[SECURITY PATCH 105/117] util/mkimage: Unify more of the PE32 and PE32+ header set-up

[Daniel Kiper]

From: Peter Jones <pjones@redhat.com>

There's quite a bit of code duplication in the code that sets the optional
header for PE32 and PE32+. The two are very similar with the exception of
a few fields that have type grub_uint64_t instead of grub_uint32_t.

Factor out the common code and add a PE_OHDR() macro that simplifies the
set-up and make the code more readable.

Signed-off-by: Peter Jones <pjones@redhat.com>
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
---
 util/mkimage.c | 111 ++++++++++++++++++++++++++-------------------------------
 1 file changed, 51 insertions(+), 60 deletions(-)

diff --git a/util/mkimage.c b/util/mkimage.c
index b94bfb781..a039039db 100644
--- a/util/mkimage.c
+++ b/util/mkimage.c
@@ -816,6 +816,21 @@ grub_install_get_image_targets_string (void)
   return formats;
 }
 
+/*
+ * tmp_ is just here so the compiler knows we'll never derefernce a NULL.
+ * It should get fully optimized away.
+ */
+#define PE_OHDR(o32, o64, field) (*(           \
+{                                              \
+  __typeof__((o64)->field) tmp_;               \
+  __typeof__((o64)->field) *ret_ = &tmp_;      \
+  if (o32)                                     \
+    ret_ = (void *)(&((o32)->field));          \
+  else if (o64)                                \
+    ret_ = (void *)(&((o64)->field));          \
+  ret_;                                        \
+}))
+
 void
 grub_install_generate_image (const char *dir, const char *prefix,
                             FILE *out, const char *outname, char *mods[],
@@ -1252,6 +1267,8 @@ grub_install_generate_image (const char *dir, const char 
*prefix,
        static const grub_uint8_t stub[] = GRUB_PE32_MSDOS_STUB;
        int header_size;
        int reloc_addr;
+       struct grub_pe32_optional_header *o32 = NULL;
+       struct grub_pe64_optional_header *o64 = NULL;
 
        if (image_target->voidp_sizeof == 4)
          header_size = EFI32_HEADER_SIZE;
@@ -1293,76 +1310,50 @@ grub_install_generate_image (const char *dir, const 
char *prefix,
        /* The PE Optional header.  */
        if (image_target->voidp_sizeof == 4)
          {
-           struct grub_pe32_optional_header *o;
-
            c->optional_header_size = grub_host_to_target16 (sizeof (struct 
grub_pe32_optional_header));
 
-           o = (struct grub_pe32_optional_header *)
-             (header + GRUB_PE32_MSDOS_STUB_SIZE + GRUB_PE32_SIGNATURE_SIZE
-              + sizeof (struct grub_pe32_coff_header));
-           o->magic = grub_host_to_target16 (GRUB_PE32_PE32_MAGIC);
-           o->code_size = grub_host_to_target32 (layout.exec_size);
-           o->data_size = grub_host_to_target32 (reloc_addr - layout.exec_size
-                                            - header_size);
-           o->entry_addr = grub_host_to_target32 (layout.start_address);
-           o->code_base = grub_host_to_target32 (header_size);
+           o32 = (struct grub_pe32_optional_header *)
+              (header + GRUB_PE32_MSDOS_STUB_SIZE + GRUB_PE32_SIGNATURE_SIZE +
+               sizeof (struct grub_pe32_coff_header));
+           o32->magic = grub_host_to_target16 (GRUB_PE32_PE32_MAGIC);
+           o32->data_base = grub_host_to_target32 (header_size + 
layout.exec_size);
 
-           o->data_base = grub_host_to_target32 (header_size + 
layout.exec_size);
-
-           o->image_base = 0;
-           o->section_alignment = grub_host_to_target32 
(image_target->section_align);
-           o->file_alignment = grub_host_to_target32 
(GRUB_PE32_FILE_ALIGNMENT);
-           o->image_size = grub_host_to_target32 (pe_size);
-           o->header_size = grub_host_to_target32 (header_size);
-           o->subsystem = grub_host_to_target16 
(GRUB_PE32_SUBSYSTEM_EFI_APPLICATION);
-
-           /* Do these really matter? */
-           o->stack_reserve_size = grub_host_to_target32 (0x10000);
-           o->stack_commit_size = grub_host_to_target32 (0x10000);
-           o->heap_reserve_size = grub_host_to_target32 (0x10000);
-           o->heap_commit_size = grub_host_to_target32 (0x10000);
-    
-           o->num_data_directories = grub_host_to_target32 
(GRUB_PE32_NUM_DATA_DIRECTORIES);
-
-           o->base_relocation_table.rva = grub_host_to_target32 (reloc_addr);
-           o->base_relocation_table.size = grub_host_to_target32 
(layout.reloc_size);
-           sections = o + 1;
+           sections = o32 + 1;
          }
        else
          {
-           struct grub_pe64_optional_header *o;
-
            c->optional_header_size = grub_host_to_target16 (sizeof (struct 
grub_pe64_optional_header));
 
