From: "Philippe Mathieu-Daudé" <philmd@linaro.org>
To: Masato Imai <mii@sfc.wide.ad.jp>, qemu-devel@nongnu.org
Cc: Paolo Bonzini <pbonzini@redhat.com>,
"open list:Overall KVM CPUs" <kvm@vger.kernel.org>
Subject: Re: [PATCH v3 1/1] accel/kvm: Fix segmentation fault
Date: Tue, 7 May 2024 09:33:02 +0200 [thread overview]
Message-ID: <ef6df20a-04c9-46bd-95b4-b5bc553364ab@linaro.org> (raw)
In-Reply-To: <20240507025010.1968881-2-mii@sfc.wide.ad.jp>
Hi Masato,
On 7/5/24 04:50, Masato Imai wrote:
> When the KVM acceleration parameter is not set, executing calc_dirty_rate
> with the -r or -b option results in a segmentation fault due to accessing
> a null kvm_state pointer in the kvm_dirty_ring_enabled function. This
> commit adds a null check for kvm_status to prevent segmentation faults.
>
> Signed-off-by: Masato Imai <mii@sfc.wide.ad.jp>
> ---
> accel/kvm/kvm-all.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
> index c0be9f5eed..544293be8a 100644
> --- a/accel/kvm/kvm-all.c
> +++ b/accel/kvm/kvm-all.c
> @@ -2329,7 +2329,7 @@ bool kvm_vcpu_id_is_valid(int vcpu_id)
>
> bool kvm_dirty_ring_enabled(void)
> {
> - return kvm_state->kvm_dirty_ring_size ? true : false;
> + return kvm_state && kvm_state->kvm_dirty_ring_size;
I missed the previous iterations of this patch. I disagree
with this approach, we shouldn't call kvm_dirty_ring_enabled()
if kvm_state is NULL, this is a bad API usage. So I'd rather
assert(kvm_state) here and force the callers to check for
kvm_enabled() before calling.
> }
>
> static void query_stats_cb(StatsResultList **result, StatsTarget target,
prev parent reply other threads:[~2024-05-07 7:33 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-07 2:50 [PATCH v3 0/1] accel/kvm: Fix segmentation fault Masato Imai
2024-05-07 2:50 ` [PATCH v3 1/1] " Masato Imai
2024-05-07 3:35 ` Zhijian Li (Fujitsu) via
2024-05-07 7:33 ` Philippe Mathieu-Daudé [this message]
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