7a7d4237e3
[ Upstream commit f91717007217d975aa975ddabd91ae1a107b9bff ]
The struct bpf_fib_lookup is supposed to be of size 64. A recent commit
59b418c7063d ("bpf: Add a check for struct bpf_fib_lookup size") added
a static assertion to check this property so that future changes to the
structure will not accidentally break this assumption.
As it immediately turned out, on some 32-bit arm systems, when AEABI=n,
the total size of the structure was equal to 68, see [1]. This happened
because the bpf_fib_lookup structure contains a union of two 16-bit
fields:
union {
__u16 tot_len;
__u16 mtu_result;
};
which was supposed to compile to a 16-bit-aligned 16-bit field. On the
aforementioned setups it was instead both aligned and padded to 32-bits.
Declare this inner union as __attribute__((packed, aligned(2))) such
that it always is of size 2 and is aligned to 16 bits.
[1] https://lore.kernel.org/all/CA+G9fYtsoP51f-oP_Sp5MOq-Ffv8La2RztNpwvE6+R1VtFiLrw@mail.gmail.com/#t
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Fixes: e1850ea9bd9e ("bpf: bpf_fib_lookup return MTU value as output when looked up")
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20240403123303.1452184-1-aspsk@isovalent.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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| .. | ||
| tc_act | ||
| bpf_common.h | ||
| bpf_perf_event.h | ||
| bpf.h | ||
| btf.h | ||
| const.h | ||
| erspan.h | ||
| ethtool.h | ||
| fadvise.h | ||
| fcntl.h | ||
| filter.h | ||
| fs.h | ||
| fscrypt.h | ||
| hw_breakpoint.h | ||
| if_link.h | ||
| if_tun.h | ||
| if_xdp.h | ||
| in.h | ||
| kcmp.h | ||
| kvm.h | ||
| mman.h | ||
| mount.h | ||
| netdev.h | ||
| netlink.h | ||
| openat2.h | ||
| perf_event.h | ||
| pkt_cls.h | ||
| pkt_sched.h | ||
| prctl.h | ||
| sched.h | ||
| seccomp.h | ||
| seg6_local.h | ||
| seg6.h | ||
| stat.h | ||
| stddef.h | ||
| tcp.h | ||
| tls.h | ||
| types.h | ||
| usbdevice_fs.h | ||
| vhost.h | ||