On Tue, 18 May 2021 10:20:31 +0300 Mike Rapoport rppt@kernel.org wrote:
From: Mike Rapoport rppt@linux.ibm.com
Introduce "memfd_secret" system call with the ability to create memory areas visible only in the context of the owning process and not mapped not only to other processes but in the kernel page tables as well.
...
--- a/mm/Kconfig +++ b/mm/Kconfig @@ -901,4 +901,9 @@ config KMAP_LOCAL # struct io_mapping based helper. Selected by drivers that need them config IO_MAPPING bool
+config SECRETMEM
- def_bool ARCH_HAS_SET_DIRECT_MAP && !EMBEDDED
- select STRICT_DEVMEM
endmenu
WARNING: unmet direct dependencies detected for STRICT_DEVMEM Depends on [n]: MMU [=y] && DEVMEM [=n] && (ARCH_HAS_DEVMEM_IS_ALLOWED [=y] || GENERIC_LIB_DEVMEM_IS_ALLOWED [=n]) Selected by [y]: - SECRETMEM [=y]
so I went back to the v19 version, with
--- a/mm/Kconfig~mm-introduce-memfd_secret-system-call-to-create-secret-memory-areas-fix +++ a/mm/Kconfig @@ -907,6 +907,5 @@ config IO_MAPPING
config SECRETMEM def_bool ARCH_HAS_SET_DIRECT_MAP && !EMBEDDED - select STRICT_DEVMEM
endmenu _