9eca508375
The bpf_map_lookup_elem is added in the bpf program. Without previous patch, the test change will trigger the following error: $ ./test_maps ... ; value_p = bpf_map_lookup_elem(map, &key); 20: (bf) r1 = r7 21: (bf) r2 = r8 22: (85) call bpf_map_lookup_elem#1 ; if (!value_p || *value_p != 123) 23: (15) if r0 == 0x0 goto pc+16 R0=map_value(id=2,off=0,ks=4,vs=4,imm=0) R6=inv1 R7=map_ptr(id=0,off=0,ks=4,vs=4,imm=0) R8=fp-8,call_-1 R10=fp0,call_-1 fp-8=mmmmmmmm ; if (!value_p || *value_p != 123) 24: (61) r1 = *(u32 *)(r0 +0) R0=map_value(id=2,off=0,ks=4,vs=4,imm=0) R6=inv1 R7=map_ptr(id=0,off=0,ks=4,vs=4,imm=0) R8=fp-8,call_-1 R10=fp0,call_-1 fp-8=mmmmmmmm bpf_spin_lock cannot be accessed directly by load/store With the kernel fix in the previous commit, the error goes away. Signed-off-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
54 lines
1.1 KiB
C
54 lines
1.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright (c) 2018 Facebook */
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#include <stddef.h>
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#include <linux/bpf.h>
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#include <linux/types.h>
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#include "bpf_helpers.h"
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struct bpf_map_def SEC("maps") mim_array = {
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.type = BPF_MAP_TYPE_ARRAY_OF_MAPS,
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.key_size = sizeof(int),
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/* must be sizeof(__u32) for map in map */
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.value_size = sizeof(__u32),
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.max_entries = 1,
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.map_flags = 0,
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};
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struct bpf_map_def SEC("maps") mim_hash = {
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.type = BPF_MAP_TYPE_HASH_OF_MAPS,
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.key_size = sizeof(int),
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/* must be sizeof(__u32) for map in map */
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.value_size = sizeof(__u32),
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.max_entries = 1,
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.map_flags = 0,
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};
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SEC("xdp_mimtest")
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int xdp_mimtest0(struct xdp_md *ctx)
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{
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int value = 123;
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int *value_p;
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int key = 0;
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void *map;
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map = bpf_map_lookup_elem(&mim_array, &key);
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if (!map)
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return XDP_DROP;
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bpf_map_update_elem(map, &key, &value, 0);
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value_p = bpf_map_lookup_elem(map, &key);
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if (!value_p || *value_p != 123)
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return XDP_DROP;
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map = bpf_map_lookup_elem(&mim_hash, &key);
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if (!map)
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return XDP_DROP;
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bpf_map_update_elem(map, &key, &value, 0);
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return XDP_PASS;
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}
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int _version SEC("version") = 1;
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char _license[] SEC("license") = "GPL";
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