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Commit 4e234eed authored by Kees Cook's avatar Kees Cook Committed by Herbert Xu
Browse files

crypto: tcrypt - Remove VLA usage 

In the quest to remove all stack VLA usage from the kernel[1], this
allocates the return code buffers before starting jiffie timers, rather
than using stack space for the array. Additionally cleans up some exit
paths and make sure that the num_mb module_param() is used only once
per execution to avoid possible races in the value changing.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=qPXydAacU1RqZWA@mail.gmail.com



Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
parent e99ce921

crypto/tcrypt.c

+79 −39
Original line number Diff line number Diff line
@@ -158,9 +158,9 @@ struct test_mb_aead_data { 
};



static int do_mult_aead_op(struct test_mb_aead_data *data, int enc,

				u32 num_mb)

				u32 num_mb, int *rc)

{

	int i, rc[num_mb], err = 0;

	int i, err = 0;



	/* Fire up a bunch of concurrent requests */

	for (i = 0; i < num_mb; i++) {
@@ -188,18 +188,26 @@ static int test_mb_aead_jiffies(struct test_mb_aead_data *data, int enc, 
{

	unsigned long start, end;

	int bcount;

	int ret;

	int ret = 0;

	int *rc;



	rc = kcalloc(num_mb, sizeof(*rc), GFP_KERNEL);

	if (!rc)

		return -ENOMEM;



	for (start = jiffies, end = start + secs * HZ, bcount = 0;

	     time_before(jiffies, end); bcount++) {

		ret = do_mult_aead_op(data, enc, num_mb);

		ret = do_mult_aead_op(data, enc, num_mb, rc);

		if (ret)

			return ret;

			goto out;

	}



	pr_cont("%d operations in %d seconds (%ld bytes)\n",

		bcount * num_mb, secs, (long)bcount * blen * num_mb);

	return 0;



out:

	kfree(rc);

	return ret;

}



static int test_mb_aead_cycles(struct test_mb_aead_data *data, int enc,
@@ -208,10 +216,15 @@ static int test_mb_aead_cycles(struct test_mb_aead_data *data, int enc, 
	unsigned long cycles = 0;

	int ret = 0;

	int i;

	int *rc;



	rc = kcalloc(num_mb, sizeof(*rc), GFP_KERNEL);

	if (!rc)

		return -ENOMEM;



	/* Warm-up run. */

	for (i = 0; i < 4; i++) {

		ret = do_mult_aead_op(data, enc, num_mb);

		ret = do_mult_aead_op(data, enc, num_mb, rc);

		if (ret)

			goto out;

	}
@@ -221,7 +234,7 @@ static int test_mb_aead_cycles(struct test_mb_aead_data *data, int enc, 
		cycles_t start, end;



		start = get_cycles();

		ret = do_mult_aead_op(data, enc, num_mb);

		ret = do_mult_aead_op(data, enc, num_mb, rc);

		end = get_cycles();



		if (ret)
@@ -230,11 +243,11 @@ static int test_mb_aead_cycles(struct test_mb_aead_data *data, int enc, 
		cycles += end - start;

	}



out:

	if (ret == 0)

	pr_cont("1 operation in %lu cycles (%d bytes)\n",

		(cycles + 4) / (8 * num_mb), blen);



out:

	kfree(rc);

	return ret;

}
@@ -705,9 +718,10 @@ struct test_mb_ahash_data { 
	char *xbuf[XBUFSIZE];

};



static inline int do_mult_ahash_op(struct test_mb_ahash_data *data, u32 num_mb)

static inline int do_mult_ahash_op(struct test_mb_ahash_data *data, u32 num_mb,

				   int *rc)

{

	int i, rc[num_mb], err = 0;

	int i, err = 0;



	/* Fire up a bunch of concurrent requests */

	for (i = 0; i < num_mb; i++)
@@ -731,18 +745,26 @@ static int test_mb_ahash_jiffies(struct test_mb_ahash_data *data, int blen, 
{

	unsigned long start, end;

	int bcount;

	int ret;

	int ret = 0;

	int *rc;



	rc = kcalloc(num_mb, sizeof(*rc), GFP_KERNEL);

	if (!rc)

		return -ENOMEM;



	for (start = jiffies, end = start + secs * HZ, bcount = 0;

	     time_before(jiffies, end); bcount++) {

		ret = do_mult_ahash_op(data, num_mb);

		ret = do_mult_ahash_op(data, num_mb, rc);

		if (ret)

			return ret;

			goto out;

	}



	pr_cont("%d operations in %d seconds (%ld bytes)\n",

		bcount * num_mb, secs, (long)bcount * blen * num_mb);

	return 0;



out:

	kfree(rc);

	return ret;

}



static int test_mb_ahash_cycles(struct test_mb_ahash_data *data, int blen,
@@ -751,10 +773,15 @@ static int test_mb_ahash_cycles(struct test_mb_ahash_data *data, int blen, 
	unsigned long cycles = 0;

	int ret = 0;

	int i;

	int *rc;



	rc = kcalloc(num_mb, sizeof(*rc), GFP_KERNEL);

	if (!rc)

		return -ENOMEM;



