Re: [Linux-usb-users] Possible bug in usb storage (2.6.11 kernel)

[Atsushi Nemoto <anemo@mba.ocn.ne.jp>]

>>>>> On Thu, 8 Sep 2005 16:40:16 -0400 (EDT), Alan Stern <stern@rowland.harvard.edu> said:

stern> I've long thought that usb-storage should allocate its own
stern> transfer buffer for sense data.  In the past people have said,
stern> "No, don't bother, it's not really needed."  Here's a good
stern> reason for doing it.

stern> Expect a patch before long.

Did you already create the patch?  If not, how about this (against 2.6.13) ?


Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>

diff -u linux-2.6.13/drivers/usb/storage/transport.c linux/drivers/usb/storage/transport.c
--- linux-2.6.13/drivers/usb/storage/transport.c	2005-08-29 08:41:01.000000000 +0900
+++ linux/drivers/usb/storage/transport.c	2005-09-27 18:03:32.000000000 +0900
@@ -638,7 +638,8 @@
 
 		/* use the new buffer we have */
 		old_request_buffer = srb->request_buffer;
-		srb->request_buffer = srb->sense_buffer;
+		srb->request_buffer =
+			kmalloc(max(dma_get_cache_alignment(), 18), GFP_NOIO);
 
 		/* set the buffer length for transfer */
 		old_request_bufflen = srb->request_bufflen;
@@ -655,7 +656,13 @@
 		/* issue the auto-sense command */
 		old_resid = srb->resid;
 		srb->resid = 0;
-		temp_result = us->transport(us->srb, us);
+		if (srb->request_buffer) {
+			temp_result = us->transport(us->srb, us);
+			memcpy(srb->sense_buffer, srb->request_buffer, 18);
+			kfree(srb->request_buffer);
+		} else {
+			temp_result = USB_STOR_TRANSPORT_FAILED;
+		}
 
 		/* let's clean up right away */
 		srb->resid = old_resid;


---
Atsushi Nemoto
-
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