From: David Gibson <david@gibson.dropbear.id.au>
To: Serhii Popovych <spopovyc@redhat.com>
Cc: linux-kernel@vger.kernel.org, michael@ellerman.id.au,
paulus@samba.org, linuxppc-dev@lists.ozlabs.org,
kvm-ppc@vger.kernel.org
Subject: Re: [PATCH 4/4] KVM: PPC: Book3S HV: Remove redundant parameter from resize_hpt_release()
Date: Thu, 30 Nov 2017 14:53:31 +1100 [thread overview]
Message-ID: <20171130035331.GR3023@umbus.fritz.box> (raw)
In-Reply-To: <1511973506-65683-5-git-send-email-spopovyc@redhat.com>
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On Wed, Nov 29, 2017 at 11:38:26AM -0500, Serhii Popovych wrote:
> There is no need to pass it explicitly from the caller:
> struct kvm_resize_hpt already contains it.
>
> Additional benefit from this change is that BUG_ON()
> assertion now checks that mutex is held on kvm instance
> associated with resize structure we going to release.
>
> Also kill check for resize being NULL to make code
> simpler and we called with resize != NULL in all
> places except kvm_vm_ioctl_resize_hpt_commit().
>
> Signed-off-by: Serhii Popovych <spopovyc@redhat.com>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
> ---
> arch/powerpc/kvm/book3s_64_mmu_hv.c | 16 ++++++++--------
> 1 file changed, 8 insertions(+), 8 deletions(-)
>
> diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
> index 690f061..a74a0ad 100644
> --- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
> +++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
> @@ -1415,12 +1415,11 @@ static void resize_hpt_pivot(struct kvm_resize_hpt *resize)
> resize_hpt_debug(resize, "resize_hpt_pivot() done\n");
> }
>
> -static void resize_hpt_release(struct kvm *kvm, struct kvm_resize_hpt *resize)
> +static void resize_hpt_release(struct kvm_resize_hpt *resize)
> {
> - BUG_ON(!mutex_is_locked(&kvm->lock));
> + struct kvm *kvm = resize->kvm;
>
> - if (!resize)
> - return;
> + BUG_ON(!mutex_is_locked(&kvm->lock));
>
> if (resize->error != -EBUSY) {
> kvmppc_free_hpt(&resize->hpt);
> @@ -1469,7 +1468,7 @@ static void resize_hpt_prepare_work(struct work_struct *work)
> resize->error = err;
>
> if (kvm->arch.resize_hpt != resize)
> - resize_hpt_release(kvm, resize);
> + resize_hpt_release(resize);
>
> mutex_unlock(&kvm->lock);
> }
> @@ -1499,13 +1498,13 @@ long kvm_vm_ioctl_resize_hpt_prepare(struct kvm *kvm,
> if (ret == -EBUSY)
> ret = 100; /* estimated time in ms */
> else if (ret)
> - resize_hpt_release(kvm, resize);
> + resize_hpt_release(resize);
>
> goto out;
> }
>
> /* not suitable, cancel it */
> - resize_hpt_release(kvm, resize);
> + resize_hpt_release(resize);
> }
>
> ret = 0;
> @@ -1590,7 +1589,8 @@ long kvm_vm_ioctl_resize_hpt_commit(struct kvm *kvm,
> kvm->arch.mmu_ready = 1;
> smp_mb();
> out_no_hpt:
> - resize_hpt_release(kvm, resize);
> + if (resize)
> + resize_hpt_release(resize);
> mutex_unlock(&kvm->lock);
> return ret;
> }
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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next prev parent reply other threads:[~2017-11-30 4:03 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-29 16:38 [PATCH 0/4] Fix use after free in HPT resizing code and related minor improvements Serhii Popovych
2017-11-29 16:38 ` [PATCH 1/4] KVM: PPC: Book3S HV: Drop prepare_done from struct kvm_resize_hpt and cleanups Serhii Popovych
2017-11-30 3:40 ` David Gibson
2017-11-29 16:38 ` [PATCH 2/4] KVM: PPC: Book3S HV: Improve kvmppc_allocate_hpt()/kvmppc_free_hpt() Serhii Popovych
2017-11-30 3:45 ` David Gibson
2017-11-29 16:38 ` [PATCH 3/4] KVM: PPC: Book3S HV: Fix use after free in case of multiple resize requests Serhii Popovych
2017-11-30 3:51 ` David Gibson
2017-11-29 16:38 ` [PATCH 4/4] KVM: PPC: Book3S HV: Remove redundant parameter from resize_hpt_release() Serhii Popovych
2017-11-30 3:53 ` David Gibson [this message]
2017-11-30 3:54 ` [PATCH 0/4] Fix use after free in HPT resizing code and related minor improvements David Gibson
2017-12-04 6:10 ` David Gibson
2017-12-04 12:22 ` Michael Ellerman
2017-12-04 14:43 ` Serhii Popovych
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