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| author | Michael Ellerman <mpe@ellerman.id.au> | 2017-07-14 08:51:23 +0200 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-07-18 11:54:24 +0200 |
| commit | 029d9252b116fa52a95150819e62af1f6e420fe5 (patch) | |
| tree | 6f7832ca67de31a117dbb1b3346bfae3ec1a348e /arch/powerpc/include/asm/pgtable.h | |
| parent | powerpc/mm/hash: Refactor hash__mark_rodata_ro() (diff) | |
| download | linux-029d9252b116fa52a95150819e62af1f6e420fe5.tar.xz linux-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/include/asm/pgtable.h')
| -rw-r--r-- | arch/powerpc/include/asm/pgtable.h | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h index dd01212935ac..afae9a336136 100644 --- a/arch/powerpc/include/asm/pgtable.h +++ b/arch/powerpc/include/asm/pgtable.h @@ -80,6 +80,13 @@ unsigned long vmalloc_to_phys(void *vmalloc_addr); void pgtable_cache_add(unsigned shift, void (*ctor)(void *)); void pgtable_cache_init(void); + +#ifdef CONFIG_STRICT_KERNEL_RWX +void mark_initmem_nx(void); +#else +static inline void mark_initmem_nx(void) { } +#endif + #endif /* __ASSEMBLY__ */ #endif /* _ASM_POWERPC_PGTABLE_H */ |