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=qpxydaacu1rq...@mail.gmail.com Signed-off-by: Kees Cook <keesc...@chromium.org> --- crypto/tcrypt.c | 118 +++++++++++++++++++++++++++++++++++++------------------- 1 file changed, 79 insertions(+), 39 deletions(-) diff --git a/crypto/tcrypt.c b/crypto/tcrypt.c index 51fe7c8744ae..e721faab6fc8 100644 --- a/crypto/tcrypt.c +++ b/crypto/tcrypt.c @@ -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); + 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); + 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); + 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"); -- 2.7.4 -- Kees Cook Pixel Security
