cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

core_kern.c (3043B)

      1// SPDX-License-Identifier: GPL-2.0
      2/* Copyright (c) 2021 Facebook */
      3#include "vmlinux.h"
      4
      5#include <bpf/bpf_helpers.h>
      6#include <bpf/bpf_tracing.h>
      7#include <bpf/bpf_core_read.h>
      8
      9#define ATTR __always_inline
     10#include "test_jhash.h"
     11
     12struct {
     13	__uint(type, BPF_MAP_TYPE_ARRAY);
     14	__type(key, u32);
     15	__type(value, u32);
     16	__uint(max_entries, 256);
     17} array1 SEC(".maps");
     18
     19struct {
     20	__uint(type, BPF_MAP_TYPE_ARRAY);
     21	__type(key, u32);
     22	__type(value, u32);
     23	__uint(max_entries, 256);
     24} array2 SEC(".maps");
     25
     26static __noinline int randmap(int v, const struct net_device *dev)
     27{
     28	struct bpf_map *map = (struct bpf_map *)&array1;
     29	int key = bpf_get_prandom_u32() & 0xff;
     30	int *val;
     31
     32	if (bpf_get_prandom_u32() & 1)
     33		map = (struct bpf_map *)&array2;
     34
     35	val = bpf_map_lookup_elem(map, &key);
     36	if (val)
     37		*val = bpf_get_prandom_u32() + v + dev->mtu;
     38
     39	return 0;
     40}
     41
     42SEC("tp_btf/xdp_devmap_xmit")
     43int BPF_PROG(tp_xdp_devmap_xmit_multi, const struct net_device
     44	     *from_dev, const struct net_device *to_dev, int sent, int drops,
     45	     int err)
     46{
     47	return randmap(from_dev->ifindex, from_dev);
     48}
     49
     50SEC("fentry/eth_type_trans")
     51int BPF_PROG(fentry_eth_type_trans, struct sk_buff *skb,
     52	     struct net_device *dev, unsigned short protocol)
     53{
     54	return randmap(dev->ifindex + skb->len, dev);
     55}
     56
     57SEC("fexit/eth_type_trans")
     58int BPF_PROG(fexit_eth_type_trans, struct sk_buff *skb,
     59	     struct net_device *dev, unsigned short protocol)
     60{
     61	return randmap(dev->ifindex + skb->len, dev);
     62}
     63
     64volatile const int never;
     65
     66struct __sk_bUfF /* it will not exist in vmlinux */ {
     67	int len;
     68} __attribute__((preserve_access_index));
     69
     70struct bpf_testmod_test_read_ctx /* it exists in bpf_testmod */ {
     71	size_t len;
     72} __attribute__((preserve_access_index));
     73
     74SEC("tc")
     75int balancer_ingress(struct __sk_buff *ctx)
     76{
     77	void *data_end = (void *)(long)ctx->data_end;
     78	void *data = (void *)(long)ctx->data;
     79	void *ptr;
     80	int ret = 0, nh_off, i = 0;
     81
     82	nh_off = 14;
     83
     84	/* pragma unroll doesn't work on large loops */
     85#define C do { \
     86	ptr = data + i; \
     87	if (ptr + nh_off > data_end) \
     88		break; \
     89	ctx->tc_index = jhash(ptr, nh_off, ctx->cb[0] + i++); \
     90	if (never) { \
     91		/* below is a dead code with unresolvable CO-RE relo */ \
     92		i += ((struct __sk_bUfF *)ctx)->len; \
     93		/* this CO-RE relo may or may not resolve
     94		 * depending on whether bpf_testmod is loaded.
     95		 */ \
     96		i += ((struct bpf_testmod_test_read_ctx *)ctx)->len; \
     97	} \
     98	} while (0);
     99#define C30 C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;C;
    100	C30;C30;C30; /* 90 calls */
    101	return 0;
    102}
    103
    104typedef int (*func_proto_typedef___match)(long);
    105typedef int (*func_proto_typedef___doesnt_match)(char *);
    106typedef int (*func_proto_typedef_nested1)(func_proto_typedef___match);
    107
    108int proto_out[3];
    109
    110SEC("raw_tracepoint/sys_enter")
    111int core_relo_proto(void *ctx)
    112{
    113	proto_out[0] = bpf_core_type_exists(func_proto_typedef___match);
    114	proto_out[1] = bpf_core_type_exists(func_proto_typedef___doesnt_match);
    115	proto_out[2] = bpf_core_type_exists(func_proto_typedef_nested1);
    116
    117	return 0;
    118}
    119
    120char LICENSE[] SEC("license") = "GPL";