samples/bpf/spintest_kern.c

   1 /* Copyright (c) 2016, Facebook
   2  *
   3  * This program is free software; you can redistribute it and/or
   4  * modify it under the terms of version 2 of the GNU General Public
   5  * License as published by the Free Software Foundation.
   6  */
   7 #include <linux/skbuff.h>
   8 #include <linux/netdevice.h>
   9 #include <linux/version.h>
  10 #include <uapi/linux/bpf.h>
  11 #include <uapi/linux/perf_event.h>
  12 #include <bpf/bpf_helpers.h>
  13 #include <bpf/bpf_tracing.h>
  14
  15 struct {
  16         __uint(type, BPF_MAP_TYPE_HASH);
  17         __type(key, long);
  18         __type(value, long);
  19         __uint(max_entries, 1024);
  20 } my_map SEC(".maps");
  21 struct {
  22         __uint(type, BPF_MAP_TYPE_PERCPU_HASH);
  23         __uint(key_size, sizeof(long));
  24         __uint(value_size, sizeof(long));
  25         __uint(max_entries, 1024);
  26 } my_map2 SEC(".maps");
  27
  28 struct {
  29         __uint(type, BPF_MAP_TYPE_STACK_TRACE);
  30         __uint(key_size, sizeof(u32));
  31         __uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
  32         __uint(max_entries, 10000);
  33 } stackmap SEC(".maps");
  34
  35 #define PROG(foo) \
  36 int foo(struct pt_regs *ctx) \
  37 { \
  38         long v = PT_REGS_IP(ctx), *val; \
  39 \
  40         val = bpf_map_lookup_elem(&my_map, &v); \
  41         bpf_map_update_elem(&my_map, &v, &v, BPF_ANY); \
  42         bpf_map_update_elem(&my_map2, &v, &v, BPF_ANY); \
  43         bpf_map_delete_elem(&my_map2, &v); \
  44         bpf_get_stackid(ctx, &stackmap, BPF_F_REUSE_STACKID); \
  45         return 0; \
  46 }
  47
  48 /* add kprobes to all possible *spin* functions */
  49 SEC("kprobe/spin_unlock")PROG(p1)
  50 SEC("kprobe/spin_lock")PROG(p2)
  51 SEC("kprobe/mutex_spin_on_owner")PROG(p3)
  52 SEC("kprobe/rwsem_spin_on_owner")PROG(p4)
  53 SEC("kprobe/spin_unlock_irqrestore")PROG(p5)
  54 SEC("kprobe/_raw_spin_unlock_irqrestore")PROG(p6)
  55 SEC("kprobe/_raw_spin_unlock_bh")PROG(p7)
  56 SEC("kprobe/_raw_spin_unlock")PROG(p8)
  57 SEC("kprobe/_raw_spin_lock_irqsave")PROG(p9)
  58 SEC("kprobe/_raw_spin_trylock_bh")PROG(p10)
  59 SEC("kprobe/_raw_spin_lock_irq")PROG(p11)
  60 SEC("kprobe/_raw_spin_trylock")PROG(p12)
  61 SEC("kprobe/_raw_spin_lock")PROG(p13)
  62 SEC("kprobe/_raw_spin_lock_bh")PROG(p14)
  63 /* and to inner bpf helpers */
  64 SEC("kprobe/htab_map_update_elem")PROG(p15)
  65 SEC("kprobe/__htab_percpu_map_update_elem")PROG(p16)
  66 SEC("kprobe/htab_map_alloc")PROG(p17)
  67
  68 char _license[] SEC("license") = "GPL";
  69 u32 _version SEC("version") = LINUX_VERSION_CODE;