crypto: testmgr - Allow different compression results

The following error is triggered by the ThunderX ZIP driver
if the testmanager is enabled:

[  199.069437] ThunderX-ZIP 0000:03:00.0: Found ZIP device 0 177d:a01a on Node 0
[  199.073573] alg: comp: Compression test 1 failed for deflate-generic: output len = 37

The reason for this error is the verification of the compression
results. Verifying the compression result only works if all
algorithm parameters are identical, in this case to the software
implementation.

Different compression engines like the ThunderX ZIP coprocessor
might yield different compression results by tuning the
algorithm parameters. In our case the compressed result is
shorter than the test vector.

We should not forbid different compression results but only
check that compression -> decompression yields the same
result. This is done already in the acomp test. Do something
similar for test_comp().

Signed-off-by: Mahipal Challa <mchalla@cavium.com>
Signed-off-by: Balakrishna Bhamidipati <bbhamidipati@cavium.com>
[jglauber@cavium.com: removed unrelated printk changes, rewrote commit msg,
 fixed whitespace and unneeded initialization]
Signed-off-by: Jan Glauber <jglauber@cavium.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

crypto/testmgr.c

@@ -1342,19 +1342,30 @@ static int test_comp(struct crypto_comp *tfm,
 		     int ctcount, int dtcount)
 {
 	const char *algo = crypto_tfm_alg_driver_name(crypto_comp_tfm(tfm));
+	char *output, *decomp_output;
 	unsigned int i;
-	char result[COMP_BUF_SIZE];
 	int ret;
 
+	output = kmalloc(COMP_BUF_SIZE, GFP_KERNEL);
+	if (!output)
+		return -ENOMEM;
+
+	decomp_output = kmalloc(COMP_BUF_SIZE, GFP_KERNEL);
+	if (!decomp_output) {
+		kfree(output);
+		return -ENOMEM;
+	}
+
 	for (i = 0; i < ctcount; i++) {
 		int ilen;
 		unsigned int dlen = COMP_BUF_SIZE;
 
-		memset(result, 0, sizeof (result));
+		memset(output, 0, sizeof(COMP_BUF_SIZE));
+		memset(decomp_output, 0, sizeof(COMP_BUF_SIZE));
 
 		ilen = ctemplate[i].inlen;
 		ret = crypto_comp_compress(tfm, ctemplate[i].input,
-		                           ilen, result, &dlen);
+					   ilen, output, &dlen);
 		if (ret) {
 			printk(KERN_ERR "alg: comp: compression failed "
 			       "on test %d for %s: ret=%d\n", i + 1, algo,
@@ -1362,7 +1373,17 @@ static int test_comp(struct crypto_comp *tfm,
 			goto out;
 		}
 
-		if (dlen != ctemplate[i].outlen) {
+		ilen = dlen;
+		dlen = COMP_BUF_SIZE;
+		ret = crypto_comp_decompress(tfm, output,
+					     ilen, decomp_output, &dlen);
+		if (ret) {
+			pr_err("alg: comp: compression failed: decompress: on test %d for %s failed: ret=%d\n",
+			       i + 1, algo, -ret);
+			goto out;
+		}
+
+		if (dlen != ctemplate[i].inlen) {
 			printk(KERN_ERR "alg: comp: Compression test %d "
 			       "failed for %s: output len = %d\n", i + 1, algo,
 			       dlen);
@@ -1370,10 +1391,11 @@ static int test_comp(struct crypto_comp *tfm,
 			goto out;
 		}
 
-		if (memcmp(result, ctemplate[i].output, dlen)) {
-			printk(KERN_ERR "alg: comp: Compression test %d "
-			       "failed for %s\n", i + 1, algo);
-			hexdump(result, dlen);
+		if (memcmp(decomp_output, ctemplate[i].input,
+			   ctemplate[i].inlen)) {
+			pr_err("alg: comp: compression failed: output differs: on test %d for %s\n",
+			       i + 1, algo);
+			hexdump(decomp_output, dlen);
 			ret = -EINVAL;
 			goto out;
 		}
@@ -1383,11 +1405,11 @@ static int test_comp(struct crypto_comp *tfm,
 		int ilen;
 		unsigned int dlen = COMP_BUF_SIZE;
 
-		memset(result, 0, sizeof (result));
+		memset(decomp_output, 0, sizeof(COMP_BUF_SIZE));
 
 		ilen = dtemplate[i].inlen;
 		ret = crypto_comp_decompress(tfm, dtemplate[i].input,
-		                             ilen, result, &dlen);
+					     ilen, decomp_output, &dlen);
 		if (ret) {
 			printk(KERN_ERR "alg: comp: decompression failed "
 			       "on test %d for %s: ret=%d\n", i + 1, algo,
@@ -1403,10 +1425,10 @@ static int test_comp(struct crypto_comp *tfm,
 			goto out;
 		}
 
-		if (memcmp(result, dtemplate[i].output, dlen)) {
+		if (memcmp(decomp_output, dtemplate[i].output, dlen)) {
 			printk(KERN_ERR "alg: comp: Decompression test %d "
 			       "failed for %s\n", i + 1, algo);
-			hexdump(result, dlen);
+			hexdump(decomp_output, dlen);
 			ret = -EINVAL;
 			goto out;
 		}
@@ -1415,11 +1437,13 @@ static int test_comp(struct crypto_comp *tfm,
 	ret = 0;
 
 out:
+	kfree(decomp_output);
+	kfree(output);
 	return ret;
 }
 
 static int test_acomp(struct crypto_acomp *tfm,
-		      const struct comp_testvec *ctemplate,
+			      const struct comp_testvec *ctemplate,
 		      const struct comp_testvec *dtemplate,
 		      int ctcount, int dtcount)
 {