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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Converted from tools/testing/selftests/bpf/verifier/basic_stack.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_HASH);
  10         __uint(max_entries, 1);
  11         __type(key, long long);
  12         __type(value, long long);
  13 } map_hash_8b SEC(".maps");
  14
  15 SEC("socket")
  16 __description("stack out of bounds")
  17 __failure __msg("invalid write to stack")
  18 __failure_unpriv
  19 __naked void stack_out_of_bounds(void)
  20 {
  21         asm volatile ("                                 \
  22         r1 = 0;                                         \
  23         *(u64*)(r10 + 8) = r1;                          \
  24         exit;                                           \
  25 "       ::: __clobber_all);
  26 }
  27
  28 SEC("socket")
  29 __description("uninitialized stack1")
  30 __failure __msg("invalid indirect read from stack")
  31 __failure_unpriv
  32 __naked void uninitialized_stack1(void)
  33 {
  34         asm volatile ("                                 \
  35         r2 = r10;                                       \
  36         r2 += -8;                                       \
  37         r1 = %[map_hash_8b] ll;                         \
  38         call %[bpf_map_lookup_elem];                    \
  39         exit;                                           \
  40 "       :
  41         : __imm(bpf_map_lookup_elem),
  42           __imm_addr(map_hash_8b)
  43         : __clobber_all);
  44 }
  45
  46 SEC("socket")
  47 __description("uninitialized stack2")
  48 __failure __msg("invalid read from stack")
  49 __failure_unpriv
  50 __naked void uninitialized_stack2(void)
  51 {
  52         asm volatile ("                                 \
  53         r2 = r10;                                       \
  54         r0 = *(u64*)(r2 - 8);                           \
  55         exit;                                           \
  56 "       ::: __clobber_all);
  57 }
  58
  59 SEC("socket")
  60 __description("invalid fp arithmetic")
  61 __failure __msg("R1 subtraction from stack pointer")
  62 __failure_unpriv
  63 __naked void invalid_fp_arithmetic(void)
  64 {
  65         /* If this gets ever changed, make sure JITs can deal with it. */
  66         asm volatile ("                                 \
  67         r0 = 0;                                         \
  68         r1 = r10;                                       \
  69         r1 -= 8;                                        \
  70         *(u64*)(r1 + 0) = r0;                           \
  71         exit;                                           \
  72 "       ::: __clobber_all);
  73 }
  74
  75 SEC("socket")
  76 __description("non-invalid fp arithmetic")
  77 __success __success_unpriv __retval(0)
  78 __naked void non_invalid_fp_arithmetic(void)
  79 {
  80         asm volatile ("                                 \
  81         r0 = 0;                                         \
  82         *(u64*)(r10 - 8) = r0;                          \
  83         exit;                                           \
  84 "       ::: __clobber_all);
  85 }
  86
  87 SEC("socket")
  88 __description("misaligned read from stack")
  89 __failure __msg("misaligned stack access")
  90 __failure_unpriv
  91 __naked void misaligned_read_from_stack(void)
  92 {
  93         asm volatile ("                                 \
  94         r2 = r10;                                       \
  95         r0 = *(u64*)(r2 - 4);                           \
  96         exit;                                           \
  97 "       ::: __clobber_all);
  98 }
  99
 100 char _license[] SEC("license") = "GPL";