-           o = (struct grub_pe64_optional_header *) 
-             (header + GRUB_PE32_MSDOS_STUB_SIZE + GRUB_PE32_SIGNATURE_SIZE
-              + sizeof (struct grub_pe32_coff_header));
-           o->magic = grub_host_to_target16 (GRUB_PE32_PE64_MAGIC);
-           o->code_size = grub_host_to_target32 (layout.exec_size);
-           o->data_size = grub_host_to_target32 (reloc_addr - layout.exec_size
-                                            - header_size);
-           o->entry_addr = grub_host_to_target32 (layout.start_address);
-           o->code_base = grub_host_to_target32 (header_size);
-           o->image_base = 0;
-           o->section_alignment = grub_host_to_target32 
(image_target->section_align);
-           o->file_alignment = grub_host_to_target32 
(GRUB_PE32_FILE_ALIGNMENT);
-           o->image_size = grub_host_to_target32 (pe_size);
-           o->header_size = grub_host_to_target32 (header_size);
-           o->subsystem = grub_host_to_target16 
(GRUB_PE32_SUBSYSTEM_EFI_APPLICATION);
+           o64 = (struct grub_pe64_optional_header *)
+                 (header + GRUB_PE32_MSDOS_STUB_SIZE + 
GRUB_PE32_SIGNATURE_SIZE +
+                   sizeof (struct grub_pe32_coff_header));
+           o64->magic = grub_host_to_target16 (GRUB_PE32_PE64_MAGIC);
 
-           /* Do these really matter? */
-           o->stack_reserve_size = grub_host_to_target32 (0x10000);
-           o->stack_commit_size = grub_host_to_target32 (0x10000);
-           o->heap_reserve_size = grub_host_to_target32 (0x10000);
-           o->heap_commit_size = grub_host_to_target32 (0x10000);
-    
-           o->num_data_directories
-             = grub_host_to_target32 (GRUB_PE32_NUM_DATA_DIRECTORIES);
-
-           o->base_relocation_table.rva = grub_host_to_target32 (reloc_addr);
-           o->base_relocation_table.size = grub_host_to_target32 
(layout.reloc_size);
-           sections = o + 1;
+           sections = o64 + 1;
          }
+
+       PE_OHDR (o32, o64, code_size) = grub_host_to_target32 
(layout.exec_size);
+       PE_OHDR (o32, o64, data_size) = grub_host_to_target32 (reloc_addr - 
layout.exec_size - header_size);
+       PE_OHDR (o32, o64, entry_addr) = grub_host_to_target32 
(layout.start_address);
+       PE_OHDR (o32, o64, code_base) = grub_host_to_target32 (header_size);
+
+       PE_OHDR (o32, o64, image_base) = 0;
+       PE_OHDR (o32, o64, section_alignment) = grub_host_to_target32 
(image_target->section_align);
+       PE_OHDR (o32, o64, file_alignment) = grub_host_to_target32 
(GRUB_PE32_FILE_ALIGNMENT);
+       PE_OHDR (o32, o64, image_size) = grub_host_to_target32 (pe_size);
+       PE_OHDR (o32, o64, header_size) = grub_host_to_target32 (header_size);
+       PE_OHDR (o32, o64, subsystem) = grub_host_to_target16 
(GRUB_PE32_SUBSYSTEM_EFI_APPLICATION);
+
+       /* Do these really matter? */
+       PE_OHDR (o32, o64, stack_reserve_size) = grub_host_to_target32 
(0x10000);
+       PE_OHDR (o32, o64, stack_commit_size) = grub_host_to_target32 (0x10000);
+       PE_OHDR (o32, o64, heap_reserve_size) = grub_host_to_target32 (0x10000);
+       PE_OHDR (o32, o64, heap_commit_size) = grub_host_to_target32 (0x10000);
+
+       PE_OHDR (o32, o64, num_data_directories) = grub_host_to_target32 
(GRUB_PE32_NUM_DATA_DIRECTORIES);
+       PE_OHDR (o32, o64, base_relocation_table.rva) = grub_host_to_target32 
(reloc_addr);
+       PE_OHDR (o32, o64, base_relocation_table.size) = grub_host_to_target32 
(layout.reloc_size);
+
        /* The sections.  */
        text_section = sections;
        strcpy (text_section->name, ".text");
-- 
2.11.0