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authorPratyush Yadav <p.yadav@ti.com>2022-04-20 15:50:22 +0530
committerMark Brown <broonie@kernel.org>2022-04-21 14:17:56 +0100
commit8868c03f3ca584abec7bb53d6c3f7c5ab6b60949 (patch)
tree62f44dd0a9e96f8a87dc34171fa0d5097cea3aa5
parent8c235cc25087495c4288d94f547e9d3061004991 (diff)
downloadlinux-8868c03f3ca584abec7bb53d6c3f7c5ab6b60949.tar.bz2
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 <p.yadav@ti.com> Link: https://lore.kernel.org/r/20220420102022.3310970-1-p.yadav@ti.com Signed-off-by: Mark Brown <broonie@kernel.org>
-rw-r--r--drivers/spi/spi-mem.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index 0e8dafc62d94..60c968c1dc6e 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -10,6 +10,7 @@
#include <linux/pm_runtime.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi-mem.h>
+#include <linux/sched/task_stack.h>
#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;
}