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  1. 17 10月, 2018 3 次提交
    • J
      nfp: bpf: double check vNIC capabilities after object sharing · 44b6fed0
      由 Jakub Kicinski 提交于 
      Program translation stage checks that program can be offloaded to
the netdev which was passed during the load (bpf_attr->prog_ifindex).
After program sharing was introduced, however, the netdev on which
program is loaded can theoretically be different, and therefore
we should recheck the program size and max stack size at load time.

This was found by code inspection, AFAIK today all vNICs have
identical caps.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      44b6fed0
    • J
      nfp: bpf: protect against mis-initializing atomic counters · 527db74b
      由 Jakub Kicinski 提交于 
      Atomic operations on the NFP are currently always in big endian.
The driver keeps track of regions of memory storing atomic values
and byte swaps them accordingly.  There are corner cases where
the map values may be initialized before the driver knows they
are used as atomic counters.  This can happen either when the
datapath is performing the update and the stack contents are
unknown or when map is updated before the program which will
use it for atomic values is loaded.

To avoid situation where user initializes the value to 0 1 2 3
and then after loading a program which uses the word as an atomic
counter starts reading 3 2 1 0 - only allow atomic counters to be
initialized to endian-neutral values.

For updates from the datapath the stack information may not be
as precise, so just allow initializing such values to 0.

Example code which would break:
struct bpf_map_def SEC("maps") rxcnt = {
       .type = BPF_MAP_TYPE_HASH,
       .key_size = sizeof(__u32),
       .value_size = sizeof(__u64),
       .max_entries = 1,
};

int xdp_prog1()
{
      	__u64 nonzeroval = 3;
	__u32 key = 0;
	__u64 *value;

	value = bpf_map_lookup_elem(&rxcnt, &key);
	if (!value)
		bpf_map_update_elem(&rxcnt, &key, &nonzeroval, BPF_ANY);
	else
		__sync_fetch_and_add(value, 1);

	return XDP_PASS;
}

$ offload bpftool map dump
key: 00 00 00 00 value: 00 00 00 03 00 00 00 00

should be:

$ offload bpftool map dump
key: 00 00 00 00 value: 03 00 00 00 00 00 00 00
Reported-by: NDavid Beckett <david.beckett@netronome.com>
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      527db74b
    • A
      libbpf: Per-symbol visibility for DSO · ab9e0848
      由 Andrey Ignatov 提交于 
      Make global symbols in libbpf DSO hidden by default with
-fvisibility=hidden and export symbols that are part of ABI explicitly
with __attribute__((visibility("default"))).

This is common practice that should prevent from accidentally exporting
a symbol, that is not supposed to be a part of ABI what, in turn,
improves both libbpf developer- and user-experiences. See [1] for more
details.

Export control becomes more important since more and more projects use
libbpf.

The patch doesn't export a bunch of netlink related functions since as
agreed in [2] they'll be reworked. That doesn't break bpftool since
bpftool links libbpf statically.

[1] https://www.akkadia.org/drepper/dsohowto.pdf (2.2 Export Control)
[2] https://www.mail-archive.com/netdev@vger.kernel.org/msg251434.htmlSigned-off-by: NAndrey Ignatov <rdna@fb.com>
Signed-off-by: NAlexei Starovoitov <ast@kernel.org>
      ab9e0848
  3. 16 10月, 2018 37 次提交