diff options
| author | Eric Dumazet | 2014-10-10 04:48:14 -0700 |
|---|---|---|
| committer | David S. Miller | 2014-10-10 15:37:28 -0400 |
| commit | 42b0270b40e2ad692ef59e28233202ee6f293e1e (patch) | |
| tree | 69d6d03af07645ea074a68433d24b2bf3ace9f22 | |
| parent | 1fadee0c364572f2b2e098b34001fbaa82ee2e00 (diff) | |
fm10k: fix race accessing page->_count
This is illegal to use atomic_set(&page->_count, 2) even if we 'own'
the page. Other entities in the kernel need to use get_page_unless_zero()
to get a reference to the page before testing page properties, so we could
loose a refcount increment.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
| -rw-r--r-- | drivers/net/ethernet/intel/fm10k/fm10k_main.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/net/ethernet/intel/fm10k/fm10k_main.c b/drivers/net/ethernet/intel/fm10k/fm10k_main.c index 6c800a330d66..9d7118a0d67a 100644 --- a/drivers/net/ethernet/intel/fm10k/fm10k_main.c +++ b/drivers/net/ethernet/intel/fm10k/fm10k_main.c @@ -219,11 +219,10 @@ static bool fm10k_can_reuse_rx_page(struct fm10k_rx_buffer *rx_buffer, /* flip page offset to other buffer */ rx_buffer->page_offset ^= FM10K_RX_BUFSZ; - /* since we are the only owner of the page and we need to - * increment it, just set the value to 2 in order to avoid - * an unnecessary locked operation + /* Even if we own the page, we are not allowed to use atomic_set() + * This would break get_page_unless_zero() users. */ - atomic_set(&page->_count, 2); + atomic_inc(&page->_count); #else /* move offset up to the next cache line */ rx_buffer->page_offset += truesize; |