[RESEND PATCH] rsi: Remove stack VLA usage

From: Tobin C. Harding
Date: Sun Mar 11 2018 - 21:44:09 EST


The kernel would like to have all stack VLA usage removed[1]. rsi uses
a VLA based on 'blksize'. Elsewhere in the SDIO code maximum block size
is defined using a magic number. We can use a pre-processor defined
constant and declare the array to maximum size. We add a check before
accessing the array in case of programmer error.

[1]: https://lkml.org/lkml/2018/3/7/621

Signed-off-by: Tobin C. Harding <me@xxxxxxxx>
---

RESEND: add wireless mailing list to CC's (requested by Kalle)

drivers/net/wireless/rsi/rsi_91x_hal.c | 13 +++++++------
drivers/net/wireless/rsi/rsi_91x_sdio.c | 9 +++++++--
2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/drivers/net/wireless/rsi/rsi_91x_hal.c b/drivers/net/wireless/rsi/rsi_91x_hal.c
index 1176de646942..839ebdd602df 100644
--- a/drivers/net/wireless/rsi/rsi_91x_hal.c
+++ b/drivers/net/wireless/rsi/rsi_91x_hal.c
@@ -641,7 +641,7 @@ static int ping_pong_write(struct rsi_hw *adapter, u8 cmd, u8 *addr, u32 size)
u32 cmd_addr;
u16 cmd_resp, cmd_req;
u8 *str;
- int status;
+ int status, ret;

if (cmd == PING_WRITE) {
cmd_addr = PING_BUFFER_ADDRESS;
@@ -655,12 +655,13 @@ static int ping_pong_write(struct rsi_hw *adapter, u8 cmd, u8 *addr, u32 size)
str = "PONG_VALID";
}

- status = hif_ops->load_data_master_write(adapter, cmd_addr, size,
+ ret = hif_ops->load_data_master_write(adapter, cmd_addr, size,
block_size, addr);
- if (status) {
- rsi_dbg(ERR_ZONE, "%s: Unable to write blk at addr %0x\n",
- __func__, *addr);
- return status;
+ if (ret) {
+ if (ret != -EINVAL)
+ rsi_dbg(ERR_ZONE, "%s: Unable to write blk at addr %0x\n",
+ __func__, *addr);
+ return ret;
}

status = bl_cmd(adapter, cmd_req, cmd_resp, str);
diff --git a/drivers/net/wireless/rsi/rsi_91x_sdio.c b/drivers/net/wireless/rsi/rsi_91x_sdio.c
index b0cf41195051..b766578b591a 100644
--- a/drivers/net/wireless/rsi/rsi_91x_sdio.c
+++ b/drivers/net/wireless/rsi/rsi_91x_sdio.c
@@ -20,6 +20,8 @@
#include "rsi_common.h"
#include "rsi_hal.h"

+#define RSI_MAX_BLOCK_SIZE 256
+
/**
* rsi_sdio_set_cmd52_arg() - This function prepares cmd 52 read/write arg.
* @rw: Read/write
@@ -362,7 +364,7 @@ static int rsi_setblocklength(struct rsi_hw *adapter, u32 length)
rsi_dbg(INIT_ZONE, "%s: Setting the block length\n", __func__);

status = sdio_set_block_size(dev->pfunction, length);
- dev->pfunction->max_blksize = 256;
+ dev->pfunction->max_blksize = RSI_MAX_BLOCK_SIZE;
adapter->block_size = dev->pfunction->max_blksize;

rsi_dbg(INFO_ZONE,
@@ -567,9 +569,12 @@ static int rsi_sdio_load_data_master_write(struct rsi_hw *adapter,
{
u32 num_blocks, offset, i;
u16 msb_address, lsb_address;
- u8 temp_buf[block_size];
+ u8 temp_buf[RSI_MAX_BLOCK_SIZE];
int status;

+ if (block_size > RSI_MAX_BLOCK_SIZE)
+ return -EINVAL;
+
num_blocks = instructions_sz / block_size;
msb_address = base_address >> 16;

--
2.7.4