1. 04 Mar, 2020 23 commits
  2. 03 Mar, 2020 11 commits
  3. 02 Mar, 2020 6 commits
    • Jesper Dangaard Brouer's avatar
      mvneta: add XDP ethtool errors stats for TX to driver · 15070919
      Jesper Dangaard Brouer authored
      Adding ethtool stats for when XDP transmitted packets overrun the TX
      queue. This is recorded separately for XDP_TX and ndo_xdp_xmit. This
      is an important aid for troubleshooting XDP based setups.
      
      It is currently a known weakness and property of XDP that there isn't
      any push-back or congestion feedback when transmitting frames via XDP.
      It's easy to realise when redirecting from a higher speed link into a
      slower speed link, or simply two ingress links into a single egress.
      The situation can also happen when Ethernet flow control is active.
      
      For testing the patch and provoking the situation to occur on my
      Espressobin board, I configured the TX-queue to be smaller (434) than
      RX-queue (512) and overload network with large MTU size frames (as a
      larger frame takes longer to transmit).
      
      Hopefully the upcoming XDP TX hook can be extended to provide insight
      into these TX queue overflows, to allow programmable adaptation
      strategies.
      Signed-off-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
      Acked-by: default avatarLorenzo Bianconi <lorenzo@kernel.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      15070919
    • David S. Miller's avatar
      Merge branch 'net-zl-array' · 0b56a29f
      David S. Miller authored
      More zero-length array transformations from Gustavo A. R. Silva.
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      0b56a29f
    • Gustavo A. R. Silva's avatar
      tehuti: Replace zero-length array with flexible-array member · 23640d64
      Gustavo A. R. Silva authored
      The current codebase makes use of the zero-length array language
      extension to the C90 standard, but the preferred mechanism to declare
      variable-length types such as these ones is a flexible array member[1][2],
      introduced in C99:
      
      struct foo {
              int stuff;
              struct boo array[];
      };
      
      By making use of the mechanism above, we will get a compiler warning
      in case the flexible array does not occur last in the structure, which
      will help us prevent some kind of undefined behavior bugs from being
      inadvertently introduced[3] to the codebase from now on.
      
      Also, notice that, dynamic memory allocations won't be affected by
      this change:
      
      "Flexible array members have incomplete type, and so the sizeof operator
      may not be applied. As a quirk of the original implementation of
      zero-length arrays, sizeof evaluates to zero."[1]
      
      This issue was found with the help of Coccinelle.
      
      [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
      [2] https://github.com/KSPP/linux/issues/21
      [3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
      Signed-off-by: default avatarGustavo A. R. Silva <gustavo@embeddedor.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      23640d64
    • Gustavo A. R. Silva's avatar
      r8152: Replace zero-length array with flexible-array member · ee3bc9c2
      Gustavo A. R. Silva authored
      The current codebase makes use of the zero-length array language
      extension to the C90 standard, but the preferred mechanism to declare
      variable-length types such as these ones is a flexible array member[1][2],
      introduced in C99:
      
      struct foo {
              int stuff;
              struct boo array[];
      };
      
      By making use of the mechanism above, we will get a compiler warning
      in case the flexible array does not occur last in the structure, which
      will help us prevent some kind of undefined behavior bugs from being
      inadvertently introduced[3] to the codebase from now on.
      
      Also, notice that, dynamic memory allocations won't be affected by
      this change:
      
      "Flexible array members have incomplete type, and so the sizeof operator
      may not be applied. As a quirk of the original implementation of
      zero-length arrays, sizeof evaluates to zero."[1]
      
      This issue was found with the help of Coccinelle.
      
      [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
      [2] https://github.com/KSPP/linux/issues/21
      [3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
      Signed-off-by: default avatarGustavo A. R. Silva <gustavo@embeddedor.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      ee3bc9c2
    • Gustavo A. R. Silva's avatar
      net: atlantic: Replace zero-length array with flexible-array member · 0fcf4666
      Gustavo A. R. Silva authored
      The current codebase makes use of the zero-length array language
      extension to the C90 standard, but the preferred mechanism to declare
      variable-length types such as these ones is a flexible array member[1][2],
      introduced in C99:
      
      struct foo {
              int stuff;
              struct boo array[];
      };
      
      By making use of the mechanism above, we will get a compiler warning
      in case the flexible array does not occur last in the structure, which
      will help us prevent some kind of undefined behavior bugs from being
      inadvertently introduced[3] to the codebase from now on.
      
      Also, notice that, dynamic memory allocations won't be affected by
      this change:
      
      "Flexible array members have incomplete type, and so the sizeof operator
      may not be applied. As a quirk of the original implementation of
      zero-length arrays, sizeof evaluates to zero."[1]
      
      This issue was found with the help of Coccinelle.
      
      [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
      [2] https://github.com/KSPP/linux/issues/21
      [3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
      Signed-off-by: default avatarGustavo A. R. Silva <gustavo@embeddedor.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      0fcf4666
    • Gustavo A. R. Silva's avatar
      bna: bnad: Replace zero-length array with flexible-array member · 8f5c69f9
      Gustavo A. R. Silva authored
      The current codebase makes use of the zero-length array language
      extension to the C90 standard, but the preferred mechanism to declare
      variable-length types such as these ones is a flexible array member[1][2],
      introduced in C99:
      
      struct foo {
              int stuff;
              struct boo array[];
      };
      
      By making use of the mechanism above, we will get a compiler warning
      in case the flexible array does not occur last in the structure, which
      will help us prevent some kind of undefined behavior bugs from being
      inadvertently introduced[3] to the codebase from now on.
      
      Also, notice that, dynamic memory allocations won't be affected by
      this change:
      
      "Flexible array members have incomplete type, and so the sizeof operator
      may not be applied. As a quirk of the original implementation of
      zero-length arrays, sizeof evaluates to zero."[1]
      
      This issue was found with the help of Coccinelle.
      
      [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
      [2] https://github.com/KSPP/linux/issues/21
      [3] commit 76497732 ("cxgb3/l2t: Fix undefined behaviour")
      Signed-off-by: default avatarGustavo A. R. Silva <gustavo@embeddedor.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      8f5c69f9