Avoid taking an extra trip down the mmap tree by checking the vmas
directly. mprotect (per POSIX) tolerates partial failure.
Signed-off-by: Pedro Falcato <pedro.falcato@xxxxxxxxx>
---
mm/mprotect.c | 12 +++---------
1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 222ab434da5..b1980ea1cc3 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -589,6 +589,9 @@ mprotect_fixup(struct vma_iterator *vmi, struct mmu_gather *tlb,
unsigned long charged = 0;
int error;
+ if (!can_modify_vma(vma))
+ return -EPERM;
+
if (newflags == oldflags) {
*pprev = vma;
return 0;
@@ -747,15 +750,6 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
}
}
- /*
- * checking if memory is sealed.
- * can_modify_mm assumes we have acquired the lock on MM.
- */
- if (unlikely(!can_modify_mm(current->mm, start, end))) {
- error = -EPERM;
- goto out;
- }
-
prev = vma_prev(&vmi);
if (start > vma->vm_start)
prev = vma;
--
2.46.0
