From mboxrd@z Thu Jan 1 00:00:00 1970 From: Davidlohr Bueso Subject: Re: [PATCH 1/5] lib/rhashtable: convert param sanitations to WARN_ON Date: Fri, 1 Jun 2018 09:53:47 -0700 Message-ID: <20180601165347.kvruerdm3gu57ifv@linux-r8p5> References: <20180601160125.30031-1-dave@stgolabs.net> <20180601160125.30031-2-dave@stgolabs.net> <20180601160944.ji2gsp3pyunlj476@gondor.apana.org.au> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Return-path: Content-Disposition: inline In-Reply-To: <20180601160944.ji2gsp3pyunlj476@gondor.apana.org.au> Sender: linux-kernel-owner@vger.kernel.org To: Herbert Xu Cc: akpm@linux-foundation.org, torvalds@linux-foundation.org, tgraf@suug.ch, manfred@colorfullife.com, mhocko@kernel.org, guillaume.knispel@supersonicimagine.com, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, Davidlohr Bueso List-Id: linux-api@vger.kernel.org On Sat, 02 Jun 2018, Herbert Xu wrote: >On Fri, Jun 01, 2018 at 09:01:21AM -0700, Davidlohr Bueso wrote: >> For the purpose of making rhashtable_init() unable to fail, >> we can replace the returning -EINVAL with WARN_ONs whenever >> the caller passes bogus parameters during initialization. >> >> Signed-off-by: Davidlohr Bueso >> --- >> lib/rhashtable.c | 9 ++++----- >> 1 file changed, 4 insertions(+), 5 deletions(-) >> >> diff --git a/lib/rhashtable.c b/lib/rhashtable.c >> index 9427b5766134..05a4b1b8b8ce 100644 >> --- a/lib/rhashtable.c >> +++ b/lib/rhashtable.c >> @@ -1024,12 +1024,11 @@ int rhashtable_init(struct rhashtable *ht, >> >> size = HASH_DEFAULT_SIZE; >> >> - if ((!params->key_len && !params->obj_hashfn) || >> - (params->obj_hashfn && !params->obj_cmpfn)) >> - return -EINVAL; >> + WARN_ON((!params->key_len && !params->obj_hashfn) || >> + (params->obj_hashfn && !params->obj_cmpfn)); >> >> - if (params->nulls_base && params->nulls_base < (1U << RHT_BASE_SHIFT)) >> - return -EINVAL; >> + WARN_ON(params->nulls_base && >> + params->nulls_base < (1U << RHT_BASE_SHIFT)); > >I still don't like this. > >Yes for your use-case you will never crash and a WARN_ON is fine. >However, rhashtable is used in all sorts of contexts and returning >an error makes sense for quite a number of them. Curious, are these users setting up the param structure dynamically or something that they can pass along bogus values? If that's the case then yes, I definitely agree.