forked from luck/tmp_suning_uos_patched
e4d9c23207
A handful of samples and selftests fail to build on s390, because
after commit 0ebeea8ca8 ("bpf: Restrict bpf_probe_read{, str}()
only to archs where they work") bpf_probe_read is not available
anymore.
Fix by using bpf_probe_read_kernel.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200720114806.88823-1-iii@linux.ibm.com
55 lines
1.7 KiB
C
55 lines
1.7 KiB
C
/* Copyright (c) 2013-2015 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/skbuff.h>
|
|
#include <linux/netdevice.h>
|
|
#include <uapi/linux/bpf.h>
|
|
#include <linux/version.h>
|
|
#include <bpf/bpf_helpers.h>
|
|
#include <bpf/bpf_tracing.h>
|
|
|
|
#define _(P) \
|
|
({ \
|
|
typeof(P) val = 0; \
|
|
bpf_probe_read_kernel(&val, sizeof(val), &(P)); \
|
|
val; \
|
|
})
|
|
|
|
/* kprobe is NOT a stable ABI
|
|
* kernel functions can be removed, renamed or completely change semantics.
|
|
* Number of arguments and their positions can change, etc.
|
|
* In such case this bpf+kprobe example will no longer be meaningful
|
|
*/
|
|
SEC("kprobe/__netif_receive_skb_core")
|
|
int bpf_prog1(struct pt_regs *ctx)
|
|
{
|
|
/* attaches to kprobe netif_receive_skb,
|
|
* looks for packets on loobpack device and prints them
|
|
*/
|
|
char devname[IFNAMSIZ];
|
|
struct net_device *dev;
|
|
struct sk_buff *skb;
|
|
int len;
|
|
|
|
/* non-portable! works for the given kernel only */
|
|
skb = (struct sk_buff *) PT_REGS_PARM1(ctx);
|
|
dev = _(skb->dev);
|
|
len = _(skb->len);
|
|
|
|
bpf_probe_read_kernel(devname, sizeof(devname), dev->name);
|
|
|
|
if (devname[0] == 'l' && devname[1] == 'o') {
|
|
char fmt[] = "skb %p len %d\n";
|
|
/* using bpf_trace_printk() for DEBUG ONLY */
|
|
bpf_trace_printk(fmt, sizeof(fmt), skb, len);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
char _license[] SEC("license") = "GPL";
|
|
u32 _version SEC("version") = LINUX_VERSION_CODE;
|