--- kernel/linux/hash.c.orig	2015-05-05 00:16:41 UTC
+++ kernel/linux/hash.c
@@ -1,91 +0,0 @@
-// Copyright 2004-present Facebook. All Rights Reserved.
-
-#include <linux/init.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-
-/* Crypto */
-#include <linux/crypto.h>
-#include <linux/err.h>
-#include <linux/scatterlist.h>
-#include <crypto/sha.h>
-
-#include "hash.h"
-
-unsigned char *kernel_text_hash(void) {
-  return (unsigned char *) hash_data((void *) TEXT_SEGMENT_START,
-                                     TEXT_SEGMENT_END - TEXT_SEGMENT_START);
-}
-
-/**
- * @brief Generic function for performing a SHA-1 hash of a memory range
- *
- * @param data - Beginning memory address to perform hash
- * @param len - size in bytes of the address range to hash
- *
- * @return allocated buffer containing the hash string; or NULL upon error.
- */
-unsigned char *hash_data(const void *data, size_t len) {
-  struct scatterlist sg;
-  struct hash_desc desc;
-  size_t out_len = SHA1_DIGEST_SIZE * 2 + 1;
-  unsigned char hashtext[SHA1_DIGEST_SIZE];
-  unsigned char *hashtext_out = kmalloc(out_len, GFP_KERNEL);
-
-  if (!hashtext_out) {
-    printk(KERN_INFO "Could not allocate space for hash\n");
-    return NULL;
-  }
-
-  sg_init_one(&sg, data, len);
-  desc.flags = 0;
-  desc.tfm = crypto_alloc_hash("sha1", 0, CRYPTO_ALG_ASYNC);
-
-  crypto_hash_init(&desc);
-  crypto_hash_update(&desc, &sg, sg.length);
-  crypto_hash_final(&desc, hashtext);
-
-  snprintf(hashtext_out,
-           out_len,
-           "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x"
-           "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
-           hashtext[0], hashtext[1], hashtext[2], hashtext[3],
-           hashtext[4], hashtext[5], hashtext[6], hashtext[7],
-           hashtext[8], hashtext[9], hashtext[10], hashtext[11],
-           hashtext[12], hashtext[13], hashtext[14], hashtext[15],
-           hashtext[16], hashtext[17], hashtext[18], hashtext[19]
-  );
-
-  if (desc.tfm) {
-    crypto_free_hash(desc.tfm);
-  }
-
-  return hashtext_out;
-}
-
-/**
- * @brief Callback for the sysfs object read. This happens when a file is
- *        read(2) (or equivalent) from within sysfs. E.g. cat /sys/foo/bar will
- *        call bar's *_show callback method.
- *
- * @param obj - reference to a kernel object within the sysfs filesystem
- * @param attr - attribute of said kernel object
- * @param buf - buffer that will be allocated and filled with the hash
- *
- * @return size in bytes of the hash string; or -1 upon error.
- */
-ssize_t text_segment_hash_show(struct kobject *obj,
-                               struct attribute *attr,
-                               char *buf) {
-  ssize_t ret;
-  char *hash = kernel_text_hash();
-
-  if (hash) {
-    ret = scnprintf(buf, PAGE_SIZE, "%s\n", hash);
-    kfree(hash);
-  } else {
-    ret = -1;
-  }
-
-  return ret;
-}