samples/bpf/spintest_kern.c

0001 /* Copyright (c) 2016, Facebook
0002  *
0003  * This program is free software; you can redistribute it and/or
0004  * modify it under the terms of version 2 of the GNU General Public
0005  * License as published by the Free Software Foundation.
0006  */
0007 #include <linux/skbuff.h>
0008 #include <linux/netdevice.h>
0009 #include <linux/version.h>
0010 #include <uapi/linux/bpf.h>
0011 #include <uapi/linux/perf_event.h>
0012 #include <bpf/bpf_helpers.h>
0013 #include <bpf/bpf_tracing.h>
0014
0015 struct {
0016     __uint(type, BPF_MAP_TYPE_HASH);
0017     __type(key, long);
0018     __type(value, long);
0019     __uint(max_entries, 1024);
0020 } my_map SEC(".maps");
0021 struct {
0022     __uint(type, BPF_MAP_TYPE_PERCPU_HASH);
0023     __uint(key_size, sizeof(long));
0024     __uint(value_size, sizeof(long));
0025     __uint(max_entries, 1024);
0026 } my_map2 SEC(".maps");
0027
0028 struct {
0029     __uint(type, BPF_MAP_TYPE_STACK_TRACE);
0030     __uint(key_size, sizeof(u32));
0031     __uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
0032     __uint(max_entries, 10000);
0033 } stackmap SEC(".maps");
0034
0035 #define PROG(foo) \
0036 int foo(struct pt_regs *ctx) \
0037 { \
0038     long v = PT_REGS_IP(ctx), *val; \
0039 \
0040     val = bpf_map_lookup_elem(&my_map, &v); \
0041     bpf_map_update_elem(&my_map, &v, &v, BPF_ANY); \
0042     bpf_map_update_elem(&my_map2, &v, &v, BPF_ANY); \
0043     bpf_map_delete_elem(&my_map2, &v); \
0044     bpf_get_stackid(ctx, &stackmap, BPF_F_REUSE_STACKID); \
0045     return 0; \
0046 }
0047
0048 /* add kprobes to all possible *spin* functions */
0049 SEC("kprobe/spin_unlock")PROG(p1)
0050 SEC("kprobe/spin_lock")PROG(p2)
0051 SEC("kprobe/mutex_spin_on_owner")PROG(p3)
0052 SEC("kprobe/rwsem_spin_on_owner")PROG(p4)
0053 SEC("kprobe/spin_unlock_irqrestore")PROG(p5)
0054 SEC("kprobe/_raw_spin_unlock_irqrestore")PROG(p6)
0055 SEC("kprobe/_raw_spin_unlock_bh")PROG(p7)
0056 SEC("kprobe/_raw_spin_unlock")PROG(p8)
0057 SEC("kprobe/_raw_spin_lock_irqsave")PROG(p9)
0058 SEC("kprobe/_raw_spin_trylock_bh")PROG(p10)
0059 SEC("kprobe/_raw_spin_lock_irq")PROG(p11)
0060 SEC("kprobe/_raw_spin_trylock")PROG(p12)
0061 SEC("kprobe/_raw_spin_lock")PROG(p13)
0062 SEC("kprobe/_raw_spin_lock_bh")PROG(p14)
0063 /* and to inner bpf helpers */
0064 SEC("kprobe/htab_map_update_elem")PROG(p15)
0065 SEC("kprobe/__htab_percpu_map_update_elem")PROG(p16)
0066 SEC("kprobe/htab_map_alloc")PROG(p17)
0067
0068 char _license[] SEC("license") = "GPL";
0069 u32 _version SEC("version") = LINUX_VERSION_CODE;