Re: [linux-next:master 12996/13245] WARNING: modpost: vmlinux: section mismatch in reference: vmap_init_free_space+0x2 (section: .text.unlikely) -> vmlist (section: .init.data)

[Uladzislau Rezki <urezki@gmail.com>]

On Thu, Jan 11, 2024 at 08:29:04PM +0800, kernel test robot wrote:
> tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
> head:   9e21984d62c56a0f6d1fc6f76b646212cfd7fe88
> commit: 86817057732a9ce9cefdb6f513b6554a55ebbbbb [12996/13245] mm: vmalloc: remove global vmap_area_root rb-tree
> config: um-defconfig (https://download.01.org/0day-ci/archive/20240111/202401112056.I41bELL4-lkp@intel.com/config)
> compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
> reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240111/202401112056.I41bELL4-lkp@intel.com/reproduce)
> 
> If you fix the issue in a separate patch/commit (i.e. not just a new version of
> the same patch/commit), kindly add following tags
> | Reported-by: kernel test robot <lkp@intel.com>
> | Closes: https://lore.kernel.org/oe-kbuild-all/202401112056.I41bELL4-lkp@intel.com/
> 
> All warnings (new ones prefixed by >>, old ones prefixed by <<):
> 
> WARNING: modpost: missing MODULE_DESCRIPTION() in vmlinux.o
> >> WARNING: modpost: vmlinux: section mismatch in reference: vmap_init_free_space+0x2 (section: .text.unlikely) -> vmlist (section: .init.data)
> WARNING: modpost: missing MODULE_DESCRIPTION() in fs/binfmt_misc.o
> WARNING: modpost: missing MODULE_DESCRIPTION() in fs/isofs/isofs.o
> WARNING: modpost: missing MODULE_DESCRIPTION() in fs/autofs/autofs4.o
> WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/block/loop.o
> WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/ppp/ppp_generic.o
> WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/slip/slip.o
> WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/net/slip/slhc.o
> 
> -- 
> 0-DAY CI Kernel Test Service
> https://github.com/intel/lkp-tests/wiki

I have sent out the patch, but just in case please see it below:

<snip>
From 998f605679409acdfe625c03b36917db70b6773b Mon Sep 17 00:00:00 2001
From: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Date: Thu, 11 Jan 2024 14:03:53 +0100
Subject: [PATCH 2/2] mm: vmalloc: Mark vmap_init_free_space() with __init tag

The vmap_init_free_space() function is called only once
therefore tag it with __init. Apart of that it access the
"vmlist" variable that is located in ".init.data" section.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202401112056.I41bELL4-lkp@intel.com/
Fixes: 86817057732 ("mm: vmalloc: remove global vmap_area_root rb-tree")
Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com>
---
 mm/vmalloc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 43a6608e1397..257981e37936 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -4834,7 +4834,7 @@ module_init(proc_vmalloc_init);
 
 #endif
 
-static void vmap_init_free_space(void)
+static void __init vmap_init_free_space(void)
 {
 	unsigned long vmap_start = 1;
 	const unsigned long vmap_end = ULONG_MAX;
-- 
2.39.2
<snip>

it can be folded into the: 86817057732 ("mm: vmalloc: remove global vmap_area_root rb-tree")
or applied as a separate patch.

--
Uladzislau Rezki