Linus,

Please pull the latest efi-urgent-for-linus git tree from:

   git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git 
efi-urgent-for-linus

   # HEAD: 7425826f4f7ac60f2538b06a7f0a5d1006405159 efi/bgrt: Skip 
efi_bgrt_init() in case of non-EFI boot

Misc fixes:

 - three boot crash fixes for uncommon configurations,
 - silence a boot warning under virtualization,
 - plus a GCC 7 related (harmless) build warning fix.

 Thanks,

        Ingo

------------------>
Arnd Bergmann (1):
      efi: Remove duplicate 'const' specifiers

Baoquan He (1):
      x86/efi: Correct EFI identity mapping under 'efi=old_map' when KASLR is 
enabled

Dave Young (1):
      efi/bgrt: Skip efi_bgrt_init() in case of non-EFI boot

Juergen Gross (1):
      efi: Don't issue error message when booted under Xen

Sai Praneeth (1):
      x86/efi: Disable runtime services on kexec kernel if booted with 
efi=old_map


 arch/x86/platform/efi/efi.c               |  6 ++-
 arch/x86/platform/efi/efi_64.c            | 79 +++++++++++++++++++++++++++----
 arch/x86/platform/efi/quirks.c            |  3 ++
 drivers/firmware/efi/efi-bgrt.c           |  3 ++
 drivers/firmware/efi/libstub/secureboot.c |  4 +-
 5 files changed, 83 insertions(+), 12 deletions(-)

diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c
index 7e76a4d8304b..43b96f5f78ba 100644
--- a/arch/x86/platform/efi/efi.c
+++ b/arch/x86/platform/efi/efi.c
@@ -828,9 +828,11 @@ static void __init kexec_enter_virtual_mode(void)
 
        /*
         * We don't do virtual mode, since we don't do runtime services, on
-        * non-native EFI
+        * non-native EFI. With efi=old_map, we don't do runtime services in
+        * kexec kernel because in the initial boot something else might
+        * have been mapped at these virtual addresses.
         */
-       if (!efi_is_native()) {
+       if (!efi_is_native() || efi_enabled(EFI_OLD_MEMMAP)) {
                efi_memmap_unmap();
                clear_bit(EFI_RUNTIME_SERVICES, &efi.flags);
                return;
diff --git a/arch/x86/platform/efi/efi_64.c b/arch/x86/platform/efi/efi_64.c
index c488625c9712..eb8dff15a7f6 100644
--- a/arch/x86/platform/efi/efi_64.c
+++ b/arch/x86/platform/efi/efi_64.c
@@ -71,11 +71,13 @@ static void __init early_code_mapping_set_exec(int 
executable)
 
 pgd_t * __init efi_call_phys_prolog(void)
 {
-       unsigned long vaddress;
-       pgd_t *save_pgd;
+       unsigned long vaddr, addr_pgd, addr_p4d, addr_pud;
+       pgd_t *save_pgd, *pgd_k, *pgd_efi;
+       p4d_t *p4d, *p4d_k, *p4d_efi;
+       pud_t *pud;
 
        int pgd;
-       int n_pgds;
+       int n_pgds, i, j;
 
        if (!efi_enabled(EFI_OLD_MEMMAP)) {
                save_pgd = (pgd_t *)read_cr3();
@@ -88,10 +90,49 @@ pgd_t * __init efi_call_phys_prolog(void)
        n_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT), PGDIR_SIZE);
        save_pgd = kmalloc_array(n_pgds, sizeof(*save_pgd), GFP_KERNEL);
 
+       /*
+        * Build 1:1 identity mapping for efi=old_map usage. Note that
+        * PAGE_OFFSET is PGDIR_SIZE aligned when KASLR is disabled, while
+        * it is PUD_SIZE ALIGNED with KASLR enabled. So for a given physical
+        * address X, the pud_index(X) != pud_index(__va(X)), we can only copy
+        * PUD entry of __va(X) to fill in pud entry of X to build 1:1 mapping.
+        * This means here we can only reuse the PMD tables of the direct 
mapping.
+        */
        for (pgd = 0; pgd < n_pgds; pgd++) {
-               save_pgd[pgd] = *pgd_offset_k(pgd * PGDIR_SIZE);
-               vaddress = (unsigned long)__va(pgd * PGDIR_SIZE);
-               set_pgd(pgd_offset_k(pgd * PGDIR_SIZE), 
*pgd_offset_k(vaddress));
+               addr_pgd = (unsigned long)(pgd * PGDIR_SIZE);
+               vaddr = (unsigned long)__va(pgd * PGDIR_SIZE);
+               pgd_efi = pgd_offset_k(addr_pgd);
+               save_pgd[pgd] = *pgd_efi;
+
+               p4d = p4d_alloc(&init_mm, pgd_efi, addr_pgd);
+               if (!p4d) {
+                       pr_err("Failed to allocate p4d table!\n");
+                       goto out;
+               }
+
+               for (i = 0; i < PTRS_PER_P4D; i++) {
+                       addr_p4d = addr_pgd + i * P4D_SIZE;
+                       p4d_efi = p4d + p4d_index(addr_p4d);
+
+                       pud = pud_alloc(&init_mm, p4d_efi, addr_p4d);
+                       if (!pud) {
+                               pr_err("Failed to allocate pud table!\n");
+                               goto out;
+                       }
+
+                       for (j = 0; j < PTRS_PER_PUD; j++) {
+                               addr_pud = addr_p4d + j * PUD_SIZE;
+
+                               if (addr_pud > (max_pfn << PAGE_SHIFT))
+                                       break;
+
+                               vaddr = (unsigned long)__va(addr_pud);
+
+                               pgd_k = pgd_offset_k(vaddr);
+                               p4d_k = p4d_offset(pgd_k, vaddr);
+                               pud[j] = *pud_offset(p4d_k, vaddr);
+                       }
+               }
        }
 out:
        __flush_tlb_all();
@@ -104,8 +145,11 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd)
        /*
         * After the lock is released, the original page table is restored.
         */
-       int pgd_idx;
+       int pgd_idx, i;
        int nr_pgds;
+       pgd_t *pgd;
+       p4d_t *p4d;
+       pud_t *pud;
 
