This is set of patches to kill set_fs() on the ARM architecture, as part
of the broader effort described at

I have tested the oabi-compat changes using the LTP tests for the three
modified syscalls using an Armv7 kernel and a Debian 5 OABI user space.

I also tested the syscall_get_nr() in all combinations of OABI/EABI
kernel user space and fixed the bugs I found after Russell pointed out
one of those issues.
ARM: uaccess: remove set_fs() implementation

There are no remaining callers of set_fs(), so just remove it
along with all associated code that operates on

There are still further optimizations that can be done:

- In get_user(), the address check could be moved entirely
  into the out of line code, rather than passing a constant
  as an argument,

- I assume the DACR handling can be simplified as we now
  only change it during user access when CONFIG_CPU_SW_DOMAIN_PAN
  is set, but not during set_fs().

Signed-off-by: Arnd Bergmann <>
11 files changed