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

Pull EFI updates from Ingo Molnar:
 "The main changes in this cycle were:

   - Drop the unused EFI_SYSTEM_TABLES efi.flags bit and ensure the
     ARM/arm64 EFI System Table mapping is read-only (Ard Biesheuvel)

   - Add a comment to explain that one of the code paths in the x86/pat
     code is only executed for EFI boot (Matt Fleming)

   - Improve Secure Boot status checks on arm64 and handle unexpected
     errors (Linn Crosetto)

   - Remove the global EFI memory map variable 'memmap' as the same
     information is already available in efi::memmap (Matt Fleming)

   - Add EFI Memory Attribute table support for ARM/arm64 (Ard
     Biesheuvel)

   - Add EFI GOP framebuffer support for ARM/arm64 (Ard Biesheuvel)

   - Add EFI Bootloader Control driver for storing reboot(2) data in EFI
     variables for consumption by bootloaders (Jeremy Compostella)

   - Add Core EFI capsule support (Matt Fleming)

   - Add EFI capsule char driver (Kweh, Hock Leong)

   - Unify EFI memory map code for ARM and arm64 (Ard Biesheuvel)

   - Add generic EFI support for detecting when firmware corrupts CPU
     status register bits (like IRQ flags) when performing EFI runtime
     service calls (Mark Rutland)

  ... and other misc cleanups"

* 'efi-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (46 commits)
  efivarfs: Make efivarfs_file_ioctl() static
  efi: Merge boolean flag arguments
  efi/capsule: Move 'capsule' to the stack in efi_capsule_supported()
  efibc: Fix excessive stack footprint warning
  efi/capsule: Make efi_capsule_pending() lockless
  efi: Remove unnecessary (and buggy) .memmap initialization from the Xen EFI driver
  efi/runtime-wrappers: Remove ARCH_EFI_IRQ_FLAGS_MASK #ifdef
  x86/efi: Enable runtime call flag checking
  arm/efi: Enable runtime call flag checking
  arm64/efi: Enable runtime call flag checking
  efi/runtime-wrappers: Detect firmware IRQ flag corruption
  efi/runtime-wrappers: Remove redundant #ifdefs
  x86/efi: Move to generic {__,}efi_call_virt()
  arm/efi: Move to generic {__,}efi_call_virt()
  arm64/efi: Move to generic {__,}efi_call_virt()
  efi/runtime-wrappers: Add {__,}efi_call_virt() templates
  efi/arm-init: Reserve rather than unmap the memory map for ARM as well
  efi: Add misc char driver interface to update EFI firmware
  x86/efi: Force EFI reboot to process pending capsules
  efi: Add 'capsule' update support
  ...

1 files changed, 66 insertions, 11 deletions

diff --git a/drivers/firmware/efi/libstub/arm-stub.c b/drivers/firmware/efi/libstub/arm-stub.c
index 414deb85c2e5..993aa56755f6 100644
--- a/drivers/firmware/efi/libstub/arm-stub.c
+++ b/drivers/firmware/efi/libstub/arm-stub.c
@@ -20,27 +20,49 @@
 
 bool __nokaslr;
 
-static int efi_secureboot_enabled(efi_system_table_t *sys_table_arg)
+static int efi_get_secureboot(efi_system_table_t *sys_table_arg)
 {
-        static efi_guid_t const var_guid = EFI_GLOBAL_VARIABLE_GUID;
-        static efi_char16_t const var_name[] = {
+        static efi_char16_t const sb_var_name[] = {
                 'S', 'e', 'c', 'u', 'r', 'e', 'B', 'o', 'o', 't', 0 };
+        static efi_char16_t const sm_var_name[] = {
+                'S', 'e', 't', 'u', 'p', 'M', 'o', 'd', 'e', 0 };
 
+        efi_guid_t var_guid = EFI_GLOBAL_VARIABLE_GUID;
         efi_get_variable_t *f_getvar = sys_table_arg->runtime->get_variable;
-        unsigned long size = sizeof(u8);
-        efi_status_t status;
         u8 val;
+        unsigned long size = sizeof(val);
+        efi_status_t status;
 
