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linux-next/samples/bpf/spintest_kern.c
Daniel T. Lee 3677d0a131 samples: bpf: Refactor kprobe tracing programs with libbpf
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 kprobe tracing programs with libbbpf
bpf loader.

    - For kprobe events pointing to system calls, the SYSCALL() macro in
    trace_common.h was used.
    - Adding a kprobe 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/20200823085334.9413-3-danieltimlee@gmail.com
2020-08-24 20:59:35 -07:00

70 lines
2.1 KiB
C

/* Copyright (c) 2016, Facebook
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of version 2 of the GNU General Public
* License as published by the Free Software Foundation.
*/
#include <linux/skbuff.h>
#include <linux/netdevice.h>
#include <linux/version.h>
#include <uapi/linux/bpf.h>
#include <uapi/linux/perf_event.h>
#include <bpf/bpf_helpers.h>
#include <bpf/bpf_tracing.h>
struct {
__uint(type, BPF_MAP_TYPE_HASH);
__type(key, long);
__type(value, long);
__uint(max_entries, 1024);
} my_map SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
__uint(key_size, sizeof(long));
__uint(value_size, sizeof(long));
__uint(max_entries, 1024);
} my_map2 SEC(".maps");
struct {
__uint(type, BPF_MAP_TYPE_STACK_TRACE);
__uint(key_size, sizeof(u32));
__uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
__uint(max_entries, 10000);
} stackmap SEC(".maps");
#define PROG(foo) \
int foo(struct pt_regs *ctx) \
{ \
long v = PT_REGS_IP(ctx), *val; \
\
val = bpf_map_lookup_elem(&my_map, &v); \
bpf_map_update_elem(&my_map, &v, &v, BPF_ANY); \
bpf_map_update_elem(&my_map2, &v, &v, BPF_ANY); \
bpf_map_delete_elem(&my_map2, &v); \
bpf_get_stackid(ctx, &stackmap, BPF_F_REUSE_STACKID); \
return 0; \
}
/* add kprobes to all possible *spin* functions */
SEC("kprobe/spin_unlock")PROG(p1)
SEC("kprobe/spin_lock")PROG(p2)
SEC("kprobe/mutex_spin_on_owner")PROG(p3)
SEC("kprobe/rwsem_spin_on_owner")PROG(p4)
SEC("kprobe/spin_unlock_irqrestore")PROG(p5)
SEC("kprobe/_raw_spin_unlock_irqrestore")PROG(p6)
SEC("kprobe/_raw_spin_unlock_bh")PROG(p7)
SEC("kprobe/_raw_spin_unlock")PROG(p8)
SEC("kprobe/_raw_spin_lock_irqsave")PROG(p9)
SEC("kprobe/_raw_spin_trylock_bh")PROG(p10)
SEC("kprobe/_raw_spin_lock_irq")PROG(p11)
SEC("kprobe/_raw_spin_trylock")PROG(p12)
SEC("kprobe/_raw_spin_lock")PROG(p13)
SEC("kprobe/_raw_spin_lock_bh")PROG(p14)
/* and to inner bpf helpers */
SEC("kprobe/htab_map_update_elem")PROG(p15)
SEC("kprobe/__htab_percpu_map_update_elem")PROG(p16)
SEC("kprobe/htab_map_alloc")PROG(p17)
char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;