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| author | Daniel Borkmann <daniel@iogearbox.net> | 2015-03-05 23:27:51 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2015-03-06 21:50:55 -0500 |
| commit | 3ba67dabaa58e3223325f0a813a6e830fb5f5cc5 (patch) | |
| tree | 96e4798c1ed9bcaf56f8e7db339544facdb8703d /kernel/bpf | |
| parent | 58025e46ea2d39f1840d5b1be5edea3297cfd23f (diff) | |
| download | linux-3ba67dabaa58e3223325f0a813a6e830fb5f5cc5.tar.gz linux-3ba67dabaa58e3223325f0a813a6e830fb5f5cc5.tar.bz2 linux-3ba67dabaa58e3223325f0a813a6e830fb5f5cc5.zip | |
ebpf: bpf_map_*: fix linker error on avr32 and openrisc arch
Fengguang reported, that on openrisc and avr32 architectures, we
get the following linker errors on *_defconfig builds that have
no bpf syscall support:
net/built-in.o:(.rodata+0x1cd0): undefined reference to `bpf_map_lookup_elem_proto'
net/built-in.o:(.rodata+0x1cd4): undefined reference to `bpf_map_update_elem_proto'
net/built-in.o:(.rodata+0x1cd8): undefined reference to `bpf_map_delete_elem_proto'
Fix it up by providing built-in weak definitions of the symbols,
so they can be overridden when the syscall is enabled. I think
the issue might be that gcc is not able to optimize all that away.
This patch fixes the linker errors for me, tested with Fengguang's
make.cross [1] script.
[1] https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Fixes: d4052c4aea0c ("ebpf: remove CONFIG_BPF_SYSCALL ifdefs in socket filter code")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/core.c | 5 |
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index a64e7a207d2b..50603aec766a 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -656,6 +656,11 @@ void bpf_prog_free(struct bpf_prog *fp) } EXPORT_SYMBOL_GPL(bpf_prog_free); +/* Weak definitions of helper functions in case we don't have bpf syscall. */ +const struct bpf_func_proto bpf_map_lookup_elem_proto __weak; +const struct bpf_func_proto bpf_map_update_elem_proto __weak; +const struct bpf_func_proto bpf_map_delete_elem_proto __weak; + /* To execute LD_ABS/LD_IND instructions __bpf_prog_run() may call * skb_copy_bits(), so provide a weak definition of it for NET-less config. */ |