This patch-set introduces the possibility of protecting memory that has been allocated dynamically.
The memory is managed in pools: when a memory pool is turned into R/O, all the memory that is part of it, will become R/O. A R/O pool can be destroyed, to recover its memory, but it cannot be turned back into R/W mode. This is intentional. This feature is meant for data that doesn't need further modifications after initialization. However the data might need to be released, for example as part of module unloading. To do this, the memory must first be freed, then the pool can be destroyed. An example is provided, in the form of self-testing. Changes since v15: [http://www.openwall.com/lists/kernel-hardening/2018/02/11/4] - Fixed remaining broken comments - Fixed remaining broken "Returns" instead of "Return:" in kernel-doc - Converted "Return:" values to lists - Fixed SPDX license statements Igor Stoppa (6): genalloc: track beginning of allocations genalloc: selftest struct page: add field for vm_struct Protectable Memory Pmalloc: self-test Documentation for Pmalloc Documentation/core-api/index.rst | 1 + Documentation/core-api/pmalloc.rst | 114 +++++++ include/linux/genalloc-selftest.h | 26 ++ include/linux/genalloc.h | 7 +- include/linux/mm_types.h | 1 + include/linux/pmalloc.h | 242 ++++++++++++++ include/linux/vmalloc.h | 1 + init/main.c | 2 + lib/Kconfig | 15 + lib/Makefile | 1 + lib/genalloc-selftest.c | 400 ++++++++++++++++++++++ lib/genalloc.c | 658 +++++++++++++++++++++++++++---------- mm/Kconfig | 15 + mm/Makefile | 2 + mm/pmalloc-selftest.c | 64 ++++ mm/pmalloc-selftest.h | 24 ++ mm/pmalloc.c | 501 ++++++++++++++++++++++++++++ mm/usercopy.c | 33 ++ mm/vmalloc.c | 18 +- 19 files changed, 1950 insertions(+), 175 deletions(-) create mode 100644 Documentation/core-api/pmalloc.rst create mode 100644 include/linux/genalloc-selftest.h create mode 100644 include/linux/pmalloc.h create mode 100644 lib/genalloc-selftest.c create mode 100644 mm/pmalloc-selftest.c create mode 100644 mm/pmalloc-selftest.h create mode 100644 mm/pmalloc.c -- 2.14.1