powerpc/mmu: add is_strict_kernel_rwx() helper

Add a helper to know whether STRICT_KERNEL_RWX is enabled.

This is based on rodata_enabled flag which is defined only
when CONFIG_STRICT_KERNEL_RWX is selected.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
This commit is contained in:
Christophe Leroy 2019-02-21 19:08:45 +00:00 committed by Michael Ellerman
parent 02d5d13b45
commit 28ea38b9cb
2 changed files with 12 additions and 3 deletions

View file

@ -289,6 +289,17 @@ static inline u16 get_mm_addr_key(struct mm_struct *mm, unsigned long address)
}
#endif /* CONFIG_PPC_MEM_KEYS */
#ifdef CONFIG_STRICT_KERNEL_RWX
static inline bool strict_kernel_rwx_enabled(void)
{
return rodata_enabled;
}
#else
static inline bool strict_kernel_rwx_enabled(void)
{
return false;
}
#endif
#endif /* !__ASSEMBLY__ */
/* The kernel use the constants below to index in the page sizes array.

View file

@ -108,12 +108,10 @@ static void __init MMU_setup(void)
__map_without_bats = 1;
__map_without_ltlbs = 1;
}
#ifdef CONFIG_STRICT_KERNEL_RWX
if (rodata_enabled) {
if (strict_kernel_rwx_enabled()) {
__map_without_bats = 1;
__map_without_ltlbs = 1;
}
#endif
}
/*