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authorAlan Stern <stern@rowland.harvard.edu>2009-11-04 11:35:53 -0500
committerGreg Kroah-Hartman <gregkh@suse.de>2009-11-17 16:46:34 -0800
commitfca94748c5136ff390eadc443871b82f1f77dcd6 (patch)
tree494d3707070aaf4dd952e2bd69f69c76012cc905
parent5294bea40666db5c5d6c336b8e4e55d69fa576ca (diff)
USB: usbmon: fix bug in mon_buff_area_shrink
This patch (as1299b) fixes a bug in an error-handling path of usbmon's binary interface. The storage area for URB data is divided into fixed-size blocks. If an URB's data can't be copied, the area reserved for it should be decreased to the size of the truncated information (rounded up to a block boundary). Rounding up the amount to be removed and subtracting it from the reserved size is definitely the wrong thing to do. Also, when the data for an isochronous URB can't be copied, we can still copy the isoc packet descriptors. In fact the current code does copy the descriptors, but then sets the capture length to 0 so they remain inaccessible. The capture length should be reduced to the length of the descriptors, not set to 0. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Acked-by: Pete Zaitcev <zaitcev@redhat.com> CC: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
-rw-r--r--drivers/usb/mon/mon_bin.c11
1 files changed, 7 insertions, 4 deletions
diff --git a/drivers/usb/mon/mon_bin.c b/drivers/usb/mon/mon_bin.c
index 9ed3e741bee..10f3205798e 100644
--- a/drivers/usb/mon/mon_bin.c
+++ b/drivers/usb/mon/mon_bin.c
@@ -348,12 +348,12 @@ static unsigned int mon_buff_area_alloc_contiguous(struct mon_reader_bin *rp,
/*
* Return a few (kilo-)bytes to the head of the buffer.
- * This is used if a DMA fetch fails.
+ * This is used if a data fetch fails.
*/
static void mon_buff_area_shrink(struct mon_reader_bin *rp, unsigned int size)
{
- size = (size + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
+ /* size &= ~(PKT_ALIGN-1); -- we're called with aligned size */
rp->b_cnt -= size;
if (rp->b_in < size)
rp->b_in += rp->b_size;
@@ -433,6 +433,7 @@ static void mon_bin_event(struct mon_reader_bin *rp, struct urb *urb,
unsigned int urb_length;
unsigned int offset;
unsigned int length;
+ unsigned int delta;
unsigned int ndesc, lendesc;
unsigned char dir;
struct mon_bin_hdr *ep;
@@ -537,8 +538,10 @@ static void mon_bin_event(struct mon_reader_bin *rp, struct urb *urb,
if (length != 0) {
ep->flag_data = mon_bin_get_data(rp, offset, urb, length);
if (ep->flag_data != 0) { /* Yes, it's 0x00, not '0' */
- ep->len_cap = 0;
- mon_buff_area_shrink(rp, length);
+ delta = (ep->len_cap + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
+ ep->len_cap -= length;
+ delta -= (ep->len_cap + PKT_ALIGN-1) & ~(PKT_ALIGN-1);
+ mon_buff_area_shrink(rp, delta);
}
} else {
ep->flag_data = data_tag;