[PATCH v6 1/8] mfd: cros_ec: Use a zero-length array for command data

Javier Martinez Canillas
2015-06-04T08:07:06Z

Commit 1b84f2a4cd4a ("mfd: cros_ec: Use fixed size arrays to transfer
data with the EC") modified the struct cros_ec_command fields to not
use pointers for the input and output buffers and use fixed length
arrays instead.

This change was made because the cros_ec ioctl API uses that struct
cros_ec_command to allow user-space to send commands to the EC and
to get data from the EC. So using pointers made the API not 64-bit
safe. Unfortunately this approach was not flexible enough for all
the use-cases since there may be a need to send larger commands
on newer versions of the EC command protocol.

So to avoid to choose a constant length that it may be too big for
most commands and thus wasting memory and CPU cycles on copy from
and to user-space or having a size that is too small for some big
commands, use a zero-length array that is both 64-bit safe and
flexible. The same buffer is used for both output and input data
so the maximum of these values should be used to allocate it.

Suggested-by: Gwendal Grignou <gwendal@chromium.org>
Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Tested-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Lee Jones <lee.jones@linaro.org>
---

Changes since v5: None

Changes since v4: None

Changes since v3:
- Added acked-by tag from Lee Jones.

Changes since v2:
- Set the version field in the cros_ec_command. Reported by Heiko Stuebner.
- Use kmalloc/kfree instead of pre-allocating using variables in the stack.
Suggested by Lee Jones.

Changes since v1:
- Add Heiko Stuebner Tested-by tag
- Removed a new blank line at EOF warning. Reported by Heiko Stuebner
- Use kmalloc instead of kzalloc when the message is later initialized
Suggested by Gwendal Grignou
- Pre-allocate struct cros_ec_command instead of dynamically allocate it
whenever is possible. Suggested by Gwendal Grignou
- Pre-allocate buffers for the usual cases and only allocate dynamically
in the heap for bigger sizes. Suggested by Gwendal Grignou
- Don't access the cros_ec_command received from user-space before doing
a copy_from_user. Suggested by Gwendal Grignou
- Only copy from user-space outsize bytes and copy_to_user insize bytes
Suggested by Gwendal Grignou
- ec_device_ioctl_xcmd() must return the numbers of bytes read and not 0
on success. Suggested by Gwendal Grignou
- Rename alloc_cmd_msg to alloc_lightbar_cmd_msg. Suggested by Gwendal Grignou
---
drivers/i2c/busses/i2c-cros-ec-tunnel.c | 45 ++++++---
drivers/input/keyboard/cros_ec_keyb.c | 29 ++++--
drivers/mfd/cros_ec.c | 28 ++++--
drivers/mfd/cros_ec_i2c.c | 4 +-
drivers/mfd/cros_ec_spi.c | 2 +-
drivers/platform/chrome/cros_ec_dev.c | 65 +++++++-----
drivers/platform/chrome/cros_ec_lightbar.c | 152 +++++++++++++++++++---------
drivers/platform/chrome/cros_ec_lpc.c | 8 +-
drivers/platform/chrome/cros_ec_sysfs.c | 154 ++++++++++++++++++-----------
include/linux/mfd/cros_ec.h | 6 +-
10 files changed, 318 insertions(+), 175 deletions(-)

diff --git a/drivers/i2c/busses/i2c-cros-ec-tunnel.c b/drivers/i2c/busses/i2c-cros-ec-tunnel.c
index fa8dedd8c3a2..a0d95ff682ae 100644
--- a/drivers/i2c/busses/i2c-cros-ec-tunnel.c
+++ b/drivers/i2c/busses/i2c-cros-ec-tunnel.c
@@ -182,8 +182,9 @@ static int ec_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg i2c_msgs[],
const u16 bus_num = bus->remote_bus;
int request_len;
int response_len;
+ int alloc_size;
int result;
- struct cros_ec_command msg = { };
+ struct cros_ec_command *msg;

request_len = ec_i2c_count_message(i2c_msgs, num);
if (request_len < 0) {
@@ -198,25 +199,39 @@ static int ec_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg i2c_msgs[],
return response_len;
}

- result = ec_i2c_construct_message(msg.outdata, i2c_msgs, num, bus_num);
- if (result)
- return result;
+ alloc_size = max(request_len, response_len);
+ msg = kmalloc(sizeof(*msg) + alloc_size, GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;

