diff options
Diffstat (limited to 'arch/powerpc/mm')
| -rw-r--r-- | arch/powerpc/mm/hash_utils_64.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c index ed190e42bbc5..36e00371ba5a 100644 --- a/arch/powerpc/mm/hash_utils_64.c +++ b/arch/powerpc/mm/hash_utils_64.c @@ -921,7 +921,7 @@ void demote_segment_4k(struct mm_struct *mm, unsigned long addr) * Userspace sets the subpage permissions using the subpage_prot system call. * * Result is 0: full permissions, _PAGE_RW: read-only, - * _PAGE_USER or _PAGE_USER|_PAGE_RW: no access. + * _PAGE_RWX: no access. */ static int subpage_protection(struct mm_struct *mm, unsigned long ea) { @@ -947,8 +947,13 @@ static int subpage_protection(struct mm_struct *mm, unsigned long ea) /* extract 2-bit bitfield for this 4k subpage */ spp >>= 30 - 2 * ((ea >> 12) & 0xf); - /* turn 0,1,2,3 into combination of _PAGE_USER and _PAGE_RW */ - spp = ((spp & 2) ? _PAGE_USER : 0) | ((spp & 1) ? _PAGE_RW : 0); + /* + * 0 -> full premission + * 1 -> Read only + * 2 -> no access. + * We return the flag that need to be cleared. + */ + spp = ((spp & 2) ? _PAGE_RWX : 0) | ((spp & 1) ? _PAGE_WRITE : 0); return spp; } |