linux-kernel - Re: [PATCH] kvm/eventfd:do wildcard calculation before list_for_each_entry

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Date:   Fri, 11 Sep 2020 19:23:40 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Yi Li <yili@...hong.com>
Cc:     yilikernel@...il.com, linux-kernel@...r.kernel.org,
        kvm@...r.kernel.org
Subject: Re: [PATCH] kvm/eventfd:do wildcard calculation before
 list_for_each_entry_safe

On 11/09/20 07:56, Yi Li wrote:
> There is no need to calculate wildcard in each loop
> since wildcard is not changed.
> 
> Signed-off-by: Yi Li <yili@...hong.com>
> ---
>  virt/kvm/eventfd.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
> index d6408bb497dc..c2323c27a28b 100644
> --- a/virt/kvm/eventfd.c
> +++ b/virt/kvm/eventfd.c
> @@ -853,15 +853,17 @@ kvm_deassign_ioeventfd_idx(struct kvm *kvm, enum kvm_bus bus_idx,
>  	struct eventfd_ctx       *eventfd;
>  	struct kvm_io_bus	 *bus;
>  	int                       ret = -ENOENT;
> +	bool                      wildcard;
>  
>  	eventfd = eventfd_ctx_fdget(args->fd);
>  	if (IS_ERR(eventfd))
>  		return PTR_ERR(eventfd);
>  
> +	wildcard = !(args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH);
> +
>  	mutex_lock(&kvm->slots_lock);
>  
>  	list_for_each_entry_safe(p, tmp, &kvm->ioeventfds, list) {
> -		bool wildcard = !(args->flags & KVM_IOEVENTFD_FLAG_DATAMATCH);
>  
>  		if (p->bus_idx != bus_idx ||
>  		    p->eventfd != eventfd  ||
> 

Queued, thanks.

Paolo