Re: [PATCH] Fix pointer cast for 32 bits arch

From: Dan Carpenter
Date: Mon Apr 13 2015 - 08:31:43 EST


On Mon, Apr 13, 2015 at 01:25:15PM +0200, Peter Senna Tschudin wrote:
> Line 4677 of http://pastebin.com/2bi9Dg7k looks like a bug
>
> diff -u -p a/arch/powerpc/kernel/signal_32.c b/arch/powerpc/kernel/signal_32.c
> - regs->nip = (unsigned long) (unsigned long)ksig->ka.sa.sa_handler;

I don't know about "bug" but it does look uninentional, yes.

Double casting is probably a good thing to print a static checker
warning about.

Other static checkers complain about:

1) ~(char)foo;

(char)foo is type promoted to an int before the bitwise NOT.

2) (long *)&some_int

3) some_function((struct foo *)ptr);

Casting function arguments is almost always wrong. I check this
with Smatch. I don't remember the details.

4) (long long)(x + y)

Probably it should be (long long)x + y

regards,
dan carpenter

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