Commit 51161bfc authored Apr 19, 2020 by Leon Romanovsky Committed by David S. Miller Apr 21, 2020

kernel/module: Hide vermagic header file from general use

VERMAGIC* definitions are not supposed to be used by the drivers,
see this [1] bug report, so introduce special define to guard inclusion
of this header file and define it in kernel/modules.h and in internal
script that generates *.mod.c files.

In-tree module build:
➜  kernel git:(vermagic) ✗ make clean
➜  kernel git:(vermagic) ✗ make M=drivers/infiniband/hw/mlx5
➜  kernel git:(vermagic) ✗ modinfo drivers/infiniband/hw/mlx5/mlx5_ib.ko
filename:	/images/leonro/src/kernel/drivers/infiniband/hw/mlx5/mlx5_ib.ko
<...>
vermagic:       5.6.0+ SMP mod_unload modversions

Out-of-tree module build:
➜  mlx5 make -C /images/leonro/src/kernel clean M=/tmp/mlx5
➜  mlx5 make -C /images/leonro/src/kernel M=/tmp/mlx5
➜  mlx5 modinfo /tmp/mlx5/mlx5_ib.ko
filename:       /tmp/mlx5/mlx5_ib.ko
<...>
vermagic:       5.6.0+ SMP mod_unload modversions

[1] https://lore.kernel.org/lkml/20200411155623.GA22175@zn.tnic


Reported-by: Borislav Petkov <bp@suse.de>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Jessica Yu <jeyu@kernel.org>
Co-developed-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent b4f37219

include/linux/vermagic.h

+5 −0

Original line number	Diff line number	Diff line
		/* SPDX-License-Identifier: GPL-2.0 */

		#ifndef INCLUDE_VERMAGIC
		#error "This header can be included from kernel/module.c or *.mod.c only"
		#endif

		#include <generated/utsrelease.h>

		/* Simply sanity version stamp for modules. */

kernel/module.c

+3 −0

Original line number	Diff line number	Diff line
		@@ -4,6 +4,9 @@
		Copyright (C) 2001 Rusty Russell, 2002, 2010 Rusty Russell IBM.

		*/

		#define INCLUDE_VERMAGIC

		#include <linux/export.h>
		#include <linux/extable.h>
		#include <linux/moduleloader.h>

scripts/mod/modpost.c

+1 −0

Original line number	Diff line number	Diff line
		@@ -2251,6 +2251,7 @@ static void add_header(struct buffer b, struct module mod)
		* Include build-salt.h after module.h in order to
		* inherit the definitions.
		*/
		buf_printf(b, "#define INCLUDE_VERMAGIC\n");
		buf_printf(b, "#include <linux/build-salt.h>\n");
		buf_printf(b, "#include <linux/vermagic.h>\n");
		buf_printf(b, "#include <linux/compiler.h>\n");

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