Re: [PATCH 000/109] remove in-kernel calls to syscalls
From: Matthew Wilcox
Date: Thu Mar 29 2018 - 10:20:41 EST
On Thu, Mar 29, 2018 at 01:22:37PM +0200, Dominik Brodowski wrote:
> At least on 64-bit x86, it will likely be a hard requirement from v4.17
> onwards to not call system call functions in the kernel: It is better to
> use use a different calling convention for system calls there, where
> struct pt_regs is decoded on-the-fly in a syscall wrapper which then hands
> processing over to the actual syscall function. This means that only those
> parameters which are actually needed for a specific syscall are passed on
> during syscall entry, instead of filling in six CPU registers with random
> user space content all the time (which may cause serious trouble down the
> call chain).[*]
How do we stop new ones from springing up? Some kind of linker trick
like was used to, er, "dissuade" people from using gets()?