Re: WARN_ON() which sometimes sucks

From: Paul Mackerras
Date: Wed Aug 01 2007 - 00:21:07 EST


Linus Torvalds writes:

> Umm. The WARN_ON() might actually get a "long long" value for all we know.
> Ie it's perfectly possible that the WARN_ON might look like
>
> /* Must not have high bits on */
> WARN_ON(offset & 0xffffffff00000000);
>
> which on a 32-bit pcc would apparently do the wrong thing entirely as it
> stands now. No?

Actually, because of the typeof in the powerpc WARN_ON, I think it
would fail to build since we'd be passing a long long value to an
inline asm, or at least I hope it would fail to build. :)

But your criticism is correct with regard to the powerpc BUG_ON, and
you're correct that a long wouldn't be sufficient if someone passes in
a long long. Oh well. I guess we just wear the extra two
instructions.

Paul.
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