blob: 5644e5cfe71bd30bd63e81074f491692c4c68b13 [file] [log] [blame]
/*
* Copyright (c) 2017 Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <spi.h>
#include <syscall_handler.h>
#include <string.h>
/* This assumes that bufs and buf_copy are copies from the values passed
* as syscall arguments.
*/
static void copy_and_check(struct spi_buf_set *bufs,
struct spi_buf *buf_copy,
int writable, void *ssf)
{
size_t i;
if (bufs->count == 0) {
bufs->buffers = NULL;
return;
}
/* Validate the array of struct spi_buf instances */
Z_OOPS(Z_SYSCALL_MEMORY_ARRAY_READ(bufs->buffers,
bufs->count,
sizeof(struct spi_buf)));
/* Not worried abuot overflow here: _SYSCALL_MEMORY_ARRAY_READ()
* takes care of it.
*/
bufs->buffers = memcpy(buf_copy,
bufs->buffers,
bufs->count * sizeof(struct spi_buf));
for (i = 0; i < bufs->count; i++) {
/* Now for each array element, validate the memory buffers
* that they point to
*/
const struct spi_buf *buf = &bufs->buffers[i];
Z_OOPS(Z_SYSCALL_MEMORY(buf->buf, buf->len, writable));
}
}
/* This function is only here so tx_buf_copy and rx_buf_copy can be allocated
* using VLA. It assumes that both tx_bufs and rx_bufs will receive a copy of
* the values passed to the syscall as arguments. It also assumes that the
* count member has been verified and is a value that won't lead to stack
* overflow.
*/
static u32_t copy_bufs_and_transceive(struct device *dev,
const struct spi_config *config,
struct spi_buf_set *tx_bufs,
struct spi_buf_set *rx_bufs,
void *ssf)
{
struct spi_buf tx_buf_copy[tx_bufs->count ? tx_bufs->count : 1];
struct spi_buf rx_buf_copy[rx_bufs->count ? rx_bufs->count : 1];
copy_and_check(tx_bufs, tx_buf_copy, 0, ssf);
copy_and_check(rx_bufs, rx_buf_copy, 1, ssf);
return z_impl_spi_transceive((struct device *)dev, config,
tx_bufs, rx_bufs);
}
Z_SYSCALL_HANDLER(spi_transceive, dev, config_p, tx_bufs, rx_bufs)
{
const struct spi_config *config = (const struct spi_config *)config_p;
struct spi_buf_set tx_bufs_copy;
struct spi_buf_set rx_bufs_copy;
struct spi_config config_copy;
Z_OOPS(Z_SYSCALL_MEMORY_READ(config, sizeof(*config)));
Z_OOPS(Z_SYSCALL_DRIVER_SPI(dev, transceive));
if (tx_bufs) {
const struct spi_buf_set *tx =
(const struct spi_buf_set *)tx_bufs;
Z_OOPS(Z_SYSCALL_MEMORY_READ(tx_bufs,
sizeof(struct spi_buf_set)));
memcpy(&tx_bufs_copy, tx, sizeof(tx_bufs_copy));
Z_OOPS(Z_SYSCALL_VERIFY(tx_bufs_copy.count < 32));
} else {
memset(&tx_bufs_copy, 0, sizeof(tx_bufs_copy));
}
if (rx_bufs) {
const struct spi_buf_set *rx =
(const struct spi_buf_set *)rx_bufs;
Z_OOPS(Z_SYSCALL_MEMORY_READ(rx_bufs,
sizeof(struct spi_buf_set)));
memcpy(&rx_bufs_copy, rx, sizeof(rx_bufs_copy));
Z_OOPS(Z_SYSCALL_VERIFY(rx_bufs_copy.count < 32));
} else {
memset(&rx_bufs_copy, 0, sizeof(rx_bufs_copy));
}
memcpy(&config_copy, config, sizeof(*config));
if (config_copy.cs) {
const struct spi_cs_control *cs = config_copy.cs;
Z_OOPS(Z_SYSCALL_MEMORY_READ(cs, sizeof(*cs)));
if (cs->gpio_dev) {
Z_OOPS(Z_SYSCALL_OBJ(cs->gpio_dev, K_OBJ_DRIVER_GPIO));
}
}
/* ssf is implicit system call stack frame parameter, used by
* _SYSCALL_* APIs when something goes wrong.
*/
return copy_bufs_and_transceive((struct device *)dev,
&config_copy,
&tx_bufs_copy,
&rx_bufs_copy,
ssf);
}
Z_SYSCALL_HANDLER(spi_release, dev, config_p)
{
const struct spi_config *config = (const struct spi_config *)config_p;
Z_OOPS(Z_SYSCALL_MEMORY_READ(config, sizeof(*config)));
Z_OOPS(Z_SYSCALL_DRIVER_SPI(dev, release));
return z_impl_spi_release((struct device *)dev, config);
}