- msg.version = 0;
- msg.command = EC_CMD_I2C_PASSTHRU;
- msg.outsize = request_len;
- msg.insize = response_len;
+ result = ec_i2c_construct_message(msg->data, i2c_msgs, num, bus_num);
+ if (result) {
+ dev_err(dev, "Error constructing EC i2c message %d\n", result);
+ goto exit;
+ }

- result = cros_ec_cmd_xfer(bus->ec, &msg);
- if (result < 0)
- return result;
+ msg->version = 0;
+ msg->command = EC_CMD_I2C_PASSTHRU;
+ msg->outsize = request_len;
+ msg->insize = response_len;

- result = ec_i2c_parse_response(msg.indata, i2c_msgs, &num);
- if (result < 0)
- return result;
+ result = cros_ec_cmd_xfer(bus->ec, msg);
+ if (result < 0) {
+ dev_err(dev, "Error transferring EC i2c message %d\n", result);
+ goto exit;
+ }
+
+ result = ec_i2c_parse_response(msg->data, i2c_msgs, &num);
+ if (result < 0) {
+ dev_err(dev, "Error parsing EC i2c message %d\n", result);
+ goto exit;
+ }

/* Indicate success by saying how many messages were sent */
- return num;
+ result = num;
+exit:
+ kfree(msg);
+ return result;
}

static u32 ec_i2c_functionality(struct i2c_adapter *adap)
diff --git a/drivers/input/keyboard/cros_ec_keyb.c b/drivers/input/keyboard/cros_ec_keyb.c
index b50c5b8b8a4d..974154a74505 100644
--- a/drivers/input/keyboard/cros_ec_keyb.c
+++ b/drivers/input/keyboard/cros_ec_keyb.c
@@ -148,19 +148,28 @@ static void cros_ec_keyb_process(struct cros_ec_keyb *ckdev,

static int cros_ec_keyb_get_state(struct cros_ec_keyb *ckdev, uint8_t *kb_state)
{
- int ret;
- struct cros_ec_command msg = {
- .command = EC_CMD_MKBP_STATE,
- .insize = ckdev->cols,
- };
+ int ret = 0;
+ struct cros_ec_command *msg;

- ret = cros_ec_cmd_xfer(ckdev->ec, &msg);
- if (ret < 0)
- return ret;
+ msg = kmalloc(sizeof(*msg) + ckdev->cols, GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;

- memcpy(kb_state, msg.indata, ckdev->cols);
+ msg->version = 0;
+ msg->command = EC_CMD_MKBP_STATE;
+ msg->insize = ckdev->cols;
+ msg->outsize = 0;

- return 0;
+ ret = cros_ec_cmd_xfer(ckdev->ec, msg);
+ if (ret < 0) {
+ dev_err(ckdev->dev, "Error transferring EC message %d\n", ret);
+ goto exit;
+ }
+
+ memcpy(kb_state, msg->data, ckdev->cols);
+exit:
+ kfree(msg);
+ return ret;
}

static irqreturn_t cros_ec_keyb_irq(int irq, void *data)
diff --git a/drivers/mfd/cros_ec.c b/drivers/mfd/cros_ec.c
index 1574a9352a6d..4a0f6dfcd376 100644
--- a/drivers/mfd/cros_ec.c
+++ b/drivers/mfd/cros_ec.c
@@ -41,7 +41,7 @@ int cros_ec_prepare_tx(struct cros_ec_device *ec_dev,
out[2] = msg->outsize;
csum = out[0] + out[1] + out[2];
for (i = 0; i < msg->outsize; i++)
- csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->outdata[i];
+ csum += out[EC_MSG_TX_HEADER_BYTES + i] = msg->data[i];
out[EC_MSG_TX_HEADER_BYTES + msg->outsize] = (uint8_t)(csum & 0xff);

return EC_MSG_TX_PROTO_BYTES + msg->outsize;
@@ -75,11 +75,20 @@ int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
ret = ec_dev->cmd_xfer(ec_dev, msg);
if (msg->result == EC_RES_IN_PROGRESS) {
int i;
- struct cros_ec_command status_msg = { };
+ struct cros_ec_command *status_msg;
struct ec_response_get_comms_status *status;

- status_msg.command = EC_CMD_GET_COMMS_STATUS;
- status_msg.insize = sizeof(*status);
+ status_msg = kmalloc(sizeof(*status_msg) + sizeof(*status),
+ GFP_KERNEL);
+ if (!status_msg) {
+ ret = -ENOMEM;
+ goto exit;
+ }
+
+ status_msg->version = 0;
+ status_msg->command = EC_CMD_GET_COMMS_STATUS;
+ status_msg->insize = sizeof(*status);
+ status_msg->outsize = 0;

