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 7 char _license[] SEC("license") = "GPL"; 8 9 struct callback_ctx { 10 int dummy; 11 }; 12 13 #define VM_EXEC 0x00000004 14 #define DNAME_INLINE_LEN 32 15 16 pid_t target_pid = 0; 17 char d_iname[DNAME_INLINE_LEN] = {0}; 18 __u32 found_vm_exec = 0; 19 __u64 addr = 0; 20 int find_zero_ret = -1; 21 int find_addr_ret = -1; 22 23 static 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 37 SEC("raw_tp/sys_enter") 38 int 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 53 SEC("perf_event") 54 int 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 } 70