nvidia-open-gpu-kernel-modules/kernel-open/nvidia-uvm/uvm_kvmalloc_test.c

/*******************************************************************************
    Copyright (c) 2016 NVIDIA Corporation

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        The above copyright notice and this permission notice shall be
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#include "uvm_common.h"
#include "uvm_linux.h"
#include "uvm_kvmalloc.h"
#include "uvm_test.h"

typedef enum
{
    ALLOC_TYPE_MALLOC,
    ALLOC_TYPE_ZALLOC,
    ALLOC_TYPE_REALLOC_NULL,
    ALLOC_TYPE_REALLOC_ZERO,
    ALLOC_TYPE_MAX
} alloc_type_t;

static NV_STATUS check_alloc(void *p, size_t size)
{
    if (size == 0) {
        TEST_CHECK_RET(p == ZERO_SIZE_PTR);
        TEST_CHECK_RET(uvm_kvsize(p) == 0);
    }
    else if (size <= UVM_KMALLOC_THRESHOLD) {
        TEST_CHECK_RET(!is_vmalloc_addr(p));

        // In theory it's possible to use kmalloc yet have ksize(p) be larger
        // than our arbitrary UVM_KMALLOC_THRESHOLD. In practice, as long as
        // UVM_KMALLOC_THRESHOLD is a multiple of PAGE_SIZE, that's highly
        // unlikely.
        TEST_CHECK_RET(uvm_kvsize(p) == ksize(p));
        TEST_CHECK_RET(uvm_kvsize(p) >= size);
    }
    else {
        TEST_CHECK_RET(is_vmalloc_addr(p));
        TEST_CHECK_RET(uvm_kvsize(p) == size);
    }

    return NV_OK;
}

static NV_STATUS test_uvm_kvmalloc(void)
{
    static const size_t sizes[] = {0, UVM_KMALLOC_THRESHOLD, UVM_KMALLOC_THRESHOLD + 1};
    uint8_t *p;
    uint8_t expected;
    size_t i, j, size;
    alloc_type_t alloc_type;

    for (i = 0; i < ARRAY_SIZE(sizes); i++) {
        size = sizes[i];
        for (alloc_type = 0; alloc_type < ALLOC_TYPE_MAX; alloc_type++) {
            switch (alloc_type) {
                case ALLOC_TYPE_MALLOC:
                    p = uvm_kvmalloc(size);
                    break;
                case ALLOC_TYPE_ZALLOC:
                    p = uvm_kvmalloc_zero(size);
                    break;
                case ALLOC_TYPE_REALLOC_NULL:
                    p = uvm_kvrealloc(NULL, size);
                    break;
                case ALLOC_TYPE_REALLOC_ZERO:
                    p = uvm_kvrealloc(ZERO_SIZE_PTR, size);
                    break;
                default:
                    UVM_ASSERT(0);
                    p = NULL;
            }
            if (!p)
                return NV_ERR_NO_MEMORY;

            // On failure, this macro returns and thus leaks the allocation. But
            // if the check fails, our allocation state is messed up so we can't
            // reasonably free the allocation anyway.
            MEM_NV_CHECK_RET(check_alloc(p, size), NV_OK);

            // Scribble on the allocation to make sure we don't crash
            if (alloc_type == ALLOC_TYPE_ZALLOC) {
                expected = 0;
            }
            else {
                expected = (uint8_t)(current->pid + i);
                memset(p, expected, size);
            }

            for (j = 0; j < size; j++) {
                if (p[j] != expected) {
                    UVM_TEST_PRINT("p[%zu] is 0x%x instead of expected value 0x%x\n", j, p[j], expected);
                    uvm_kvfree(p);
                    TEST_CHECK_RET(0);
                }
            }

            uvm_kvfree(p);
        }
    }

    return NV_OK;
}

static NV_STATUS test_uvm_kvrealloc(void)
{
    size_t i, j, k, old_size, new_size;
    uint8_t *old_p, *new_p;
    uint8_t expected = (uint8_t)current->pid;

    static const size_t sizes[] = {0,
                                   UVM_KMALLOC_THRESHOLD / 2,
                                   UVM_KMALLOC_THRESHOLD,
                                   UVM_KMALLOC_THRESHOLD + 1,
                                   2*UVM_KMALLOC_THRESHOLD};

    // uvm_kvrealloc(NULL, size) and uvm_kvrealloc(ZERO_SIZE_PTR, size) are
    // tested in test_uvm_alloc so we don't have to do them here.

    for (i = 0; i < ARRAY_SIZE(sizes); i++) {
        old_size = sizes[i];
        for (j = 0; j < ARRAY_SIZE(sizes); j++) {
            new_size = sizes[j];

            old_p = uvm_kvmalloc(old_size);
            if (!old_p)
                return NV_ERR_NO_MEMORY;
            MEM_NV_CHECK_RET(check_alloc(old_p, old_size), NV_OK);

            ++expected;
            memset(old_p, expected, old_size);

            new_p = uvm_kvrealloc(old_p, new_size);
            if (!new_p) {
                uvm_kvfree(old_p);
                return NV_ERR_NO_MEMORY;
            }

            // At this point, either new_p == old_p or old_p should have been
            // freed. In either case there's no need to free old_p.

            MEM_NV_CHECK_RET(check_alloc(new_p, new_size), NV_OK);

            // Make sure the data is still present
            for (k = 0; k < min(new_size, old_size); k++) {
                if (new_p[k] != expected) {
                    UVM_TEST_PRINT("new_p[%zu] is 0x%x instead of expected value 0x%x\n", k, new_p[k], expected);
                    uvm_kvfree(new_p);
                    TEST_CHECK_RET(0);
                }
            }

            // Exercise the free-via-realloc path
            TEST_CHECK_RET(uvm_kvrealloc(new_p, 0) == ZERO_SIZE_PTR);
        }
    }

    return NV_OK;
}

NV_STATUS uvm_test_kvmalloc(UVM_TEST_KVMALLOC_PARAMS *params, struct file *filp)
{
    NV_STATUS status = test_uvm_kvmalloc();
    if (status != NV_OK)
        return status;
    return test_uvm_kvrealloc();
}