bpf/progs/bpf_syscall_macro.c

0001 // SPDX-License-Identifier: GPL-2.0
0002 /* Copyright 2022 Sony Group Corporation */
0003 #include <vmlinux.h>
0004
0005 #include <bpf/bpf_core_read.h>
0006 #include <bpf/bpf_helpers.h>
0007 #include <bpf/bpf_tracing.h>
0008 #include "bpf_misc.h"
0009
0010 int arg1 = 0;
0011 unsigned long arg2 = 0;
0012 unsigned long arg3 = 0;
0013 unsigned long arg4_cx = 0;
0014 unsigned long arg4 = 0;
0015 unsigned long arg5 = 0;
0016
0017 int arg1_core = 0;
0018 unsigned long arg2_core = 0;
0019 unsigned long arg3_core = 0;
0020 unsigned long arg4_core_cx = 0;
0021 unsigned long arg4_core = 0;
0022 unsigned long arg5_core = 0;
0023
0024 int option_syscall = 0;
0025 unsigned long arg2_syscall = 0;
0026 unsigned long arg3_syscall = 0;
0027 unsigned long arg4_syscall = 0;
0028 unsigned long arg5_syscall = 0;
0029
0030 const volatile pid_t filter_pid = 0;
0031
0032 SEC("kprobe/" SYS_PREFIX "sys_prctl")
0033 int BPF_KPROBE(handle_sys_prctl)
0034 {
0035     struct pt_regs *real_regs;
0036     pid_t pid = bpf_get_current_pid_tgid() >> 32;
0037     unsigned long tmp = 0;
0038
0039     if (pid != filter_pid)
0040         return 0;
0041
0042     real_regs = PT_REGS_SYSCALL_REGS(ctx);
0043
0044     /* test for PT_REGS_PARM */
0045
0046 #if !defined(bpf_target_arm64) && !defined(bpf_target_s390)
0047     bpf_probe_read_kernel(&tmp, sizeof(tmp), &PT_REGS_PARM1_SYSCALL(real_regs));
0048 #endif
0049     arg1 = tmp;
0050     bpf_probe_read_kernel(&arg2, sizeof(arg2), &PT_REGS_PARM2_SYSCALL(real_regs));
0051     bpf_probe_read_kernel(&arg3, sizeof(arg3), &PT_REGS_PARM3_SYSCALL(real_regs));
0052     bpf_probe_read_kernel(&arg4_cx, sizeof(arg4_cx), &PT_REGS_PARM4(real_regs));
0053     bpf_probe_read_kernel(&arg4, sizeof(arg4), &PT_REGS_PARM4_SYSCALL(real_regs));
0054     bpf_probe_read_kernel(&arg5, sizeof(arg5), &PT_REGS_PARM5_SYSCALL(real_regs));
0055
0056     /* test for the CORE variant of PT_REGS_PARM */
0057     arg1_core = PT_REGS_PARM1_CORE_SYSCALL(real_regs);
0058     arg2_core = PT_REGS_PARM2_CORE_SYSCALL(real_regs);
0059     arg3_core = PT_REGS_PARM3_CORE_SYSCALL(real_regs);
0060     arg4_core_cx = PT_REGS_PARM4_CORE(real_regs);
0061     arg4_core = PT_REGS_PARM4_CORE_SYSCALL(real_regs);
0062     arg5_core = PT_REGS_PARM5_CORE_SYSCALL(real_regs);
0063
0064     return 0;
0065 }
0066
0067 SEC("ksyscall/prctl")
0068 int BPF_KSYSCALL(prctl_enter, int option, unsigned long arg2,
0069          unsigned long arg3, unsigned long arg4, unsigned long arg5)
0070 {
0071     pid_t pid = bpf_get_current_pid_tgid() >> 32;
0072
0073     if (pid != filter_pid)
0074         return 0;
0075
0076     option_syscall = option;
0077     arg2_syscall = arg2;
0078     arg3_syscall = arg3;
0079     arg4_syscall = arg4;
0080     arg5_syscall = arg5;
0081     return 0;
0082 }
0083
0084 char _license[] SEC("license") = "GPL";