diff mbox series

ath11k: Silence clang -Wsometimes-uninitialized in ath11k_update_per_peer_stats_from_txcompl

Message ID 20200130015905.18610-1-natechancellor@gmail.com (mailing list archive)
State New, archived
Headers show
Series ath11k: Silence clang -Wsometimes-uninitialized in ath11k_update_per_peer_stats_from_txcompl | expand

Commit Message

Nathan Chancellor Jan. 30, 2020, 1:59 a.m. UTC
Clang warns a few times (trimmed for brevity):

../drivers/net/wireless/ath/ath11k/debugfs_sta.c:185:7: warning:
variable 'rate_idx' is used uninitialized whenever 'if' condition is
false [-Wsometimes-uninitialized]

It is not wrong, rate_idx is only initialized in the first if block.
However, this is not necessarily an issue in practice because rate_idx
will only be used when initialized because
ath11k_accumulate_per_peer_tx_stats only uses rate_idx when flags is not
set to RATE_INFO_FLAGS_HE_MCS, RATE_INFO_FLAGS_VHT_MCS, or
RATE_INFO_FLAGS_MCS. Still, it is not good to stick uninitialized values
into another function so initialize it to zero to prevent any issues
down the line.

Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Link: https://github.com/ClangBuiltLinux/linux/issues/832
Reported-by: ci_notify@linaro.org
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
 drivers/net/wireless/ath/ath11k/debugfs_sta.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Nick Desaulniers Feb. 3, 2020, 3:18 p.m. UTC | #1
On Thu, Jan 30, 2020 at 1:59 AM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> Clang warns a few times (trimmed for brevity):
>
> ../drivers/net/wireless/ath/ath11k/debugfs_sta.c:185:7: warning:
> variable 'rate_idx' is used uninitialized whenever 'if' condition is
> false [-Wsometimes-uninitialized]
>
> It is not wrong, rate_idx is only initialized in the first if block.
> However, this is not necessarily an issue in practice because rate_idx
> will only be used when initialized because
> ath11k_accumulate_per_peer_tx_stats only uses rate_idx when flags is not
> set to RATE_INFO_FLAGS_HE_MCS, RATE_INFO_FLAGS_VHT_MCS, or
> RATE_INFO_FLAGS_MCS. Still, it is not good to stick uninitialized values
> into another function so initialize it to zero to prevent any issues
> down the line.
>
> Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
> Link: https://github.com/ClangBuiltLinux/linux/issues/832
> Reported-by: ci_notify@linaro.org
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>

Thanks for the patch. A bit tricky to follow that this (previously) is safe.
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>

> ---
>  drivers/net/wireless/ath/ath11k/debugfs_sta.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/ath/ath11k/debugfs_sta.c b/drivers/net/wireless/ath/ath11k/debugfs_sta.c
> index 743760c9bcae..a5bdd16d6d46 100644
> --- a/drivers/net/wireless/ath/ath11k/debugfs_sta.c
> +++ b/drivers/net/wireless/ath/ath11k/debugfs_sta.c
> @@ -136,7 +136,7 @@ void ath11k_update_per_peer_stats_from_txcompl(struct ath11k *ar,
>         struct ath11k_sta *arsta;
>         struct ieee80211_sta *sta;
>         u16 rate;
> -       u8 rate_idx;
> +       u8 rate_idx = 0;
>         int ret;
>         u8 mcs;
>
> --
> 2.25.0
>
> --
> You received this message because you are subscribed to the Google Groups "Clang Built Linux" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20200130015905.18610-1-natechancellor%40gmail.com.
Kalle Valo Feb. 11, 2020, 2:24 p.m. UTC | #2
Nathan Chancellor <natechancellor@gmail.com> wrote:

