cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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tracex1_kern.c (1805B)

      1/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
      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 <uapi/linux/bpf.h>
     10#include <linux/version.h>
     11#include <bpf/bpf_helpers.h>
     12#include <bpf/bpf_tracing.h>
     13
     14#define _(P)                                                                   \
     15	({                                                                     \
     16		typeof(P) val = 0;                                             \
     17		bpf_probe_read_kernel(&val, sizeof(val), &(P));                \
     18		val;                                                           \
     19	})
     20
     21/* kprobe is NOT a stable ABI
     22 * kernel functions can be removed, renamed or completely change semantics.
     23 * Number of arguments and their positions can change, etc.
     24 * In such case this bpf+kprobe example will no longer be meaningful
     25 */
     26SEC("kprobe/__netif_receive_skb_core")
     27int bpf_prog1(struct pt_regs *ctx)
     28{
     29	/* attaches to kprobe __netif_receive_skb_core,
     30	 * looks for packets on loobpack device and prints them
     31	 */
     32	char devname[IFNAMSIZ];
     33	struct net_device *dev;
     34	struct sk_buff *skb;
     35	int len;
     36
     37	/* non-portable! works for the given kernel only */
     38	bpf_probe_read_kernel(&skb, sizeof(skb), (void *)PT_REGS_PARM1(ctx));
     39	dev = _(skb->dev);
     40	len = _(skb->len);
     41
     42	bpf_probe_read_kernel(devname, sizeof(devname), dev->name);
     43
     44	if (devname[0] == 'l' && devname[1] == 'o') {
     45		char fmt[] = "skb %p len %d\n";
     46		/* using bpf_trace_printk() for DEBUG ONLY */
     47		bpf_trace_printk(fmt, sizeof(fmt), skb, len);
     48	}
     49
     50	return 0;
     51}
     52
     53char _license[] SEC("license") = "GPL";
     54u32 _version SEC("version") = LINUX_VERSION_CODE;