Merge branch 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull EFI fixes from Ingo Molnar:
 "Two EFI fixes: a quirk for weird systabs, plus add more robust error
  handling in the old 1:1 mapping code"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: Allow the number of EFI configuration tables entries to be zero
  efi/x86/Add missing error handling to old_memmap 1:1 mapping code

4 files changed, 14 insertions, 3 deletions

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index e1cb01a22fa8..a7189a3b4d70 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -85,6 +85,8 @@ static efi_status_t __init phys_efi_set_virtual_address_map(
         pgd_t *save_pgd;
 
         save_pgd = efi_call_phys_prolog();
+        if (!save_pgd)
+                return EFI_ABORTED;
 
         /* Disable interrupts around EFI calls: */
         local_irq_save(flags);
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index cf0347f61b21..08ce8177c3af 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -84,13 +84,15 @@ pgd_t * __init efi_call_phys_prolog(void)
 
         if (!efi_enabled(EFI_OLD_MEMMAP)) {
                 efi_switch_mm(&efi_mm);
-                return NULL;
+                return efi_mm.pgd;
         }
 
         early_code_mapping_set_exec(1);
 
         n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
         save_pgd = kmalloc_array(n_pgds, sizeof(*save_pgd), GFP_KERNEL);
+        if (!save_pgd)
+                return NULL;
 
         /*
          * Build 1:1 identity mapping for efi=old_map usage. Note that
@@ -138,10 +140,11 @@ pgd_t * __init efi_call_phys_prolog(void)
                 pgd_offset_k(pgd * PGDIR_SIZE)->pgd &= ~_PAGE_NX;
         }
 
-out:
         __flush_tlb_all();
-
         return save_pgd;
+out:
+        efi_call_phys_epilog(save_pgd);
+        return NULL;
 }
 
 void __init efi_call_phys_epilog(pgd_t *save_pgd)
diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index feb77777c8b8..632b83885867 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -513,6 +513,9 @@ int __init efi_reuse_config(u64 tables, int nr_tables)
         void *p, *tablep;
         struct efi_setup_data *data;
 
+        if (nr_tables == 0)
+                return 0;
+
         if (!efi_setup)
                 return 0;
 
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 55b77c576c42..521a541d02ad 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -636,6 +636,9 @@ int __init efi_config_init(efi_config_table_type_t *arch_tables)
         void *config_tables;
         int sz, ret;
 
+        if (efi.systab->nr_tables == 0)
+                return 0;
+
         if (efi_enabled(EFI_64BIT))
                 sz = sizeof(efi_config_table_64_t);
         else