linux-kernel - [PATCH] drm/amd/display: No need for Null pointer check before kfree

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Date:   Wed, 28 Dec 2022 00:09:51 +0530
From:   Deepak R Varma <drv@...lo.com>
To:     Harry Wentland <harry.wentland@....com>,
        Leo Li <sunpeng.li@....com>,
        Rodrigo Siqueira <Rodrigo.Siqueira@....com>,
        Alex Deucher <alexander.deucher@....com>,
        Christian König <christian.koenig@....com>,
        "Pan, Xinhui" <Xinhui.Pan@....com>,
        David Airlie <airlied@...il.com>,
        Daniel Vetter <daniel@...ll.ch>, amd-gfx@...ts.freedesktop.org,
        dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org
Cc:     Saurabh Singh Sengar <ssengar@...rosoft.com>,
        Praveen Kumar <kumarpraveen@...ux.microsoft.com>,
        Deepak R Varma <drv@...lo.com>
Subject: [PATCH] drm/amd/display: No need for Null pointer check before kfree

kfree() & vfree() internally performs NULL check on the pointer handed
to it and take no action if it indeed is NULL. Hence there is no need
for a pre-check of the memory pointer before handing it to
kfree()/vfree().

Issue reported by ifnullfree.cocci Coccinelle semantic patch script.

Signed-off-by: Deepak R Varma <drv@...lo.com>
---
 drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c | 3 +--
 drivers/gpu/drm/amd/display/dc/clk_mgr/dcn32/dcn32_clk_mgr.c | 3 +--
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c
index 3ce0ee0d012f..694a9d3d92ae 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn30/dcn30_clk_mgr.c
@@ -577,8 +577,7 @@ void dcn3_clk_mgr_construct(

 void dcn3_clk_mgr_destroy(struct clk_mgr_internal *clk_mgr)
 {
-	if (clk_mgr->base.bw_params)
-		kfree(clk_mgr->base.bw_params);
+	kfree(clk_mgr->base.bw_params);

 	if (clk_mgr->wm_range_table)
 		dm_helpers_free_gpu_mem(clk_mgr->base.ctx, DC_MEM_ALLOC_TYPE_GART,
diff --git a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn32/dcn32_clk_mgr.c b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn32/dcn32_clk_mgr.c
index 200fcec19186..ba9814f88f48 100644
--- a/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn32/dcn32_clk_mgr.c
+++ b/drivers/gpu/drm/amd/display/dc/clk_mgr/dcn32/dcn32_clk_mgr.c
@@ -783,8 +783,7 @@ void dcn32_clk_mgr_construct(

 void dcn32_clk_mgr_destroy(struct clk_mgr_internal *clk_mgr)
 {
-	if (clk_mgr->base.bw_params)
-		kfree(clk_mgr->base.bw_params);
+	kfree(clk_mgr->base.bw_params);

 	if (clk_mgr->wm_range_table)
 		dm_helpers_free_gpu_mem(clk_mgr->base.ctx, DC_MEM_ALLOC_TYPE_GART,
--
2.34.1