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b191b0fd74
This patch adds a gen_epilogue test to test a main prog
using a bpf_tail_call.
A non test_loader test is used. The tailcall target program,
"test_epilogue_subprog", needs to be used in a struct_ops map
before it can be loaded. Another struct_ops map is also needed
to host the actual "test_epilogue_tailcall" struct_ops program
that does the bpf_tail_call. The earlier test_loader patch
will attach all struct_ops maps but the bpf_testmod.c does
not support >1 attached struct_ops.
The earlier patch used the test_loader which has already covered
checking for the patched pro/epilogue instructions. This is done
by the __xlated tag.
This patch goes for the regular skel load and syscall test to do
the tailcall test that can also allow to directly pass the
the "struct st_ops_args *args" as ctx_in to the
SEC("syscall") program.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240829210833.388152-8-martin.lau@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
59 lines
1.3 KiB
C
59 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */
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#include <vmlinux.h>
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#include <bpf/bpf_tracing.h>
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#include "bpf_misc.h"
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#include "../bpf_testmod/bpf_testmod.h"
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#include "../bpf_testmod/bpf_testmod_kfunc.h"
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char _license[] SEC("license") = "GPL";
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static __noinline __used int subprog(struct st_ops_args *args)
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{
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args->a += 1;
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return args->a;
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}
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SEC("struct_ops/test_epilogue_subprog")
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int BPF_PROG(test_epilogue_subprog, struct st_ops_args *args)
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{
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subprog(args);
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return args->a;
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}
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struct {
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__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
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__uint(max_entries, 1);
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__uint(key_size, sizeof(__u32));
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__uint(value_size, sizeof(__u32));
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__array(values, void (void));
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} epilogue_map SEC(".maps") = {
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.values = {
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[0] = (void *)&test_epilogue_subprog,
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}
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};
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SEC("struct_ops/test_epilogue_tailcall")
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int test_epilogue_tailcall(unsigned long long *ctx)
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{
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bpf_tail_call(ctx, &epilogue_map, 0);
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return 0;
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}
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SEC(".struct_ops.link")
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struct bpf_testmod_st_ops epilogue_tailcall = {
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.test_epilogue = (void *)test_epilogue_tailcall,
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};
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SEC(".struct_ops.link")
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struct bpf_testmod_st_ops epilogue_subprog = {
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.test_epilogue = (void *)test_epilogue_subprog,
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};
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SEC("syscall")
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int syscall_epilogue_tailcall(struct st_ops_args *args)
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{
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return bpf_kfunc_st_ops_test_epilogue(args);
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}
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