Add selftest that establishes dead code-eliminated valid global subprog (global_dead) and makes sure that it's not possible to freplace it, as it's effectively not there. This test will fail with unexpected success before 2afae08c9dcb ("bpf: Validate global subprogs lazily"). v2->v3: - add missing err assignment (Alan); - undo unnecessary signature changes in verifier_global_subprogs.c (Eduard); v1->v2: - don't rely on assembly output in verifier log, which changes between compiler versions (CI). Acked-by: Eduard Zingerman <eddyz87@gmail.com> Reviewed-by: Alan Maguire <alan.maguire@oracle.com> Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/r/20231211174131.2324306-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov <ast@kernel.org>
12 lines
185 B
C
12 lines
185 B
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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SEC("freplace")
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int freplace_prog(void)
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{
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return 0;
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}
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char _license[] SEC("license") = "GPL";
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