v2:
Use grub_efi_get_secureboot to get secure boot status

v3:
Fix null sb_context->file_path due to missing assignment of chainloaded image's
file_path  (bsc#1216081) 

---
 grub-core/loader/efi/chainloader.c |   62 +++++++++++++++++++++----------------
 1 file changed, 36 insertions(+), 26 deletions(-)

--- a/grub-core/loader/efi/chainloader.c
+++ b/grub-core/loader/efi/chainloader.c
@@ -305,40 +305,41 @@
 static grub_efi_boolean_t
 read_header (void *data, grub_efi_uint32_t size, pe_coff_loader_image_context_t *context)
 {
-  grub_efi_guid_t guid = SHIM_LOCK_GUID;
-  grub_efi_shim_lock_t *shim_lock;
-  grub_efi_status_t status;
-
-  shim_lock = grub_efi_locate_protocol (&guid, NULL);
+  char *msdos = (char *)data;
+  struct grub_pe32_header_no_msdos_stub *pe32 = (struct grub_pe32_header_no_msdos_stub *)data;
 
-  if (!shim_lock)
+  if (size < sizeof (*pe32))
     {
-      grub_error (GRUB_ERR_BAD_ARGUMENT, "no shim lock protocol");
+      grub_error (GRUB_ERR_BAD_ARGUMENT, "Invalid image");
       return 0;
     }
 
-  status = shim_lock->context (data, size, context);
-
-  if (status == GRUB_EFI_SUCCESS)
+  if (grub_memcmp (msdos, "MZ", 2) == 0)
     {
-      grub_dprintf ("chain", "context success\n");
-      return 1;
+      grub_uint32_t off = *((grub_uint32_t *) (msdos + 0x3c));
+      pe32 = (struct grub_pe32_header_no_msdos_stub *) ((char *)data + off);
     }
 
-  switch (status)
+  if (grub_memcmp (pe32->signature, "PE\0\0", 4) != 0 ||
+      pe32->coff_header.machine != GRUB_PE32_MACHINE_X86_64 ||
+      pe32->optional_header.magic != GRUB_PE32_PE64_MAGIC)
     {
-      case GRUB_EFI_UNSUPPORTED:
-      grub_error (GRUB_ERR_BAD_ARGUMENT, "context error unsupported");
-      break;
-      case GRUB_EFI_INVALID_PARAMETER:
-      grub_error (GRUB_ERR_BAD_ARGUMENT, "context error invalid parameter");
-      break;
-      default:
-      grub_error (GRUB_ERR_BAD_ARGUMENT, "context error code");
-      break;
+      grub_error (GRUB_ERR_BAD_ARGUMENT, "Not supported image");
+      return 0;
     }
 
-  return 0;
+  context->number_of_rva_and_sizes = pe32->optional_header.num_data_directories;
+  context->size_of_headers = pe32->optional_header.header_size;
+  context->image_size = pe32->optional_header.image_size;
+  context->image_address = pe32->optional_header.image_base;
+  context->entry_point = pe32->optional_header.entry_addr;
+  context->reloc_dir = &pe32->optional_header.base_relocation_table;
+  context->sec_dir = &pe32->optional_header.certificate_table;
+  context->number_of_sections = pe32->coff_header.num_sections;
+  context->pe_hdr = pe32;
+  context->first_section = (struct grub_pe32_section_table *)((char *)(&pe32->optional_header) + pe32->coff_header.optional_header_size);
+
+  return 1;
 }
 
 static void*
@@ -607,6 +608,9 @@
   if (buffer)
     b->free_pool (buffer);
 
+  if (grub_errno)
+    grub_print_error ();
+
   return 0;
 
 }
@@ -825,6 +829,31 @@
   status = b->load_image (0, grub_efi_image_handle, file_path,
 			  boot_image, size,
 			  &image_handle);
+#ifdef SUPPORT_SECURE_BOOT
+  if (status == GRUB_EFI_SECURITY_VIOLATION && grub_efi_get_secureboot () != GRUB_EFI_SECUREBOOT_MODE_ENABLED)
+    {
+      /* If it failed with security violation while not in secure boot mode,
+         the firmware might be broken. We try to workaround on that by forcing
+         the SB method! (bsc#887793) */
+      struct grub_secureboot_chainloader_context *sb_context;
+
+      grub_dprintf ("chain", "Possible firmware flaw! Security violation while not in secure boot mode.\n");
+      sb_context = grub_malloc (sizeof (*sb_context));
+      if (!sb_context)
+	goto fail;
+      sb_context->cmdline = cmdline;
+      sb_context->cmdline_len = cmdline_len;
+      sb_context->fsize = size;
+      sb_context->dev_handle = dev_handle;
+      sb_context->address = address;
+      sb_context->pages = pages;
+      sb_context->file_path = file_path;
+      grub_file_close (file);
+      grub_loader_set_ex (grub_secureboot_chainloader_boot,
+	      grub_secureboot_chainloader_unload, sb_context, 0);
+      return 0;
+    }
+#endif
   if (status != GRUB_EFI_SUCCESS)
     {
       if (status == GRUB_EFI_OUT_OF_RESOURCES)