From 29d2fef8be1165a26984a94fbcf81d68c1442fc5 Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Thu, 8 May 2014 19:25:56 +0300 Subject: [PATCH] usb: catch attempts to submit urbs with a vmalloc'd transfer buffer Save someone else the debug cycles of figuring out why a driver's transfer request is failing or causing undefined system behavior. Buffers submitted for dma must come from GFP allocated / DMA-able memory. Return -EAGAIN matching the return value for dma_mapping_error() cases. Acked-by: Alan Stern Cc: Sarah Sharp Cc: Mathias Nyman Signed-off-by: Dan Williams Signed-off-by: Mathias Nyman Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/hcd.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c index 9c4e2922b04d..adddc66c9e8d 100644 --- a/drivers/usb/core/hcd.c +++ b/drivers/usb/core/hcd.c @@ -1502,6 +1502,9 @@ int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb, ret = -EAGAIN; else urb->transfer_flags |= URB_DMA_MAP_PAGE; + } else if (is_vmalloc_addr(urb->transfer_buffer)) { + WARN_ONCE(1, "transfer buffer not dma capable\n"); + ret = -EAGAIN; } else { urb->transfer_dma = dma_map_single( hcd->self.controller, -- 2.25.1