From e2f506a3fadf7310df96a7cd6476fb75459f91d7 Mon Sep 17 00:00:00 2001 From: Harshitha Sai Neelati Date: Thu, 16 Feb 2023 12:43:32 +0530 Subject: msm: kgsl: Make sure that pool pages don't have any extra references Before putting a page back in the pool be sure that it doesn't have any additional references that would be a signal that somebody else is looking at the page and that it would be a bad idea to keep it around and run the risk of accidentally handing it to a different process. Change-Id: Ic0dedbad0cf2ffb34b76ad23e393c5a911114b82 Signed-off-by: Jordan Crouse Signed-off-by: Harshitha Sai Neelati --- drivers/gpu/msm/kgsl_pool.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/gpu/msm/kgsl_pool.c b/drivers/gpu/msm/kgsl_pool.c index 4a9997b02155..52453e5a0791 100644 --- a/drivers/gpu/msm/kgsl_pool.c +++ b/drivers/gpu/msm/kgsl_pool.c @@ -1,4 +1,5 @@ /* Copyright (c) 2016-2017, The Linux Foundation. All rights reserved. + * Copyright (c) 2023 Qualcomm Innovation Center, Inc. All rights reserved. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 and @@ -78,6 +79,15 @@ _kgsl_pool_zero_page(struct page *p) static void _kgsl_pool_add_page(struct kgsl_page_pool *pool, struct page *p) { + /* + * Sanity check to make sure we don't re-pool a page that + * somebody else has a reference to. + */ + if (WARN_ON_ONCE(unlikely(page_count(p) > 1))) { + __free_pages(p, pool->pool_order); + return; + } + spin_lock(&pool->list_lock); list_add_tail(&p->lru, &pool->page_list); pool->page_count++; -- cgit v1.2.3