From 029d9252b116fa52a95150819e62af1f6e420fe5 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Fri, 14 Jul 2017 16:51:23 +1000 Subject: powerpc/mm: Mark __init memory no-execute when STRICT_KERNEL_RWX=y Currently even with STRICT_KERNEL_RWX we leave the __init text marked executable after init, which is bad. Add a hook to mark it NX (no-execute) before we free it, and implement it for radix and hash. Note that we use __init_end as the end address, not _einittext, because overlaps_kernel_text() uses __init_end, because there are additional executable sections other than .init.text between __init_begin and __init_end. Tested on radix and hash with: 0:mon> p $__init_begin *** 400 exception occurred Fixes: 1e0fc9d1eb2b ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs") Signed-off-by: Michael Ellerman --- arch/powerpc/mm/pgtable-radix.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/powerpc/mm/pgtable-radix.c') diff --git a/arch/powerpc/mm/pgtable-radix.c b/arch/powerpc/mm/pgtable-radix.c index 336e52ec652c..5cc50d47ce3f 100644 --- a/arch/powerpc/mm/pgtable-radix.c +++ b/arch/powerpc/mm/pgtable-radix.c @@ -162,6 +162,14 @@ void radix__mark_rodata_ro(void) radix__change_memory_range(start, end, _PAGE_WRITE); } + +void radix__mark_initmem_nx(void) +{ + unsigned long start = (unsigned long)__init_begin; + unsigned long end = (unsigned long)__init_end; + + radix__change_memory_range(start, end, _PAGE_EXEC); +} #endif /* CONFIG_STRICT_KERNEL_RWX */ static inline void __meminit print_mapping(unsigned long start, -- cgit v1.2.3