diff options
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index d44bee96a5fe..7a0707a48047 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -88,6 +88,11 @@ static void unmap_region(struct mm_struct *mm, * w: (no) no w: (no) no w: (copy) copy w: (no) no * x: (no) no x: (no) yes x: (no) yes x: (yes) yes * + * On arm64, PROT_EXEC has the following behaviour for both MAP_SHARED and + * MAP_PRIVATE: + * r: (no) no + * w: (no) no + * x: (yes) yes */ pgprot_t protection_map[16] = { __P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111, @@ -2653,16 +2658,18 @@ static inline void verify_mm_writelocked(struct mm_struct *mm) * anonymous maps. eventually we may be able to do some * brk-specific accounting here. */ -static int do_brk(unsigned long addr, unsigned long len) +static int do_brk(unsigned long addr, unsigned long request) { struct mm_struct *mm = current->mm; struct vm_area_struct *vma, *prev; - unsigned long flags; + unsigned long flags, len; struct rb_node **rb_link, *rb_parent; pgoff_t pgoff = addr >> PAGE_SHIFT; int error; - len = PAGE_ALIGN(len); + len = PAGE_ALIGN(request); + if (len < request) + return -ENOMEM; if (!len) return 0; @@ -3061,6 +3068,14 @@ out: return ERR_PTR(ret); } +bool vma_is_special_mapping(const struct vm_area_struct *vma, + const struct vm_special_mapping *sm) +{ + return vma->vm_private_data == sm && + (vma->vm_ops == &special_mapping_vmops || + vma->vm_ops == &legacy_special_mapping_vmops); +} + /* * Called with mm->mmap_sem held for writing. * Insert a new vma covering the given region, with the given flags. |