selftest.c

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#include <linux/bug.h>
#include <linux/kernel.h>

#include "opcode.h"
#include "selftest.h"

struct selftest_opcode {
    unsigned int expected_size;
    const uint8_t *insn;
    const char *desc;
};

static const struct selftest_opcode selftest_opcodes[] = {
    /* REP MOVS */
    {1, "\xf3\xa4",         "rep movsb <mem8>, <mem8>"},
    {4, "\xf3\xa5",         "rep movsl <mem32>, <mem32>"},

    /* MOVZX / MOVZXD */
    {1, "\x66\x0f\xb6\x51\xf8", "movzwq <mem8>, <reg16>"},
    {1, "\x0f\xb6\x51\xf8",     "movzwq <mem8>, <reg32>"},

    /* MOVSX / MOVSXD */
    {1, "\x66\x0f\xbe\x51\xf8", "movswq <mem8>, <reg16>"},
    {1, "\x0f\xbe\x51\xf8",     "movswq <mem8>, <reg32>"},

#ifdef CONFIG_X86_64
    /* MOVZX / MOVZXD */
    {1, "\x49\x0f\xb6\x51\xf8", "movzbq <mem8>, <reg64>"},
    {2, "\x49\x0f\xb7\x51\xf8", "movzbq <mem16>, <reg64>"},

    /* MOVSX / MOVSXD */
    {1, "\x49\x0f\xbe\x51\xf8", "movsbq <mem8>, <reg64>"},
    {2, "\x49\x0f\xbf\x51\xf8", "movsbq <mem16>, <reg64>"},
    {4, "\x49\x63\x51\xf8",     "movslq <mem32>, <reg64>"},
#endif
};

static bool selftest_opcode_one(const struct selftest_opcode *op)
{
    unsigned size;

    kmemcheck_opcode_decode(op->insn, &size);

    if (size == op->expected_size)
        return true;

    printk(KERN_WARNING "kmemcheck: opcode %s: expected size %d, got %d\n",
        op->desc, op->expected_size, size);
    return false;
}

static bool selftest_opcodes_all(void)
{
    bool pass = true;
    unsigned int i;

    for (i = 0; i < ARRAY_SIZE(selftest_opcodes); ++i)
        pass = pass && selftest_opcode_one(&selftest_opcodes[i]);

    return pass;
}

bool kmemcheck_selftest(void)
{
    bool pass = true;

    pass = pass && selftest_opcodes_all();

    return pass;
}