diff options
Diffstat (limited to 'mm/gup.c')
| -rw-r--r-- | mm/gup.c | 16 |
1 files changed, 9 insertions, 7 deletions
@@ -1,3 +1,4 @@ +// SPDX-License-Identifier: GPL-2.0-only #include <linux/kernel.h> #include <linux/errno.h> #include <linux/err.h> @@ -1041,10 +1042,6 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, BUG_ON(ret >= nr_pages); } - if (!pages) - /* If it's a prefault don't insist harder */ - return ret; - if (ret > 0) { nr_pages -= ret; pages_done += ret; @@ -1060,8 +1057,12 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, pages_done = ret; break; } - /* VM_FAULT_RETRY triggered, so seek to the faulting offset */ - pages += ret; + /* + * VM_FAULT_RETRY triggered, so seek to the faulting offset. + * For the prefault case (!pages) we only update counts. + */ + if (likely(pages)) + pages += ret; start += ret << PAGE_SHIFT; /* @@ -1084,7 +1085,8 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, pages_done++; if (!nr_pages) break; - pages++; + if (likely(pages)) + pages++; start += PAGE_SIZE; } if (lock_dropped && *locked) { |