ashmem: Fix ASHMEM_SET_PROT_MASK.
Change-Id: I1412cc9560de8c4feb1162fc30922f0e3362a476
Signed-off-by: Arve Hjønnevåg <arve@android.com>
diff --git a/mm/ashmem.c b/mm/ashmem.c
index 04e886e..7b75f41 100644
--- a/mm/ashmem.c
+++ b/mm/ashmem.c
@@ -236,6 +236,14 @@
return ret;
}
+static inline unsigned long
+calc_vm_may_flags(unsigned long prot)
+{
+ return _calc_vm_trans(prot, PROT_READ, VM_MAYREAD ) |
+ _calc_vm_trans(prot, PROT_WRITE, VM_MAYWRITE) |
+ _calc_vm_trans(prot, PROT_EXEC, VM_MAYEXEC);
+}
+
static int ashmem_mmap(struct file *file, struct vm_area_struct *vma)
{
struct ashmem_area *asma = file->private_data;
@@ -250,10 +258,12 @@
}
/* requested protection bits must match our allowed protection mask */
- if (unlikely((vma->vm_flags & ~asma->prot_mask) & PROT_MASK)) {
+ if (unlikely((vma->vm_flags & ~calc_vm_prot_bits(asma->prot_mask)) &
+ calc_vm_prot_bits(PROT_MASK))) {
ret = -EPERM;
goto out;
}
+ vma->vm_flags &= ~calc_vm_may_flags(~asma->prot_mask);
if (!asma->file) {
char *name = ASHMEM_NAME_DEF;