Re: [PATCH] powerpc/ptrace: Fix cppcheck issue in gpr32_set_common/gpr32_get_common.

Hi Daniel,
On Wed, Aug 24, 2016 at 12:21:23PM +1000, Daniel Axtens wrote:

Hi Simon,

quoted

The ckpt_regs usage in gpr32_set_common/gpr32_get_common()
will lead to cppcheck error.

[arch/powerpc/kernel/ptrace.c:2062]: (error) Uninitialized variable: ckpt_regs
[arch/powerpc/kernel/ptrace.c:2130]: (error) Uninitialized variable: ckpt_regs

A straightforward fix to clean it.

I'm always happy to see cppcheck warnings fixed :)

Thanks for raising this issue :)

quoted

 static int gpr32_get_common(struct task_struct *target,
 		     const struct user_regset *regset,
 		     unsigned int pos, unsigned int count,
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
 			    void *kbuf, void __user *ubuf, bool tm_active)
+#else
+			    void *kbuf, void __user *ubuf)
+#endif

I wonder if it might be possible to avoid some of the ifdefs and general
churn by making the tm_active argument __maybe_unused rather than
ifdefing around it?

In particular, it would mean the two hunks in the function definitions
and these these two hunks at the call site would be unnecessary:

I think keeping tm_active argument for "ifndef CONFIG_PPC_TRANSACTIONAL_MEM" 
case (with __maybe_unused prefix) will be somehow strange -- Whatever
value is provided in the caller function for tm_active, programmer might be 
puzzled and cost sometime to think about it.  I don't like to use 
"__maybe_unused" to bypass this warning.

Thanks,
- Simon