Re-enable CONFIG_MODVERSIONS in a slightly weaker form

This enables CONFIG_MODVERSIONS again, but allows for missing symbol CRC
information in order to work around the issue that newer binutils
versions seem to occasionally drop the CRC on the floor.  binutils 2.26
seems to work fine, while binutils 2.27 seems to break MODVERSIONS of
symbols that have been defined in assembler files.

[ We've had random missing CRC's before - it may be an old problem that
  just is now reliably triggered with the weak asm symbols and a new
  version of binutils ]

Some day I really do want to remove MODVERSIONS entirely.  Sadly, today
does not appear to be that day: Debian people apparently do want the
option to enable MODVERSIONS to make it easier to have external modules
across kernel versions, and this seems to be a fairly minimal fix for
the annoying problem.

Cc: Ben Hutchings <ben@decadent.org.uk>
Acked-by: Michal Marek <mmarek@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/init/Kconfig b/init/Kconfig
index c4fbc1e55c2539a37486f990efde1d29d44db7a7..34407f15e6d34da57be238f69441f1dad9e60764 100644 (file)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1945,7 +1945,6 @@ config MODULE_FORCE_UNLOAD
 
 config MODVERSIONS
        bool "Module versioning support"
-       depends on BROKEN
        help
          Usually, you have to use modules compiled with your kernel.
          Saying Y here makes it sometimes possible to use modules

diff --git a/kernel/module.c b/kernel/module.c
index f57dd63186e63c647e4566c828b1258fbcdb8724..0e54d5bf0097f57954d4848db6a830f5a0bc7072 100644 (file)
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -1301,8 +1301,9 @@ static int check_version(Elf_Shdr *sechdrs,
                goto bad_version;
        }
 
-       pr_warn("%s: no symbol version for %s\n", mod->name, symname);
-       return 0;
+       /* Broken toolchain. Warn once, then let it go.. */
+       pr_warn_once("%s: no symbol version for %s\n", mod->name, symname);
+       return 1;
 
 bad_version:
        pr_warn("%s: disagrees about version of symbol %s\n",