[PATCH v3 1/2] axis-fifo: use devm_kasprintf() for allocating formatted strings

Prathu Baronia
2023-05-18T14:52:12Z

In various places, string buffers of a fixed size are allocated, and
filled using snprintf() with the same fixed size, which is error-prone.

Replace this by calling devm_kasprintf() instead, which always uses the
appropriate size.

Also fix an old smatch warning reported by lkp introduced by commit
d2d7aa53891e. In the mentioned commit we had used "%pa" format specifier
for a void* type and hence smatch complained about its use instead of
"%p".

Fixes: d2d7aa53891e ("staging: axis-fifo: convert to use miscdevice")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Link: https://lore.kernel.org/r/202305150358.nt1BkbXz-lkp@intel.com/
Signed-off-by: Prathu Baronia <prathubaronia2011@gmail.com>
---
V2 -> V3: Fix smatch warnings from kernel test robot
V1 -> V2: Split into logical commits and fix commit message

drivers/staging/axis-fifo/axis-fifo.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/staging/axis-fifo/axis-fifo.c b/drivers/staging/axis-fifo/axis-fifo.c
index 7a21f2423204..d71bdc6dd961 100644
--- a/drivers/staging/axis-fifo/axis-fifo.c
+++ b/drivers/staging/axis-fifo/axis-fifo.c
@@ -816,10 +816,6 @@ static int axis_fifo_probe(struct platform_device *pdev)
* ----------------------------
*/

- device_name = devm_kzalloc(dev, 32, GFP_KERNEL);
- if (!device_name)
- return -ENOMEM;
-
/* allocate device wrapper memory */
fifo = devm_kzalloc(dev, sizeof(*fifo), GFP_KERNEL);
if (!fifo)
@@ -857,7 +853,11 @@ static int axis_fifo_probe(struct platform_device *pdev)
dev_dbg(fifo->dt_device, "remapped memory to 0x%p\n", fifo->base_addr);

/* create unique device name */
- snprintf(device_name, 32, "%s_%pa", DRIVER_NAME, &r_mem->start);
+ device_name = devm_kasprintf(dev, GFP_KERNEL, "%s_%pa", DRIVER_NAME, &r_mem->start);
+ if (!device_name) {
+ rc = -ENOMEM;
+ goto err_initial;
+ }
dev_dbg(fifo->dt_device, "device name [%s]\n", device_name);

/* ----------------------------
@@ -906,8 +906,8 @@ static int axis_fifo_probe(struct platform_device *pdev)
if (rc < 0)
goto err_initial;

- dev_info(fifo->dt_device, "axis-fifo created at %pa mapped to 0x%pa, irq=%i\n",
- &r_mem->start, &fifo->base_addr, fifo->irq);
+ dev_info(fifo->dt_device, "axis-fifo created at %pa mapped to 0x%p, irq=%i\n",
+ &r_mem->start, fifo->base_addr, fifo->irq);

return 0;

base-commit: 4d6d4c7f541d7027beed4fb86eb2c451bd8d6fff
--
2.34.1