On Mon, Oct 25, 2010 at 03:10:29PM -0700, Christopher Li wrote:
> On Mon, Oct 25, 2010 at 2:31 PM, Dave Jones <davej@xxxxxxxxxx> wrote:
> > I just ran sparse on a kernel tree for the first time in ages, and got
> > hundreds of warnings, many of which related to the tracepoint macros
> > in the kernel, which use the new asm goto feature.
> >
> > Looking at the git log of sparse, I see there was some support added
> > for asm goto, but it seems to choke every time, printing ..
> >
> > include/trace/events/kmem.h:45:1: error: bad asm output
> > include/trace/events/kmem.h:45:1: error: incompatible types in comparison expression (different address spaces)
> >
> >
> > (this is with a sparse built from git head from a few minutes ago)
>
> Do you have a smaller test case to reproduce the error?
I tried unwinding some of the nested macros, and came up with ..
# define __ASM_FORM(x) " " #x " "
# define JUMP_LABEL_INITIAL_NOP ".byte 0xe9 \n\t .long 0\n\t"
# define __ASM_SEL(a,b) __ASM_FORM(b)
#define _ASM_PTR __ASM_SEL(.long, .quad)
# define JUMP_LABEL(key, label) \
do { \
asm goto("1:" \
JUMP_LABEL_INITIAL_NOP \
".pushsection __jump_table, \"a\" \n\t"\
_ASM_PTR "1b, %l[" #label "], %c0 \n\t" \
".popsection \n\t" \
: : "i" (key) : : label); \
} while (0)
int main(int argc, char *argv[])
{
JUMP_LABEL("1", do_trace );
return 1;
do_trace:
return 0;
}
gcc seems to not choke on it, but sparse still does, so I think I managed
to untangle things correctly..
Dave
--
To unsubscribe from this list: send the line "unsubscribe linux-sparse" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