/*
* Query the EC's status until it's no longer busy or
@@ -88,20 +97,23 @@ int cros_ec_cmd_xfer(struct cros_ec_device *ec_dev,
for (i = 0; i < EC_COMMAND_RETRIES; i++) {
usleep_range(10000, 11000);

- ret = ec_dev->cmd_xfer(ec_dev, &status_msg);
+ ret = ec_dev->cmd_xfer(ec_dev, status_msg);
if (ret < 0)
break;

- msg->result = status_msg.result;
- if (status_msg.result != EC_RES_SUCCESS)
+ msg->result = status_msg->result;
+ if (status_msg->result != EC_RES_SUCCESS)
break;

status = (struct ec_response_get_comms_status *)
- status_msg.indata;
+ status_msg->data;
if (!(status->flags & EC_COMMS_STATUS_PROCESSING))
break;
}
+
+ kfree(status_msg);
}
+exit:
mutex_unlock(&ec_dev->lock);

return ret;
diff --git a/drivers/mfd/cros_ec_i2c.c b/drivers/mfd/cros_ec_i2c.c
index 82b4d6148698..fbf7819f5de5 100644
--- a/drivers/mfd/cros_ec_i2c.c
+++ b/drivers/mfd/cros_ec_i2c.c
@@ -76,7 +76,7 @@ static int cros_ec_cmd_xfer_i2c(struct cros_ec_device *ec_dev,
/* copy message payload and compute checksum */
sum = out_buf[0] + out_buf[1] + out_buf[2];
for (i = 0; i < msg->outsize; i++) {
- out_buf[3 + i] = msg->outdata[i];
+ out_buf[3 + i] = msg->data[i];
sum += out_buf[3 + i];
}
out_buf[3 + msg->outsize] = sum;
@@ -109,7 +109,7 @@ static int cros_ec_cmd_xfer_i2c(struct cros_ec_device *ec_dev,
/* copy response packet payload and compute checksum */
sum = in_buf[0] + in_buf[1];
for (i = 0; i < len; i++) {
- msg->indata[i] = in_buf[2 + i];
+ msg->data[i] = in_buf[2 + i];
sum += in_buf[2 + i];
}
dev_dbg(ec_dev->dev, "packet: %*ph, sum = %02x\n",
diff --git a/drivers/mfd/cros_ec_spi.c b/drivers/mfd/cros_ec_spi.c
index 27bd52e5e8b7..573730fec947 100644
--- a/drivers/mfd/cros_ec_spi.c
+++ b/drivers/mfd/cros_ec_spi.c
@@ -299,7 +299,7 @@ static int cros_ec_cmd_xfer_spi(struct cros_ec_device *ec_dev,
for (i = 0; i < len; i++) {
sum += ptr[i + 2];
if (ec_msg->insize)
- ec_msg->indata[i] = ptr[i + 2];
+ ec_msg->data[i] = ptr[i + 2];
}
sum &= 0xff;

diff --git a/drivers/platform/chrome/cros_ec_dev.c b/drivers/platform/chrome/cros_ec_dev.c
index 4232c8136939..14111e32658b 100644
--- a/drivers/platform/chrome/cros_ec_dev.c
+++ b/drivers/platform/chrome/cros_ec_dev.c
@@ -20,6 +20,7 @@
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/platform_device.h>
+#include <linux/slab.h>
#include <linux/uaccess.h>

#include "cros_ec_dev.h"
@@ -36,28 +37,31 @@ static int ec_get_version(struct cros_ec_device *ec, char *str, int maxlen)
static const char * const current_image_name[] = {
"unknown", "read-only", "read-write", "invalid",
};
- struct cros_ec_command msg = {
- .version = 0,
- .command = EC_CMD_GET_VERSION,
- .outdata = { 0 },
- .outsize = 0,
- .indata = { 0 },
- .insize = sizeof(*resp),
- };
+ struct cros_ec_command *msg;
int ret;

- ret = cros_ec_cmd_xfer(ec, &msg);
+ msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ msg->version = 0;
+ msg->command = EC_CMD_GET_VERSION;
+ msg->insize = sizeof(*resp);
+ msg->outsize = 0;
+
+ ret = cros_ec_cmd_xfer(ec, msg);
if (ret < 0)
- return ret;
+ goto exit;

