From mboxrd@z Thu Jan 1 00:00:00 1970 From: Suraj Jitindar Singh Date: Mon, 03 Dec 2018 00:06:50 +0000 Subject: Re: [PATCH] KVM: PPC: Book3S HV: NULL check before some freeing functions is not needed. Message-Id: <1543795610.7535.2.camel@gmail.com> List-Id: References: <1543760930050-1499171309-0-diffsplit-thomas@m3y3r.de> <1543760930051-2094322096-1-diffsplit-thomas@m3y3r.de> In-Reply-To: <1543760930051-2094322096-1-diffsplit-thomas@m3y3r.de> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Thomas Meyer , paulus@ozlabs.org, benh@kernel.crashing.org, mpe@ellerman.id.au, kvm-ppc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org On Sun, 2018-12-02 at 21:52 +0100, Thomas Meyer wrote: > NULL check before some freeing functions is not needed. Technically true, however I think a comment should be added then to make it clearer to someone reading the code why this is ok. See below. Suraj. > > Signed-off-by: Thomas Meyer > --- > > diff -u -p a/arch/powerpc/kvm/book3s_hv_nested.c > b/arch/powerpc/kvm/book3s_hv_nested.c > --- a/arch/powerpc/kvm/book3s_hv_nested.c > +++ b/arch/powerpc/kvm/book3s_hv_nested.c > @@ -1252,8 +1252,7 @@ static long int __kvmhv_nested_page_faul > rmapp = &memslot->arch.rmap[gfn - memslot->base_gfn]; > ret = kvmppc_create_pte(kvm, gp->shadow_pgtable, pte, n_gpa, > level, > mmu_seq, gp->shadow_lpid, rmapp, > &n_rmap); > - if (n_rmap) > - kfree(n_rmap); > + kfree(n_rmap); e.g. /* n_rmap set to NULL in kvmppc_create_pte if reference preserved */ > if (ret = -EAGAIN) > ret = RESUME_GUEST; /* Let the guest try > again */ >