From: Liu Song <liu.song11@xxxxxxxxxx> Subject: 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@xxxxxxxxxx Reviewed-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Liu Song <liu.song11@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/mprotect.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/mm/mprotect.c~mm-mprotectc-avoid-repeated-assignment-in-do_mprotect_pkey +++ a/mm/mprotect.c @@ -563,7 +563,7 @@ static int do_mprotect_pkey(unsigned lon 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 lon goto out; } } + if (start > vma->vm_start) prev = vma; + else + prev = vma->vm_prev; for (nstart = start ; ; ) { unsigned long mask_off_old_flags; _
