| Message ID | 20190226053855.7020-1-natechancellor@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | e7140639b1de65bba435a6bd772d134901141f86 |
| Headers | show |
| Series | powerpc/xmon: Fix opcode being uninitialized in print_insn_powerpc | expand |
| Context | Check | Description |
|---|---|---|
| snowpatch_ozlabs/apply_patch | success | next/apply_patch Successfully applied |
| snowpatch_ozlabs/build-ppc64le | success | build succeeded & removed 0 sparse warning(s) |
| snowpatch_ozlabs/build-ppc64be | success | build succeeded & removed 0 sparse warning(s) |
| snowpatch_ozlabs/build-ppc64e | success | build succeeded & removed 0 sparse warning(s) |
| snowpatch_ozlabs/build-pmac32 | warning | build succeeded but added 17 new sparse warning(s) |
| snowpatch_ozlabs/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 8 lines checked |
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 >
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;
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(-)