[PATCH v2 1/4] x86/mm: surround level4_kernel_pgt with #ifdef CONFIG_X86_5LEVEL...#endif

From: Du Changbin
Date: Fri Oct 19 2018 - 08:49:37 EST


The level4_kernel_pgt is only defined when X86_5LEVEL is enabled. So
surround level4_kernel_pgt with #ifdef CONFIG_X86_5LEVEL...#endif to
make code correct.

Signed-off-by: Du Changbin <changbin.du@xxxxxxxxx>
Acked-by: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx>
---
arch/x86/include/asm/pgtable_64.h | 2 ++
arch/x86/kernel/head64.c | 13 ++++++-------
2 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h
index 9c85b54bf03c..9333f7fa5bdb 100644
--- a/arch/x86/include/asm/pgtable_64.h
+++ b/arch/x86/include/asm/pgtable_64.h
@@ -16,7 +16,9 @@
#include <linux/threads.h>
#include <asm/fixmap.h>

+#ifdef CONFIG_X86_5LEVEL
extern p4d_t level4_kernel_pgt[512];
+#endif
extern p4d_t level4_ident_pgt[512];
extern pud_t level3_kernel_pgt[512];
extern pud_t level3_ident_pgt[512];
diff --git a/arch/x86/kernel/head64.c b/arch/x86/kernel/head64.c
index ddee1f0870c4..4a59ef93c258 100644
--- a/arch/x86/kernel/head64.c
+++ b/arch/x86/kernel/head64.c
@@ -151,16 +151,15 @@ unsigned long __head __startup_64(unsigned long physaddr,

pgd = fixup_pointer(&early_top_pgt, physaddr);
p = pgd + pgd_index(__START_KERNEL_map);
- if (la57)
- *p = (unsigned long)level4_kernel_pgt;
- else
- *p = (unsigned long)level3_kernel_pgt;
- *p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;
-
+#ifdef CONFIG_X86_5LEVEL
if (la57) {
+ *p = (unsigned long)level4_kernel_pgt;
p4d = fixup_pointer(&level4_kernel_pgt, physaddr);
p4d[511] += load_delta;
- }
+ } else
+#endif
+ *p = (unsigned long)level3_kernel_pgt;
+ *p += _PAGE_TABLE_NOENC - __START_KERNEL_map + load_delta;

pud = fixup_pointer(&level3_kernel_pgt, physaddr);
pud[510] += load_delta;
--
2.17.1