[PATCH AUTOSEL 5.0 080/262] powerpc/xmon: Fix opcode being uninitialized in print_insn_powerpc

Sasha Levin
2019-03-27T18:04:34Z

From: Nathan Chancellor <natechancellor@gmail.com>

[ Upstream commit e7140639b1de65bba435a6bd772d134901141f86 ]

When building with -Wsometimes-uninitialized, Clang warns:

arch/powerpc/xmon/ppc-dis.c:157:7: warning: variable 'opcode' is used
uninitialized whenever 'if' condition is false
[-Wsometimes-uninitialized]
if (cpu_has_feature(CPU_FTRS_POWER9))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/powerpc/xmon/ppc-dis.c:167:7: note: uninitialized use occurs here
if (opcode == NULL)
^~~~~~
arch/powerpc/xmon/ppc-dis.c:157:3: note: remove the 'if' if its
condition is always true
if (cpu_has_feature(CPU_FTRS_POWER9))
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/powerpc/xmon/ppc-dis.c:132:38: note: initialize the variable
'opcode' to silence this warning
const struct powerpc_opcode *opcode;
^
= NULL
1 warning generated.

This warning seems to make no sense on the surface because opcode is set
to NULL right below this statement. However, there is a comma instead of
semicolon to end the dialect assignment, meaning that the opcode
assignment only happens in the if statement. Properly terminate that
line so that Clang no longer warns.

Fixes: 5b102782c7f4 ("powerpc/xmon: Enable disassembly files (compilation changes)")
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/xmon/ppc-dis.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/xmon/ppc-dis.c b/arch/powerpc/xmon/ppc-dis.c
index 9deea5ee13f6..27f1e6415036 100644
--- a/arch/powerpc/xmon/ppc-dis.c
+++ b/arch/powerpc/xmon/ppc-dis.c
@@ -158,7 +158,7 @@ int print_insn_powerpc (unsigned long insn, unsigned long memaddr)
dialect |= (PPC_OPCODE_POWER5 | PPC_OPCODE_POWER6 | PPC_OPCODE_POWER7
| PPC_OPCODE_POWER8 | PPC_OPCODE_POWER9 | PPC_OPCODE_HTM
| PPC_OPCODE_ALTIVEC | PPC_OPCODE_ALTIVEC2
- | PPC_OPCODE_VSX | PPC_OPCODE_VSX3),
+ | PPC_OPCODE_VSX | PPC_OPCODE_VSX3);

/* Get the major opcode of the insn. */
opcode = NULL;
--
2.19.1