[PATCH v2 1/3] Bring in linux/limits.h

[Simon Glass]

Hi Tom,

On Fri, 18 Apr 2025 at 15:39, Tom Rini <trini at konsulko.com> wrote:
>
> On Fri, Apr 18, 2025 at 04:59:13AM -0600, Simon Glass wrote:
>
> > From: Simon Glass <simon.glass at canonical.com>
> >
> > Add part of this file from Linux v6.14 so we can include it from the
> > linux/overflow.h file. Drop the relevant section from kernel.h
> >
> > The top of the file is omitted since it defines things used in mbedos
> > and we get an error on SIZE_MAX.
> >
> > Signed-off-by: Simon Glass <simon.glass at canonical.com>
> > ---
> > Error is:
> >
> >   In file included from include/limits.h:6,
> >                  from lib/mbedtls/external/mbedtls/library/constant_time.c:14:
> >   include/linux/limits.h:7:35: error: missing binary operator before token "0"
> >     7 | #define SIZE_MAX        (~(size_t)0)
> >       |                                   ^
> >   lib/mbedtls/external/mbedtls/library/constant_time_internal.h:65:6: note: in expansion of macro ‘SIZE_MAX’
> >    65 | #if (SIZE_MAX > 0xffffffffffffffffULL)
> >       |      ^~~~~~~~
> >   include/linux/limits.h:7:35: error: missing binary operator before token "0"
> >     7 | #define SIZE_MAX        (~(size_t)0)
> >       |                                   ^
> >   lib/mbedtls/external/mbedtls/library/constant_time_internal.h:71:8: note: in expansion of macro ‘SIZE_MAX’
> >    71 | #elif (SIZE_MAX > 0xffffffff) || defined(MBEDTLS_HAVE_INT64)
> >       |        ^~~~~~~~
> >   make[3]: *** [scripts/Makefile.build:256: lib/mbedtls/external/mbedtls/library/constant_time.o] Error 1
> >   make[2]: *** [scripts/Makefile.build:398: lib/mbedtls] Error 2
> >
> > Changes in v2:
> > - Add new patch to bring in linux/limits.h
> >
> >  include/limits.h       |  2 ++
> >  include/linux/kernel.h | 12 ------------
> >  include/linux/limits.h | 21 +++++++++++++++++++++
> >  3 files changed, 23 insertions(+), 12 deletions(-)
> >  create mode 100644 include/linux/limits.h
>
> Ugh. I think we need to:
> - Fix lib/string.c (and Fixes commit 7c7361b98d6e ("lib: implement
>   strnstr()")) to not bring in <limits.h> as that should be limited to
>   mbedtls usage.
> - Not bring <linux/limits.h> to <limits.h> to start with at least (we
>   can worry about handling wrappers around overflow protection there
>   separately).

There are quite a few places which need the limits. If I remove the
dups from kernel.h then some things don't compile, at least not
without including linux/limits,h in limits,h (which it seems to me we
should do).

So is this something you would like to take over, or do we need Linaro
do fix up mbedtls, or...?

Regards,
Simon