- if (msg.result != EC_RES_SUCCESS) {
+ if (msg->result != EC_RES_SUCCESS) {
snprintf(str, maxlen,
"%s\nUnknown EC version: EC returned %d\n",
- CROS_EC_DEV_VERSION, msg.result);
- return 0;
+ CROS_EC_DEV_VERSION, msg->result);
+ ret = -EINVAL;
+ goto exit;
}

- resp = (struct ec_response_get_version *)msg.indata;
+ resp = (struct ec_response_get_version *)msg->data;
if (resp->current_image >= ARRAY_SIZE(current_image_name))
resp->current_image = 3; /* invalid */

@@ -65,7 +69,10 @@ static int ec_get_version(struct cros_ec_device *ec, char *str, int maxlen)
resp->version_string_ro, resp->version_string_rw,
current_image_name[resp->current_image]);

- return 0;
+ ret = 0;
+exit:
+ kfree(msg);
+ return ret;
}

/* Device file ops */
@@ -110,20 +117,32 @@ static ssize_t ec_device_read(struct file *filp, char __user *buffer,
static long ec_device_ioctl_xcmd(struct cros_ec_device *ec, void __user *arg)
{
long ret;
- struct cros_ec_command s_cmd = { };
+ struct cros_ec_command u_cmd;
+ struct cros_ec_command *s_cmd;

- if (copy_from_user(&s_cmd, arg, sizeof(s_cmd)))
+ if (copy_from_user(&u_cmd, arg, sizeof(u_cmd)))
return -EFAULT;

- ret = cros_ec_cmd_xfer(ec, &s_cmd);
+ s_cmd = kmalloc(sizeof(*s_cmd) + max(u_cmd.outsize, u_cmd.insize),
+ GFP_KERNEL);
+ if (!s_cmd)
+ return -ENOMEM;
+
+ if (copy_from_user(s_cmd, arg, sizeof(*s_cmd) + u_cmd.outsize)) {
+ ret = -EFAULT;
+ goto exit;
+ }
+
+ ret = cros_ec_cmd_xfer(ec, s_cmd);
/* Only copy data to userland if data was received. */
if (ret < 0)
- return ret;
+ goto exit;

- if (copy_to_user(arg, &s_cmd, sizeof(s_cmd)))
- return -EFAULT;
-
- return 0;
+ if (copy_to_user(arg, s_cmd, sizeof(*s_cmd) + u_cmd.insize))
+ ret = -EFAULT;
+exit:
+ kfree(s_cmd);
+ return ret;
}

static long ec_device_ioctl_readmem(struct cros_ec_device *ec, void __user *arg)
diff --git a/drivers/platform/chrome/cros_ec_lightbar.c b/drivers/platform/chrome/cros_ec_lightbar.c
index b4ff47a9069a..560e5d41b7ae 100644
--- a/drivers/platform/chrome/cros_ec_lightbar.c
+++ b/drivers/platform/chrome/cros_ec_lightbar.c
@@ -31,6 +31,7 @@
#include <linux/sched.h>
#include <linux/types.h>
#include <linux/uaccess.h>
+#include <linux/slab.h>

#include "cros_ec_dev.h"

@@ -91,54 +92,79 @@ out:
return ret;
}

-#define INIT_MSG(P, R) { \
- .command = EC_CMD_LIGHTBAR_CMD, \
- .outsize = sizeof(*P), \
- .insize = sizeof(*R), \
- }
+static struct cros_ec_command *alloc_lightbar_cmd_msg(void)
+{
+ struct cros_ec_command *msg;
+ int len;
+
+ len = max(sizeof(struct ec_params_lightbar),
+ sizeof(struct ec_response_lightbar));
+
+ msg = kmalloc(sizeof(*msg) + len, GFP_KERNEL);
+ if (!msg)
+ return NULL;
+
+ msg->version = 0;
+ msg->command = EC_CMD_LIGHTBAR_CMD;
+ msg->outsize = sizeof(struct ec_params_lightbar);
+ msg->insize = sizeof(struct ec_response_lightbar);
+
+ return msg;
+}

static int get_lightbar_version(struct cros_ec_device *ec,
uint32_t *ver_ptr, uint32_t *flg_ptr)
{
struct ec_params_lightbar *param;
struct ec_response_lightbar *resp;
- struct cros_ec_command msg = INIT_MSG(param, resp);
+ struct cros_ec_command *msg;
int ret;

- param = (struct ec_params_lightbar *)msg.outdata;
- param->cmd = LIGHTBAR_CMD_VERSION;
- ret = cros_ec_cmd_xfer(ec, &msg);
- if (ret < 0)
+ msg = alloc_lightbar_cmd_msg();
+ if (!msg)
return 0;

