kexec: crash: don't save swapper_pg_dir for !CONFIG_MMU configurations

nommu platforms don't have very interesting swapper_pg_dir pointers and
usually just #define them to NULL, meaning that we can't include them in
the vmcoreinfo on the kexec crash path.

This patch only saves the swapper_pg_dir if we have an MMU.

Signed-off-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Simon Horman <horms@verge.net.au>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/kernel/kexec.c b/kernel/kexec.c
index a6a675cb9818..769e347c5196 100644
--- a/kernel/kexec.c
+++ b/kernel/kexec.c
@@ -1462,7 +1462,9 @@ static int __init crash_save_vmcoreinfo_init(void)
 
         VMCOREINFO_SYMBOL(init_uts_ns);
         VMCOREINFO_SYMBOL(node_online_map);
+#ifdef CONFIG_MMU
         VMCOREINFO_SYMBOL(swapper_pg_dir);
+#endif
         VMCOREINFO_SYMBOL(_stext);
         VMCOREINFO_SYMBOL(vmlist);