linux-kernel - RE: [EXT] [PATCH] qedr: Remove unnecessary synchronize_irq() before free

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 for Android: free password hash cracker in your pocket

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

Message-ID: <CH0PR18MB41293954D3162904680FB6F0A1CC9@CH0PR18MB4129.namprd18.prod.outlook.com>
Date:   Sun, 15 May 2022 10:12:04 +0000
From:   Michal Kalderon <mkalderon@...vell.com>
To:     "cgel.zte@...il.com" <cgel.zte@...il.com>
CC:     Ariel Elior <aelior@...vell.com>, "jgg@...pe.ca" <jgg@...pe.ca>,
        "leon@...nel.org" <leon@...nel.org>,
        "linux-rdma@...r.kernel.org" <linux-rdma@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Minghao Chi <chi.minghao@....com.cn>,
        Zeal Robot <zealci@....com.cn>
Subject: RE: [EXT] [PATCH] qedr: Remove unnecessary synchronize_irq() before
 free_irq()

> -----Original Message-----
> From: cgel.zte@...il.com <cgel.zte@...il.com>
> Sent: Friday, May 13, 2022 11:17 AM
> To: Michal Kalderon <mkalderon@...vell.com>
> Cc: Ariel Elior <aelior@...vell.com>; jgg@...pe.ca; leon@...nel.org; linux-
> rdma@...r.kernel.org; linux-kernel@...r.kernel.org; Minghao Chi
> <chi.minghao@....com.cn>; Zeal Robot <zealci@....com.cn>
> Subject: [EXT] [PATCH] qedr: Remove unnecessary synchronize_irq() before
> free_irq()
> 
> External Email
> 
> ----------------------------------------------------------------------
> From: Minghao Chi <chi.minghao@....com.cn>
> 
> Calling synchronize_irq() right before free_irq() is quite useless. On one
> hand the IRQ can easily fire again before free_irq() is entered, on the
> other hand free_irq() itself calls synchronize_irq() internally (in a race
> condition free way), before any state associated with the IRQ is freed.
> 
> Reported-by: Zeal Robot <zealci@....com.cn>
> Signed-off-by: Minghao Chi <chi.minghao@....com.cn>
> ---
>  drivers/infiniband/hw/qedr/main.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/drivers/infiniband/hw/qedr/main.c
> b/drivers/infiniband/hw/qedr/main.c
> index 65ce6d0f1885..5152f10d2e6d 100644
> --- a/drivers/infiniband/hw/qedr/main.c
> +++ b/drivers/infiniband/hw/qedr/main.c
> @@ -500,7 +500,6 @@ static void qedr_sync_free_irqs(struct qedr_dev
> *dev)
>  		if (dev->int_info.msix_cnt) {
>  			idx = i * dev->num_hwfns + dev->affin_hwfn_idx;
>  			vector = dev->int_info.msix[idx].vector;
> -			synchronize_irq(vector);
>  			free_irq(vector, &dev->cnq_array[i]);
>  		}
>  	}
> --
> 2.25.1
> 

Thanks, 

Acked-by: Michal Kalderon <michal.kalderon@...vell.com>