x86/mm: Initialize PGD cache during mm initialization

Poking-mm initialization might require to duplicate the PGD in early
stage. Initialize the PGD cache earlier to prevent boot failures.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: 4fc19708b165 ("x86/alternatives: Initialize temporary mm for patching")
Link: http://lkml.kernel.org/r/20190505011124.39692-1-namit@vmware.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/init/main.c b/init/main.c
index 95dd9406ee31..9dc2f3b4f753 100644
--- a/init/main.c
+++ b/init/main.c
@@ -506,6 +506,8 @@ void __init __weak mem_encrypt_init(void) { }
 
 void __init __weak poking_init(void) { }
 
+void __init __weak pgd_cache_init(void) { }
+
 bool initcall_debug;
 core_param(initcall_debug, initcall_debug, bool, 0644);
 
@@ -537,6 +539,7 @@ static void __init mm_init(void)
         init_espfix_bsp();
         /* Should be run after espfix64 is set up. */
         pti_init();
+        pgd_cache_init();
 }
 
 void __init __weak arch_call_rest_init(void)