From: Jarod Wilson Subject: Re: [PATCH 3/7] crypto: testmgr: fix warning Date: Mon, 19 Oct 2009 10:03:48 -0400 Message-ID: <4ADC71C4.3020805@redhat.com> References: <1255906474-25091-1-git-send-email-felipe.contreras@gmail.com> <1255906474-25091-4-git-send-email-felipe.contreras@gmail.com> <4ADC707E.2040802@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Felipe Contreras , linux-kernel@vger.kernel.org, Herbert Xu , "David S. Miller" , Geert Uytterhoeven , Neil Horman , linux-crypto@vger.kernel.org To: Jiri Kosina Return-path: Received: from mx1.redhat.com ([209.132.183.28]:2736 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751534AbZJSOFC (ORCPT ); Mon, 19 Oct 2009 10:05:02 -0400 In-Reply-To: <4ADC707E.2040802@redhat.com> Sender: linux-crypto-owner@vger.kernel.org List-ID: On 10/19/09 9:58 AM, Jarod Wilson wrote: > On 10/19/09 9:52 AM, Jiri Kosina wrote: >> On Mon, 19 Oct 2009, Felipe Contreras wrote: >> >>> crypto/testmgr.c: In function ?test_cprng?: >>> crypto/testmgr.c:1204: warning: ?err? may be used uninitialized in >>> this function >>> >>> Signed-off-by: Felipe Contreras >>> --- >>> crypto/testmgr.c | 2 +- >>> 1 files changed, 1 insertions(+), 1 deletions(-) >>> >>> diff --git a/crypto/testmgr.c b/crypto/testmgr.c >>> index 6d5b746..1f2357b 100644 >>> --- a/crypto/testmgr.c >>> +++ b/crypto/testmgr.c >>> @@ -1201,7 +1201,7 @@ static int test_cprng(struct crypto_rng *tfm, >>> struct cprng_testvec *template, >>> unsigned int tcount) >>> { >>> const char *algo = crypto_tfm_alg_driver_name(crypto_rng_tfm(tfm)); >>> - int err, i, j, seedsize; >>> + int err = 0, i, j, seedsize; >>> u8 *seed; >>> char result[32]; >> >> As it is not obvious to me immediately why/whether tcount couldn't be >> zero >> (which would cause uninitialized use of 'err'), I am not merging this >> through trivial tree. Herbert? > > I believe I'm the guilty party who wrote the code in question. > Initializing err to 0 isn't correct. tcount should always be at least 1, > if its 0, test_cprng has been called with invalid parameters. I believe > err would best be initialized to -EINVAL, lest the caller think they > were successful. ...and I need to re-read said code more carefully. tcount is desc->suite.cprng.count, which is ANSI_CPRNG_AES_TEST_VECTORS, which is #define'd to 6, and is the count of how many cprng test vectors there are. If someone changes that to 0, then I guess a retval of 0 would actually be correct, since no tests failed... So yeah, I rescind my claim that initializing err to 0 is incorrect, I think that's just fine. -- Jarod Wilson jarod@redhat.com