Re: [linux-usb-devel] [PATCH 3/7] USB: add direction bit to urb-transfer_flags
On Mon, 30 Jul 2007, Pete Zaitcev wrote:
On Mon, 30 Jul 2007 17:06:16 -0400 (EDT), Alan Stern [EMAIL PROTECTED]
wrote:
--- usb-2.6.orig/drivers/usb/core/urb.c
+++ usb-2.6/drivers/usb/core/urb.c
@@ -309,7 +309,21 @@ int usb_submit_urb(struct urb *urb, gfp_
xfertype = usb_endpoint_type(ep-desc);
- is_out = usb_pipeout(urb-pipe);
+ if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
+ struct usb_ctrlrequest *setup =
+ (struct usb_ctrlrequest *) urb-setup_packet;
+
+ if (!setup)
+ return -ENOEXEC;
I welcome this. I should be able to rip some code out of usbmon now.
The comment in usb.h says:
* (Note
* that transfer_buffer and setup_packet must still be set because not all
* host controllers use DMA, nor do virtual root hubs).
But in case of data, this happens when a driver attempts to set up DMA
with a highmem page without doing a kmap first. I think we never enforced
the above comment.
It is enforced only for host controllers that use PIO, and only in
the most rudimentary way -- the driver crashes if the field isn't set!
And I think that I managed to oops usbmon by dereferencing
garbage in transfer_buffer before but I may not remember right.
But the setup packet should be mapped to be used, right? There's no
good reason for setup_packet not to be mapped, right?
Not that I can think of. Nobody ever sends setup packet contents
through scatter-gather buffers.
Alan Stern
P.S.: I appreciate the critical review!
-
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Re: [linux-usb-devel] [PATCH 3/7] USB: add direction bit to urb-transfer_flags
On Mon, 30 Jul 2007, David Brownell wrote:
On Monday 30 July 2007, Alan Stern wrote:
+static inline int usb_urb_dir_in(struct urb *urb)
+{
+ return (urb-transfer_flags URB_DIR_MASK) != URB_DIR_OUT;
+}
Clearer would be: == URB_DIR_IN ... or does that generate bad code?
I didn't actually check the generated code before submitting the patch.
A quick test with gcc 4.1.2 on x86 shows that the two sources give rise
to identical objects. I guess the same will probably be true on other
architectures too.
Okay, I'll change it.
Alan Stern
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Re: [linux-usb-devel] [PATCH 3/7] USB: add direction bit to urb-transfer_flags
On Mon, 30 Jul 2007 17:06:16 -0400 (EDT), Alan Stern [EMAIL PROTECTED] wrote:
--- usb-2.6.orig/drivers/usb/core/urb.c
+++ usb-2.6/drivers/usb/core/urb.c
@@ -309,7 +309,21 @@ int usb_submit_urb(struct urb *urb, gfp_
xfertype = usb_endpoint_type(ep-desc);
- is_out = usb_pipeout(urb-pipe);
+ if (xfertype == USB_ENDPOINT_XFER_CONTROL) {
+ struct usb_ctrlrequest *setup =
+ (struct usb_ctrlrequest *) urb-setup_packet;
+
+ if (!setup)
+ return -ENOEXEC;
I welcome this. I should be able to rip some code out of usbmon now.
The comment in usb.h says:
* (Note
* that transfer_buffer and setup_packet must still be set because not all
* host controllers use DMA, nor do virtual root hubs).
But in case of data, this happens when a driver attempts to set up DMA
with a highmem page without doing a kmap first. I think we never enforced
the above comment. And I think that I managed to oops usbmon by dereferencing
garbage in transfer_buffer before but I may not remember right.
But the setup packet should be mapped to be used, right? There's no
good reason for setup_packet not to be mapped, right?
-- Pete
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Re: [linux-usb-devel] [PATCH 3/7] USB: add direction bit to urb-transfer_flags
On Monday 30 July 2007, Alan Stern wrote:
+static inline int usb_urb_dir_in(struct urb *urb)
+{
+ return (urb-transfer_flags URB_DIR_MASK) != URB_DIR_OUT;
+}
Clearer would be: == URB_DIR_IN ... or does that generate bad code?
-
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