VM: add "vm_mmap()" helper function
This continues the theme started with vm_brk() and vm_munmap():
vm_mmap() does the same thing as do_mmap(), but additionally does the
required VM locking.
This uninlines (and rewrites it to be clearer) do_mmap(), which sadly
duplicates it in mm/mmap.c and mm/nommu.c. But that way we don't have
to export our internal do_mmap_pgoff() function.
Some day we hopefully don't have to export do_mmap() either, if all
modular users can become the simpler vm_mmap() instead. We're actually
very close to that already, with the notable exception of the (broken)
use in i810, and a couple of stragglers in binfmt_elf.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 8beb9ce..1457be3 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6336,13 +6336,11 @@
if (npages && !old.rmap) {
unsigned long userspace_addr;
- down_write(¤t->mm->mmap_sem);
- userspace_addr = do_mmap(NULL, 0,
+ userspace_addr = vm_mmap(NULL, 0,
npages * PAGE_SIZE,
PROT_READ | PROT_WRITE,
map_flags,
0);
- up_write(¤t->mm->mmap_sem);
if (IS_ERR((void *)userspace_addr))
return PTR_ERR((void *)userspace_addr);