Subject: Re: linux-next: build warnings in Linus' tree

From: Borislav Petkov <[email-masked]>
Date: Tue, 23 Nov 2021 08:04:34 +0100

On Tue, Nov 23, 2021 at 09:44:19AM +1100, Stephen Rothwell wrote:
> Hi all,
> 
> Building Linus' tree, today's linux-next build (x86_64 allmodconfig)
> produced these warnings:
> 
> WARNING: modpost: vmlinux.o(.text.unlikely+0x63df): Section mismatch in reference from the function prepare_command_line() to the variable .init.data:builtin_cmdline
> The function prepare_command_line() references
> the variable __initdata builtin_cmdline.
> This is often because prepare_command_line lacks a __initdata 
> annotation or the annotation of builtin_cmdline is wrong.

Doesn't trigger with my toolchain, because it simply inlines that
function.

Anyway, fix is trivial, thanks for reporting.

---
>From 4f4226a7dce0c5b6d911574f7fa5870c4ee693ff Mon Sep 17 00:00:00 2001
From: Borislav Petkov <[email-masked]>
Date: Tue, 23 Nov 2021 07:53:57 +0100
Subject: [PATCH] x86/boot: Mark prepare_command_line() __init

Fix:

  WARNING: modpost: vmlinux.o(.text.unlikely+0x64d0): Section mismatch in reference \
   from the function prepare_command_line() to the variable .init.data:command_line
  The function prepare_command_line() references
  the variable __initdata command_line.
  This is often because prepare_command_line lacks a __initdata
  annotation or the annotation of command_line is wrong.

Apparently some toolchains do different inlining decisions.

Reported-by: Stephen Rothwell <[email-masked]>
Signed-off-by: Borislav Petkov <[email-masked]>
Link: https://lore.kernel.org/r/[email-masked]
---
 arch/x86/kernel/setup.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index c410be738ae7..6a190c7f4d71 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -742,7 +742,7 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
 	return 0;
 }
 
-static char *prepare_command_line(void)
+static char * __init prepare_command_line(void)
 {
 #ifdef CONFIG_CMDLINE_BOOL
 #ifdef CONFIG_CMDLINE_OVERRIDE
-- 
2.29.2

-- 
Regards/Gruss,
    Boris.

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