FROMLIST: staging: android: ashmem: remove usage of list iterator after the loop...

In preparation to limit the scope of a list iterator to the list
traversal loop, use a dedicated pointer to point to the found element
[1].

Before, the code implicitly used the head when no element was found
when using &pos->list. Since the new variable is only set if an
element was found, the head needs to be used explicitly if the
variable is NULL.

Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
[sw0312.kim: cherry-pick commit 4f49a861af66 of https://android.googlesource.com/kernel/common/+/refs/heads/android15-6.6 to support waydroid on tizen]
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Change-Id: Ifaf19dd876a513a1952fac448079d664aebdf604

diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index ddbde3f..a1e2458 100644 (file)
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -703,30 +703,33 @@ static int ashmem_pin(struct ashmem_area *asma, size_t pgstart, size_t pgend,
 static int ashmem_unpin(struct ashmem_area *asma, size_t pgstart, size_t pgend,
                        struct ashmem_range **new_range)
 {
-       struct ashmem_range *range, *next;
+       struct ashmem_range *range = NULL, *iter, *next;
        unsigned int purged = ASHMEM_NOT_PURGED;
 
 restart:
-       list_for_each_entry_safe(range, next, &asma->unpinned_list, unpinned) {
+       list_for_each_entry_safe(iter, next, &asma->unpinned_list, unpinned) {
                /* short circuit: this is our insertion point */
-               if (range_before_page(range, pgstart))
+               if (range_before_page(iter, pgstart)) {
+                       range = iter;
                        break;
+               }
 
                /*
                 * The user can ask us to unpin pages that are already entirely
                 * or partially pinned. We handle those two cases here.
                 */
-               if (page_range_subsumed_by_range(range, pgstart, pgend))
+               if (page_range_subsumed_by_range(iter, pgstart, pgend))
                        return 0;
-               if (page_range_in_range(range, pgstart, pgend)) {
-                       pgstart = min(range->pgstart, pgstart);
-                       pgend = max(range->pgend, pgend);
-                       purged |= range->purged;
-                       range_del(range);
+               if (page_range_in_range(iter, pgstart, pgend)) {
+                       pgstart = min(iter->pgstart, pgstart);
+                       pgend = max(iter->pgend, pgend);
+                       purged |= iter->purged;
+                       range_del(iter);
                        goto restart;
                }
        }
 
+       range = list_prepare_entry(range, &asma->unpinned_list, unpinned);
        range_alloc(asma, range, purged, pgstart, pgend, new_range);
        return 0;
 }