find_vma.c (1524B)
1// SPDX-License-Identifier: GPL-2.0 2/* Copyright (c) 2021 Facebook */ 3#include "vmlinux.h" 4#include <bpf/bpf_helpers.h> 5#include <bpf/bpf_tracing.h> 6 7char _license[] SEC("license") = "GPL"; 8 9struct callback_ctx { 10 int dummy; 11}; 12 13#define VM_EXEC 0x00000004 14#define DNAME_INLINE_LEN 32 15 16pid_t target_pid = 0; 17char d_iname[DNAME_INLINE_LEN] = {0}; 18__u32 found_vm_exec = 0; 19__u64 addr = 0; 20int find_zero_ret = -1; 21int find_addr_ret = -1; 22 23static long check_vma(struct task_struct *task, struct vm_area_struct *vma, 24 struct callback_ctx *data) 25{ 26 if (vma->vm_file) 27 bpf_probe_read_kernel_str(d_iname, DNAME_INLINE_LEN - 1, 28 vma->vm_file->f_path.dentry->d_iname); 29 30 /* check for VM_EXEC */ 31 if (vma->vm_flags & VM_EXEC) 32 found_vm_exec = 1; 33 34 return 0; 35} 36 37SEC("raw_tp/sys_enter") 38int handle_getpid(void) 39{ 40 struct task_struct *task = bpf_get_current_task_btf(); 41 struct callback_ctx data = {}; 42 43 if (task->pid != target_pid) 44 return 0; 45 46 find_addr_ret = bpf_find_vma(task, addr, check_vma, &data, 0); 47 48 /* this should return -ENOENT */ 49 find_zero_ret = bpf_find_vma(task, 0, check_vma, &data, 0); 50 return 0; 51} 52 53SEC("perf_event") 54int handle_pe(void) 55{ 56 struct task_struct *task = bpf_get_current_task_btf(); 57 struct callback_ctx data = {}; 58 59 if (task->pid != target_pid) 60 return 0; 61 62 find_addr_ret = bpf_find_vma(task, addr, check_vma, &data, 0); 63 64 /* In NMI, this should return -EBUSY, as the previous call is using 65 * the irq_work. 66 */ 67 find_zero_ret = bpf_find_vma(task, 0, check_vma, &data, 0); 68 return 0; 69}