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Input: stmpe-keypad - remove VLA usage

PATCH In review Gustavo A. R. Silva 2 participants 3 messages Mar 9, 2018 – Mar 10, 2018

Subsystems (3)
HID Arm STM32 Input drivers
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Gustavo A. R. Silva

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#0 lore raw

PATCH 1/1 Input: stmpe-keypad - remove VLA usage

In preparation to enabling -Wvla, remove VLA and replace it with a fixed-length array instead.

Fixed as part of the directive to remove all VLAs from the kernel: https://lkml.org/lkml/2018/3/7/621

Signed-off-by Gustavo A. R. Silva <[email protected]>
---
 drivers/input/keyboard/stmpe-keypad.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)
drivers/input/keyboard/stmpe-keypad.c +6 -4
index 8c6c0b9..cfa1dbe 100644
@@ -48,6 +48,8 @@
 #define STMPE_KEYPAD_KEYMAP_MAX_SIZE \
 	(STMPE_KEYPAD_MAX_ROWS * STMPE_KEYPAD_MAX_COLS)
 
+#define MAX_NUM_DATA			5
+
 /**
  * struct stmpe_keypad_variant - model-specific attributes
  * @auto_increment: whether the KPC_DATA_BYTE register address

@@ -74,7 +76,7 @@ struct stmpe_keypad_variant {
 static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
 	[STMPE1601] = {
 		.auto_increment		= true,
-		.num_data		= 5,
+		.num_data		= MAX_NUM_DATA,
 		.num_normal_data	= 3,
 		.max_cols		= 8,
 		.max_rows		= 8,

@@ -84,7 +86,7 @@ static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
 	[STMPE2401] = {
 		.auto_increment		= false,
 		.set_pullup		= true,
-		.num_data		= 3,
+		.num_data		= MAX_NUM_DATA - 2,
 		.num_normal_data	= 2,
 		.max_cols		= 8,
 		.max_rows		= 12,

@@ -94,7 +96,7 @@ static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
 	[STMPE2403] = {
 		.auto_increment		= true,
 		.set_pullup		= true,
-		.num_data		= 5,
+		.num_data		= MAX_NUM_DATA,
 		.num_normal_data	= 3,
 		.max_cols		= 8,
 		.max_rows		= 12,

@@ -156,7 +158,7 @@ static irqreturn_t stmpe_keypad_irq(int irq, void *dev)
 	struct stmpe_keypad *keypad = dev;
 	struct input_dev *input = keypad->input;
 	const struct stmpe_keypad_variant *variant = keypad->variant;
-	u8 fifo[variant->num_data];
+	u8 fifo[MAX_NUM_DATA];
 	int ret;
 	int i;
Signature · 1 line
2.7.4
maintainer
#1 lore raw
Quoted 34 lines · Gustavo A. R. Silva

In preparation to enabling -Wvla, remove VLA and replace it with a fixed-length array instead.

Fixed as part of the directive to remove all VLAs from the kernel: https://lkml.org/lkml/2018/3/7/621

Signed-off-by Gustavo A. R. Silva <[email protected]>
---
 drivers/input/keyboard/stmpe-keypad.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)
drivers/input/keyboard/stmpe-keypad.c +3 -1
index 8c6c0b9..cfa1dbe 100644
@@ -48,6 +48,8 @@
 #define STMPE_KEYPAD_KEYMAP_MAX_SIZE \
 	(STMPE_KEYPAD_MAX_ROWS * STMPE_KEYPAD_MAX_COLS)
 
+#define MAX_NUM_DATA			5
+
 /**
  * struct stmpe_keypad_variant - model-specific attributes
  * @auto_increment: whether the KPC_DATA_BYTE register address

@@ -74,7 +76,7 @@ struct stmpe_keypad_variant {
 static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
 	[STMPE1601] = {
 		.auto_increment		= true,
-		.num_data		= 5,
+		.num_data		= MAX_NUM_DATA,
 		.num_normal_data	= 3,
 		.max_cols		= 8,
 		.max_rows		= 8,

drivers/input/keyboard/stmpe-keypad.c static const struct stmpe_keypad_variant stmpe_keypad_variants[] = { · line 89

Quoted 5 lines
drivers/input/keyboard/stmpe-keypad.c +1 -1
@@ -84,7 +86,7 @@ static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
 	[STMPE2401] = {
 		.auto_increment		= false,
 		.set_pullup		= true,
-		.num_data		= 3,
+		.num_data		= MAX_NUM_DATA - 2,

Logically MAX_NUM_DATA - 2 does not mean anything, it is simply a way for you to get to 3, so I'd rather we did not do that.

