On Sat, 2019-05-04 at 04:28 +0200, Sebastian Gottschall wrote:
Using fpu code in kernel space in a kernel module is a derived work of the kernel itself? dont get me wrong, but this is absurd. i mean you limit the use of cpu instructions. the use of cpu instructions should be free of any licensing issue. i would even argument you are violating the license of the cpu ower given to the kernel by executing it, by restricting its use for no reason
Using FPU code in kernel space in a kernel module does not require the use of kernel_fpu_begin/end().
The kernel module could simply disable preemption, save the FPU registers, use the FPU, restore the FPU registers, and reenable preemption.
However, using kernel_fpu_begin/end() does get that module some nice optimizations that are specific to Linux.