diff options
| author | Dmitriy Vyukov <dvyukov@google.com> | 2015-09-08 10:52:44 +0200 |
|---|---|---|
| committer | Jeff Kirsher <jeffrey.t.kirsher@intel.com> | 2015-12-12 23:09:48 -0800 |
| commit | 9eab46b7cb8d0b0dcf014bf7b25e0e72b9e4d929 (patch) | |
| tree | 33d44739cb702dddf3d371285c3ff4b24f134c7e /drivers | |
| parent | 18f7ce5412027232890143ccfae23668d0872d27 (diff) | |
| download | linux-9eab46b7cb8d0b0dcf014bf7b25e0e72b9e4d929.tar.bz2 | |
e1000: fix data race between tx_ring->next_to_clean
e1000_clean_tx_irq cleans buffers and sets tx_ring->next_to_clean,
then e1000_xmit_frame reuses the cleaned buffers. But there are no
memory barriers when buffers gets recycled, so the recycled buffers
can be corrupted.
Use smp_store_release to update tx_ring->next_to_clean and
smp_load_acquire to read tx_ring->next_to_clean to properly
hand off buffers from e1000_clean_tx_irq to e1000_xmit_frame.
The data race was found with KernelThreadSanitizer (KTSAN).
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/net/ethernet/intel/e1000/e1000.h | 7 | ||||
| -rw-r--r-- | drivers/net/ethernet/intel/e1000/e1000_main.c | 5 |
2 files changed, 9 insertions, 3 deletions
diff --git a/drivers/net/ethernet/intel/e1000/e1000.h b/drivers/net/ethernet/intel/e1000/e1000.h index 69707108d23c..98fe5a2cd6e3 100644 --- a/drivers/net/ethernet/intel/e1000/e1000.h +++ b/drivers/net/ethernet/intel/e1000/e1000.h @@ -213,8 +213,11 @@ struct e1000_rx_ring { }; #define E1000_DESC_UNUSED(R) \ - ((((R)->next_to_clean > (R)->next_to_use) \ - ? 0 : (R)->count) + (R)->next_to_clean - (R)->next_to_use - 1) +({ \ + unsigned int clean = smp_load_acquire(&(R)->next_to_clean); \ + unsigned int use = READ_ONCE((R)->next_to_use); \ + (clean > use ? 0 : (R)->count) + clean - use - 1; \ +}) #define E1000_RX_DESC_EXT(R, i) \ (&(((union e1000_rx_desc_extended *)((R).desc))[i])) diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c index fd7be860c201..068023595d84 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_main.c +++ b/drivers/net/ethernet/intel/e1000/e1000_main.c @@ -3876,7 +3876,10 @@ static bool e1000_clean_tx_irq(struct e1000_adapter *adapter, eop_desc = E1000_TX_DESC(*tx_ring, eop); } - tx_ring->next_to_clean = i; + /* Synchronize with E1000_DESC_UNUSED called from e1000_xmit_frame, + * which will reuse the cleaned buffers. + */ + smp_store_release(&tx_ring->next_to_clean, i); netdev_completed_queue(netdev, pkts_compl, bytes_compl); |