +606,7 @@ static void _rtl92cu_init_chipn_one_out_ep_priority(struct ieee80211_hw *hw, break; default: WARN_ON(1); /* Shall not reach here! */ - break; + return; } _rtl92c_init_chipn_reg_priority(hw, value, value, value, value, value, value);
Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. As a precursor to removing[2] this[3] macro[4], just initialize this variable to NULL, and avoid sending garbage by returning. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Signed-off-by: Kees Cook <keescook@chromium.org> --- drivers/net/wireless/realtek/rtlwifi/rtl8192cu/hw.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)