Re: [PATCH 3/3] trusted-keys: avoid scattring va_end()

From: Mimi Zohar
Date: Mon Jan 17 2011 - 16:06:53 EST


On Mon, 2011-01-17 at 09:44 +0900, Tetsuo Handa wrote:
> From 65b41710a476deae2e0899a4df40c02d199a4ee3 Mon Sep 17 00:00:00 2001
> From: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>
> Date: Mon, 17 Jan 2011 09:27:27 +0900
> Subject: [PATCH 3/3] trusted-keys: avoid scattring va_end()
>
> We can avoid scattering va_end() within the
>
> va_start();
> for (;;) {
>
> }
> va_end();
>
> loop, assuming that crypto_shash_init()/crypto_shash_update() return 0 on
> success and negative value otherwise.
>
> Make TSS_authhmac()/TSS_checkhmac1()/TSS_checkhmac2() similar to TSS_rawhmac()
> by removing "va_end()/goto" from the loop.
>
> Signed-off-by: Tetsuo Handa <penguin-kernel@xxxxxxxxxxxxxxxxxxx>

The patch looks good. Would you mind making the one change below?

Acked-by: Mimi Zohar <zohar@xxxxxxxxxx>

> ---
> security/keys/trusted_defined.c | 30 +++++++++++++-----------------
> 1 files changed, 13 insertions(+), 17 deletions(-)
>
> diff --git a/security/keys/trusted_defined.c b/security/keys/trusted_defined.c
> index f7d0677..2836c6d 100644
> --- a/security/keys/trusted_defined.c
> +++ b/security/keys/trusted_defined.c
> @@ -150,17 +150,15 @@ static int TSS_authhmac(unsigned char *digest, const unsigned char *key,
> data = va_arg(argp, unsigned char *);
> if (!data) {
> ret = -EINVAL;
> - va_end(argp);
> - goto out;
> + break;
> }
> ret = crypto_shash_update(&sdesc->shash, data, dlen);
> - if (ret < 0) {
> - va_end(argp);
> - goto out;
> - }
> + if (ret < 0)
> + break;
> }
> va_end(argp);
> - ret = crypto_shash_final(&sdesc->shash, paramdigest);
> + if (!ret)
> + ret = crypto_shash_final(&sdesc->shash, paramdigest);
> if (!ret)

Change the existing '(!ret)' to '(ret < 0)', like the rest of the code?
It's not wrong, but ....

> ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
> paramdigest, TPM_NONCE_SIZE, h1,
> @@ -229,13 +227,12 @@ static int TSS_checkhmac1(unsigned char *buffer,
> break;
> dpos = va_arg(argp, unsigned int);
> ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
> - if (ret < 0) {
> - va_end(argp);
> - goto out;
> - }
> + if (ret < 0)
> + break;
> }
> va_end(argp);
> - ret = crypto_shash_final(&sdesc->shash, paramdigest);
> + if (!ret)
> + ret = crypto_shash_final(&sdesc->shash, paramdigest);
> if (ret < 0)
> goto out;
>
> @@ -323,13 +320,12 @@ static int TSS_checkhmac2(unsigned char *buffer,
> break;
> dpos = va_arg(argp, unsigned int);
> ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
> - if (ret < 0) {
> - va_end(argp);
> - goto out;
> - }
> + if (ret < 0)
> + break;
> }
> va_end(argp);
> - ret = crypto_shash_final(&sdesc->shash, paramdigest);
> + if (!ret)
> + ret = crypto_shash_final(&sdesc->shash, paramdigest);
> if (ret < 0)
> goto out;
>


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