e1000: fix data race between tx_ring->next_to_clean
authorDmitriy Vyukov <dvyukov@google.com>
Tue, 8 Sep 2015 08:52:44 +0000 (10:52 +0200)
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>
Sun, 13 Dec 2015 07:09:48 +0000 (23:09 -0800)
commit9eab46b7cb8d0b0dcf014bf7b25e0e72b9e4d929
tree33d44739cb702dddf3d371285c3ff4b24f134c7e
parent18f7ce5412027232890143ccfae23668d0872d27
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>
drivers/net/ethernet/intel/e1000/e1000.h
drivers/net/ethernet/intel/e1000/e1000_main.c