From 79b2c87287aa911d879fc2e60de4d48747bf4ad7 Mon Sep 17 00:00:00 2001
From: Fredrik Noring <noring@nocrew.org>
Date: Wed, 27 Mar 2019 19:12:50 +0100
Subject: [PATCH] kbuild: modversions: Fix relative CRC byte order
interpretation
Git-commit: 54a7151b1496cddbb7a83546b7998103e98edc88
Patch-mainline: v5.1-rc3
References: bsc#1131290
Fix commit 56067812d5b0 ("kbuild: modversions: add infrastructure for
emitting relative CRCs") where CRCs are interpreted in host byte order
rather than proper kernel byte order. The bug is conditional on
CONFIG_MODULE_REL_CRCS.
For example, when loading a BE module into a BE kernel compiled with a LE
system, the error "disagrees about version of symbol module_layout" is
produced. A message such as "Found checksum D7FA6856 vs module 5668FAD7"
will be given with debug enabled, which indicates an obvious endian
problem within __kcrctab within the kernel image.
The general solution is to use the macro TO_NATIVE, as is done in
similar cases throughout modpost.c. With this correction it has been
verified that a BE kernel compiled with a LE system accepts BE modules.
This change has also been verified with a LE kernel compiled with a LE
system, in which case TO_NATIVE returns its value unmodified since the
byte orders match. This is by far the common case.
Fixes: 56067812d5b0 ("kbuild: modversions: add infrastructure for emitting relative CRCs")
Signed-off-by: Fredrik Noring <noring@nocrew.org>
Cc: stable@vger.kernel.org
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Jessica Yu <jeyu@suse.de>
---
scripts/mod/modpost.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/scripts/mod/modpost.c b/scripts/mod/modpost.c
index fde9aa09a3ea..626a3d8578ce 100644
--- a/scripts/mod/modpost.c
+++ b/scripts/mod/modpost.c
@@ -631,7 +631,7 @@ static void handle_modversions(struct module *mod, struct elf_info *info,
info->sechdrs[sym->st_shndx].sh_offset -
(info->hdr->e_type != ET_REL ?
info->sechdrs[sym->st_shndx].sh_addr : 0);
- crc = *crcp;
+ crc = TO_NATIVE(*crcp);
}
sym_update_crc(symname + strlen(CRC_PFX), mod, crc,
export);
--
2.16.4