79d49ba048
Add several BPF kselftest cases for tail calls which test the various patch directions, and that multiple locations are patched in same and different programs. # ./test_progs -n 45 #45/1 tailcall_1:OK #45/2 tailcall_2:OK #45/3 tailcall_3:OK #45/4 tailcall_4:OK #45/5 tailcall_5:OK #45 tailcalls:OK Summary: 1/5 PASSED, 0 SKIPPED, 0 FAILED I've also verified the JITed dump after each of the rewrite cases that it matches expectations. Also regular test_verifier suite passes fine which contains further tail call tests: # ./test_verifier [...] Summary: 1563 PASSED, 0 SKIPPED, 0 FAILED Checked under JIT, interpreter and JIT + hardening. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/3d6cbecbeb171117dccfe153306e479798fb608d.1574452833.git.daniel@iogearbox.net
41 lines
720 B
C
41 lines
720 B
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/bpf.h>
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#include "bpf_helpers.h"
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struct {
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__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
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__uint(max_entries, 3);
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__uint(key_size, sizeof(__u32));
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__uint(value_size, sizeof(__u32));
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} jmp_table SEC(".maps");
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static volatile int selector;
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#define TAIL_FUNC(x) \
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SEC("classifier/" #x) \
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int bpf_func_##x(struct __sk_buff *skb) \
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{ \
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return x; \
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}
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TAIL_FUNC(0)
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TAIL_FUNC(1)
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TAIL_FUNC(2)
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SEC("classifier")
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int entry(struct __sk_buff *skb)
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{
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int idx = 0;
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if (selector == 1234)
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idx = 1;
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else if (selector == 5678)
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idx = 2;
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bpf_tail_call(skb, &jmp_table, idx);
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return 3;
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}
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char __license[] SEC("license") = "GPL";
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int _version SEC("version") = 1;
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