mirror of
https://github.com/torvalds/linux.git
synced 2024-12-21 18:42:44 +00:00
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
94 lines
2.2 KiB
C
94 lines
2.2 KiB
C
/* 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 <uapi/linux/seccomp.h>
|
|
#include <uapi/linux/unistd.h>
|
|
#include "syscall_nrs.h"
|
|
#include <bpf/bpf_helpers.h>
|
|
#include <bpf/bpf_tracing.h>
|
|
|
|
#define PROG(F) SEC("kprobe/"__stringify(F)) int bpf_func_##F
|
|
|
|
struct {
|
|
__uint(type, BPF_MAP_TYPE_PROG_ARRAY);
|
|
__uint(key_size, sizeof(u32));
|
|
__uint(value_size, sizeof(u32));
|
|
#ifdef __mips__
|
|
__uint(max_entries, 6000); /* MIPS n64 syscalls start at 5000 */
|
|
#else
|
|
__uint(max_entries, 1024);
|
|
#endif
|
|
} progs SEC(".maps");
|
|
|
|
SEC("kprobe/__seccomp_filter")
|
|
int bpf_prog1(struct pt_regs *ctx)
|
|
{
|
|
int sc_nr = (int)PT_REGS_PARM1(ctx);
|
|
|
|
/* dispatch into next BPF program depending on syscall number */
|
|
bpf_tail_call(ctx, &progs, sc_nr);
|
|
|
|
/* fall through -> unknown syscall */
|
|
if (sc_nr >= __NR_getuid && sc_nr <= __NR_getsid) {
|
|
char fmt[] = "syscall=%d (one of get/set uid/pid/gid)\n";
|
|
bpf_trace_printk(fmt, sizeof(fmt), sc_nr);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
/* we jump here when syscall number == __NR_write */
|
|
PROG(SYS__NR_write)(struct pt_regs *ctx)
|
|
{
|
|
struct seccomp_data sd;
|
|
|
|
bpf_probe_read_kernel(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
|
|
if (sd.args[2] == 512) {
|
|
char fmt[] = "write(fd=%d, buf=%p, size=%d)\n";
|
|
bpf_trace_printk(fmt, sizeof(fmt),
|
|
sd.args[0], sd.args[1], sd.args[2]);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
PROG(SYS__NR_read)(struct pt_regs *ctx)
|
|
{
|
|
struct seccomp_data sd;
|
|
|
|
bpf_probe_read_kernel(&sd, sizeof(sd), (void *)PT_REGS_PARM2(ctx));
|
|
if (sd.args[2] > 128 && sd.args[2] <= 1024) {
|
|
char fmt[] = "read(fd=%d, buf=%p, size=%d)\n";
|
|
bpf_trace_printk(fmt, sizeof(fmt),
|
|
sd.args[0], sd.args[1], sd.args[2]);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
#ifdef __NR_mmap2
|
|
PROG(SYS__NR_mmap2)(struct pt_regs *ctx)
|
|
{
|
|
char fmt[] = "mmap2\n";
|
|
|
|
bpf_trace_printk(fmt, sizeof(fmt));
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
#ifdef __NR_mmap
|
|
PROG(SYS__NR_mmap)(struct pt_regs *ctx)
|
|
{
|
|
char fmt[] = "mmap\n";
|
|
|
|
bpf_trace_printk(fmt, sizeof(fmt));
|
|
return 0;
|
|
}
|
|
#endif
|
|
|
|
char _license[] SEC("license") = "GPL";
|
|
u32 _version SEC("version") = LINUX_VERSION_CODE;
|