From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Wed, 27 Aug 2008 10:18:28 +1000
Subject: [CRYPTO] tcrpyt: Remove unnecessary kmap/kunmap calls
Message-id: E1KY8k0-0002Gr-00@gondolin.me.apana.org.au
O-Subject: [PATCH 7/19] crypto: tcrpyt - Remove unnecessary kmap/kunmap calls
Bugzilla: 446522

RHEL5 bugzilla #446522

crypto: tcrpyt - Remove unnecessary kmap/kunmap calls

Noticed by Neil Horman: we are doing unnecessary kmap/kunmap calls
on kmalloced memory.  This patch removes them.  For the purposes of
testing SG construction, the underlying crypto code already does plenty
of kmap/kunmap calls anyway.

There is also an issue with testing the last segment when encrypting.
The additional part produced by AEAD wasn't tested.  Similarly, on
decryption the additional part of the AEAD input is mistaken for
corruption.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/crypto/tcrypt.c b/crypto/tcrypt.c
index 0a6b43b..7e47e8d 100644
--- a/crypto/tcrypt.c
+++ b/crypto/tcrypt.c
@@ -27,7 +27,6 @@
 #include <linux/scatterlist.h>
 #include <linux/string.h>
 #include <linux/ncrypto.h>
-#include <linux/highmem.h>
 #include <linux/moduleparam.h>
 #include <linux/jiffies.h>
 #include <linux/timex.h>
@@ -35,7 +34,7 @@
 #include "tcrypt.h"
 
 /*
- * Need to kmalloc() memory for testing kmap().
+ * Need to kmalloc() memory for testing.
  */
 #define TVMEMSIZE	16384
 #define XBUFSIZE	32768
@@ -420,13 +419,12 @@ static void test_aead(char *algo, int enc, struct aead_testvec *template,
 				goto next_one;
 			}
 
-			q = kmap(sg_page(&sg[0])) + sg[0].offset;
+			q = input;
 			hexdump(q, template[i].rlen);
 
 			printk(KERN_INFO "enc/dec: %s\n",
 			       memcmp(q, template[i].result,
 				      template[i].rlen) ? "fail" : "pass");
-			kunmap(sg_page(&sg[0]));
 next_one:
 			if (!template[i].key)
 				kfree(key);
@@ -525,25 +523,34 @@ next_one:
 
 			for (k = 0, temp = 0; k < template[i].np; k++) {
 				printk(KERN_INFO "page %u\n", k);
-				q = kmap(sg_page(&sg[k])) + sg[k].offset;
-				hexdump(q, template[i].tap[k]);
+				q = &xbuf[IDX[k]];
+
+				n = template[i].tap[k];
+				if (k == template[i].np - 1)
+					n += enc ? authsize : -authsize;
+				hexdump(q, n);
 				printk(KERN_INFO "%s\n",
-				       memcmp(q, template[i].result + temp,
-					      template[i].tap[k] -
-					      (k < template[i].np - 1 || enc ?
-					       0 : authsize)) ?
+				       memcmp(q, template[i].result + temp, n) ?
 				       "fail" : "pass");
 
-				for (n = 0; q[template[i].tap[k] + n]; n++)
-					;
+				q += n;
+				if (k == template[i].np - 1 && !enc) {
+					if (memcmp(q, template[i].input +
+						      temp + n, authsize))
+						n = authsize;
+					else
+						n = 0;
+				} else {
+					for (n = 0; q[n]; n++)
+						;
+				}
 				if (n) {
 					printk("Result buffer corruption %u "
 					       "bytes:\n", n);
-					hexdump(&q[template[i].tap[k]], n);
+					hexdump(q, n);
 				}
 
 				temp += template[i].tap[k];
-				kunmap(sg_page(&sg[k]));
 			}
 		}
 	}
@@ -652,13 +659,12 @@ static void test_cipher(char *algo, int enc,
 				goto out;
 			}
 
-			q = kmap(sg_page(&sg[0])) + sg[0].offset;
+			q = data;
 			hexdump(q, template[i].rlen);
 
 			printk("%s\n",
 			       memcmp(q, template[i].result,
 				      template[i].rlen) ? "fail" : "pass");
-			kunmap(sg_page(&sg[0]));
 		}
 		kfree(data);
 	}
@@ -740,7 +746,7 @@ static void test_cipher(char *algo, int enc,
 			temp = 0;
 			for (k = 0; k < template[i].np; k++) {
 				printk("page %u\n", k);
-				q = kmap(sg_page(&sg[k])) + sg[k].offset;
+				q = &xbuf[IDX[k]];
 				hexdump(q, template[i].tap[k]);
 				printk("%s\n",
 					memcmp(q, template[i].result + temp,
@@ -755,7 +761,6 @@ static void test_cipher(char *algo, int enc,
 					hexdump(&q[template[i].tap[k]], n);
 				}
 				temp += template[i].tap[k];
-				kunmap(sg_page(&sg[k]));
 			}
 		}
 	}