Currently on arm64 compat kuser helper are enabled by default. To be on pair with arm32, this patchset makes it possible to disable the kuser helpers by adding a CONFIG_KUSER_HELPERS option which is enabled by default to avoid compatibility issues. When the config option is disabled: - The kuser helpers-related code is not compiled with the kernel. - The kuser helpers mapping, for any compat process, at 0xffff0000 is not done. - Any attempt to use a kuser helper from a compat process will result in a segfault. Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Signed-off-by: Vincenzo Frascino <vincenzo.frascino@xxxxxxx> Vincenzo Frascino (4): arm64: compat: Alloc separate pages for vectors and sigpage arm64: compat: Split kuser32 arm64: compat: Refactor aarch32_alloc_vdso_pages() arm64: compat: Add KUSER_HELPERS config option arch/arm64/Kconfig | 30 ++++++ arch/arm64/include/asm/elf.h | 6 +- arch/arm64/include/asm/processor.h | 4 +- arch/arm64/include/asm/signal32.h | 2 - arch/arm64/kernel/Makefile | 5 +- arch/arm64/kernel/kuser32.S | 65 +------------ arch/arm64/kernel/signal32.c | 5 +- arch/arm64/kernel/sigreturn32.S | 46 +++++++++ arch/arm64/kernel/vdso.c | 150 +++++++++++++++++++++++------ 9 files changed, 211 insertions(+), 102 deletions(-) create mode 100644 arch/arm64/kernel/sigreturn32.S -- 2.21.0
