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

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Converted from tools/testing/selftests/bpf/verifier/div_overflow.c */
   3
   4 #include <linux/bpf.h>
   5 #include <bpf/bpf_helpers.h>
   6 #include <limits.h>
   7 #include "bpf_misc.h"
   8
   9 /* Just make sure that JITs used udiv/umod as otherwise we get
  10  * an exception from INT_MIN/-1 overflow similarly as with div
  11  * by zero.
  12  */
  13
  14 SEC("tc")
  15 __description("DIV32 overflow, check 1")
  16 __success __retval(0)
  17 __naked void div32_overflow_check_1(void)
  18 {
  19         asm volatile ("                                 \
  20         w1 = -1;                                        \
  21         w0 = %[int_min];                                \
  22         w0 /= w1;                                       \
  23         exit;                                           \
  24 "       :
  25         : __imm_const(int_min, INT_MIN)
  26         : __clobber_all);
  27 }
  28
  29 SEC("tc")
  30 __description("DIV32 overflow, check 2")
  31 __success __retval(0)
  32 __naked void div32_overflow_check_2(void)
  33 {
  34         asm volatile ("                                 \
  35         w0 = %[int_min];                                \
  36         w0 /= -1;                                       \
  37         exit;                                           \
  38 "       :
  39         : __imm_const(int_min, INT_MIN)
  40         : __clobber_all);
  41 }
  42
  43 SEC("tc")
  44 __description("DIV64 overflow, check 1")
  45 __success __retval(0)
  46 __naked void div64_overflow_check_1(void)
  47 {
  48         asm volatile ("                                 \
  49         r1 = -1;                                        \
  50         r2 = %[llong_min] ll;                           \
  51         r2 /= r1;                                       \
  52         w0 = 0;                                         \
  53         if r0 == r2 goto l0_%=;                         \
  54         w0 = 1;                                         \
  55 l0_%=:  exit;                                           \
  56 "       :
  57         : __imm_const(llong_min, LLONG_MIN)
  58         : __clobber_all);
  59 }
  60
  61 SEC("tc")
  62 __description("DIV64 overflow, check 2")
  63 __success __retval(0)
  64 __naked void div64_overflow_check_2(void)
  65 {
  66         asm volatile ("                                 \
  67         r1 = %[llong_min] ll;                           \
  68         r1 /= -1;                                       \
  69         w0 = 0;                                         \
  70         if r0 == r1 goto l0_%=;                         \
  71         w0 = 1;                                         \
  72 l0_%=:  exit;                                           \
  73 "       :
  74         : __imm_const(llong_min, LLONG_MIN)
  75         : __clobber_all);
  76 }
  77
  78 SEC("tc")
  79 __description("MOD32 overflow, check 1")
  80 __success __retval(INT_MIN)
  81 __naked void mod32_overflow_check_1(void)
  82 {
  83         asm volatile ("                                 \
  84         w1 = -1;                                        \
  85         w0 = %[int_min];                                \
  86         w0 %%= w1;                                      \
  87         exit;                                           \
  88 "       :
  89         : __imm_const(int_min, INT_MIN)
  90         : __clobber_all);
  91 }
  92
  93 SEC("tc")
  94 __description("MOD32 overflow, check 2")
  95 __success __retval(INT_MIN)
  96 __naked void mod32_overflow_check_2(void)
  97 {
  98         asm volatile ("                                 \
  99         w0 = %[int_min];                                \
 100         w0 %%= -1;                                      \
 101         exit;                                           \
 102 "       :
 103         : __imm_const(int_min, INT_MIN)
 104         : __clobber_all);
 105 }
 106
 107 SEC("tc")
 108 __description("MOD64 overflow, check 1")
 109 __success __retval(1)
 110 __naked void mod64_overflow_check_1(void)
 111 {
 112         asm volatile ("                                 \
 113         r1 = -1;                                        \
 114         r2 = %[llong_min] ll;                           \
 115         r3 = r2;                                        \
 116         r2 %%= r1;                                      \
 117         w0 = 0;                                         \
 118         if r3 != r2 goto l0_%=;                         \
 119         w0 = 1;                                         \
 120 l0_%=:  exit;                                           \
 121 "       :
 122         : __imm_const(llong_min, LLONG_MIN)
 123         : __clobber_all);
 124 }
 125
 126 SEC("tc")
 127 __description("MOD64 overflow, check 2")
 128 __success __retval(1)
 129 __naked void mod64_overflow_check_2(void)
 130 {
 131         asm volatile ("                                 \
 132         r2 = %[llong_min] ll;                           \
 133         r3 = r2;                                        \
 134         r2 %%= -1;                                      \
 135         w0 = 0;                                         \
 136         if r3 != r2 goto l0_%=;                         \
 137         w0 = 1;                                         \
 138 l0_%=:  exit;                                           \
 139 "       :
 140         : __imm_const(llong_min, LLONG_MIN)
 141         : __clobber_all);
 142 }
 143
 144 char _license[] SEC("license") = "GPL";