[PATCH 0/3] xtensa: allow handling protection faults in noMMU

[Max Filippov]

Hello,

most xtensa cores have some sort of memory protection mechanism, even
those without full MMU. This series separates protection fault handling
from the CONFIG_MMU setting and allows noMMU configurations to also
do it. This improves userspace behavior in case of errors such as
passing NULL pointer to a syscall that expects a valid memory pointer:
instead of killing the process the kernel is now able to return -EINVAL
from a syscall.

Max Filippov (3):
  xtensa: move asid_cache from fault.c to mmu.c
  xtensa: extract vmalloc_fault code into a function
  xtensa: noMMU: allow handling protection faults

 arch/xtensa/Kconfig        |  11 ++++
 arch/xtensa/kernel/traps.c |  20 +++----
 arch/xtensa/mm/Makefile    |   3 +-
 arch/xtensa/mm/fault.c     | 112 +++++++++++++++++++------------------
 arch/xtensa/mm/mmu.c       |   2 +
 5 files changed, 83 insertions(+), 65 deletions(-)

-- 
2.30.2