Check return value of range_alloc, ashmem_shrink_scan and
register_shrinker. Handle errors correctly.

Signed-off-by: Arvind Yadav <arvind.yadav...@gmail.com>
---
 drivers/staging/android/ashmem.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/staging/android/ashmem.c b/drivers/staging/android/ashmem.c
index ca9a53c..eacc48d 100644
--- a/drivers/staging/android/ashmem.c
+++ b/drivers/staging/android/ashmem.c
@@ -595,6 +595,7 @@ static int ashmem_pin(struct ashmem_area *asma, size_t 
pgstart, size_t pgend)
 {
        struct ashmem_range *range, *next;
        int ret = ASHMEM_NOT_PURGED;
+       int err;
 
        list_for_each_entry_safe(range, next, &asma->unpinned_list, unpinned) {
                /* moved past last applicable page; we can short circuit */
@@ -643,8 +644,11 @@ static int ashmem_pin(struct ashmem_area *asma, size_t 
pgstart, size_t pgend)
                         * more complicated, we allocate a new range for the
                         * second half and adjust the first chunk's endpoint.
                         */
-                       range_alloc(asma, range, range->purged,
-                                   pgend + 1, range->pgend);
+                       err = range_alloc(asma, range, range->purged,
+                                         pgend + 1, range->pgend);
+                       if (err)
+                               return err;
+
                        range_shrink(range, range->pgstart, pgstart - 1);
                        break;
                }
@@ -800,7 +804,9 @@ static long ashmem_ioctl(struct file *file, unsigned int 
cmd, unsigned long arg)
                                .nr_to_scan = LONG_MAX,
                        };
                        ret = ashmem_shrink_count(&ashmem_shrinker, &sc);
-                       ashmem_shrink_scan(&ashmem_shrinker, &sc);
+                       if (ret)
+                               return ret;
+                       ret = ashmem_shrink_scan(&ashmem_shrinker, &sc);
                }
                break;
        }
@@ -870,12 +876,18 @@ static int __init ashmem_init(void)
                goto out_free2;
        }
 
-       register_shrinker(&ashmem_shrinker);
+       ret = register_shrinker(&ashmem_shrinker);
+       if (unlikely(ret)) {
+               pr_err("failed to register shrinker!\n");
+               goto out_free3;
+       }
 
        pr_info("initialized\n");
 
        return 0;
 
+out_free3:
+       misc_deregister(&ashmem_misc);
 out_free2:
        kmem_cache_destroy(ashmem_range_cachep);
 out_free1:
-- 
2.7.4

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