Can we do

#define STMPE1601_NUM_DATA 5
#define STMPE2401_NUM_DATA 3
#define STMPE2403_NUM_DATA 5

#define MAX_NUM_DATA		max3(STMPE1601_NUM_DATA, \
				     STMPE2401_NUM_DATA, \
				     STMPE2403_NUM_DATA)

or simply

/* Make sure it covers all cases above */
#define MAX_NUM_DATA 5

Quoted 24 lines
drivers/input/keyboard/stmpe-keypad.c +2 -2
 		.num_normal_data	= 2,
 		.max_cols		= 8,
 		.max_rows		= 12,

@@ -94,7 +96,7 @@ static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
 	[STMPE2403] = {
 		.auto_increment		= true,
 		.set_pullup		= true,
-		.num_data		= 5,
+		.num_data		= MAX_NUM_DATA,
 		.num_normal_data	= 3,
 		.max_cols		= 8,
 		.max_rows		= 12,

@@ -156,7 +158,7 @@ static irqreturn_t stmpe_keypad_irq(int irq, void *dev)
 	struct stmpe_keypad *keypad = dev;
 	struct input_dev *input = keypad->input;
 	const struct stmpe_keypad_variant *variant = keypad->variant;
-	u8 fifo[variant->num_data];
+	u8 fifo[MAX_NUM_DATA];
 	int ret;
 	int i;
Signature · 1 line
2.7.4

Thanks.

Signature · 1 line
Dmitry
author
#2 lore raw

Hi Dmitry,

Quoted 35 lines · Dmitry Torokhov
Quoted 34 lines · Gustavo A. R. Silva

In preparation to enabling -Wvla, remove VLA and replace it with a fixed-length array instead.

Fixed as part of the directive to remove all VLAs from the kernel: https://lkml.org/lkml/2018/3/7/621

Signed-off-by Gustavo A. R. Silva <[email protected]>
---
  drivers/input/keyboard/stmpe-keypad.c | 10 ++++++----
  1 file changed, 6 insertions(+), 4 deletions(-)
drivers/input/keyboard/stmpe-keypad.c +3 -1
index 8c6c0b9..cfa1dbe 100644
@@ -48,6 +48,8 @@
  #define STMPE_KEYPAD_KEYMAP_MAX_SIZE \
  	(STMPE_KEYPAD_MAX_ROWS * STMPE_KEYPAD_MAX_COLS)
 
+#define MAX_NUM_DATA			5
+
  /**
   * struct stmpe_keypad_variant - model-specific attributes
   * @auto_increment: whether the KPC_DATA_BYTE register address

@@ -74,7 +76,7 @@ struct stmpe_keypad_variant {
  static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
  	[STMPE1601] = {
  		.auto_increment		= true,
-		.num_data		= 5,
+		.num_data		= MAX_NUM_DATA,
  		.num_normal_data	= 3,
  		.max_cols		= 8,
  		.max_rows		= 8,

@@ -84,7 +86,7 @@ static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
Quoted 9 lines

drivers/input/keyboard/stmpe-keypad.c static const struct stmpe_keypad_variant stmpe_keypad_variants[] = { · line 89

Quoted 5 lines
drivers/input/keyboard/stmpe-keypad.c +1 -1
  	[STMPE2401] = {
  		.auto_increment		= false,
  		.set_pullup		= true,
-		.num_data		= 3,
+		.num_data		= MAX_NUM_DATA - 2,

Logically MAX_NUM_DATA - 2 does not mean anything, it is simply a way for you to get to 3, so I'd rather we did not do that.

Yeah. I agree.

Quoted 10 lines

Can we do

#define STMPE1601_NUM_DATA 5
#define STMPE2401_NUM_DATA 3
#define STMPE2403_NUM_DATA 5

#define MAX_NUM_DATA		max3(STMPE1601_NUM_DATA, \
				     STMPE2401_NUM_DATA, \
				     STMPE2403_NUM_DATA)
Quoted 4 lines

or simply

/* Make sure it covers all cases above */
#define MAX_NUM_DATA 5

This one works just fine.

I'll send v2 of this patch shortly.

Thanks for the feedback.
I appreciate it.
--
Gustavo

Quoted 28 lines
Quoted 25 lines
drivers/input/keyboard/stmpe-keypad.c +2 -2
  		.num_normal_data	= 2,
  		.max_cols		= 8,
  		.max_rows		= 12,

@@ -94,7 +96,7 @@ static const struct stmpe_keypad_variant stmpe_keypad_variants[] = {
  	[STMPE2403] = {
  		.auto_increment		= true,
  		.set_pullup		= true,
-		.num_data		= 5,
+		.num_data		= MAX_NUM_DATA,
  		.num_normal_data	= 3,
  		.max_cols		= 8,
  		.max_rows		= 12,

@@ -156,7 +158,7 @@ static irqreturn_t stmpe_keypad_irq(int irq, void *dev)
  	struct stmpe_keypad *keypad = dev;
  	struct input_dev *input = keypad->input;
  	const struct stmpe_keypad_variant *variant = keypad->variant;
-	u8 fifo[variant->num_data];
+	u8 fifo[MAX_NUM_DATA];
  	int ret;
  	int i;
Signature · 1 line
2.7.4

Thanks.