Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 6757ccc5 authored by Peter Beutner's avatar Peter Beutner Committed by Linus Torvalds
Browse files

[PATCH] dvb: core: fix race condition in FE_READ_STATUS ioctl 



Fix a race condition where an application which issued a FE_READ_STATUS ioctl
directly after FE_SET_FRONTEND would see an old status, i.e.  FE_READ_STATUS
would be executed before the frontend thread has even seen the tungin request
from FE_SET_FRONTEND.

Signed-off-by: default avatarPeter Beutner <p.beutner@gmx.net>
Signed-off-by: default avatarJohannes Stezenbach <js@linuxtv.org>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 25a26ec3

drivers/media/dvb/dvb-core/dvb_frontend.c

+13 −3
Original line number Diff line number Diff line
@@ -626,11 +626,21 @@ static int dvb_frontend_ioctl(struct inode *inode, struct file *file, 
		break;

	}



	case FE_READ_STATUS:

		if (fe->ops->read_status)

			err = fe->ops->read_status(fe, (fe_status_t*) parg);

	case FE_READ_STATUS: {

		fe_status_t* status = parg;



		/* if retune was requested but hasn't occured yet, prevent

		 * that user get signal state from previous tuning */

		if(fepriv->state == FESTATE_RETUNE) {

			err=0;

			*status = 0;

			break;

		}



		if (fe->ops->read_status)

			err = fe->ops->read_status(fe, status);

		break;

	}

	case FE_READ_BER:

		if (fe->ops->read_ber)

			err = fe->ops->read_ber(fe, (__u32*) parg);