-        status = f_getvar((efi_char16_t *)var_name, (efi_guid_t *)&var_guid,
+        status = f_getvar((efi_char16_t *)sb_var_name, (efi_guid_t *)&var_guid,
                           NULL, &size, &val);
 
+        if (status != EFI_SUCCESS)
+                goto out_efi_err;
+
+        if (val == 0)
+                return 0;
+
+        status = f_getvar((efi_char16_t *)sm_var_name, (efi_guid_t *)&var_guid,
+                          NULL, &size, &val);
+
+        if (status != EFI_SUCCESS)
+                goto out_efi_err;
+
+        if (val == 1)
+                return 0;
+
+        return 1;
+
+out_efi_err:
         switch (status) {
-        case EFI_SUCCESS:
-                return val;
         case EFI_NOT_FOUND:
                 return 0;
+        case EFI_DEVICE_ERROR:
+                return -EIO;
+        case EFI_SECURITY_VIOLATION:
+                return -EACCES;
         default:
-                return 1;
+                return -EINVAL;
         }
 }
 
@@ -147,6 +169,25 @@ void efi_char16_printk(efi_system_table_t *sys_table_arg,
         out->output_string(out, str);
 }
 
+static struct screen_info *setup_graphics(efi_system_table_t *sys_table_arg)
+{
+        efi_guid_t gop_proto = EFI_GRAPHICS_OUTPUT_PROTOCOL_GUID;
+        efi_status_t status;
+        unsigned long size;
+        void **gop_handle = NULL;
+        struct screen_info *si = NULL;
+
+        size = 0;
+        status = efi_call_early(locate_handle, EFI_LOCATE_BY_PROTOCOL,
+                                &gop_proto, NULL, &size, gop_handle);
+        if (status == EFI_BUFFER_TOO_SMALL) {
+                si = alloc_screen_info(sys_table_arg);
+                if (!si)
+                        return NULL;
+                efi_setup_gop(sys_table_arg, si, &gop_proto, size);
+        }
+        return si;
+}
 
 /*
  * This function handles the architcture specific differences between arm and
@@ -185,6 +226,8 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
         efi_guid_t loaded_image_proto = LOADED_IMAGE_PROTOCOL_GUID;
         unsigned long reserve_addr = 0;
         unsigned long reserve_size = 0;
+        int secure_boot = 0;
+        struct screen_info *si;
 
         /* Check if we were booted by the EFI firmware */
         if (sys_table->hdr.signature != EFI_SYSTEM_TABLE_SIGNATURE)
@@ -237,6 +280,8 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
                         __nokaslr = true;
         }
 
+        si = setup_graphics(sys_table);
+
         status = handle_kernel_image(sys_table, image_addr, &image_size,
                                      &reserve_addr,
                                      &reserve_size,
@@ -250,12 +295,21 @@ unsigned long efi_entry(void *handle, efi_system_table_t *sys_table,
         if (status != EFI_SUCCESS)
                 pr_efi_err(sys_table, "Failed to parse EFI cmdline options\n");
 
+        secure_boot = efi_get_secureboot(sys_table);
+        if (secure_boot > 0)
+                pr_efi(sys_table, "UEFI Secure Boot is enabled.\n");
+
+        if (secure_boot < 0) {
+                pr_efi_err(sys_table,
+                        "could not determine UEFI Secure Boot status.\n");
+        }
+
         /*
          * Unauthenticated device tree data is a security hazard, so
          * ignore 'dtb=' unless UEFI Secure Boot is disabled.
          */
-        if (efi_secureboot_enabled(sys_table)) {
-                pr_efi(sys_table, "UEFI Secure Boot is enabled.\n");
+        if (secure_boot != 0 && strstr(cmdline_ptr, "dtb=")) {
+                pr_efi(sys_table, "Ignoring DTB from command line.\n");
         } else {
                 status = handle_cmdline_files(sys_table, image, cmdline_ptr,
                                               "dtb=",
@@ -309,6 +363,7 @@ fail_free_image:
         efi_free(sys_table, image_size, *image_addr);
         efi_free(sys_table, reserve_size, reserve_addr);
 fail_free_cmdline:
+        free_screen_info(sys_table, si);
         efi_free(sys_table, cmdline_size, (unsigned long)cmdline_ptr);
 fail:
         return EFI_ERROR;