1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright (c) 2024 Meta Platforms, Inc. and affiliates. */ 3 #include <vmlinux.h> 4 #include <bpf/bpf_helpers.h> 5 #include <bpf/bpf_tracing.h> 6 #include <bpf/usdt.bpf.h> 7 8 char _license[] SEC("license") = "GPL"; 9 10 __u64 entry_stack1[32], exit_stack1[32]; 11 __u64 entry_stack1_recur[32], exit_stack1_recur[32]; 12 __u64 entry_stack2[32]; 13 __u64 entry_stack3[32]; 14 __u64 entry_stack4[32], exit_stack4[32]; 15 __u64 usdt_stack[32]; 16 17 int entry1_len, exit1_len; 18 int entry1_recur_len, exit1_recur_len; 19 int entry2_len, exit2_len; 20 int entry3_len, exit3_len; 21 int entry4_len, exit4_len; 22 int usdt_len; 23 24 #define SZ sizeof(usdt_stack) 25 26 SEC("uprobe//proc/self/exe:target_1") 27 int BPF_UPROBE(uprobe_1) 28 { 29 /* target_1 is recursive wit depth of 2, so we capture two separate 30 * stack traces, depending on which occurence it is 31 */ 32 static bool recur = false; 33 34 if (!recur) 35 entry1_len = bpf_get_stack(ctx, &entry_stack1, SZ, BPF_F_USER_STACK); 36 else 37 entry1_recur_len = bpf_get_stack(ctx, &entry_stack1_recur, SZ, BPF_F_USER_STACK); 38 39 recur = true; 40 return 0; 41 } 42 43 SEC("uretprobe//proc/self/exe:target_1") 44 int BPF_URETPROBE(uretprobe_1) 45 { 46 /* see above, target_1 is recursive */ 47 static bool recur = false; 48 49 /* NOTE: order of returns is reversed to order of entries */ 50 if (!recur) 51 exit1_recur_len = bpf_get_stack(ctx, &exit_stack1_recur, SZ, BPF_F_USER_STACK); 52 else 53 exit1_len = bpf_get_stack(ctx, &exit_stack1, SZ, BPF_F_USER_STACK); 54 55 recur = true; 56 return 0; 57 } 58 59 SEC("uprobe//proc/self/exe:target_2") 60 int BPF_UPROBE(uprobe_2) 61 { 62 entry2_len = bpf_get_stack(ctx, &entry_stack2, SZ, BPF_F_USER_STACK); 63 return 0; 64 } 65 66 /* no uretprobe for target_2 */ 67 68 SEC("uprobe//proc/self/exe:target_3") 69 int BPF_UPROBE(uprobe_3) 70 { 71 entry3_len = bpf_get_stack(ctx, &entry_stack3, SZ, BPF_F_USER_STACK); 72 return 0; 73 } 74 75 /* no uretprobe for target_3 */ 76 77 SEC("uprobe//proc/self/exe:target_4") 78 int BPF_UPROBE(uprobe_4) 79 { 80 entry4_len = bpf_get_stack(ctx, &entry_stack4, SZ, BPF_F_USER_STACK); 81 return 0; 82 } 83 84 SEC("uretprobe//proc/self/exe:target_4") 85 int BPF_URETPROBE(uretprobe_4) 86 { 87 exit4_len = bpf_get_stack(ctx, &exit_stack4, SZ, BPF_F_USER_STACK); 88 return 0; 89 } 90 91 SEC("usdt//proc/self/exe:uretprobe_stack:target") 92 int BPF_USDT(usdt_probe) 93 { 94 usdt_len = bpf_get_stack(ctx, &usdt_stack, SZ, BPF_F_USER_STACK); 95 return 0; 96 } 97