	/* Warm-up run. */

	for (i = 0; i < 4; i++) {

		ret = do_mult_ahash_op(data, num_mb);

		ret = do_mult_ahash_op(data, num_mb, rc);

		if (ret)

			goto out;

	}
@@ -764,7 +791,7 @@ static int test_mb_ahash_cycles(struct test_mb_ahash_data *data, int blen, 
		cycles_t start, end;



		start = get_cycles();

		ret = do_mult_ahash_op(data, num_mb);

		ret = do_mult_ahash_op(data, num_mb, rc);

		end = get_cycles();



		if (ret)
@@ -773,11 +800,11 @@ static int test_mb_ahash_cycles(struct test_mb_ahash_data *data, int blen, 
		cycles += end - start;

	}



out:

	if (ret == 0)

	pr_cont("1 operation in %lu cycles (%d bytes)\n",

		(cycles + 4) / (8 * num_mb), blen);



out:

	kfree(rc);

	return ret;

}
@@ -1118,9 +1145,9 @@ struct test_mb_skcipher_data { 
};



static int do_mult_acipher_op(struct test_mb_skcipher_data *data, int enc,

				u32 num_mb)

				u32 num_mb, int *rc)

{

	int i, rc[num_mb], err = 0;

	int i, err = 0;



	/* Fire up a bunch of concurrent requests */

	for (i = 0; i < num_mb; i++) {
@@ -1148,18 +1175,26 @@ static int test_mb_acipher_jiffies(struct test_mb_skcipher_data *data, int enc, 
{

	unsigned long start, end;

	int bcount;

	int ret;

	int ret = 0;

	int *rc;



	rc = kcalloc(num_mb, sizeof(*rc), GFP_KERNEL);

	if (!rc)

		return -ENOMEM;



	for (start = jiffies, end = start + secs * HZ, bcount = 0;

	     time_before(jiffies, end); bcount++) {

		ret = do_mult_acipher_op(data, enc, num_mb);

		ret = do_mult_acipher_op(data, enc, num_mb, rc);

		if (ret)

			return ret;

			goto out;

	}



	pr_cont("%d operations in %d seconds (%ld bytes)\n",

		bcount * num_mb, secs, (long)bcount * blen * num_mb);

	return 0;



out:

	kfree(rc);

	return ret;

}



static int test_mb_acipher_cycles(struct test_mb_skcipher_data *data, int enc,
@@ -1168,10 +1203,15 @@ static int test_mb_acipher_cycles(struct test_mb_skcipher_data *data, int enc, 
	unsigned long cycles = 0;

	int ret = 0;

	int i;

	int *rc;



	rc = kcalloc(num_mb, sizeof(*rc), GFP_KERNEL);

	if (!rc)

		return -ENOMEM;



	/* Warm-up run. */

	for (i = 0; i < 4; i++) {

		ret = do_mult_acipher_op(data, enc, num_mb);

		ret = do_mult_acipher_op(data, enc, num_mb, rc);

		if (ret)

			goto out;

	}
@@ -1181,7 +1221,7 @@ static int test_mb_acipher_cycles(struct test_mb_skcipher_data *data, int enc, 
		cycles_t start, end;



		start = get_cycles();

		ret = do_mult_acipher_op(data, enc, num_mb);

		ret = do_mult_acipher_op(data, enc, num_mb, rc);

		end = get_cycles();



		if (ret)
@@ -1190,11 +1230,11 @@ static int test_mb_acipher_cycles(struct test_mb_skcipher_data *data, int enc, 
		cycles += end - start;

	}



out:

	if (ret == 0)

	pr_cont("1 operation in %lu cycles (%d bytes)\n",

		(cycles + 4) / (8 * num_mb), blen);



out:

	kfree(rc);

	return ret;

}
@@ -1606,7 +1646,7 @@ static inline int tcrypt_test(const char *alg) 
	return ret;

}



static int do_test(const char *alg, u32 type, u32 mask, int m)

static int do_test(const char *alg, u32 type, u32 mask, int m, u32 num_mb)

{

	int i;

	int ret = 0;
@@ -1621,7 +1661,7 @@ static int do_test(const char *alg, u32 type, u32 mask, int m) 
		}



		for (i = 1; i < 200; i++)

			ret += do_test(NULL, 0, 0, i);

			ret += do_test(NULL, 0, 0, i, num_mb);

		break;



	case 1:
@@ -2903,7 +2943,7 @@ static int __init tcrypt_mod_init(void) 
			goto err_free_tv;

	}



	err = do_test(alg, type, mask, mode);

	err = do_test(alg, type, mask, mode, num_mb);



	if (err) {

		printk(KERN_ERR "tcrypt: one or more tests failed!\n");