* [PATCH] powerpc/xmon: Fix opcode being uninitialized in print_insn_powerpc
@ 2019-02-26 5:38 Nathan Chancellor
2019-02-26 5:43 ` Nick Desaulniers
2019-02-28 9:21 ` Michael Ellerman
0 siblings, 2 replies; 3+ messages in thread
From: Nathan Chancellor @ 2019-02-26 5:38 UTC (permalink / raw)
To: Benjamin Herrenschmidt, Paul Mackerras, Michael Ellerman
Cc: Nick Desaulniers, Nathan Chancellor, linuxppc-dev, linux-kernel,
Joel Stanley
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)")
Link: https://github.com/ClangBuiltLinux/linux/issues/390
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
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;
--
2.21.0
^ permalink raw reply related [flat|nested] 3+ messages in thread* Re: [PATCH] powerpc/xmon: Fix opcode being uninitialized in print_insn_powerpc
2019-02-26 5:38 [PATCH] powerpc/xmon: Fix opcode being uninitialized in print_insn_powerpc Nathan Chancellor
@ 2019-02-26 5:43 ` Nick Desaulniers
2019-02-28 9:21 ` Michael Ellerman
1 sibling, 0 replies; 3+ messages in thread
From: Nick Desaulniers @ 2019-02-26 5:43 UTC (permalink / raw)
To: Nathan Chancellor; +Cc: LKML, Paul Mackerras, Joel Stanley, linuxppc-dev
On Mon, Feb 25, 2019 at 9:39 PM Nathan Chancellor
<natechancellor@gmail.com> wrote:
>
> 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)")
> Link: https://github.com/ClangBuiltLinux/linux/issues/390
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
haha! (shows office mates). Nice find, and fix!
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
> ---
> 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;
> --
> 2.21.0
>
--
Thanks,
~Nick Desaulniers
^ permalink raw reply [flat|nested] 3+ messages in thread* Re: powerpc/xmon: Fix opcode being uninitialized in print_insn_powerpc
2019-02-26 5:38 [PATCH] powerpc/xmon: Fix opcode being uninitialized in print_insn_powerpc Nathan Chancellor
2019-02-26 5:43 ` Nick Desaulniers
@ 2019-02-28 9:21 ` Michael Ellerman
1 sibling, 0 replies; 3+ messages in thread
From: Michael Ellerman @ 2019-02-28 9:21 UTC (permalink / raw)
To: Nathan Chancellor, Benjamin Herrenschmidt, Paul Mackerras
Cc: linuxppc-dev, Nathan Chancellor, Nick Desaulniers, linux-kernel,
Joel Stanley
On Tue, 2019-02-26 at 05:38:55 UTC, Nathan Chancellor wrote:
> 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)")
> Link: https://github.com/ClangBuiltLinux/linux/issues/390
> Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
> Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Applied to powerpc next, thanks.
https://git.kernel.org/powerpc/c/e7140639b1de65bba435a6bd772d1349
cheers
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2019-02-28 9:28 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2019-02-26 5:38 [PATCH] powerpc/xmon: Fix opcode being uninitialized in print_insn_powerpc Nathan Chancellor
2019-02-26 5:43 ` Nick Desaulniers
2019-02-28 9:21 ` Michael Ellerman
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).