arch/x86/mm/kmemcheck/selftest.c

   1 #include <linux/bug.h>
   2 #include <linux/kernel.h>
   3
   4 #include "opcode.h"
   5 #include "selftest.h"
   6
   7 struct selftest_opcode {
   8         unsigned int expected_size;
   9         const uint8_t *insn;
  10         const char *desc;
  11 };
  12
  13 static const struct selftest_opcode selftest_opcodes[] = {
  14         /* REP MOVS */
  15         {1, "\xf3\xa4",                 "rep movsb <mem8>, <mem8>"},
  16         {4, "\xf3\xa5",                 "rep movsl <mem32>, <mem32>"},
  17
  18         /* MOVZX / MOVZXD */
  19         {1, "\x66\x0f\xb6\x51\xf8",     "movzwq <mem8>, <reg16>"},
  20         {1, "\x0f\xb6\x51\xf8",         "movzwq <mem8>, <reg32>"},
  21
  22         /* MOVSX / MOVSXD */
  23         {1, "\x66\x0f\xbe\x51\xf8",     "movswq <mem8>, <reg16>"},
  24         {1, "\x0f\xbe\x51\xf8",         "movswq <mem8>, <reg32>"},
  25
  26 #ifdef CONFIG_X86_64
  27         /* MOVZX / MOVZXD */
  28         {1, "\x49\x0f\xb6\x51\xf8",     "movzbq <mem8>, <reg64>"},
  29         {2, "\x49\x0f\xb7\x51\xf8",     "movzbq <mem16>, <reg64>"},
  30
  31         /* MOVSX / MOVSXD */
  32         {1, "\x49\x0f\xbe\x51\xf8",     "movsbq <mem8>, <reg64>"},
  33         {2, "\x49\x0f\xbf\x51\xf8",     "movsbq <mem16>, <reg64>"},
  34         {4, "\x49\x63\x51\xf8",         "movslq <mem32>, <reg64>"},
  35 #endif
  36 };
  37
  38 static bool selftest_opcode_one(const struct selftest_opcode *op)
  39 {
  40         unsigned size;
  41
  42         kmemcheck_opcode_decode(op->insn, &size);
  43
  44         if (size == op->expected_size)
  45                 return true;
  46
  47         printk(KERN_WARNING "kmemcheck: opcode %s: expected size %d, got %d\n",
  48                 op->desc, op->expected_size, size);
  49         return false;
  50 }
  51
  52 static bool selftest_opcodes_all(void)
  53 {
  54         bool pass = true;
  55         unsigned int i;
  56
  57         for (i = 0; i < ARRAY_SIZE(selftest_opcodes); ++i)
  58                 pass = pass && selftest_opcode_one(&selftest_opcodes[i]);
  59
  60         return pass;
  61 }
  62
  63 bool kmemcheck_selftest(void)
  64 {
  65         bool pass = true;
  66
  67         pass = pass && selftest_opcodes_all();
  68
  69         return pass;
  70 }