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From:   Jiasheng Jiang <jiasheng@iscas.ac.cn>
To:     dmitry.baryshkov@linaro.org, robdclark@gmail.com,
        quic_abhinavk@quicinc.com, sean@poorly.run, airlied@gmail.com,
        daniel@ffwll.ch, marijn.suijten@somainline.org, vkoul@kernel.org,
        dianders@chromium.org, marex@denx.de, vladimir.lypak@gmail.com
Cc:     linux-arm-msm@vger.kernel.org, dri-devel@lists.freedesktop.org,
        freedreno@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        Jiasheng Jiang <jiasheng@iscas.ac.cn>
Subject: [PATCH v2] drm/msm/dsi: Add missing check for alloc_ordered_workqueue
Date:   Mon,  9 Jan 2023 10:50:44 +0800
Message-Id: <20230109025044.27766-1-jiasheng@iscas.ac.cn>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Add check for the return value of alloc_ordered_workqueue as it may return
NULL pointer and cause NULL pointer dereference.
Moreover, change the "goto fail" into "return ret" and drop the "fail"
label since they are the same.

Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
---
Changelog:

v1 -> v2:

1. Change the "goto fail" into "return ret" and drop the "fail" label.
---
 drivers/gpu/drm/msm/dsi/dsi_host.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/msm/dsi/dsi_host.c b/drivers/gpu/drm/msm/dsi/dsi_host.c
index 89aadd3b3202..819f5be5fd77 100644
--- a/drivers/gpu/drm/msm/dsi/dsi_host.c
+++ b/drivers/gpu/drm/msm/dsi/dsi_host.c
@@ -1884,7 +1884,7 @@ int msm_dsi_host_init(struct msm_dsi *msm_dsi)
 	msm_host = devm_kzalloc(&pdev->dev, sizeof(*msm_host), GFP_KERNEL);
 	if (!msm_host) {
 		ret = -ENOMEM;
-		goto fail;
+		return ret;
 	}
 
 	msm_host->pdev = pdev;
@@ -1893,14 +1893,14 @@ int msm_dsi_host_init(struct msm_dsi *msm_dsi)
 	ret = dsi_host_parse_dt(msm_host);
 	if (ret) {
 		pr_err("%s: failed to parse dt\n", __func__);
-		goto fail;
+		return ret;
 	}
 
 	msm_host->ctrl_base = msm_ioremap_size(pdev, "dsi_ctrl", &msm_host->ctrl_size);
 	if (IS_ERR(msm_host->ctrl_base)) {
 		pr_err("%s: unable to map Dsi ctrl base\n", __func__);
 		ret = PTR_ERR(msm_host->ctrl_base);
-		goto fail;
+		return ret;
 	}
 
 	pm_runtime_enable(&pdev->dev);
@@ -1909,7 +1909,7 @@ int msm_dsi_host_init(struct msm_dsi *msm_dsi)
 	if (!msm_host->cfg_hnd) {
 		ret = -EINVAL;
 		pr_err("%s: get config failed\n", __func__);
-		goto fail;
+		return ret;
 	}
 	cfg = msm_host->cfg_hnd->cfg;
 
@@ -1917,7 +1917,7 @@ int msm_dsi_host_init(struct msm_dsi *msm_dsi)
 	if (msm_host->id < 0) {
 		ret = msm_host->id;
 		pr_err("%s: unable to identify DSI host index\n", __func__);
-		goto fail;
+		return ret;
 	}
 
 	/* fixup base address by io offset */
@@ -1927,19 +1927,19 @@ int msm_dsi_host_init(struct msm_dsi *msm_dsi)
 					    cfg->regulator_data,
 					    &msm_host->supplies);
 	if (ret)
-		goto fail;
+		return ret;
 
 	ret = dsi_clk_init(msm_host);
 	if (ret) {
 		pr_err("%s: unable to initialize dsi clks\n", __func__);
-		goto fail;
+		return ret;
 	}
 
 	msm_host->rx_buf = devm_kzalloc(&pdev->dev, SZ_4K, GFP_KERNEL);
 	if (!msm_host->rx_buf) {
 		ret = -ENOMEM;
 		pr_err("%s: alloc rx temp buf failed\n", __func__);
-		goto fail;
+		return ret;
 	}
 
 	ret = devm_pm_opp_set_clkname(&pdev->dev, "byte");
@@ -1977,15 +1977,17 @@ int msm_dsi_host_init(struct msm_dsi *msm_dsi)
 
 	/* setup workqueue */
 	msm_host->workqueue = alloc_ordered_workqueue("dsi_drm_work", 0);
+	if (!msm_host->workqueue) {
+		ret = -ENOMEM;
+		return ret;
+	}
+
 	INIT_WORK(&msm_host->err_work, dsi_err_worker);
 
 	msm_dsi->id = msm_host->id;
 
 	DBG("Dsi Host %d initialized", msm_host->id);
 	return 0;
-
-fail:
-	return ret;
 }
 
 void msm_dsi_host_destroy(struct mipi_dsi_host *host)
-- 
2.25.1