From 8868c03f3ca584abec7bb53d6c3f7c5ab6b60949 Mon Sep 17 00:00:00 2001
From: Pratyush Yadav
Date: Wed, 20 Apr 2022 15:50:22 +0530
Subject: [PATCH] spi: spi-mem: check if data buffers are on stack
The buffers passed in the data phase must be DMA-able. Programmers often
don't realise this requirement and pass in buffers that reside on the
stack. This can be hard to spot when reviewing code. Reject ops if their
data buffer is on the stack to avoid this.
Signed-off-by: Pratyush Yadav
Link: https://lore.kernel.org/r/20220420102022.3310970-1-p.yadav@ti.com
Signed-off-by: Mark Brown
---
drivers/spi/spi-mem.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index 0e8dafc62d94f..60c968c1dc6e1 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -10,6 +10,7 @@
#include
#include
#include
+#include
#include "internals.h"
@@ -211,6 +212,15 @@ static int spi_mem_check_op(const struct spi_mem_op *op)
!spi_mem_buswidth_is_valid(op->data.buswidth))
return -EINVAL;
+ /* Buffers must be DMA-able. */
+ if (WARN_ON_ONCE(op->data.dir == SPI_MEM_DATA_IN &&
+ object_is_on_stack(op->data.buf.in)))
+ return -EINVAL;
+
+ if (WARN_ON_ONCE(op->data.dir == SPI_MEM_DATA_OUT &&
+ object_is_on_stack(op->data.buf.out)))
+ return -EINVAL;
+
return 0;
}
--
2.39.5