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@gmail.com --- mm/mprotect.c | 12 +++--------- 1 file changed, 3 insertions(+), 9 deletions(-)
diff --git a/mm/mprotect.c b/mm/mprotect.c index 446f8e5f10d9..0c5d6d06107d 100644 --- a/mm/mprotect.c +++ b/mm/mprotect.c @@ -611,6 +611,9 @@ 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; @@ -769,15 +772,6 @@ 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;