linux-kernel - RE: [PATCH v2 1/3] mei: vsc: Call wake

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

Message-ID: <MW5PR11MB5787130A75404600F47A7D9C8D562@MW5PR11MB5787.namprd11.prod.outlook.com>
Date: Thu, 22 Feb 2024 03:26:18 +0000
From: "Wu, Wentong" <wentong.wu@...el.com>
To: Sakari Ailus <sakari.ailus@...ux.intel.com>
CC: Hans de Goede <hdegoede@...hat.com>, "Winkler, Tomas"
	<tomas.winkler@...el.com>, Arnd Bergmann <arnd@...db.de>, Greg Kroah-Hartman
	<gregkh@...uxfoundation.org>, "linux-kernel@...r.kernel.org"
	<linux-kernel@...r.kernel.org>
Subject: RE: [PATCH v2 1/3] mei: vsc: Call wake_up() in the threaded IRQ
 handler

> From: Sakari Ailus <sakari.ailus@...ux.intel.com>
> 
> The hard IRQ handler vsc_tp_irq() is called with a raw spinlock taken.
> wake_up() acquires a spinlock, a sleeping lock on PREEMPT_RT.

Does this mean we can't use wake_up() in isr? 

BR,
Wentong

> This leads to sleeping in atomic context.
> 
> Move the wake_up() call to the threaded IRQ handler vsc_tp_thread_isr()
> where it can be safely called.
> 
> Fixes: 566f5ca97680 ("mei: Add transport driver for IVSC device")
> Signed-off-by: Sakari Ailus <sakari.ailus@...ux.intel.com>
> ---
>  drivers/misc/mei/vsc-tp.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/misc/mei/vsc-tp.c b/drivers/misc/mei/vsc-tp.c index
> 6f4a4be6ccb5..2b69ada9349e 100644
> --- a/drivers/misc/mei/vsc-tp.c
> +++ b/drivers/misc/mei/vsc-tp.c
> @@ -416,8 +416,6 @@ static irqreturn_t vsc_tp_isr(int irq, void *data)
> 
>  	atomic_inc(&tp->assert_cnt);
> 
> -	wake_up(&tp->xfer_wait);
> -
>  	return IRQ_WAKE_THREAD;
>  }
> 
> @@ -425,6 +423,8 @@ static irqreturn_t vsc_tp_thread_isr(int irq, void
> *data)  {
>  	struct vsc_tp *tp = data;
> 
> +	wake_up(&tp->xfer_wait);
> +
>  	if (tp->event_notify)
>  		tp->event_notify(tp->event_notify_context);
> 
> --
> 2.39.2