Re: remove the last set_fs() in common code, and remove it for x86 and powerpc v3

From: Alexey Dobriyan
Date: Fri Sep 04 2020 - 13:58:38 EST


On Fri, Sep 04, 2020 at 08:00:24AM +0200, Ingo Molnar wrote:
> * Christoph Hellwig <hch@xxxxxx> wrote:
> > this series removes the last set_fs() used to force a kernel address
> > space for the uaccess code in the kernel read/write/splice code, and then
> > stops implementing the address space overrides entirely for x86 and
> > powerpc.
>
> Cool! For the x86 bits:
>
> Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>

set_fs() is older than some kernel hackers!

$ cd linux-0.11/
$ find . -type f -name '*.h' | xargs grep -e set_fs -w -n -A3
./include/asm/segment.h:61:extern inline void set_fs(unsigned long val)
./include/asm/segment.h-62-{
./include/asm/segment.h-63- __asm__("mov %0,%%fs"::"a" ((unsigned short) val));
./include/asm/segment.h-64-}