// SPDX-License-Identifier: GPL-2.0-or-later

static bool compare_legacy_flags(vm_flags_t legacy_flags, vma_flags_t flags)
{
        const unsigned long legacy_val = legacy_flags;
        /* The lower word should contain the precise same value. */
        const unsigned long flags_lower = flags.__vma_flags[0];
#if NUM_VMA_FLAGS > BITS_PER_LONG
        int i;

        /* All bits in higher flag values should be zero. */
        for (i = 1; i < NUM_VMA_FLAGS / BITS_PER_LONG; i++) {
                if (flags.__vma_flags[i] != 0)
                        return false;
        }
#endif

        static_assert(sizeof(legacy_flags) == sizeof(unsigned long));

        return legacy_val == flags_lower;
}

static bool test_copy_vma(void)
{
        vm_flags_t vm_flags = VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE;
        struct mm_struct mm = {};
        bool need_locks = false;
        VMA_ITERATOR(vmi, &mm, 0);
        struct vm_area_struct *vma, *vma_new, *vma_next;

        /* Move backwards and do not merge. */

        vma = alloc_and_link_vma(&mm, 0x3000, 0x5000, 3, vm_flags);
        vma_new = copy_vma(&vma, 0, 0x2000, 0, &need_locks);
        ASSERT_NE(vma_new, vma);
        ASSERT_EQ(vma_new->vm_start, 0);
        ASSERT_EQ(vma_new->vm_end, 0x2000);
        ASSERT_EQ(vma_new->vm_pgoff, 0);
        vma_assert_attached(vma_new);

        cleanup_mm(&mm, &vmi);

        /* Move a VMA into position next to another and merge the two. */

        vma = alloc_and_link_vma(&mm, 0, 0x2000, 0, vm_flags);
        vma_next = alloc_and_link_vma(&mm, 0x6000, 0x8000, 6, vm_flags);
        vma_new = copy_vma(&vma, 0x4000, 0x2000, 4, &need_locks);
        vma_assert_attached(vma_new);

        ASSERT_EQ(vma_new, vma_next);

        cleanup_mm(&mm, &vmi);
        return true;
}

static bool test_vma_flags_unchanged(void)
{
        vma_flags_t flags = EMPTY_VMA_FLAGS;
        vm_flags_t legacy_flags = 0;
        int bit;
        struct vm_area_struct vma;
        struct vm_area_desc desc;


        vma.flags = EMPTY_VMA_FLAGS;
        desc.vma_flags = EMPTY_VMA_FLAGS;

        for (bit = 0; bit < BITS_PER_LONG; bit++) {
                vma_flags_t mask = mk_vma_flags(bit);

                legacy_flags |= (1UL << bit);

                /* Individual flags. */
                vma_flags_set(&flags, bit);
                ASSERT_TRUE(compare_legacy_flags(legacy_flags, flags));

                /* Via mask. */
                vma_flags_set_mask(&flags, mask);
                ASSERT_TRUE(compare_legacy_flags(legacy_flags, flags));

                /* Same for VMA. */
                vma_set_flags(&vma, bit);
                ASSERT_TRUE(compare_legacy_flags(legacy_flags, vma.flags));
                vma_set_flags_mask(&vma, mask);
                ASSERT_TRUE(compare_legacy_flags(legacy_flags, vma.flags));

                /* Same for VMA descriptor. */
                vma_desc_set_flags(&desc, bit);
                ASSERT_TRUE(compare_legacy_flags(legacy_flags, desc.vma_flags));
                vma_desc_set_flags_mask(&desc, mask);
                ASSERT_TRUE(compare_legacy_flags(legacy_flags, desc.vma_flags));
        }

        return true;
}

static bool test_vma_flags_cleared(void)
{
        const vma_flags_t empty = EMPTY_VMA_FLAGS;
        vma_flags_t flags;
        int i;

        /* Set all bits high. */
        memset(&flags, 1, sizeof(flags));
        /* Try to clear. */
        vma_flags_clear_all(&flags);
        /* Equal to EMPTY_VMA_FLAGS? */
        ASSERT_EQ(memcmp(&empty, &flags, sizeof(flags)), 0);
        /* Make sure every unsigned long entry in bitmap array zero. */
        for (i = 0; i < sizeof(flags) / BITS_PER_LONG; i++) {
                const unsigned long val = flags.__vma_flags[i];

                ASSERT_EQ(val, 0);
        }

        return true;
}

/*
 * Assert that VMA flag functions that operate at the system word level function
 * correctly.
 */
static bool test_vma_flags_word(void)
{
        vma_flags_t flags = EMPTY_VMA_FLAGS;
        const vma_flags_t comparison =
                mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT, 64, 65);

        /* Set some custom high flags. */
        vma_flags_set(&flags, 64, 65);
        /* Now overwrite the first word. */
        vma_flags_overwrite_word(&flags, VM_READ | VM_WRITE);
        /* Ensure they are equal. */
        ASSERT_EQ(memcmp(&flags, &comparison, sizeof(flags)), 0);

        flags = EMPTY_VMA_FLAGS;
        vma_flags_set(&flags, 64, 65);

