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| author |   Michael Ellerman <mpe@ellerman.id.au> | 2017-07-14 16:51:23 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-07-18 19:54:24 +1000 |
| commit | 029d9252b116fa52a95150819e62af1f6e420fe5 (patch) | |
| tree | 6f7832ca67de31a117dbb1b3346bfae3ec1a348e /arch/powerpc/mm/pgtable-radix.c | |
| parent | powerpc/mm/hash: Refactor hash__mark_rodata_ro() (diff) | |
| download | linux-dev-029d9252b116fa52a95150819e62af1f6e420fe5.tar.xz linux-dev-029d9252b116fa52a95150819e62af1f6e420fe5.zip | |
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 <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/mm/pgtable-radix.c')
| -rw-r--r-- | arch/powerpc/mm/pgtable-radix.c | 8 |
1 files changed, 8 insertions, 0 deletions
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, |