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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Converted from tools/testing/selftests/bpf/verifier/prevent_map_lookup.c */
   3
   4 #include <linux/bpf.h>
   5 #include <bpf/bpf_helpers.h>
   6 #include "bpf_misc.h"
   7
   8 struct {
   9         __uint(type, BPF_MAP_TYPE_STACK_TRACE);
  10         __uint(max_entries, 1);
  11         __type(key, __u32);
  12         __type(value, __u64);
  13 } map_stacktrace SEC(".maps");
  14
  15 struct {
  16         __uint(type, BPF_MAP_TYPE_PROG_ARRAY);
  17         __uint(max_entries, 8);
  18         __uint(key_size, sizeof(int));
  19         __array(values, void (void));
  20 } map_prog2_socket SEC(".maps");
  21
  22 SEC("perf_event")
  23 __description("prevent map lookup in stack trace")
  24 __failure __msg("cannot pass map_type 7 into func bpf_map_lookup_elem")
  25 __naked void map_lookup_in_stack_trace(void)
  26 {
  27         asm volatile ("                                 \
  28         r1 = 0;                                         \
  29         *(u64*)(r10 - 8) = r1;                          \
  30         r2 = r10;                                       \
  31         r2 += -8;                                       \
  32         r1 = %[map_stacktrace] ll;                      \
  33         call %[bpf_map_lookup_elem];                    \
  34         exit;                                           \
  35 "       :
  36         : __imm(bpf_map_lookup_elem),
  37           __imm_addr(map_stacktrace)
  38         : __clobber_all);
  39 }
  40
  41 SEC("socket")
  42 __description("prevent map lookup in prog array")
  43 __failure __msg("cannot pass map_type 3 into func bpf_map_lookup_elem")
  44 __failure_unpriv
  45 __naked void map_lookup_in_prog_array(void)
  46 {
  47         asm volatile ("                                 \
  48         r1 = 0;                                         \
  49         *(u64*)(r10 - 8) = r1;                          \
  50         r2 = r10;                                       \
  51         r2 += -8;                                       \
  52         r1 = %[map_prog2_socket] ll;                    \
  53         call %[bpf_map_lookup_elem];                    \
  54         exit;                                           \
  55 "       :
  56         : __imm(bpf_map_lookup_elem),
  57           __imm_addr(map_prog2_socket)
  58         : __clobber_all);
  59 }
  60
  61 char _license[] SEC("license") = "GPL";