[XEN] Sync Elf parsing with libxc parser.

Signed-off-by: Keir Fraser <keir@xensource.com>

xen/common/elf.c

@@ -95,7 +95,11 @@ int parseelfimage(struct domain_setup_info *dsi)
     elf_pa_off = elf_pa_off_defined ? simple_strtoul(p+17, &p, 0) : virt_base;
 
     if ( elf_pa_off_defined && !virt_base_defined )
-        goto bad_image;
+    {
+        printk("ERROR: Neither ELF_PADDR_OFFSET nor VIRT_BASE found in"
+               " __xen_guest section.\n");
+        return -EINVAL;
+    }
 
     for ( h = 0; h < ehdr->e_phnum; h++ )
     {
@@ -104,7 +108,11 @@ int parseelfimage(struct domain_setup_info *dsi)
             continue;
         vaddr = phdr->p_paddr - elf_pa_off + virt_base;
         if ( (vaddr + phdr->p_memsz) < vaddr )
-            goto bad_image;
+        {
+            printk("ERROR: ELF program header %d is too large.\n", h);
+            return -EINVAL;
+        }
+
         if ( vaddr < kernstart )
             kernstart = vaddr;
         if ( (vaddr + phdr->p_memsz) > kernend )
@@ -127,7 +135,10 @@ int parseelfimage(struct domain_setup_info *dsi)
          (dsi->v_kernentry < kernstart) ||
          (dsi->v_kernentry > kernend) ||
          (dsi->v_start > kernstart) )
-        goto bad_image;
+    {
+        printk("ERROR: ELF start or entries are out of bounds.\n");
+        return -EINVAL;
+    }
 
     if ( (p = strstr(guestinfo, "BSD_SYMTAB")) != NULL )
             dsi->load_symtab = 1;
@@ -139,10 +150,6 @@ int parseelfimage(struct domain_setup_info *dsi)
     loadelfsymtab(dsi, 0);
 
     return 0;
-
- bad_image:
-    printk("Malformed ELF image.\n");
-    return -EINVAL;
 }
 
 int loadelfimage(struct domain_setup_info *dsi)