On Thu, 2012-12-13 at 19:37 +0100, Borislav Petkov wrote:

On Thu, Dec 13, 2012 at 10:23:10AM -0800, Joe Perches wrote:

quoted

m->ip is a u64 so, when compiling x86-32, there's a new warning
"cast to pointer from integer of different size".  This isn't new
different behavior, just a new warning.  The previous print_symbol
took a ulong and the u64 was silently truncated.

  CC      arch/x86/kernel/cpu/mcheck/mce.o
arch/x86/kernel/cpu/mcheck/mce.c: In function ‘print_mce’:
arch/x86/kernel/cpu/mcheck/mce.c:246:4: warning: cast to pointer from integer of different size [-Wint-to-pointer-cast]

If appropriate, the code could be changed to

	(void *)(unsigned long)m->ip

Can we explicitly cast it to what it is so that we can be explicit as to
what we're casting it? IOW:

	(void *)(__u64)m->ip;

Does that even work on 32bit?

No, it already is __u64.  You need (unsigned long)
or something else the same size as (void *)

from: arch/x86/include/asm/mce.h

/* Fields are zero when not available */
struct mce {
...
	__u64 ip;

Also, does the compiler bitch about this useless cast when building with
W=123?

For x86-32:

With the cast the line is silent.
Without the cast, just the warning about cast.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/