        /* Do the same with the _once() equivalent. */
        vma_flags_overwrite_word_once(&flags, VM_READ | VM_WRITE);
        ASSERT_EQ(memcmp(&flags, &comparison, sizeof(flags)), 0);

        flags = EMPTY_VMA_FLAGS;
        vma_flags_set(&flags, 64, 65);

        /* Make sure we can set a word without disturbing other bits. */
        vma_flags_set(&flags, VMA_WRITE_BIT);
        vma_flags_set_word(&flags, VM_READ);
        ASSERT_EQ(memcmp(&flags, &comparison, sizeof(flags)), 0);

        flags = EMPTY_VMA_FLAGS;
        vma_flags_set(&flags, 64, 65);

        /* Make sure we can clear a word without disturbing other bits. */
        vma_flags_set(&flags, VMA_READ_BIT, VMA_WRITE_BIT, VMA_EXEC_BIT);
        vma_flags_clear_word(&flags, VM_EXEC);
        ASSERT_EQ(memcmp(&flags, &comparison, sizeof(flags)), 0);

        return true;
}

/* Ensure that vma_flags_test() and friends works correctly. */
static bool test_vma_flags_test(void)
{
        const vma_flags_t flags = mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT,
                                               VMA_EXEC_BIT, 64, 65);
        struct vm_area_struct vma;
        struct vm_area_desc desc;

        vma.flags = flags;
        desc.vma_flags = flags;

#define do_test(...)                                            \
        ASSERT_TRUE(vma_flags_test(&flags, __VA_ARGS__));       \
        ASSERT_TRUE(vma_desc_test_flags(&desc, __VA_ARGS__))

#define do_test_all_true(...)                                   \
        ASSERT_TRUE(vma_flags_test_all(&flags, __VA_ARGS__));   \
        ASSERT_TRUE(vma_test_all_flags(&vma, __VA_ARGS__))

#define do_test_all_false(...)                                  \
        ASSERT_FALSE(vma_flags_test_all(&flags, __VA_ARGS__));  \
        ASSERT_FALSE(vma_test_all_flags(&vma, __VA_ARGS__))

        /*
         * Testing for some flags that are present, some that are not - should
         * pass. ANY flags matching should work.
         */
        do_test(VMA_READ_BIT, VMA_MAYREAD_BIT, VMA_SEQ_READ_BIT);
        /* However, the ...test_all() variant should NOT pass. */
        do_test_all_false(VMA_READ_BIT, VMA_MAYREAD_BIT, VMA_SEQ_READ_BIT);
        /* But should pass for flags present. */
        do_test_all_true(VMA_READ_BIT, VMA_WRITE_BIT, VMA_EXEC_BIT, 64, 65);
        /* Also subsets... */
        do_test_all_true(VMA_READ_BIT, VMA_WRITE_BIT, VMA_EXEC_BIT, 64);
        do_test_all_true(VMA_READ_BIT, VMA_WRITE_BIT, VMA_EXEC_BIT);
        do_test_all_true(VMA_READ_BIT, VMA_WRITE_BIT);
        do_test_all_true(VMA_READ_BIT);
        /*
         * Check _mask variant. We don't need to test extensively as macro
         * helper is the equivalent.
         */
        ASSERT_TRUE(vma_flags_test_mask(&flags, flags));
        ASSERT_TRUE(vma_flags_test_all_mask(&flags, flags));

        /* Single bits. */
        do_test(VMA_READ_BIT);
        do_test(VMA_WRITE_BIT);
        do_test(VMA_EXEC_BIT);
#if NUM_VMA_FLAG_BITS > 64
        do_test(64);
        do_test(65);
#endif

        /* Two bits. */
        do_test(VMA_READ_BIT, VMA_WRITE_BIT);
        do_test(VMA_READ_BIT, VMA_EXEC_BIT);
        do_test(VMA_WRITE_BIT, VMA_EXEC_BIT);
        /* Ordering shouldn't matter. */
        do_test(VMA_WRITE_BIT, VMA_READ_BIT);
        do_test(VMA_EXEC_BIT, VMA_READ_BIT);
        do_test(VMA_EXEC_BIT, VMA_WRITE_BIT);
#if NUM_VMA_FLAG_BITS > 64
        do_test(VMA_READ_BIT, 64);
        do_test(VMA_WRITE_BIT, 64);
        do_test(64, VMA_READ_BIT);
        do_test(64, VMA_WRITE_BIT);
        do_test(VMA_READ_BIT, 65);
        do_test(VMA_WRITE_BIT, 65);
        do_test(65, VMA_READ_BIT);
        do_test(65, VMA_WRITE_BIT);
#endif
        /* Three bits. */
        do_test(VMA_READ_BIT, VMA_WRITE_BIT, VMA_EXEC_BIT);
#if NUM_VMA_FLAG_BITS > 64
        /* No need to consider every single permutation. */
        do_test(VMA_READ_BIT, VMA_WRITE_BIT, 64);
        do_test(VMA_READ_BIT, VMA_WRITE_BIT, 65);

