makedumpfile: disable mmap read

There's a kernel bug for mapping mem ranges which end with
an address not aligned to page boundry. It's still not resolved
in upstream, so let's disable mmap read for now as a workaround.

Once upstream got a right fix we can revert this patch.

Signed-off-by: Dave Young <dyoung@redhat.com>
---
 makedumpfile.c |    7 +++++++
 1 file changed, 7 insertions(+)

--- kexec-tools/makedumpfile-1.5.4/makedumpfile.c.orig
+++ kexec-tools/makedumpfile-1.5.4/makedumpfile.c
@@ -3144,6 +3144,12 @@ out:
 	if (info->dump_level & DL_EXCLUDE_FREE)
 		setup_page_is_buddy();
 
+	/* There's a kernel bug for mapping mem ranges which end with
+	 * an address not aligned to page boundry. It's still not resolved
+	 * in upstream, so let's disable mmap read for now.
+	 */
+	info->flag_usemmap = FALSE;
+#if 0
 	if (!initialize_mmap()) {
 		/* this kernel does not support mmap of vmcore */
 		DEBUG_MSG("Kernel can't mmap vmcore, using reads.\n");
@@ -3152,6 +3158,7 @@ out:
 		DEBUG_MSG("read %s with mmap()\n", info->name_memory);
 		info->flag_usemmap = TRUE;
 	}
+#endif
 
 	return TRUE;
 }