From: Chuanhua Han
> Sent: 20 August 2018 13:44
>
> Signed-off-by: Chuanhua Han <chuanhua.han@xxxxxxx>
> ---
> Changes in v3:
> Rename variable name "val" to "opcode_addr_dummy_sum".
> Place the legitimacy of the transfer size(i.e., "pi_max_message_size(mem->spi)" and
> "opcode_addr_dummy_sum") into "if (! ctlr - > mem_ops | |! ctlr-> mem_ops->exec_op) {"
> structure and add "spi_max_transfer_size(mem->spi) and opcode_addr_dummy_sum".
> Adjust the formatting alignment of your code.
> "(unsigned long)op->data.nbytes" was modified to "(unsigned long)(op->data.nbytes)".
>
> Fixes: c36ff266dc82 ("spi: Extend the core to ease integration of SPI memory controllers")
> ---
> drivers/spi/spi-mem.c | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
> index 990770d..5ec2bc9 100644
> --- a/drivers/spi/spi-mem.c
> +++ b/drivers/spi/spi-mem.c
> @@ -328,10 +328,24 @@ EXPORT_SYMBOL_GPL(spi_mem_exec_op);
> int spi_mem_adjust_op_size(struct spi_mem *mem, struct spi_mem_op *op)
> {
> struct spi_controller *ctlr = mem->spi->controller;
> + unsigned long opcode_addr_dummy_sum = sizeof(op->cmd.opcode) +
> + op->addr.nbytes +
> + op->dummy.nbytes;
I'd split that (and shorten the variable name) to avoid line wrap. Maybe:
unsigned long len;
len = sizeof(op->cmd.opcode) + op->addr.nbytes + op->dummy.nbytes;
>
> if (ctlr->mem_ops && ctlr->mem_ops->adjust_op_size)
> return ctlr->mem_ops->adjust_op_size(mem, op);
>
> + if (!ctlr->mem_ops || !ctlr->mem_ops->exec_op) {
> + if (spi_max_message_size(mem->spi) < opcode_addr_dummy_sum ||
> + spi_max_transfer_size(mem->spi) < opcode_addr_dummy_sum)
> + return -EINVAL;
Those comparisons are lexically backwards, you want 'value op constant'.
So:
if (len > spi_max_message_size(mem->spi) ||
len > spi_max_transfer_size(mem->spi))
return -EINVAL.
Although I'm surprised you need to do both comparisons.
> +
> + op->data.nbytes = min3((unsigned long)(op->data.nbytes),
> + spi_max_transfer_size(mem->spi),
> + spi_max_message_size(mem->spi) -
> + opcode_addr_dummy_sum);
That looks like a strange limit...
> + }
> +
> return 0;
> }
> EXPORT_SYMBOL_GPL(spi_mem_adjust_op_size);
> --
> 2.7.4
David
-
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