| Message ID | 589bcff4.856d240a.3dcfb.a4be@mx.google.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
> On 9 Feb 2017, at 04:11 AM, Li Qiang <liq3ea@gmail.com> wrote: > > From: Li Qiang <liqiang6-s@360.cn> > > This issue is like the issue in e1000 network card addressed in > this commit: > e1000: eliminate infinite loops on out-of-bounds transfer start. Hi, Please see my comments below. > > Signed-off-by: Li Qiang <liqiang6-s@360.cn> > --- > > 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]; Here r->dt is index while r->dlen is length in bytes, so r->dlen should be divided by E1000_RING_DESC_LEN The same way as you do below while checking for wrap around. > } > > 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; > + } IIUC infinite loop protection already implemented by your changes for e1000e_ring_empty() > } > > 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; > + } IIUC, infinite loop protection here is covered by newly introduced call to e1000e_ring_empty(). ~Dmitry > } while (desc_offset < total_size); > > e1000e_update_rx_stats(core, size, total_size); > -- > 1.8.3.1 >
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);