f0c328f8af
For the problem of increasing fragmentation of the bpf loader programs,
instead of using bpf_loader.o, which is used in samples/bpf, this
commit refactors the existing tracepoint tracing programs with libbbpf
bpf loader.
- Adding a tracepoint event and attaching a bpf program to it was done
through bpf_program_attach().
- Instead of using the existing BPF MAP definition, MAP definition
has been refactored with the new BTF-defined MAP format.
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200823085334.9413-4-danieltimlee@gmail.com
74 lines
1.4 KiB
C
74 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/* Copyright (c) 2017 Facebook
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*/
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#include <uapi/linux/bpf.h>
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#include <bpf/bpf_helpers.h>
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struct syscalls_enter_open_args {
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unsigned long long unused;
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long syscall_nr;
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long filename_ptr;
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long flags;
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long mode;
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};
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struct syscalls_exit_open_args {
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unsigned long long unused;
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long syscall_nr;
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long ret;
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};
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struct {
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__uint(type, BPF_MAP_TYPE_ARRAY);
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__type(key, u32);
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__type(value, u32);
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__uint(max_entries, 1);
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} enter_open_map SEC(".maps");
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struct {
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__uint(type, BPF_MAP_TYPE_ARRAY);
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__type(key, u32);
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__type(value, u32);
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__uint(max_entries, 1);
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} exit_open_map SEC(".maps");
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static __always_inline void count(void *map)
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{
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u32 key = 0;
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u32 *value, init_val = 1;
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value = bpf_map_lookup_elem(map, &key);
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if (value)
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*value += 1;
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else
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bpf_map_update_elem(map, &key, &init_val, BPF_NOEXIST);
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}
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SEC("tracepoint/syscalls/sys_enter_open")
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int trace_enter_open(struct syscalls_enter_open_args *ctx)
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{
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count(&enter_open_map);
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return 0;
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}
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SEC("tracepoint/syscalls/sys_enter_openat")
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int trace_enter_open_at(struct syscalls_enter_open_args *ctx)
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{
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count(&enter_open_map);
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return 0;
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}
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SEC("tracepoint/syscalls/sys_exit_open")
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int trace_enter_exit(struct syscalls_exit_open_args *ctx)
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{
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count(&exit_open_map);
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return 0;
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}
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SEC("tracepoint/syscalls/sys_exit_openat")
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int trace_enter_exit_at(struct syscalls_exit_open_args *ctx)
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{
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count(&exit_open_map);
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return 0;
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}
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