Allow a compilation without -mcmodel=large

It's provided by Vladimir Serbinenko, and he will commit
it upstream so it should be backport patch.

Upstream-Status: Backport

Signed-off-by: Jackie Huang <jackie.huang@windriver.com>

--
diff --git a/configure.ac b/configure.ac
index 9f8fb8a..2c5e6ed 100644
--- a/configure.ac
+++ b/configure.ac
@@ -723,9 +723,7 @@ if test "$target_cpu" = x86_64; then
 		      [grub_cv_cc_mcmodel=yes],
 		      [grub_cv_cc_mcmodel=no])
   ])
-  if test "x$grub_cv_cc_mcmodel" = xno; then
-    AC_MSG_ERROR([-mcmodel=large not supported. Upgrade your gcc.])
-  else
+  if test "x$grub_cv_cc_mcmodel" = xyes; then
     TARGET_CFLAGS="$TARGET_CFLAGS -mcmodel=large"
   fi
 fi
diff --git a/grub-core/kern/efi/mm.c b/grub-core/kern/efi/mm.c
index 1409b5d..6e9dace 100644
--- a/grub-core/kern/efi/mm.c
+++ b/grub-core/kern/efi/mm.c
@@ -32,6 +32,12 @@
 #define BYTES_TO_PAGES(bytes)	(((bytes) + 0xfff) >> 12)
 #define PAGES_TO_BYTES(pages)	((pages) << 12)

+#if defined (__code_model_large__) || !defined (__x86_64__)
+#define MAX_USABLE_ADDRESS 0xffffffff
+#else
+#define MAX_USABLE_ADDRESS 0x7fffffff
+#endif
+
 /* The size of a memory map obtained from the firmware. This must be
    a multiplier of 4KB.  */
 #define MEMORY_MAP_SIZE	0x3000
@@ -58,7 +64,7 @@ grub_efi_allocate_pages (grub_efi_physical_address_t address,

 #if 1
   /* Limit the memory access to less than 4GB for 32-bit platforms.  */
-  if (address > 0xffffffff)
+  if (address > MAX_USABLE_ADDRESS)
     return 0;
 #endif

@@ -66,7 +72,7 @@ grub_efi_allocate_pages (grub_efi_physical_address_t address,
   if (address == 0)
     {
       type = GRUB_EFI_ALLOCATE_MAX_ADDRESS;
-      address = 0xffffffff;
+      address = MAX_USABLE_ADDRESS;
     }
   else
     type = GRUB_EFI_ALLOCATE_ADDRESS;
@@ -86,7 +92,7 @@ grub_efi_allocate_pages (grub_efi_physical_address_t address,
     {
       /* Uggh, the address 0 was allocated... This is too annoying,
 	 so reallocate another one.  */
-      address = 0xffffffff;
+      address = MAX_USABLE_ADDRESS;
       status = efi_call_4 (b->allocate_pages, type, GRUB_EFI_LOADER_DATA, pages, &address);
       grub_efi_free_pages (0, pages);
       if (status != GRUB_EFI_SUCCESS)
@@ -319,7 +325,7 @@ filter_memory_map (grub_efi_memory_descriptor_t *memory_map,
     {
       if (desc->type == GRUB_EFI_CONVENTIONAL_MEMORY
 #if 1
-	  && desc->physical_start <= 0xffffffff
+	  && desc->physical_start <= MAX_USABLE_ADDRESS
 #endif
 	  && desc->physical_start + PAGES_TO_BYTES (desc->num_pages) > 0x100000
 	  && desc->num_pages != 0)
@@ -337,9 +343,9 @@ filter_memory_map (grub_efi_memory_descriptor_t *memory_map,
 #if 1
 	  if (BYTES_TO_PAGES (filtered_desc->physical_start)
 	      + filtered_desc->num_pages
-	      > BYTES_TO_PAGES (0x100000000LL))
+	      > BYTES_TO_PAGES (MAX_USABLE_ADDRESS+1LL))
 	    filtered_desc->num_pages
-	      = (BYTES_TO_PAGES (0x100000000LL)
+	      = (BYTES_TO_PAGES (MAX_USABLE_ADDRESS+1LL)
 		 - BYTES_TO_PAGES (filtered_desc->physical_start));
 #endif

diff --git a/grub-core/kern/x86_64/dl.c b/grub-core/kern/x86_64/dl.c
index 65f09ef..17c1215 100644
--- a/grub-core/kern/x86_64/dl.c
+++ b/grub-core/kern/x86_64/dl.c
@@ -100,14 +100,32 @@ grub_arch_dl_relocate_symbols (grub_dl_t mod, void *ehdr)
 		    break;

 		  case R_X86_64_PC32:
-		    *addr32 += rel->r_addend + sym->st_value -
-		              (Elf64_Xword) seg->addr - rel->r_offset;
+		    {
+		      grub_int64_t value;
+		      value = ((grub_int32_t) *addr32) + rel->r_addend + sym->st_value -
+			(Elf64_Xword) seg->addr - rel->r_offset;
+		      if (value != (grub_int32_t) value)
+			return grub_error (GRUB_ERR_BAD_MODULE, "relocation out of range");
+		      *addr32 = value;
+		    }
 		    break;

                   case R_X86_64_32:
+		    {
+		      grub_uint64_t value = *addr32 + rel->r_addend + sym->st_value;
+		      if (value != (grub_uint32_t) value)
+			return grub_error (GRUB_ERR_BAD_MODULE, "relocation out of range");
+		      *addr32 = value;
+		    }
+		    break;
                   case R_X86_64_32S:
-                    *addr32 += rel->r_addend + sym->st_value;
-                    break;
+		    {
+		      grub_int64_t value = ((grub_int32_t) *addr32) + rel->r_addend + sym->st_value;
+		      if (value != (grub_int32_t) value)
+			return grub_error (GRUB_ERR_BAD_MODULE, "relocation out of range");
+		      *addr32 = value;
+		    }
+		    break;

 		  default:
 		    return grub_error (GRUB_ERR_NOT_IMPLEMENTED_YET,