[PATCH net-next v1 4/4] kernel/module: Hide vermagic header file from general use

[Leon Romanovsky <leon@kernel.org>]

From: Leon Romanovsky <leonro@mellanox.com>

VERMAGIC* definitions are not supposed to be used by the drivers,
see this [1] bug report, so simply move this header file to be visible
to kernel/* and scripts files only.

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>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
---
 kernel/module.c                      | 2 +-
 {include/linux => kernel}/vermagic.h | 0
 scripts/mod/modpost.c                | 2 +-
 3 files changed, 2 insertions(+), 2 deletions(-)
 rename {include/linux => kernel}/vermagic.h (100%)

diff --git a/kernel/module.c b/kernel/module.c
index 3447f3b74870..fce06095d341 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -29,7 +29,6 @@
 #include <linux/moduleparam.h>
 #include <linux/errno.h>
 #include <linux/err.h>
-#include <linux/vermagic.h>
 #include <linux/notifier.h>
 #include <linux/sched.h>
 #include <linux/device.h>
@@ -55,6 +54,7 @@
 #include <linux/audit.h>
 #include <uapi/linux/module.h>
 #include "module-internal.h"
+#include "vermagic.h"

 #define CREATE_TRACE_POINTS
 #include <trace/events/module.h>
diff --git a/include/linux/vermagic.h b/kernel/vermagic.h
similarity index 100%
rename from include/linux/vermagic.h
rename to kernel/vermagic.h
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index 5c3c50c5ec52..91f86261bcfe 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -2252,7 +2252,7 @@ static void add_header(struct buffer *b, struct module *mod)
 	 * inherit the definitions.
 	 */
 	buf_printf(b, "#include <linux/build-salt.h>\n");
-	buf_printf(b, "#include <linux/vermagic.h>\n");
+	buf_printf(b, "#include <../kernel/vermagic.h>\n");
 	buf_printf(b, "#include <linux/compiler.h>\n");
 	buf_printf(b, "\n");
 	buf_printf(b, "BUILD_SALT;\n");
--
2.25.2