mm/mprotect.c: avoid repeated assignment in do_mprotect_pkey()

After adjustment, the repeated assignment of "prev" is avoided, and the
readability of the code is improved.

Link: https://lkml.kernel.org/r/20211012152444.4127-1-fishland@aliyun.com
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Liu Song <liu.song11@zte.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 883e2cc85cad84ad0e67822b8ac22a0ecbae9aee..e552f5e0ccbded82e503eba25f45b8a3a938c2c2 100644 (file)
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -563,7 +563,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
        error = -ENOMEM;
        if (!vma)
                goto out;
-       prev = vma->vm_prev;
+
        if (unlikely(grows & PROT_GROWSDOWN)) {
                if (vma->vm_start >= end)
                        goto out;
@@ -581,8 +581,11 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
                                goto out;
                }
        }
+
        if (start > vma->vm_start)
                prev = vma;
+       else
+               prev = vma->vm_prev;
 
        for (nstart = start ; ; ) {
                unsigned long mask_off_old_flags;