Re: Kunit: kernel/resource.c: In function 'gfr_start': include/linux/mm.h:101:35: error: 'MAX_PHYSMEM_BITS' undeclared (first use in this function)

["Arnd Bergmann" <arnd@arndb.de>]

On Mon, Sep 9, 2024, at 20:00, Naresh Kamboju wrote:
> The arm kunit builds failed on the Linux next-20240909 due to following
> build warnings / errors with gcc-13 and clang-19 with extra Kconfigs
>
>   CONFIG_OF_KUNIT_TEST=y
>   CONFIG_KASAN=y
>   CONFIG_KUNIT=y
>   CONFIG_KUNIT_ALL_TESTS=y
>
> First seen on next-20240909
>   Good: next-20240906
>   BAD:  next-20240909
>
> Reported-by: Linux Kernel Functional Testing <lkft@linaro.org>
>

This patch below addresses the build regression, not sure if that
is what we want.

        Arnd

From 39601b1274354c710368f5cf40fe9e32540f7591 Mon Sep 17 00:00:00 2001
From: Arnd Bergmann <arnd@arndb.de>
Date: Mon, 9 Sep 2024 13:10:21 +0000
Subject: [PATCH] resource, kunit: add sparsemem dependency

The testcase now selects CONFIG_GET_FREE_REGION, but that
is only available for sparsemem configurations:

WARNING: unmet direct dependencies detected for GET_FREE_REGION
  Depends on [n]: SPARSEMEM [=n]
  Selected by [m]:
  - RESOURCE_KUNIT_TEST [=m] && RUNTIME_TESTING_MENU [=y] && KUNIT [=y]
In file included from include/linux/ioport.h:15,
                 from kernel/resource.c:15:
kernel/resource.c: In function 'gfr_start':
include/linux/mm.h:101:35: error: 'MAX_PHYSMEM_BITS' undeclared (first use in this function)
  101 | # define PHYSMEM_END    ((1ULL << MAX_PHYSMEM_BITS) - 1)
kernel/resource.c:1874:57: note: in expansion of macro 'PHYSMEM_END'
 1874 |                 end = min_t(resource_size_t, base->end, PHYSMEM_END);
      |                                                         ^~~~~~~~~~~

It may be better to extend this to non-sparsemem, but a Kconfig
dependency is the easiest way to address the build failure at the
moment.

Fixes: e2941fe697c8 ("resource, kunit: add test case for region_intersects()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index b986050fc7e0..4c081a28fe96 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2632,6 +2632,7 @@ config HASH_KUNIT_TEST
 config RESOURCE_KUNIT_TEST
 	tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
 	depends on KUNIT
+	depends on SPARSEMEM
 	default KUNIT_ALL_TESTS
 	select GET_FREE_REGION
 	help