        /* Four bits. */
        do_test(VMA_READ_BIT, VMA_WRITE_BIT, VMA_EXEC_BIT, 64);
        do_test(VMA_READ_BIT, VMA_WRITE_BIT, VMA_EXEC_BIT, 65);

        /* Five bits. */
        do_test(VMA_READ_BIT, VMA_WRITE_BIT, VMA_EXEC_BIT, 64, 65);
#endif

#undef do_test
#undef do_test_all_true
#undef do_test_all_false

        return true;
}

/* Ensure that vma_flags_clear() and friends works correctly. */
static bool test_vma_flags_clear(void)
{
        vma_flags_t flags = mk_vma_flags(VMA_READ_BIT, VMA_WRITE_BIT,
                                         VMA_EXEC_BIT, 64, 65);
        vma_flags_t mask = mk_vma_flags(VMA_EXEC_BIT, 64);
        struct vm_area_struct vma;
        struct vm_area_desc desc;

        vma.flags = flags;
        desc.vma_flags = flags;

        /* Cursory check of _mask() variant, as the helper macros imply. */
        vma_flags_clear_mask(&flags, mask);
        vma_flags_clear_mask(&vma.flags, mask);
        vma_desc_clear_flags_mask(&desc, mask);
        ASSERT_FALSE(vma_flags_test(&flags, VMA_EXEC_BIT, 64));
        ASSERT_FALSE(vma_flags_test(&vma.flags, VMA_EXEC_BIT, 64));
        ASSERT_FALSE(vma_desc_test_flags(&desc, VMA_EXEC_BIT, 64));
        /* Reset. */
        vma_flags_set(&flags, VMA_EXEC_BIT, 64);
        vma_set_flags(&vma, VMA_EXEC_BIT, 64);
        vma_desc_set_flags(&desc, VMA_EXEC_BIT, 64);

        /*
         * Clear the flags and assert clear worked, then reset flags back to
         * include specified flags.
         */
#define do_test_and_reset(...)                                  \
        vma_flags_clear(&flags, __VA_ARGS__);                   \
        vma_flags_clear(&vma.flags, __VA_ARGS__);               \
        vma_desc_clear_flags(&desc, __VA_ARGS__);               \
        ASSERT_FALSE(vma_flags_test(&flags, __VA_ARGS__));      \
        ASSERT_FALSE(vma_flags_test(&vma.flags, __VA_ARGS__));  \
        ASSERT_FALSE(vma_desc_test_flags(&desc, __VA_ARGS__));  \
        vma_flags_set(&flags, __VA_ARGS__);                     \
        vma_set_flags(&vma, __VA_ARGS__);                       \
        vma_desc_set_flags(&desc, __VA_ARGS__)

        /* Single flags. */
        do_test_and_reset(VMA_READ_BIT);
        do_test_and_reset(VMA_WRITE_BIT);
        do_test_and_reset(VMA_EXEC_BIT);
        do_test_and_reset(64);
        do_test_and_reset(65);

        /* Two flags, in different orders. */
        do_test_and_reset(VMA_READ_BIT, VMA_WRITE_BIT);
        do_test_and_reset(VMA_READ_BIT, VMA_EXEC_BIT);
        do_test_and_reset(VMA_READ_BIT, 64);
        do_test_and_reset(VMA_READ_BIT, 65);
        do_test_and_reset(VMA_WRITE_BIT, VMA_READ_BIT);
        do_test_and_reset(VMA_WRITE_BIT, VMA_EXEC_BIT);
        do_test_and_reset(VMA_WRITE_BIT, 64);
        do_test_and_reset(VMA_WRITE_BIT, 65);
        do_test_and_reset(VMA_EXEC_BIT, VMA_READ_BIT);
        do_test_and_reset(VMA_EXEC_BIT, VMA_WRITE_BIT);
        do_test_and_reset(VMA_EXEC_BIT, 64);
        do_test_and_reset(VMA_EXEC_BIT, 65);
        do_test_and_reset(64, VMA_READ_BIT);
        do_test_and_reset(64, VMA_WRITE_BIT);
        do_test_and_reset(64, VMA_EXEC_BIT);
        do_test_and_reset(64, 65);
        do_test_and_reset(65, VMA_READ_BIT);
        do_test_and_reset(65, VMA_WRITE_BIT);
        do_test_and_reset(65, VMA_EXEC_BIT);
        do_test_and_reset(65, 64);

        /* Three flags. */

#undef do_test_some_missing
#undef do_test_and_reset

        return true;
}

static void run_vma_tests(int *num_tests, int *num_fail)
{
        TEST(copy_vma);
        TEST(vma_flags_unchanged);
        TEST(vma_flags_cleared);
        TEST(vma_flags_word);
        TEST(vma_flags_test);
        TEST(vma_flags_clear);
}