Am 02.01.2018 um 04:05 schrieb He, Roger:
-----Original Message-----
From: Xiongwei Song [mailto:sxwjean@xxxxxxxxx]
Sent: Sunday, December 31, 2017 7:40 PM
To: Koenig, Christian <Christian.Koenig@xxxxxxx>; He, Roger <Hongbo.He@xxxxxxx>; airlied@xxxxxxxx
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
Subject: [PATCH] drm/ttm: optimize errors checking and free _manager when finishing
In the function ttm_page_alloc_init, kzalloc call is made for variable _manager, we need to check its return value, it may return NULL.
In the function ttm_page_alloc_fini, we need to call kfree for variable _manager, instead of make _manager NULL directly.
Signed-off-by: Xiongwei Song <sxwjean@xxxxxxxxx>
---
drivers/gpu/drm/ttm/ttm_page_alloc.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_page_alloc.c b/drivers/gpu/drm/ttm/ttm_page_alloc.c
index b5ba6441489f..e20a0b8e352b 100644
--- a/drivers/gpu/drm/ttm/ttm_page_alloc.c
+++ b/drivers/gpu/drm/ttm/ttm_page_alloc.c
@@ -1007,6 +1007,10 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
pr_info("Initializing pool allocator\n");
_manager = kzalloc(sizeof(*_manager), GFP_KERNEL);
+ if (!_manager) {
+ ret = -ENOMEM;
+ goto out;
+ }
Seems we only need above here for this patch I think.
The rest is no need, because ttm_pool_kobj_release will kfree _manager.
Yes, agree. Freeing it again in ttm_page_alloc_fini will actually double
free the memory and probably cause some problems.
Please refine the patch with only the additional error handling.
Regards,
Christian.
Thanks
Roger(Hongbo.He)
ttm_page_pool_init_locked(&_manager->wc_pool, GFP_HIGHUSER, "wc", 0);
@@ -1034,13 +1038,17 @@ int ttm_page_alloc_init(struct ttm_mem_global *glob, unsigned max_pages)
&glob->kobj, "pool");
if (unlikely(ret != 0)) {
kobject_put(&_manager->kobj);
- _manager = NULL;
- return ret;
+ goto out_free_mgr;
}
ttm_pool_mm_shrink_init(_manager);
return 0;
+out_free_mgr:
+ kfree(_manager);
+ _manager = NULL;
+out:
+ return ret;
}
void ttm_page_alloc_fini(void)
@@ -1055,6 +1063,7 @@ void ttm_page_alloc_fini(void)
ttm_page_pool_free(&_manager->pools[i], FREE_ALL_PAGES, true);
kobject_put(&_manager->kobj);
+ kfree(_manager);
_manager = NULL;
}
--
2.15.1
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