c48e51c8b0
This adds selftests that tests the success and failure path for modules kfuncs (in presence of invalid kfunc calls) for both libbpf and gen_loader. It also adds a prog_test kfunc_btf_id_list so that we can add module BTF ID set from bpf_testmod. This also introduces a couple of test cases to verifier selftests for validating whether we get an error or not depending on if invalid kfunc call remains after elimination of unreachable instructions. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211002011757.311265-10-memxor@gmail.com
51 lines
1.3 KiB
C
51 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2021 Facebook */
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#include "vmlinux.h"
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#include <bpf/bpf_helpers.h>
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#define X_0(x)
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#define X_1(x) x X_0(x)
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#define X_2(x) x X_1(x)
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#define X_3(x) x X_2(x)
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#define X_4(x) x X_3(x)
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#define X_5(x) x X_4(x)
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#define X_6(x) x X_5(x)
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#define X_7(x) x X_6(x)
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#define X_8(x) x X_7(x)
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#define X_9(x) x X_8(x)
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#define X_10(x) x X_9(x)
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#define REPEAT_256(Y) X_2(X_10(X_10(Y))) X_5(X_10(Y)) X_6(Y)
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extern const int bpf_testmod_ksym_percpu __ksym;
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extern void bpf_testmod_test_mod_kfunc(int i) __ksym;
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extern void bpf_testmod_invalid_mod_kfunc(void) __ksym __weak;
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int out_bpf_testmod_ksym = 0;
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const volatile int x = 0;
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SEC("tc")
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int load(struct __sk_buff *skb)
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{
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/* This will be kept by clang, but removed by verifier. Since it is
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* marked as __weak, libbpf and gen_loader don't error out if BTF ID
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* is not found for it, instead imm and off is set to 0 for it.
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*/
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if (x)
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bpf_testmod_invalid_mod_kfunc();
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bpf_testmod_test_mod_kfunc(42);
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out_bpf_testmod_ksym = *(int *)bpf_this_cpu_ptr(&bpf_testmod_ksym_percpu);
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return 0;
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}
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SEC("tc")
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int load_256(struct __sk_buff *skb)
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{
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/* this will fail if kfunc doesn't reuse its own btf fd index */
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REPEAT_256(bpf_testmod_test_mod_kfunc(42););
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bpf_testmod_test_mod_kfunc(42);
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return 0;
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}
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char LICENSE[] SEC("license") = "GPL";
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