How a program in user mode calls the kernel tests defined in module.

[wenhaopang]

How a program in user mode calls the kernel tests defined in module.
as described on lines 42-49 in kernel-open/nvidia-uvm/uvm_common.c

// This parameter allows a program in user mode to call the kernel tests
// defined in this module. This parameter should only be used for testing and
// must not be set to true otherwise since it breaks security when it is
// enabled. By default and for safety reasons this parameter is set to false.
int uvm_enable_builtin_tests __read_mostly = 0;
module_param(uvm_enable_builtin_tests, int, S_IRUGO);
MODULE_PARM_DESC(uvm_enable_builtin_tests,
                 "Enable the UVM built-in tests. (This is a security risk)");

[mtijanic]

Through ioctl(). The uvm_ioctl() function lists all the valid production level ioctl codes that can be made, and then it falls through to uvm_test_ioctl() which will only run the tests if the module param was specified.

[wenhaopang]

Thank you very much, I'm going to learn this part of the code.