[PATCH 3.12 24/33] mtip32xx: dynamically allocate buffer in debugfs functions

From: Jiri Slaby
Date: Tue Sep 15 2015 - 10:24:48 EST


From: David Milburn <dmilburn@xxxxxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit c8afd0dcbd14e2352258f2e2d359b36d0edd459f upstream.

Dynamically allocate buf to prevent warnings:

drivers/block/mtip32xx/mtip32xx.c: In function âmtip_hw_read_device_statusâ:
drivers/block/mtip32xx/mtip32xx.c:2823: warning: the frame size of 1056 bytes is larger than 1024 bytes
drivers/block/mtip32xx/mtip32xx.c: In function âmtip_hw_read_registersâ:
drivers/block/mtip32xx/mtip32xx.c:2894: warning: the frame size of 1056 bytes is larger than 1024 bytes
drivers/block/mtip32xx/mtip32xx.c: In function âmtip_hw_read_flagsâ:
drivers/block/mtip32xx/mtip32xx.c:2917: warning: the frame size of 1056 bytes is larger than 1024 bytes

Signed-off-by: David Milburn <dmilburn@xxxxxxxxxx>
Acked-by: Asai Thambi S P <asamymuthupa@xxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
drivers/block/mtip32xx/mtip32xx.c | 47 ++++++++++++++++++++++++++++++---------
1 file changed, 37 insertions(+), 10 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 560227b817fe..01c7270b5e84 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -2810,34 +2810,51 @@ static ssize_t show_device_status(struct device_driver *drv, char *buf)
static ssize_t mtip_hw_read_device_status(struct file *f, char __user *ubuf,
size_t len, loff_t *offset)
{
+ struct driver_data *dd = (struct driver_data *)f->private_data;
int size = *offset;
- char buf[MTIP_DFS_MAX_BUF_SIZE];
+ char *buf;
+ int rv = 0;

if (!len || *offset)
return 0;

+ buf = kzalloc(MTIP_DFS_MAX_BUF_SIZE, GFP_KERNEL);
+ if (!buf) {
+ dev_err(&dd->pdev->dev,
+ "Memory allocation: status buffer\n");
+ return -ENOMEM;
+ }
+
size += show_device_status(NULL, buf);

*offset = size <= len ? size : len;
size = copy_to_user(ubuf, buf, *offset);
if (size)
- return -EFAULT;
+ rv = -EFAULT;

- return *offset;
+ kfree(buf);
+ return rv ? rv : *offset;
}

static ssize_t mtip_hw_read_registers(struct file *f, char __user *ubuf,
size_t len, loff_t *offset)
{
struct driver_data *dd = (struct driver_data *)f->private_data;
- char buf[MTIP_DFS_MAX_BUF_SIZE];
+ char *buf;
u32 group_allocated;
int size = *offset;
- int n;
+ int n, rv = 0;

if (!len || size)
return 0;

+ buf = kzalloc(MTIP_DFS_MAX_BUF_SIZE, GFP_KERNEL);
+ if (!buf) {
+ dev_err(&dd->pdev->dev,
+ "Memory allocation: register buffer\n");
+ return -ENOMEM;
+ }
+
size += sprintf(&buf[size], "H/ S ACTive : [ 0x");

for (n = dd->slot_groups-1; n >= 0; n--)
@@ -2892,21 +2909,30 @@ static ssize_t mtip_hw_read_registers(struct file *f, char __user *ubuf,
*offset = size <= len ? size : len;
size = copy_to_user(ubuf, buf, *offset);
if (size)
- return -EFAULT;
+ rv = -EFAULT;

- return *offset;
+ kfree(buf);
+ return rv ? rv : *offset;
}

static ssize_t mtip_hw_read_flags(struct file *f, char __user *ubuf,
size_t len, loff_t *offset)
{
struct driver_data *dd = (struct driver_data *)f->private_data;
- char buf[MTIP_DFS_MAX_BUF_SIZE];
+ char *buf;
int size = *offset;
+ int rv = 0;

if (!len || size)
return 0;

+ buf = kzalloc(MTIP_DFS_MAX_BUF_SIZE, GFP_KERNEL);
+ if (!buf) {
+ dev_err(&dd->pdev->dev,
+ "Memory allocation: flag buffer\n");
+ return -ENOMEM;
+ }
+
size += sprintf(&buf[size], "Flag-port : [ %08lX ]\n",
dd->port->flags);
size += sprintf(&buf[size], "Flag-dd : [ %08lX ]\n",
@@ -2915,9 +2941,10 @@ static ssize_t mtip_hw_read_flags(struct file *f, char __user *ubuf,
*offset = size <= len ? size : len;
size = copy_to_user(ubuf, buf, *offset);
if (size)
- return -EFAULT;
+ rv = -EFAULT;

- return *offset;
+ kfree(buf);
+ return rv ? rv : *offset;
}

static const struct file_operations mtip_device_status_fops = {
--
2.5.2

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