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 <jcrouse@codeaurora.org>
Signed-off-by: Harshitha Sai Neelati <quic_hsaineel@quicinc.com>
Signed-off-by: NISARG SHETH <quic_nsheth@quicinc.com>
This commit is contained in:
NISARG SHETH 2023-11-20 15:51:40 +05:30
commit 37db312f1e

View file

@ -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
@ -83,6 +84,15 @@ _kgsl_pool_zero_page(struct page *p, unsigned int pool_order)
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;
}
_kgsl_pool_zero_page(p, pool->pool_order);
spin_lock(&pool->list_lock);