> Clang warns a few times (trimmed for brevity):
> 
> ../drivers/net/wireless/ath/ath11k/debugfs_sta.c:185:7: warning:
> variable 'rate_idx' is used uninitialized whenever 'if' condition is
> false [-Wsometimes-uninitialized]
> 
> It is not wrong, rate_idx is only initialized in the first if block.
> However, this is not necessarily an issue in practice because rate_idx
> will only be used when initialized because
> ath11k_accumulate_per_peer_tx_stats only uses rate_idx when flags is not
> set to RATE_INFO_FLAGS_HE_MCS, RATE_INFO_FLAGS_VHT_MCS, or
> RATE_INFO_FLAGS_MCS. Still, it is not good to stick uninitialized values
> into another function so initialize it to zero to prevent any issues
> down the line.
> 
> Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
> Link: https://github.com/ClangBuiltLinux/linux/issues/832
> Reported-by: ci_notify@linaro.org
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

Patch applied to ath-next branch of ath.git, thanks.

df57acc415b1 ath11k: Silence clang -Wsometimes-uninitialized in ath11k_update_per_peer_stats_from_txcompl
Nick Desaulniers March 16, 2020, 9:15 p.m. UTC | #3
Hi Kalle, I still see this warning in KernelCI builds of linux-next.
Is ath-next flowing into linux-next?  I just want to triple check that
this fix gets sent along.

On Tue, Feb 11, 2020 at 6:24 AM Kalle Valo <kvalo@codeaurora.org> wrote:
>
> Nathan Chancellor <natechancellor@gmail.com> wrote:
>
> > Clang warns a few times (trimmed for brevity):
> >
> > ../drivers/net/wireless/ath/ath11k/debugfs_sta.c:185:7: warning:
> > variable 'rate_idx' is used uninitialized whenever 'if' condition is
> > false [-Wsometimes-uninitialized]
> >
> > It is not wrong, rate_idx is only initialized in the first if block.
> > However, this is not necessarily an issue in practice because rate_idx
> > will only be used when initialized because
> > ath11k_accumulate_per_peer_tx_stats only uses rate_idx when flags is not
> > set to RATE_INFO_FLAGS_HE_MCS, RATE_INFO_FLAGS_VHT_MCS, or
> > RATE_INFO_FLAGS_MCS. Still, it is not good to stick uninitialized values
> > into another function so initialize it to zero to prevent any issues
> > down the line.
> >
> > Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
> > Link: https://github.com/ClangBuiltLinux/linux/issues/832
> > Reported-by: ci_notify@linaro.org
> > Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> > Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> > Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
>
> Patch applied to ath-next branch of ath.git, thanks.
>
> df57acc415b1 ath11k: Silence clang -Wsometimes-uninitialized in ath11k_update_per_peer_stats_from_txcompl
>
> --
> https://patchwork.kernel.org/patch/11357331/
>
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches
>
> --
> You received this message because you are subscribed to the Google Groups "Clang Built Linux" group.
> To unsubscribe from this group and stop receiving emails from it, send an email to clang-built-linux+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgid/clang-built-linux/20200211142431.243E6C433A2%40smtp.codeaurora.org.
Kalle Valo March 17, 2020, 8:29 a.m. UTC | #4
Nick Desaulniers <ndesaulniers@google.com> writes:

> Hi Kalle, I still see this warning in KernelCI builds of linux-next.
> Is ath-next flowing into linux-next?  I just want to triple check that
> this fix gets sent along.

ath-next is not pulled to linux-next. But this commit is in
wireless-drivers-next now and that tree is pulled to linux-next.
diff mbox series

Patch

diff --git a/drivers/net/wireless/ath/ath11k/debugfs_sta.c b/drivers/net/wireless/ath/ath11k/debugfs_sta.c
index 743760c9bcae..a5bdd16d6d46 100644
--- a/drivers/net/wireless/ath/ath11k/debugfs_sta.c
+++ b/drivers/net/wireless/ath/ath11k/debugfs_sta.c
@@ -136,7 +136,7 @@  void ath11k_update_per_peer_stats_from_txcompl(struct ath11k *ar,
 	struct ath11k_sta *arsta;
 	struct ieee80211_sta *sta;
 	u16 rate;
-	u8 rate_idx;
+	u8 rate_idx = 0;
 	int ret;
 	u8 mcs;