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/* 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 <linux/ptrace.h>
#include <linux/version.h>
#include <uapi/linux/bpf.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;
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