From ef02b4ca933fd4c215e169a23b2b069aab712677 Mon Sep 17 00:00:00 2001
From: Vladimir Serbinenko <phcoder@gmail.com>
Date: Mon, 26 Jan 2015 09:43:52 +0100
Subject: [PATCH] multiboot: Simplify to avoid confusing assignment.

Found by: Coverity scan.
---
 grub-core/loader/i386/multiboot_mbi.c | 29 +++++++++++++++---------
 grub-core/loader/multiboot_mbi2.c     | 32 +++++++++++++++++----------
 2 files changed, 39 insertions(+), 22 deletions(-)

diff --git a/grub-core/loader/i386/multiboot_mbi.c b/grub-core/loader/i386/multiboot_mbi.c
index f10c087f7..956d0e37b 100644
--- a/grub-core/loader/i386/multiboot_mbi.c
+++ b/grub-core/loader/i386/multiboot_mbi.c
@@ -121,6 +121,24 @@ load_kernel (grub_file_t file, const char *filename,
   return grub_multiboot_load_elf (file, filename, buffer);
 }
 
+static struct multiboot_header *
+find_header (char *buffer, grub_ssize_t len)
+{
+  struct multiboot_header *header;
+
+  /* Look for the multiboot header in the buffer.  The header should
+     be at least 12 bytes and aligned on a 4-byte boundary.  */
+  for (header = (struct multiboot_header *) buffer;
+       ((char *) header <= buffer + len - 12);
+       header = (struct multiboot_header *) ((char *) header + MULTIBOOT_HEADER_ALIGN))
+    {
+      if (header->magic == MULTIBOOT_HEADER_MAGIC
+	  && !(header->magic + header->flags + header->checksum))
+	return header;
+    }
+  return NULL;
+}
+
 grub_err_t
 grub_multiboot_load (grub_file_t file, const char *filename)
 {
@@ -143,16 +161,7 @@ grub_multiboot_load (grub_file_t file, const char *filename)
       return grub_errno;
     }
 
-  /* Look for the multiboot header in the buffer.  The header should
-     be at least 12 bytes and aligned on a 4-byte boundary.  */
-  for (header = (struct multiboot_header *) buffer;
-       ((char *) header <= buffer + len - 12) || (header = 0);
-       header = (struct multiboot_header *) ((char *) header + MULTIBOOT_HEADER_ALIGN))
-    {
-      if (header->magic == MULTIBOOT_HEADER_MAGIC
-	  && !(header->magic + header->flags + header->checksum))
-	break;
-    }
+  header = find_header (buffer, len);
 
   if (header == 0)
     {
diff --git a/grub-core/loader/multiboot_mbi2.c b/grub-core/loader/multiboot_mbi2.c
index 83e8919fa..6f74aeef7 100644
--- a/grub-core/loader/multiboot_mbi2.c
+++ b/grub-core/loader/multiboot_mbi2.c
@@ -79,6 +79,25 @@ grub_multiboot_add_elfsyms (grub_size_t num, grub_size_t entsize,
   elf_sections = data;
 }
 
+static struct multiboot_header *
+find_header (grub_properly_aligned_t *buffer, grub_ssize_t len)
+{
+  struct multiboot_header *header;
+  /* Look for the multiboot header in the buffer.  The header should
+     be at least 12 bytes and aligned on a 4-byte boundary.  */
+  for (header = (struct multiboot_header *) buffer;
+       ((char *) header <= (char *) buffer + len - 12);
+       header = (struct multiboot_header *) ((grub_uint32_t *) header + MULTIBOOT_HEADER_ALIGN / 4))
+    {
+      if (header->magic == MULTIBOOT_HEADER_MAGIC
+	  && !(header->magic + header->architecture
+	       + header->header_length + header->checksum)
+	  && header->architecture == MULTIBOOT_ARCHITECTURE_CURRENT)
+	return header;
+    }
+  return NULL;
+}
+
 grub_err_t
 grub_multiboot_load (grub_file_t file, const char *filename)
 {
@@ -107,18 +126,7 @@ grub_multiboot_load (grub_file_t file, const char *filename)
 
   COMPILE_TIME_ASSERT (MULTIBOOT_HEADER_ALIGN % 4 == 0);
 
-  /* Look for the multiboot header in the buffer.  The header should
-     be at least 12 bytes and aligned on a 4-byte boundary.  */
-  for (header = (struct multiboot_header *) buffer;
-       ((char *) header <= (char *) buffer + len - 12) || (header = 0);
-       header = (struct multiboot_header *) ((grub_uint32_t *) header + MULTIBOOT_HEADER_ALIGN / 4))
-    {
-      if (header->magic == MULTIBOOT_HEADER_MAGIC
-	  && !(header->magic + header->architecture
-	       + header->header_length + header->checksum)
-	  && header->architecture == MULTIBOOT_ARCHITECTURE_CURRENT)
-	break;
-    }
+  header = find_header (buffer, len);
 
   if (header == 0)
     {