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Subject[PATCH 4.19 18/52] spi: spi-mem: Add extra sanity checks on the op param
Date
From: Boris Brezillon <boris.brezillon@bootlin.com>

commit 380583227c0c7f52383b0cd5c0e2de93ed31d553 upstream

Some combinations are simply not valid and should be rejected before
the op is passed to the SPI controller driver.

Add an spi_mem_check_op() helper and use it in spi_mem_exec_op() and
spi_mem_supports_op() to make sure the spi-mem operation is valid.

Signed-off-by: Boris Brezillon <boris.brezillon@bootlin.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable <stable@vger.kernel.org> # 4.19
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/spi/spi-mem.c | 54 ++++++++++++++++++++++++++++++++++++++-----
1 file changed, 48 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index eb72dba71d832..cc3d425aae56c 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -12,6 +12,8 @@

#include "internals.h"

+#define SPI_MEM_MAX_BUSWIDTH 4
+
/**
* spi_controller_dma_map_mem_op_data() - DMA-map the buffer attached to a
* memory operation
@@ -149,6 +151,44 @@ static bool spi_mem_default_supports_op(struct spi_mem *mem,
}
EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);

+static bool spi_mem_buswidth_is_valid(u8 buswidth)
+{
+ if (hweight8(buswidth) > 1 || buswidth > SPI_MEM_MAX_BUSWIDTH)
+ return false;
+
+ return true;
+}
+
+static int spi_mem_check_op(const struct spi_mem_op *op)
+{
+ if (!op->cmd.buswidth)
+ return -EINVAL;
+
+ if ((op->addr.nbytes && !op->addr.buswidth) ||
+ (op->dummy.nbytes && !op->dummy.buswidth) ||
+ (op->data.nbytes && !op->data.buswidth))
+ return -EINVAL;
+
+ if (spi_mem_buswidth_is_valid(op->cmd.buswidth) ||
+ spi_mem_buswidth_is_valid(op->addr.buswidth) ||
+ spi_mem_buswidth_is_valid(op->dummy.buswidth) ||
+ spi_mem_buswidth_is_valid(op->data.buswidth))
+ return -EINVAL;
+
+ return 0;
+}
+
+static bool spi_mem_internal_supports_op(struct spi_mem *mem,
+ const struct spi_mem_op *op)
+{
+ struct spi_controller *ctlr = mem->spi->controller;
+
+ if (ctlr->mem_ops && ctlr->mem_ops->supports_op)
+ return ctlr->mem_ops->supports_op(mem, op);
+
+ return spi_mem_default_supports_op(mem, op);
+}
+
/**
* spi_mem_supports_op() - Check if a memory device and the controller it is
* connected to support a specific memory operation
@@ -166,12 +206,10 @@ EXPORT_SYMBOL_GPL(spi_mem_default_supports_op);
*/
bool spi_mem_supports_op(struct spi_mem *mem, const struct spi_mem_op *op)
{
- struct spi_controller *ctlr = mem->spi->controller;
-
- if (ctlr->mem_ops && ctlr->mem_ops->supports_op)
- return ctlr->mem_ops->supports_op(mem, op);
+ if (spi_mem_check_op(op))
+ return false;

- return spi_mem_default_supports_op(mem, op);
+ return spi_mem_internal_supports_op(mem, op);
}
EXPORT_SYMBOL_GPL(spi_mem_supports_op);

@@ -196,7 +234,11 @@ int spi_mem_exec_op(struct spi_mem *mem, const struct spi_mem_op *op)
u8 *tmpbuf;
int ret;

- if (!spi_mem_supports_op(mem, op))
+ ret = spi_mem_check_op(op);
+ if (ret)
+ return ret;
+
+ if (!spi_mem_internal_supports_op(mem, op))
return -ENOTSUPP;

if (ctlr->mem_ops) {
--
2.20.1


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