diff options
Diffstat (limited to 'samples/bpf/tracex4.bpf.c')
-rw-r--r-- | samples/bpf/tracex4.bpf.c | 54 |
1 files changed, 54 insertions, 0 deletions
diff --git a/samples/bpf/tracex4.bpf.c b/samples/bpf/tracex4.bpf.c new file mode 100644 index 000000000000..ca826750901a --- /dev/null +++ b/samples/bpf/tracex4.bpf.c @@ -0,0 +1,54 @@ +/* Copyright (c) 2015 PLUMgrid, http://plumgrid.com + * + * 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 "vmlinux.h" +#include <linux/version.h> +#include <bpf/bpf_helpers.h> +#include <bpf/bpf_tracing.h> + +struct pair { + u64 val; + u64 ip; +}; + +struct { + __uint(type, BPF_MAP_TYPE_HASH); + __type(key, long); + __type(value, struct pair); + __uint(max_entries, 1000000); +} my_map SEC(".maps"); + +/* kprobe is NOT a stable ABI. If kernel internals change this bpf+kprobe + * example will no longer be meaningful + */ +SEC("kprobe/kmem_cache_free") +int bpf_prog1(struct pt_regs *ctx) +{ + long ptr = PT_REGS_PARM2(ctx); + + bpf_map_delete_elem(&my_map, &ptr); + return 0; +} + +SEC("kretprobe/kmem_cache_alloc_node") +int bpf_prog2(struct pt_regs *ctx) +{ + long ptr = PT_REGS_RC(ctx); + long ip = 0; + + /* get ip address of kmem_cache_alloc_node() caller */ + BPF_KRETPROBE_READ_RET_IP(ip, ctx); + + struct pair v = { + .val = bpf_ktime_get_ns(), + .ip = ip, + }; + + bpf_map_update_elem(&my_map, &ptr, &v, BPF_ANY); + return 0; +} +char _license[] SEC("license") = "GPL"; +u32 _version SEC("version") = LINUX_VERSION_CODE; |