[dpdk-dev] [PATCH v4 0/9] Improve cast alignment for strict aligned machines
Olivier MATZ
olivier.matz at 6wind.com
Tue Jun 23 17:36:40 CEST 2015
Hi Cyril,
On 06/22/2015 08:34 PM, Cyril Chemparathy wrote:
> This series contains a few improvements that allow the DPDK code base
> to build properly on machines that enforce strict pointer cast
> alignment constraints.
>
> When dealing with packet data which could be arbitrarily aligned, we
> get the compiler to do the right thing by (a) making sure that header
> types are packed, and (b) introducing and using
> unaligned_uint(16|32|64)_t types when upcasting from byte pointers.
>
> In a few other instances, we know apriori that the pointer cast cannot
> possibly break alignment. This applies to the changes in mempool,
> hash, mbuf, and the ethdev stats code. Here, we simply silence the
> compiler by casting through (void *) using the RTE_PTR_(ADD|SUB)
> macros.
>
> Finally, we introduce a new rte_pktmbuf_mtod_offset() helper to return
> a type casted pointer to an offset within the packet data. This
> replaces the following commonly used pattern:
> (struct foo *)(rte_pktmbuf_mtod(m, char *) + offset)
> with:
> rte_pktmbuf_mtod_offset(m, struct foo *, offset)
>
> To ensure consistency, the above transform was applied throughout the
> code base using the coccinelle semantic patching tool.
Series
Acked-by: Olivier Matz <olivier.matz at 6wind.com>
>
> Changes in this series:
> v2: Fixes based on Olivier's comments.
> v3: Extends unaligned fixes to new code introduced on master.
> v4: Fixes based on Thomas' comments.
> Extends unaligned fixes to new code introduced on master.
>
> Cyril Chemparathy (9):
> mempool: silence -Wcast-align on pointer arithmetic
> mbuf: silence -Wcast-align on pointer arithmetic
> ethdev: silence -Wcast-align on pointer arithmetic
> hash: silence -Wcast-align on pointer arithmetic
> eal: add and use unaligned integer types
> app/test-pmd: pack simple_gre_hdr
> librte_mbuf: Add rte_pktmbuf_mtod_offset()
> librte_mbuf: Add transform for rte_pktmbuf_mtod_offset()
> librte_mbuf: Apply mtod-offset.cocci transform
>
> app/test-pmd/csumonly.c | 2 +-
> app/test-pmd/flowgen.c | 4 +-
> app/test-pmd/icmpecho.c | 2 +-
> app/test-pmd/ieee1588fwd.c | 4 +-
> app/test-pmd/rxonly.c | 21 +++++----
> app/test-pmd/txonly.c | 6 +--
> app/test/packet_burst_generator.c | 9 ++--
> app/test/test_hash_functions.c | 2 +-
> app/test/test_mbuf.c | 16 +++----
> config/common_bsdapp | 5 ++
> config/common_linuxapp | 5 ++
> drivers/net/bonding/rte_eth_bond_pmd.c | 12 +++--
> drivers/net/mlx4/mlx4.c | 9 ++--
> examples/dpdk_qat/crypto.c | 8 ++--
> examples/dpdk_qat/main.c | 5 +-
> examples/l3fwd-acl/main.c | 20 ++++----
> examples/l3fwd-power/main.c | 8 ++--
> examples/l3fwd-vf/main.c | 4 +-
> examples/l3fwd/main.c | 71 ++++++++++++----------------
> examples/load_balancer/runtime.c | 4 +-
> examples/vhost_xen/main.c | 4 +-
> lib/librte_eal/common/include/rte_common.h | 10 ++++
> lib/librte_ether/rte_ethdev.c | 24 +++++-----
> lib/librte_ether/rte_ether.h | 2 +-
> lib/librte_hash/rte_hash.c | 10 ++--
> lib/librte_ip_frag/rte_ipv4_reassembly.c | 7 ++-
> lib/librte_ip_frag/rte_ipv6_reassembly.c | 5 +-
> lib/librte_mbuf/rte_mbuf.h | 32 +++++++++----
> lib/librte_mempool/rte_mempool.c | 2 +-
> lib/librte_mempool/rte_mempool.h | 6 +--
> lib/librte_port/rte_port_ras.c | 6 +--
> lib/librte_vhost/vhost_rxtx.c | 6 +--
> scripts/cocci.sh | 64 +++++++++++++++++++++++++
> scripts/cocci/mtod-offset.cocci | 76 ++++++++++++++++++++++++++++++
> 34 files changed, 319 insertions(+), 152 deletions(-)
> create mode 100755 scripts/cocci.sh
> create mode 100644 scripts/cocci/mtod-offset.cocci
>
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