diff mbox series

[1/3] qcom: soc: llcc-slice: Clear the global drv_data pointer on error

Message ID 20181025163811.17316-2-jcrouse@codeaurora.org (mailing list archive)
State New, archived
Headers show
Series Fixes for failed LLCC probe | expand

Commit Message

Jordan Crouse Oct. 25, 2018, 4:38 p.m. UTC 
Currently the data structure for llc-slice is devm allocated and
stored as a global but never cleared if the probe function fails.
This is a problem because devm managed memory gets freed on probe
failure the API functions could access the pointer after it has been
freed.

Initialize the drv_data pointer to an error and reset it to an error
on probe failure or device destroy and add protection to the API
functions to make sure the memory doesn't get accessed.

Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
---
 drivers/soc/qcom/llcc-sdm845.c     |  6 +++
 drivers/soc/qcom/llcc-slice.c      | 71 +++++++++++++++++++++++-------
 include/linux/soc/qcom/llcc-qcom.h |  6 +++
 3 files changed, 66 insertions(+), 17 deletions(-)

Comments

Doug Anderson Oct. 26, 2018, 7:40 p.m. UTC | #1 
Hi,

On Thu, Oct 25, 2018 at 9:38 AM Jordan Crouse <jcrouse@codeaurora.org> wrote:
> + * qcom_llcc_remove - remove the sct table
> + * @pdev: Platform device pointer
> + */
> +int qcom_llcc_remove(struct platform_device *pdev);
>  #else

Funny that you didn't need to add anything to the "#else" case since
"remove" was already there.  ;-)

...in any case even though I'm not an expert on the LLCC this seems
like a good change.

Reviewed-by: Douglas Anderson <dianders@chromium.org>
Doug Anderson Dec. 10, 2018, 7:24 p.m. UTC | #2 
Hi,

On Thu, Oct 25, 2018 at 9:38 AM Jordan Crouse <jcrouse@codeaurora.org> wrote:
> @@ -142,6 +148,9 @@ int llcc_slice_activate(struct llcc_slice_desc *desc)
>         int ret;
>         u32 act_ctrl_val;
>
> +       if (IS_ERR(drv_data))
> +               return PTR_ERR(drv_data);
> +

There's a conflict with your other patch in commit ff49a5198fc1
("FROMLIST: soc: qcom: llcc-slice: Add error checks for API
functions") right here.  Maybe you should send a v2?  Presumably patch
#3 in this series would be dropped since there was some controversy
over it?

-Doug
Jordan Crouse Dec. 10, 2018, 9:32 p.m. UTC | #3 
On Mon, Dec 10, 2018 at 11:24:26AM -0800, Doug Anderson wrote:
> Hi,
> 
> On Thu, Oct 25, 2018 at 9:38 AM Jordan Crouse <jcrouse@codeaurora.org> wrote:
> > @@ -142,6 +148,9 @@ int llcc_slice_activate(struct llcc_slice_desc *desc)
> >         int ret;
> >         u32 act_ctrl_val;
> >
> > +       if (IS_ERR(drv_data))
> > +               return PTR_ERR(drv_data);
> > +
> 
> There's a conflict with your other patch in commit ff49a5198fc1
> ("FROMLIST: soc: qcom: llcc-slice: Add error checks for API
> functions") right here.  Maybe you should send a v2?  Presumably patch
> #3 in this series would be dropped since there was some controversy
> over it?

Yeah, patch 3 can be dropped. I'll try a v2 against the latest + greatest from
Andy.

Jordan
diff mbox series

Patch

diff --git a/drivers/soc/qcom/llcc-sdm845.c b/drivers/soc/qcom/llcc-sdm845.c
index 2e1e4f0a5db8..86600d97c36d 100644
--- a/drivers/soc/qcom/llcc-sdm845.c
+++ b/drivers/soc/qcom/llcc-sdm845.c
@@ -71,6 +71,11 @@  static struct llcc_slice_config sdm845_data[] =  {
 	SCT_ENTRY(LLCC_AUDHW,    22, 1024, 1, 1, 0xffc, 0x2,   0, 0, 1, 1, 0),
 };
 
