From: Nathan Chancellor <natechancellor@gmail.com> To: Giuseppe Cavallaro <peppe.cavallaro@st.com>, Alexandre Torgue <alexandre.torgue@st.com>, Jose Abreu <joabreu@synopsys.com>, "David S. Miller" <davem@davemloft.net> Cc: Maxime Coquelin <mcoquelin.stm32@gmail.com>, netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Nathan Chancellor <natechancellor@gmail.com>, Nick Desaulniers <ndesaulniers@google.com> Subject: [PATCH v2] net: stmmac: Avoid sometimes uninitialized Clang warnings Date: Thu, 7 Mar 2019 11:00:28 -0700 [thread overview] Message-ID: <20190307180027.6226-1-natechancellor@gmail.com> (raw) In-Reply-To: <20190307162101.29204-1-natechancellor@gmail.com> When building with -Wsometimes-uninitialized, Clang warns: drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:495:3: warning: variable 'ns' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:495:3: warning: variable 'ns' is used uninitialized whenever '&&' condition is false [-Wsometimes-uninitialized] drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:532:3: warning: variable 'ns' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:532:3: warning: variable 'ns' is used uninitialized whenever '&&' condition is false [-Wsometimes-uninitialized] drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:741:3: warning: variable 'sec_inc' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:741:3: warning: variable 'sec_inc' is used uninitialized whenever '&&' condition is false [-Wsometimes-uninitialized] Clang is concerned with the use of stmmac_do_void_callback (which stmmac_get_timestamp and stmmac_config_sub_second_increment wrap), as it may fail to initialize these values if the if condition was ever false (meaning the callbacks don't exist). It's not wrong because the callbacks (get_timestamp and config_sub_second_increment respectively) are the ones that initialize the variables. While it's unlikely that the callbacks are ever going to disappear and make that condition false, we can easily avoid this warning by zero initialize the variables. Link: https://github.com/ClangBuiltLinux/linux/issues/384 Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> --- v1 -> v2: * Respect reverse Christmas tree variable ordering in stmmac_hwtstamp_set. drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index e2a13ec2e30b..97c5e1aad88f 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -480,7 +480,7 @@ static void stmmac_get_tx_hwtstamp(struct stmmac_priv *priv, struct dma_desc *p, struct sk_buff *skb) { struct skb_shared_hwtstamps shhwtstamp; - u64 ns; + u64 ns = 0; if (!priv->hwts_tx_en) return; @@ -519,7 +519,7 @@ static void stmmac_get_rx_hwtstamp(struct stmmac_priv *priv, struct dma_desc *p, { struct skb_shared_hwtstamps *shhwtstamp = NULL; struct dma_desc *desc = p; - u64 ns; + u64 ns = 0; if (!priv->hwts_rx_en) return; @@ -564,8 +564,8 @@ static int stmmac_hwtstamp_set(struct net_device *dev, struct ifreq *ifr) u32 snap_type_sel = 0; u32 ts_master_en = 0; u32 ts_event_en = 0; + u32 sec_inc = 0; u32 value = 0; - u32 sec_inc; bool xmac; xmac = priv->plat->has_gmac4 || priv->plat->has_xgmac; -- 2.21.0
WARNING: multiple messages have this Message-ID (diff)
From: Nathan Chancellor <natechancellor@gmail.com> To: Giuseppe Cavallaro <peppe.cavallaro@st.com>, Alexandre Torgue <alexandre.torgue@st.com>, Jose Abreu <joabreu@synopsys.com>, "David S. Miller" <davem@davemloft.net> Cc: netdev@vger.kernel.org, Nick Desaulniers <ndesaulniers@google.com>, linux-kernel@vger.kernel.org, clang-built-linux@googlegroups.com, Maxime Coquelin <mcoquelin.stm32@gmail.com>, Nathan Chancellor <natechancellor@gmail.com>, linux-stm32@st-md-mailman.stormreply.com, linux-arm-kernel@lists.infradead.org Subject: [PATCH v2] net: stmmac: Avoid