File 0003-Retry-getting-memory-map-and-exit-boot-services-on-f.patch of Package grub

From 58d262b63abfd23fbe4983ae75097d61ca0f526a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=A1clav=20Pavl=C3=ADn?= <vpavlin@redhat.com>
Date: Mon, 29 Jul 2013 17:03:38 +0200
Subject: [PATCH 3/7] Retry getting memory map and exit boot services on
 failure

Resolves: rhbz#918824
---
 efi/x86_64/loader/linux.c | 25 +++++++++++++++++--------
 1 file changed, 17 insertions(+), 8 deletions(-)

diff --git a/efi/x86_64/loader/linux.c b/efi/x86_64/loader/linux.c
index 6d3d014..fcdb4f8 100644
--- a/efi/x86_64/loader/linux.c
+++ b/efi/x86_64/loader/linux.c
@@ -192,21 +192,30 @@ big_linux_boot (void)
   grub_efi_uintn_t desc_size;
   grub_efi_uint32_t desc_version;
   int e820_nr_map;
+  int retry = 5;
 
   params = real_mode_mem;
 
   graphics_set_kernel_params (params);
 
-  if (grub_efi_get_memory_map (&map_key, &desc_size, &desc_version) <= 0)
-    grub_fatal ("cannot get memory map");
+  /*
+   * UEFI Specification:
+   * If MapKey value is incorrect, ExitBootServices() returns EFI_INVALID_PARAMETER 
+   * and GetMemoryMap() with ExitBootServices() must be called again.
+   */
+  do {
+    if (grub_efi_get_memory_map (&map_key, &desc_size, &desc_version) <= 0)
+      grub_fatal ("cannot get memory map");
+
+    /* Pass e820 memmap. */
+    e820_map_from_efi_map ((struct e820_entry *) params->e820_map, &e820_nr_map,
+			   mmap_buf, desc_size, mmap_size);
+    params->e820_nr_map = e820_nr_map;
 
-  /* Pass e820 memmap. */
-  e820_map_from_efi_map ((struct e820_entry *) params->e820_map, &e820_nr_map,
-			 mmap_buf, desc_size, mmap_size);
-  params->e820_nr_map = e820_nr_map;
+  } while (!grub_efi_exit_boot_services (map_key) && --retry);
 
-  if (! grub_efi_exit_boot_services (map_key))
-    grub_fatal ("cannot exit boot services");
+  if (!retry)
+        grub_fatal ("cannot exit boot services");
 
   /* Note that no boot services are available from here.  */
 
-- 
1.8.3.1