+static int sdm845_qcom_llcc_remove(struct platform_device *pdev)
+{
+	return qcom_llcc_remove(pdev);
+}
+
 static int sdm845_qcom_llcc_probe(struct platform_device *pdev)
 {
 	return qcom_llcc_probe(pdev, sdm845_data, ARRAY_SIZE(sdm845_data));
@@ -87,6 +92,7 @@  static struct platform_driver sdm845_qcom_llcc_driver = {
 		.of_match_table = sdm845_qcom_llcc_of_match,
 	},
 	.probe = sdm845_qcom_llcc_probe,
+	.remove = sdm845_qcom_llcc_remove,
 };
 module_platform_driver(sdm845_qcom_llcc_driver);
 
diff --git a/drivers/soc/qcom/llcc-slice.c b/drivers/soc/qcom/llcc-slice.c
index 192ca761b2cb..cce6a23c40a2 100644
--- a/drivers/soc/qcom/llcc-slice.c
+++ b/drivers/soc/qcom/llcc-slice.c
@@ -46,7 +46,7 @@ 
 
 #define BANK_OFFSET_STRIDE	      0x80000
 
-static struct llcc_drv_data *drv_data;
+static struct llcc_drv_data *drv_data = (void *) -EPROBE_DEFER;
 
 static const struct regmap_config llcc_regmap_config = {
 	.reg_bits = 32,
@@ -68,6 +68,9 @@  struct llcc_slice_desc *llcc_slice_getd(u32 uid)
 	struct llcc_slice_desc *desc;
 	u32 sz, count;
 
+	if (IS_ERR(drv_data))
+		return ERR_CAST(drv_data);
+
 	cfg = drv_data->cfg;
 	sz = drv_data->cfg_size;
 
@@ -107,6 +110,9 @@  static int llcc_update_act_ctrl(u32 sid,
 	u32 slice_status;
 	int ret;
 
+	if (IS_ERR(drv_data))
+		return PTR_ERR(drv_data);
+
 	act_ctrl_reg = LLCC_TRP_ACT_CTRLn(sid);
 	status_reg = LLCC_TRP_STATUSn(sid);
 
@@ -142,6 +148,9 @@  int llcc_slice_activate(struct llcc_slice_desc *desc)
 	int ret;
 	u32 act_ctrl_val;
 
+	if (IS_ERR(drv_data))
+		return PTR_ERR(drv_data);
+
 	mutex_lock(&drv_data->lock);
 	if (test_bit(desc->slice_id, drv_data->bitmap)) {
 		mutex_unlock(&drv_data->lock);
@@ -176,6 +185,9 @@  int llcc_slice_deactivate(struct llcc_slice_desc *desc)
 	u32 act_ctrl_val;
 	int ret;
 
+	if (IS_ERR(drv_data))
+		return PTR_ERR(drv_data);
+
 	mutex_lock(&drv_data->lock);
 	if (!test_bit(desc->slice_id, drv_data->bitmap)) {
 		mutex_unlock(&drv_data->lock);
@@ -276,6 +288,14 @@  static int qcom_llcc_cfg_program(struct platform_device *pdev)
 	return ret;
 }
 
+int qcom_llcc_remove(struct platform_device *pdev)
+{
+	/* Set the global pointer to a error code to avoid referencing it */
+	drv_data = ERR_PTR(-ENODEV);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(qcom_llcc_remove);
+
 int qcom_llcc_probe(struct platform_device *pdev,
 		      const struct llcc_slice_config *llcc_cfg, u32 sz)
 {
@@ -287,35 +307,45 @@  int qcom_llcc_probe(struct platform_device *pdev,
 	struct platform_device *llcc_edac;
 
 	drv_data = devm_kzalloc(dev, sizeof(*drv_data), GFP_KERNEL);
-	if (!drv_data)
-		return -ENOMEM;
+	if (!drv_data) {
+		ret = -ENOMEM;
+		goto err;
+	}
 
 	llcc_banks_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
 							"llcc_base");
 	llcc_banks_base = devm_ioremap_resource(&pdev->dev, llcc_banks_res);
-	if (IS_ERR(llcc_banks_base))
-		return PTR_ERR(llcc_banks_base);
+	if (IS_ERR(llcc_banks_base)) {
+		ret = PTR_ERR(llcc_banks_base);
+		goto err;
+	}
 