sometimes uninitialized Clang warnings Date: Thu, 7 Mar 2019 11:00:28 -0700 [thread overview] Message-ID: <20190307180027.6226-1-natechancellor@gmail.com> (raw) In-Reply-To: <20190307162101.29204-1-natechancellor@gmail.com> When building with -Wsometimes-uninitialized, Clang warns: drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:495:3: warning: variable 'ns' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:495:3: warning: variable 'ns' is used uninitialized whenever '&&' condition is false [-Wsometimes-uninitialized] drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:532:3: warning: variable 'ns' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:532:3: warning: variable 'ns' is used uninitialized whenever '&&' condition is false [-Wsometimes-uninitialized] drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:741:3: warning: variable 'sec_inc' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] drivers/net/ethernet/stmicro/stmmac/stmmac_main.c:741:3: warning: variable 'sec_inc' is used uninitialized whenever '&&' condition is false [-Wsometimes-uninitialized] Clang is concerned with the use of stmmac_do_void_callback (which stmmac_get_timestamp and stmmac_config_sub_second_increment wrap), as it may fail to initialize these values if the if condition was ever false (meaning the callbacks don't exist). It's not wrong because the callbacks (get_timestamp and config_sub_second_increment respectively) are the ones that initialize the variables. While it's unlikely that the callbacks are ever going to disappear and make that condition false, we can easily avoid this warning by zero initialize the variables. Link: https://github.com/ClangBuiltLinux/linux/issues/384 Suggested-by: Nick Desaulniers <ndesaulniers@google.com> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com> --- v1 -> v2: * Respect reverse Christmas tree variable ordering in stmmac_hwtstamp_set. drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index e2a13ec2e30b..97c5e1aad88f 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -480,7 +480,7 @@ static void stmmac_get_tx_hwtstamp(struct stmmac_priv *priv, struct dma_desc *p, struct sk_buff *skb) { struct skb_shared_hwtstamps shhwtstamp; - u64 ns; + u64 ns = 0; if (!priv->hwts_tx_en) return; @@ -519,7 +519,7 @@ static void stmmac_get_rx_hwtstamp(struct stmmac_priv *priv, struct dma_desc *p, { struct skb_shared_hwtstamps *shhwtstamp = NULL; struct dma_desc *desc = p; - u64 ns; + u64 ns = 0; if (!priv->hwts_rx_en) return; @@ -564,8 +564,8 @@ static int stmmac_hwtstamp_set(struct net_device *dev, struct ifreq *ifr) u32 snap_type_sel = 0; u32 ts_master_en = 0; u32 ts_event_en = 0; + u32 sec_inc = 0; u32 value = 0; - u32 sec_inc; bool xmac; xmac = priv->plat->has_gmac4 || priv->plat->has_xgmac; -- 2.21.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2019-03-07 18:00 UTC|newest] Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-03-07 16:21 [PATCH] net: stmmac: Avoid sometimes uninitialized Clang warnings Nathan Chancellor 2019-03-07 16:21 ` Nathan Chancellor 2019-03-07 17:49 ` David Miller 2019-03-07 17:49 ` David Miller 2019-03-07 17:54 ` Nick Desaulniers 2019-03-07 17:54 ` Nick Desaulniers 2019-03-07 18:00 ` Nathan Chancellor [this message] 2019-03-07 18:00 ` [PATCH v2] " Nathan Chancellor 2019-03-07 18:12 ` Nick Desaulniers 2019-03-07 18:12 ` Nick Desaulniers 2019-03-07 18:59 ` David Miller 2019-03-07 18:59 ` David Miller 2019-03-08 4:02 ` [PATCH] net: stmmac: Avoid one more sometimes uninitialized Clang warning Nathan Chancellor 2019-03-08 4:02 ` Nathan Chancellor 2019-03-08 21:02 ` Nick Desaulniers 2019-03-08 21:02 ` Nick Desaulniers 2019-03-09 7:20 ` David Miller 2019-03-09 7:20 ` David Miller
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