Subject: [PATCH wireless-drivers] mt76x0: Remove VLA usage

From: Kees Cook <[email-masked]>
Date: Tue, 7 Aug 2018 15:50:40 -0700

Even with "const" variables, the compiler will generate warnings about
VLA usage. In the quest to remove all VLAs from the kernel[1], this uses
a #define instead of a const to do the array sizing.

[1] https://lkml.kernel.org/r/CA+55aFzCG-zNmZwX4A2FQpadafLfEzK6CC=[email-masked]

Fixes: e87b5039511a ("mt76x0: eeprom files")
Signed-off-by: Kees Cook <[email-masked]>
---
Please include this for the v4.19 merge window. The VLA was introduced
with the new source file (which I also note is missing a SPDX line), so
I'd like to avoid the kernel ever getting released with a VLA here.
---
 drivers/net/wireless/mediatek/mt76/mt76x0/eeprom.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x0/eeprom.c b/drivers/net/wireless/mediatek/mt76/mt76x0/eeprom.c
index 1ecd018f12b8..af2fd6a1bb44 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x0/eeprom.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x0/eeprom.c
@@ -81,15 +81,15 @@ mt76x0_efuse_read(struct mt76x0_dev *dev, u16 addr, u8 *data,
 	return 0;
 }
 
+#define MT_MAP_READS	DIV_ROUND_UP(MT_EFUSE_USAGE_MAP_SIZE, 16)
 static int
 mt76x0_efuse_physical_size_check(struct mt76x0_dev *dev)
 {
-	const int map_reads = DIV_ROUND_UP(MT_EFUSE_USAGE_MAP_SIZE, 16);
-	u8 data[map_reads * 16];
+	u8 data[MT_MAP_READS * 16];
 	int ret, i;
 	u32 start = 0, end = 0, cnt_free;
 
-	for (i = 0; i < map_reads; i++) {
+	for (i = 0; i < MT_MAP_READS; i++) {
 		ret = mt76x0_efuse_read(dev, MT_EE_USAGE_MAP_START + i * 16,
 					 data + i * 16, MT_EE_PHYSICAL_READ);
 		if (ret)
-- 
2.17.1

-- 
Kees Cook
Pixel Security