 	drv_data->regmap = devm_regmap_init_mmio(dev, llcc_banks_base,
 						&llcc_regmap_config);
-	if (IS_ERR(drv_data->regmap))
-		return PTR_ERR(drv_data->regmap);
+	if (IS_ERR(drv_data->regmap)) {
+		ret = PTR_ERR(drv_data->regmap);
+		goto err;
+	}
 
 	llcc_bcast_res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
 							"llcc_broadcast_base");
 	llcc_bcast_base = devm_ioremap_resource(&pdev->dev, llcc_bcast_res);
-	if (IS_ERR(llcc_bcast_base))
-		return PTR_ERR(llcc_bcast_base);
+	if (IS_ERR(llcc_bcast_base)) {
+		ret = PTR_ERR(llcc_bcast_base);
+		goto err;
+	}
 
 	drv_data->bcast_regmap = devm_regmap_init_mmio(dev, llcc_bcast_base,
 							&llcc_regmap_config);
-	if (IS_ERR(drv_data->bcast_regmap))
-		return PTR_ERR(drv_data->bcast_regmap);
+	if (IS_ERR(drv_data->bcast_regmap)) {
+		ret = PTR_ERR(drv_data->bcast_regmap);
+		goto err;
+	}
 
 	ret = regmap_read(drv_data->regmap, LLCC_COMMON_STATUS0,
 						&num_banks);
 	if (ret)
-		return ret;
+		goto err;
 
 	num_banks &= LLCC_LB_CNT_MASK;
 	num_banks >>= LLCC_LB_CNT_SHIFT;
@@ -327,8 +357,10 @@  int qcom_llcc_probe(struct platform_device *pdev,
 
 	drv_data->offsets = devm_kcalloc(dev, num_banks, sizeof(u32),
 							GFP_KERNEL);
-	if (!drv_data->offsets)
-		return -ENOMEM;
+	if (!drv_data->offsets) {
+		ret = -ENOMEM;
+		goto err;
+	}
 
 	for (i = 0; i < num_banks; i++)
 		drv_data->offsets[i] = i * BANK_OFFSET_STRIDE;
@@ -336,8 +368,10 @@  int qcom_llcc_probe(struct platform_device *pdev,
 	drv_data->bitmap = devm_kcalloc(dev,
 	BITS_TO_LONGS(drv_data->max_slices), sizeof(unsigned long),
 						GFP_KERNEL);
-	if (!drv_data->bitmap)
-		return -ENOMEM;
+	if (!drv_data->bitmap) {
+		ret = -ENOMEM;
+		goto err;
+	}
 
 	drv_data->cfg = llcc_cfg;
 	drv_data->cfg_size = sz;
@@ -346,7 +380,7 @@  int qcom_llcc_probe(struct platform_device *pdev,
 
 	ret = qcom_llcc_cfg_program(pdev);
 	if (ret)
-		return ret;
+		goto err;
 
 	drv_data->ecc_irq = platform_get_irq(pdev, 0);
 	if (drv_data->ecc_irq >= 0) {
@@ -357,6 +391,9 @@  int qcom_llcc_probe(struct platform_device *pdev,
 			dev_err(dev, "Failed to register llcc edac driver\n");
 	}
 
+	return 0;
+err:
+	drv_data = ERR_PTR(-ENODEV);
 	return ret;
 }
 EXPORT_SYMBOL_GPL(qcom_llcc_probe);
diff --git a/include/linux/soc/qcom/llcc-qcom.h b/include/linux/soc/qcom/llcc-qcom.h
index 69c285b1c990..eb71a50b8afc 100644
--- a/include/linux/soc/qcom/llcc-qcom.h
+++ b/include/linux/soc/qcom/llcc-qcom.h
@@ -162,6 +162,12 @@  int llcc_slice_deactivate(struct llcc_slice_desc *desc);
  */
 int qcom_llcc_probe(struct platform_device *pdev,
 		      const struct llcc_slice_config *table, u32 sz);
+
+/**
+ * qcom_llcc_remove - remove the sct table
+ * @pdev: Platform device pointer
+ */
+int qcom_llcc_remove(struct platform_device *pdev);
 #else
 static inline struct llcc_slice_desc *llcc_slice_getd(u32 uid)
 {