tools/testing/selftests/bpf/progs/preempt_lock.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include <vmlinux.h>
   3 #include <bpf/bpf_helpers.h>
   4 #include <bpf/bpf_tracing.h>
   5 #include "bpf_misc.h"
   6 #include "bpf_experimental.h"
   7
   8 SEC("?tc")
   9 __failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
  10 int preempt_lock_missing_1(struct __sk_buff *ctx)
  11 {
  12         bpf_preempt_disable();
  13         return 0;
  14 }
  15
  16 SEC("?tc")
  17 __failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
  18 int preempt_lock_missing_2(struct __sk_buff *ctx)
  19 {
  20         bpf_preempt_disable();
  21         bpf_preempt_disable();
  22         return 0;
  23 }
  24
  25 SEC("?tc")
  26 __failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
  27 int preempt_lock_missing_3(struct __sk_buff *ctx)
  28 {
  29         bpf_preempt_disable();
  30         bpf_preempt_disable();
  31         bpf_preempt_disable();
  32         return 0;
  33 }
  34
  35 SEC("?tc")
  36 __failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
  37 int preempt_lock_missing_3_minus_2(struct __sk_buff *ctx)
  38 {
  39         bpf_preempt_disable();
  40         bpf_preempt_disable();
  41         bpf_preempt_disable();
  42         bpf_preempt_enable();
  43         bpf_preempt_enable();
  44         return 0;
  45 }
  46
  47 static __noinline void preempt_disable(void)
  48 {
  49         bpf_preempt_disable();
  50 }
  51
  52 static __noinline void preempt_enable(void)
  53 {
  54         bpf_preempt_enable();
  55 }
  56
  57 SEC("?tc")
  58 __failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
  59 int preempt_lock_missing_1_subprog(struct __sk_buff *ctx)
  60 {
  61         preempt_disable();
  62         return 0;
  63 }
  64
  65 SEC("?tc")
  66 __failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
  67 int preempt_lock_missing_2_subprog(struct __sk_buff *ctx)
  68 {
  69         preempt_disable();
  70         preempt_disable();
  71         return 0;
  72 }
  73
  74 SEC("?tc")
  75 __failure __msg("BPF_EXIT instruction cannot be used inside bpf_preempt_disable-ed region")
  76 int preempt_lock_missing_2_minus_1_subprog(struct __sk_buff *ctx)
  77 {
  78         preempt_disable();
  79         preempt_disable();
  80         preempt_enable();
  81         return 0;
  82 }
  83
  84 static __noinline void preempt_balance_subprog(void)
  85 {
  86         preempt_disable();
  87         preempt_enable();
  88 }
  89
  90 SEC("?tc")
  91 __success int preempt_balance(struct __sk_buff *ctx)
  92 {
  93         bpf_guard_preempt();
  94         return 0;
  95 }
  96
  97 SEC("?tc")
  98 __success int preempt_balance_subprog_test(struct __sk_buff *ctx)
  99 {
 100         preempt_balance_subprog();
 101         return 0;
 102 }
 103
 104 SEC("?fentry.s/" SYS_PREFIX "sys_getpgid")
 105 __failure __msg("sleepable helper bpf_copy_from_user#")
 106 int preempt_sleepable_helper(void *ctx)
 107 {
 108         u32 data;
 109
 110         bpf_preempt_disable();
 111         bpf_copy_from_user(&data, sizeof(data), NULL);
 112         bpf_preempt_enable();
 113         return 0;
 114 }
 115
 116 int __noinline preempt_global_subprog(void)
 117 {
 118         preempt_balance_subprog();
 119         return 0;
 120 }
 121
 122 SEC("?tc")
 123 __failure __msg("global function calls are not allowed with preemption disabled")
 124 int preempt_global_subprog_test(struct __sk_buff *ctx)
 125 {
 126         preempt_disable();
 127         preempt_global_subprog();
 128         preempt_enable();
 129         return 0;
 130 }
 131
 132 char _license[] SEC("license") = "GPL";