x86-64: fix overlap of modules and fixmap areas

Plus add a build time check so this doesn't go unnoticed again.

Signed-off-by: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index 1b318e903bf6..9bfc4d72fb2e 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -88,6 +88,7 @@ void __init x86_64_start_kernel(char * real_mode_data)
         BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL));
         BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) ==
                                 (__START_KERNEL & PGDIR_MASK)));
+        BUILD_BUG_ON(__fix_to_virt(__end_of_fixed_addresses) <= MODULES_END);
 
         /* clear bss before set_intr_gate with early_idt_handler */
         clear_bss();