256eab48e7
In preparation of skipping emitting static variables in BPF skeletons, switch all current selftests uses of static variables to pass data between BPF and user-space to use global variables. All non-read-only `static volatile` variables become just plain global variables by dropping `static volatile` part. Read-only `static volatile const` variables, though, still require `volatile` modifier, otherwise compiler will ignore whatever values are set from user-space. Few static linker tests are using name-conflicting static variables to validate that static linker still properly handles static variables and doesn't trip up on name conflicts. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210507054119.270888-4-andrii@kernel.org
92 lines
1.2 KiB
C
92 lines
1.2 KiB
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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struct S {
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int v;
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};
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struct S global_variable = {};
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struct {
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__uint(type, BPF_MAP_TYPE_ARRAY);
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__uint(max_entries, 7);
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__type(key, __u32);
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__type(value, int);
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} values SEC(".maps");
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static void save_value(__u32 index, int value)
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{
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bpf_map_update_elem(&values, &index, &value, 0);
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}
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__noinline int foo(__u32 index, struct S *s)
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{
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if (s) {
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save_value(index, s->v);
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return ++s->v;
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}
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save_value(index, 0);
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return 1;
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}
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__noinline int bar(__u32 index, volatile struct S *s)
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{
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if (s) {
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save_value(index, s->v);
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return ++s->v;
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}
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save_value(index, 0);
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return 1;
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}
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__noinline int baz(struct S **s)
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{
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if (s)
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*s = 0;
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return 0;
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}
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SEC("cgroup_skb/ingress")
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int test_cls(struct __sk_buff *skb)
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{
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__u32 index = 0;
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{
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const int v = foo(index++, 0);
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save_value(index++, v);
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}
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{
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struct S s = { .v = 100 };
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foo(index++, &s);
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save_value(index++, s.v);
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}
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{
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global_variable.v = 42;
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bar(index++, &global_variable);
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save_value(index++, global_variable.v);
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}
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{
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struct S v, *p = &v;
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baz(&p);
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save_value(index++, !p);
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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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