From: Gary G. Little [glittle@broadstor.com] Sent: Wednesday, May 15, 2002 12:31 PM To: NT Developers Interest List Subject: [ntdev] Re: METHOD_DIRECT - Please help! Jamey Hanrahan in a seminar I took describes it best --- METHOD_*_DIRECT redefines the use of the input/output buffers. Input becomes a pointer to a control buffer, where as output becomes the data buffer. On entry to your drivers Dispatch control method IRP->Associated buffer points to the "control" buffer where as IRP->MdlAddress points the MDL that has been created for the data buffer. As to why "control" might be NULL, I would hazard a guess that the Input pointer was null and or the size was 0. -- Gary G. Little glittle@broadstor.com glittle@inland.net "Johnny D" wrote in message news:28233@ntdev... In an IOCTL if I am copying more than 1 page worth of data from user->kernel space and also the other way around.. am I safe with using METHOD_OUT_DIRECT? I once saw that the Irp->AssociatedIrp.SystemBuffer was NULL when inside my IOCTL handler.. this is with > 1 page worth of data being transferred in... Would someone know why that I am getting that? Thanks -Johnny ------------------------------------------------------------------------------ Join the world's largest e-mail service with MSN Hotmail. Click Here --- You are currently subscribed to ntdev as: GlennEverhart@FirstUSA.com To unsubscribe send a blank email to leave-ntdev-247T@lists.osr.com