Re: [PATCH] arch_numa: fix common code printing of phys_addr_t

[Palmer Dabbelt]

On Mon, 01 Feb 2021 19:51:07 PST (-0800), rdunlap@xxxxxxxxxxxxx wrote:
> On 2/1/21 7:36 PM, Palmer Dabbelt wrote:
> > On Wed, 27 Jan 2021 19:55:33 PST (-0800), rdunlap@xxxxxxxxxxxxx wrote:
> > > Fix build warnings in the arch_numa common code:
> > >
> > > ../include/linux/kern_levels.h:5:18: warning: format '%Lx' expects argument of type 'long long unsigned int', but argument 3 has type 'phys_addr_t' {aka 'unsigned int'} [-Wformat=]
> > > ../drivers/base/arch_numa.c:360:56: note: format string is defined here
> > >   360 |    pr_warn("Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
> > > ../drivers/base/arch_numa.c:435:39: note: format string is defined here
> > >   435 |  pr_info("Faking a node at [mem %#018Lx-%#018Lx]\n", start, end - 1);
> > >
> > > Fixes: ae3c107cd8be ("numa: Move numa implementation to common code")
> > > Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> > > Reported-by: kernel test robot <lkp@xxxxxxxxx>
> > > Cc: Atish Patra <atish.patra@xxxxxxx>
> > > Cc: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
> > > ---
> > >  drivers/base/arch_numa.c |   13 +++++++------
> > >  1 file changed, 7 insertions(+), 6 deletions(-)
> > >
> > > --- linux-next-20210125.orig/drivers/base/arch_numa.c
> > > +++ linux-next-20210125/drivers/base/arch_numa.c
> > > @@ -355,11 +355,12 @@ static int __init numa_register_nodes(vo
> > >      /* Check that valid nid is set to memblks */
> > >      for_each_mem_region(mblk) {
> > >          int mblk_nid = memblock_get_region_node(mblk);
> > > +        phys_addr_t start = mblk->base;
> > > +        phys_addr_t end = mblk->base + mblk->size - 1;
> > >
> > >          if (mblk_nid == NUMA_NO_NODE || mblk_nid >= MAX_NUMNODES) {
> > > -            pr_warn("Warning: invalid memblk node %d [mem %#010Lx-%#010Lx]\n",
> > > -                mblk_nid, mblk->base,
> > > -                mblk->base + mblk->size - 1);
> > > +            pr_warn("Warning: invalid memblk node %d [mem %pap-%pap]\n",
> > > +                mblk_nid, &start, &end);
> > >              return -EINVAL;
> > >          }
> > >      }
> > > @@ -427,14 +428,14 @@ out_free_distance:
> > >  static int __init dummy_numa_init(void)
> > >  {
> > >      phys_addr_t start = memblock_start_of_DRAM();
> > > -    phys_addr_t end = memblock_end_of_DRAM();
> > > +    phys_addr_t end = memblock_end_of_DRAM() - 1;
> > >      int ret;
> > >
> > >      if (numa_off)
> > >          pr_info("NUMA disabled\n"); /* Forced off on command line. */
> > > -    pr_info("Faking a node at [mem %#018Lx-%#018Lx]\n", start, end - 1);
> > > +    pr_info("Faking a node at [mem %pap-%pap]\n", &start, &end);
> > >
> > > -    ret = numa_add_memblk(0, start, end);
> > > +    ret = numa_add_memblk(0, start, end + 1);
> > >      if (ret) {
> > >          pr_err("NUMA init failed\n");
> > >          return ret;
> >
> > Thanks, this is on for-next.  Did you, by any chance, find %Lx documented
> > anywhere?  It's not ISO C and the GCC source code says it's a GNU extension,
> > but I couldn't find it in the documentation (or even where to add it, which I
> > guess is how I forgot to send my version fo the patch).
>
> 'man sprintf' says this:
>
>        As  a nonstandard extension, the GNU implementations treats ll and L as
>        synonyms, so that one can, for example, write llg (as a synonym for the
>        standards-compliant  Lg) and Ld (as a synonym for the standards compli-
>        ant lld).  Such usage is nonportable.
>
>
> and linux/lib/vsprintf.c has some handling for it:
>
> 	if (qualifier == 'L')
> 		spec->type = FORMAT_TYPE_LONG_LONG;
>
> and
>
> 		case 'L':
> 			if (is_sign)
> 				*va_arg(args, long long *) = val.s;
> 			else
> 				*va_arg(args, unsigned long long *) = val.u;
> 			break;
>
>
> Does that help?

The manpage does it, I guess I just wasn't reading closely enough. Thanks!