The SG list may be set up with entry size more than the requested
length. Check the usb_request->length and make sure that we don't setup
the TRBs to send/receive more than requested. This case may occur when
the SG entry is allocated up to a certain minimum size, but the request
length is less than that. It can also occur when the request is reused
for a different request length.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: a31e63b608ff ("usb: dwc3: gadget: Correct handling of scattergather lists")
Signed-off-by: Thinh Nguyen <thinhn@xxxxxxxxxxxx>
---
Changes in v2:
- Update remaining length when resume request
drivers/usb/dwc3/gadget.c | 51 +++++++++++++++++++++++++++------------
1 file changed, 35 insertions(+), 16 deletions(-)
diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index e44bfc3b5096..f9231253cbed 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -1054,27 +1054,25 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb,
* dwc3_prepare_one_trb - setup one TRB from one request
* @dep: endpoint for which this request is prepared
* @req: dwc3_request pointer
+ * @trb_length: buffer size of the TRB
* @chain: should this TRB be chained to the next?
* @node: only for isochronous endpoints. First TRB needs different type.
*/
static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
- struct dwc3_request *req, unsigned chain, unsigned node)
+ struct dwc3_request *req, unsigned int trb_length,
+ unsigned chain, unsigned node)
{
struct dwc3_trb *trb;
- unsigned int length;
dma_addr_t dma;
unsigned stream_id = req->request.stream_id;
unsigned short_not_ok = req->request.short_not_ok;
unsigned no_interrupt = req->request.no_interrupt;
unsigned is_last = req->request.is_last;
- if (req->request.num_sgs > 0) {
- length = sg_dma_len(req->start_sg);
+ if (req->request.num_sgs > 0)
dma = sg_dma_address(req->start_sg);
- } else {
- length = req->request.length;
+ else
dma = req->request.dma;
- }
trb = &dep->trb_pool[dep->trb_enqueue];
@@ -1086,7 +1084,7 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep,
req->num_trbs++;
- __dwc3_prepare_one_trb(dep, trb, dma, length, chain, node,
+ __dwc3_prepare_one_trb(dep, trb, dma, trb_length, chain, node,
stream_id, short_not_ok, no_interrupt, is_last);
}
@@ -1096,16 +1094,27 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
struct scatterlist *sg = req->start_sg;
struct scatterlist *s;
int i;
-
+ unsigned int length = req->request.length;
unsigned int remaining = req->request.num_mapped_sgs
- req->num_queued_sgs;
+ /*
+ * If we resume preparing the request, then get the remaining length of
+ * the request and resume where we left off.
+ */
+ for_each_sg(req->request.sg, s, req->num_queued_sgs, i)
+ length -= sg_dma_len(s);
+
for_each_sg(sg, s, remaining, i) {
- unsigned int length = req->request.length;
unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);
unsigned int rem = length % maxp;
+ unsigned int trb_length;
unsigned chain = true;
+ trb_length = min_t(unsigned int, length, sg_dma_len(s));
+
+ length -= trb_length;
+
/*
* IOMMU driver is coalescing the list of sgs which shares a
* page boundary into one and giving it to USB driver. With
@@ -1113,7 +1122,7 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
* sgs passed. So mark the chain bit to false if it isthe last
* mapped sg.
*/
- if (i == remaining - 1)
+ if ((i == remaining - 1) || !length)
chain = false;
if (rem && usb_endpoint_dir_out(dep->endpoint.desc) && !chain) {
@@ -1123,7 +1132,7 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
req->needs_extra_trb = true;
/* prepare normal TRB */
- dwc3_prepare_one_trb(dep, req, true, i);
+ dwc3_prepare_one_trb(dep, req, trb_length, true, i);
/* Now prepare one extra TRB to align transfer size */
trb = &dep->trb_pool[dep->trb_enqueue];
@@ -1135,7 +1144,7 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
req->request.no_interrupt,
req->request.is_last);
} else {
- dwc3_prepare_one_trb(dep, req, chain, i);
+ dwc3_prepare_one_trb(dep, req, trb_length, chain, i);
}
/*
@@ -1150,6 +1159,16 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep,
req->num_queued_sgs++;
+ /*
+ * The number of pending SG entries may not correspond to the
+ * number of mapped SG entries. If all the data are queued, then
+ * don't include unused SG entries.
+ */
+ if (length == 0) {
+ req->num_pending_sgs -= req->request.num_mapped_sgs - req->num_queued_sgs;
+ break;
+ }
+
if (!dwc3_calc_trbs_left(dep))
break;
}
@@ -1169,7 +1188,7 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
req->needs_extra_trb = true;
/* prepare normal TRB */
- dwc3_prepare_one_trb(dep, req, true, 0);
+ dwc3_prepare_one_trb(dep, req, length, true, 0);
/* Now prepare one extra TRB to align transfer size */
trb = &dep->trb_pool[dep->trb_enqueue];
@@ -1187,7 +1206,7 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
req->needs_extra_trb = true;
/* prepare normal TRB */
- dwc3_prepare_one_trb(dep, req, true, 0);
+ dwc3_prepare_one_trb(dep, req, length, true, 0);
/* Now prepare one extra TRB to handle ZLP */
trb = &dep->trb_pool[dep->trb_enqueue];
@@ -1198,7 +1217,7 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep,
req->request.no_interrupt,
req->request.is_last);
} else {
- dwc3_prepare_one_trb(dep, req, false, 0);
+ dwc3_prepare_one_trb(dep, req, length, false, 0);
}
}
--
2.28.0