        if (!efi_enabled(EFI_OLD_MEMMAP)) {
                write_cr3((unsigned long)save_pgd);
@@ -115,9 +159,28 @@ void __init efi_call_phys_epilog(pgd_t *save_pgd)
 
        nr_pgds = DIV_ROUND_UP((max_pfn << PAGE_SHIFT) , PGDIR_SIZE);
 
-       for (pgd_idx = 0; pgd_idx < nr_pgds; pgd_idx++)
+       for (pgd_idx = 0; pgd_idx < nr_pgds; pgd_idx++) {
+               pgd = pgd_offset_k(pgd_idx * PGDIR_SIZE);
                set_pgd(pgd_offset_k(pgd_idx * PGDIR_SIZE), save_pgd[pgd_idx]);
 
+               if (!(pgd_val(*pgd) & _PAGE_PRESENT))
+                       continue;
+
+               for (i = 0; i < PTRS_PER_P4D; i++) {
+                       p4d = p4d_offset(pgd,
+                                        pgd_idx * PGDIR_SIZE + i * P4D_SIZE);
+
+                       if (!(p4d_val(*p4d) & _PAGE_PRESENT))
+                               continue;
+
+                       pud = (pud_t *)p4d_page_vaddr(*p4d);
+                       pud_free(&init_mm, pud);
+               }
+
+               p4d = (p4d_t *)pgd_page_vaddr(*pgd);
+               p4d_free(&init_mm, p4d);
+       }
+
        kfree(save_pgd);
 
        __flush_tlb_all();
diff --git a/arch/x86/platform/efi/quirks.c b/arch/x86/platform/efi/quirks.c
index 26615991d69c..e0cf95a83f3f 100644
--- a/arch/x86/platform/efi/quirks.c
+++ b/arch/x86/platform/efi/quirks.c
@@ -360,6 +360,9 @@ void __init efi_free_boot_services(void)
                free_bootmem_late(start, size);
        }
 
+       if (!num_entries)
+               return;
+
        new_size = efi.memmap.desc_size * num_entries;
        new_phys = efi_memmap_alloc(num_entries);
        if (!new_phys) {
diff --git a/drivers/firmware/efi/efi-bgrt.c b/drivers/firmware/efi/efi-bgrt.c
index 04ca8764f0c0..8bf27323f7a3 100644
--- a/drivers/firmware/efi/efi-bgrt.c
+++ b/drivers/firmware/efi/efi-bgrt.c
@@ -36,6 +36,9 @@ void __init efi_bgrt_init(struct acpi_table_header *table)
        if (acpi_disabled)
                return;
 
+       if (!efi_enabled(EFI_BOOT))
+               return;
+
        if (table->length < sizeof(bgrt_tab)) {
                pr_notice("Ignoring BGRT: invalid length %u (expected %zu)\n",
                       table->length, sizeof(bgrt_tab));
diff --git a/drivers/firmware/efi/libstub/secureboot.c 
b/drivers/firmware/efi/libstub/secureboot.c
index 8c34d50a4d80..959777ec8a77 100644
--- a/drivers/firmware/efi/libstub/secureboot.c
+++ b/drivers/firmware/efi/libstub/secureboot.c
@@ -16,10 +16,10 @@
 
 /* BIOS variables */
 static const efi_guid_t efi_variable_guid = EFI_GLOBAL_VARIABLE_GUID;
-static const efi_char16_t const efi_SecureBoot_name[] = {
+static const efi_char16_t efi_SecureBoot_name[] = {
        'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0
 };
-static const efi_char16_t const efi_SetupMode_name[] = {
+static const efi_char16_t efi_SetupMode_name[] = {
        'S', 'e', 't', 'u', 'p', 'M', 'o', 'd', 'e', 0
 };
 

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