linux/samples/bpf/tracex5_user.c
Daniel T. Lee 24a6034acc samples, bpf: Move read_trace_pipe to trace_helpers
To reduce the reliance of trace samples (trace*_user) on bpf_load,
move read_trace_pipe to trace_helpers. By moving this bpf_loader helper
elsewhere, trace functions can be easily migrated to libbbpf.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200321100424.1593964-2-danieltimlee@gmail.com
2020-03-23 22:27:51 +01:00

52 lines
1.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <stdio.h>
#include <linux/bpf.h>
#include <unistd.h>
#include <linux/filter.h>
#include <linux/seccomp.h>
#include <sys/prctl.h>
#include <bpf/bpf.h>
#include "bpf_load.h"
#include <sys/resource.h>
#include "trace_helpers.h"
/* install fake seccomp program to enable seccomp code path inside the kernel,
* so that our kprobe attached to seccomp_phase1() can be triggered
*/
static void install_accept_all_seccomp(void)
{
struct sock_filter filter[] = {
BPF_STMT(BPF_RET+BPF_K, SECCOMP_RET_ALLOW),
};
struct sock_fprog prog = {
.len = (unsigned short)(sizeof(filter)/sizeof(filter[0])),
.filter = filter,
};
if (prctl(PR_SET_SECCOMP, 2, &prog))
perror("prctl");
}
int main(int ac, char **argv)
{
FILE *f;
char filename[256];
struct rlimit r = {RLIM_INFINITY, RLIM_INFINITY};
snprintf(filename, sizeof(filename), "%s_kern.o", argv[0]);
setrlimit(RLIMIT_MEMLOCK, &r);
if (load_bpf_file(filename)) {
printf("%s", bpf_log_buf);
return 1;
}
install_accept_all_seccomp();
f = popen("dd if=/dev/zero of=/dev/null count=5", "r");
(void) f;
read_trace_pipe();
return 0;
}