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[Qemu-devel] [PATCH v2] net: e1000e: fix an infinite loop issue
From: |
Li Qiang |
Subject: |
[Qemu-devel] [PATCH v2] net: e1000e: fix an infinite loop issue |
Date: |
Wed, 8 Feb 2017 18:11:24 -0800 |
From: Li Qiang <address@hidden>
This issue is like the issue in e1000 network card addressed in
this commit:
e1000: eliminate infinite loops on out-of-bounds transfer start.
Signed-off-by: Li Qiang <address@hidden>
---
Changes since v1:
make wraparound detect in e1000e_ring_empty
hw/net/e1000e_core.c | 23 +++++++++++++++++++++--
1 file changed, 21 insertions(+), 2 deletions(-)
diff --git a/hw/net/e1000e_core.c b/hw/net/e1000e_core.c
index 2b11499..d4c56c3 100644
--- a/hw/net/e1000e_core.c
+++ b/hw/net/e1000e_core.c
@@ -806,7 +806,8 @@ typedef struct E1000E_RingInfo_st {
static inline bool
e1000e_ring_empty(E1000ECore *core, const E1000E_RingInfo *r)
{
- return core->mac[r->dh] == core->mac[r->dt];
+ return core->mac[r->dh] == core->mac[r->dt] ||
+ core->mac[r->dt] >= core->mac[r->dlen];
}
static inline uint64_t
@@ -914,7 +915,7 @@ e1000e_start_xmit(E1000ECore *core, const E1000E_TxRing
*txr)
struct e1000_tx_desc desc;
bool ide = false;
const E1000E_RingInfo *txi = txr->i;
- uint32_t cause = E1000_ICS_TXQE;
+ uint32_t tdh_start = core->mac[txi->dh], cause = E1000_ICS_TXQE;
if (!(core->mac[TCTL] & E1000_TCTL_EN)) {
trace_e1000e_tx_disabled();
@@ -933,6 +934,14 @@ e1000e_start_xmit(E1000ECore *core, const E1000E_TxRing
*txr)
cause |= e1000e_txdesc_writeback(core, base, &desc, &ide, txi->idx);
e1000e_ring_advance(core, txi, 1);
+
+ /*
+ * The following avoid infinite loop, just as the e1000
+ */
+ if (core->mac[txi->dh] == tdh_start ||
+ tdh_start >= core->mac[txi->dlen] / E1000_RING_DESC_LEN) {
+ break;
+ }
}
if (!ide || !e1000e_intrmgr_delay_tx_causes(core, &cause)) {
@@ -1500,6 +1509,7 @@ e1000e_write_packet_to_guest(E1000ECore *core, struct
NetRxPkt *pkt,
size_t desc_size;
size_t desc_offset = 0;
size_t iov_ofs = 0;
+ uint32_t rdh_start;
struct iovec *iov = net_rx_pkt_get_iovec(pkt);
size_t size = net_rx_pkt_get_total_len(pkt);
@@ -1509,6 +1519,7 @@ e1000e_write_packet_to_guest(E1000ECore *core, struct
NetRxPkt *pkt,
bool do_ps = e1000e_do_ps(core, pkt, &ps_hdr_len);
rxi = rxr->i;
+ rdh_start = core->mac[rxi->dh];
do {
hwaddr ba[MAX_PS_BUFFERS];
@@ -1522,6 +1533,10 @@ e1000e_write_packet_to_guest(E1000ECore *core, struct
NetRxPkt *pkt,
desc_size = core->rx_desc_buf_size;
}
+ if (e1000e_ring_empty(core, rxi)) {
+ return;
+ }
+
base = e1000e_ring_head_descr(core, rxi);
pci_dma_read(d, base, &desc, core->rx_desc_len);
@@ -1605,6 +1620,10 @@ e1000e_write_packet_to_guest(E1000ECore *core, struct
NetRxPkt *pkt,
e1000e_ring_advance(core, rxi,
core->rx_desc_len / E1000_MIN_RX_DESC_LEN);
+ if (core->mac[rxi->dh] == rdh_start ||
+ rdh_start >= core->mac[rxi->dlen] / E1000_RING_DESC_LEN) {
+ break;
+ }
} while (desc_offset < total_size);
e1000e_update_rx_stats(core, size, total_size);
--
1.8.3.1
- [Qemu-devel] [PATCH v2] net: e1000e: fix an infinite loop issue,
Li Qiang <=