[PATCH AUTOSEL 4.19 02/23] powerpc/4xx: Fix build errors from mfdcr()

[PATCH AUTOSEL 4.19 02/23] powerpc/4xx: Fix build errors from mfdcr()

[Sasha Levin]

From: Michael Ellerman <mpe@ellerman.id.au>

[ Upstream commit eead089311f4d935ab5d1d8fbb0c42ad44699ada ]

lkp reported a build error in fsp2.o:

  CC      arch/powerpc/platforms/44x/fsp2.o
  {standard input}:577: Error: unsupported relocation against base

Which comes from:

  pr_err("GESR0: 0x%08x\n", mfdcr(base + PLB4OPB_GESR0));

Where our mfdcr() macro is stringifying "base + PLB4OPB_GESR0", and
passing that to the assembler, which obviously doesn't work.

The mfdcr() macro already checks that the argument is constant using
__builtin_constant_p(), and if not calls the out-of-line version of
mfdcr(). But in this case GCC is smart enough to notice that "base +
PLB4OPB_GESR0" will be constant, even though it's not something we can
immediately stringify into a register number.

Segher pointed out that passing the register number to the inline asm
as a constant would be better, and in fact it fixes the build error,
presumably because it gives GCC a chance to resolve the value.

While we're at it, change mtdcr() similarly.

Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Segher Boessenkool <segher@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Feng Tang <feng.tang@intel.com>
Link: https://lore.kernel.org/r/20210218123058.748882-1-mpe@ellerman.id.au
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 arch/powerpc/include/asm/dcr-native.h | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/dcr-native.h b/arch/powerpc/include/asm/dcr-native.h
index 151dff555f50..9d9e323f5e9b 100644
--- a/arch/powerpc/include/asm/dcr-native.h
+++ b/arch/powerpc/include/asm/dcr-native.h
@@ -66,8 +66,8 @@ static inline void mtdcrx(unsigned int reg, unsigned int val)
 #define mfdcr(rn)						\
 	({unsigned int rval;					\
 	if (__builtin_constant_p(rn) && rn < 1024)		\
-		asm volatile("mfdcr %0," __stringify(rn)	\
-		              : "=r" (rval));			\
+		asm volatile("mfdcr %0, %1" : "=r" (rval)	\
+			      : "n" (rn));			\
 	else if (likely(cpu_has_feature(CPU_FTR_INDEXED_DCR)))	\
 		rval = mfdcrx(rn);				\
 	else							\
@@ -77,8 +77,8 @@ static inline void mtdcrx(unsigned int reg, unsigned int val)
 #define mtdcr(rn, v)						\
 do {								\
 	if (__builtin_constant_p(rn) && rn < 1024)		\
-		asm volatile("mtdcr " __stringify(rn) ",%0"	\
-			      : : "r" (v)); 			\
+		asm volatile("mtdcr %0, %1"			\
+			      : : "n" (rn), "r" (v));		\
 	else if (likely(cpu_has_feature(CPU_FTR_INDEXED_DCR)))	\
 		mtdcrx(rn, v);					\
 	else							\
-- 
2.30.1

[PATCH AUTOSEL 4.19 14/23] net: wan: fix error return code of uhdlc_init()

[Sasha Levin]

From: Jia-Ju Bai <baijiaju1990@gmail.com>

[ Upstream commit 62765d39553cfd1ad340124fe1e280450e8c89e2 ]

When priv->rx_skbuff or priv->tx_skbuff is NULL, no error return code of
uhdlc_init() is assigned.
To fix this bug, ret is assigned with -ENOMEM in these cases.

Reported-by: TOTE Robot <oslab@tsinghua.edu.cn>
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/wan/fsl_ucc_hdlc.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
index 9ab04ef532f3..5df6e85e7ccb 100644
--- a/drivers/net/wan/fsl_ucc_hdlc.c
+++ b/drivers/net/wan/fsl_ucc_hdlc.c
@@ -201,14 +201,18 @@ static int uhdlc_init(struct ucc_hdlc_private *priv)
 	priv->rx_skbuff = kcalloc(priv->rx_ring_size,
 				  sizeof(*priv->rx_skbuff),
 				  GFP_KERNEL);
-	if (!priv->rx_skbuff)
+	if (!priv->rx_skbuff) {
+		ret = -ENOMEM;
 		goto free_ucc_pram;
+	}
 
 	priv->tx_skbuff = kcalloc(priv->tx_ring_size,
 				  sizeof(*priv->tx_skbuff),
 				  GFP_KERNEL);
-	if (!priv->tx_skbuff)
+	if (!priv->tx_skbuff) {
+		ret = -ENOMEM;
 		goto free_rx_skbuff;
+	}
 
 	priv->skb_curtx = 0;
 	priv->skb_dirtytx = 0;
-- 
2.30.1