- switch (msg.result) {
+ param = (struct ec_params_lightbar *)msg->data;
+ param->cmd = LIGHTBAR_CMD_VERSION;
+ ret = cros_ec_cmd_xfer(ec, msg);
+ if (ret < 0) {
+ ret = 0;
+ goto exit;
+ }
+
+ switch (msg->result) {
case EC_RES_INVALID_PARAM:
/* Pixel had no version command. */
if (ver_ptr)
*ver_ptr = 0;
if (flg_ptr)
*flg_ptr = 0;
- return 1;
+ ret = 1;
+ goto exit;

case EC_RES_SUCCESS:
- resp = (struct ec_response_lightbar *)msg.indata;
+ resp = (struct ec_response_lightbar *)msg->data;

/* Future devices w/lightbars should implement this command */
if (ver_ptr)
*ver_ptr = resp->version.num;
if (flg_ptr)
*flg_ptr = resp->version.flags;
- return 1;
+ ret = 1;
+ goto exit;
}

/* Anything else (ie, EC_RES_INVALID_COMMAND) - no lightbar */
- return 0;
+ ret = 0;
+exit:
+ kfree(msg);
+ return ret;
}

static ssize_t version_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
- uint32_t version, flags;
+ uint32_t version = 0, flags = 0;
struct cros_ec_device *ec = dev_get_drvdata(dev);
int ret;

@@ -158,8 +184,7 @@ static ssize_t brightness_store(struct device *dev,
const char *buf, size_t count)
{
struct ec_params_lightbar *param;
- struct ec_response_lightbar *resp;
- struct cros_ec_command msg = INIT_MSG(param, resp);
+ struct cros_ec_command *msg;
int ret;
unsigned int val;
struct cros_ec_device *ec = dev_get_drvdata(dev);
@@ -167,21 +192,30 @@ static ssize_t brightness_store(struct device *dev,
if (kstrtouint(buf, 0, &val))
return -EINVAL;

- param = (struct ec_params_lightbar *)msg.outdata;
+ msg = alloc_lightbar_cmd_msg();
+ if (!msg)
+ return -ENOMEM;
+
+ param = (struct ec_params_lightbar *)msg->data;
param->cmd = LIGHTBAR_CMD_BRIGHTNESS;
param->brightness.num = val;
ret = lb_throttle();
if (ret)
- return ret;
+ goto exit;

- ret = cros_ec_cmd_xfer(ec, &msg);
+ ret = cros_ec_cmd_xfer(ec, msg);
if (ret < 0)
- return ret;
+ goto exit;

- if (msg.result != EC_RES_SUCCESS)
- return -EINVAL;
+ if (msg->result != EC_RES_SUCCESS) {
+ ret = -EINVAL;
+ goto exit;
+ }

- return count;
+ ret = count;
+exit:
+ kfree(msg);
+ return ret;
}

@@ -196,12 +230,15 @@ static ssize_t led_rgb_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct ec_params_lightbar *param;
- struct ec_response_lightbar *resp;
- struct cros_ec_command msg = INIT_MSG(param, resp);
+ struct cros_ec_command *msg;
struct cros_ec_device *ec = dev_get_drvdata(dev);
unsigned int val[4];
int ret, i = 0, j = 0, ok = 0;

+ msg = alloc_lightbar_cmd_msg();
+ if (!msg)
+ return -ENOMEM;
+
do {
/* Skip any whitespace */
while (*buf && isspace(*buf))
@@ -215,7 +252,7 @@ static ssize_t led_rgb_store(struct device *dev, struct device_attribute *attr,
return -EINVAL;

if (i == 4) {
- param = (struct ec_params_lightbar *)msg.outdata;
+ param = (struct ec_params_lightbar *)msg->data;
param->cmd = LIGHTBAR_CMD_RGB;
param->rgb.led = val[0];
param->rgb.red = val[1];
@@ -231,12 +268,14 @@ static ssize_t led_rgb_store(struct device *dev, struct device_attribute *attr,
return ret;
}

- ret = cros_ec_cmd_xfer(ec, &msg);
+ ret = cros_ec_cmd_xfer(ec, msg);
if (ret < 0)
- return ret;
+ goto exit;

- if (msg.result != EC_RES_SUCCESS)
- return -EINVAL;
+ if (msg->result != EC_RES_SUCCESS) {
+ ret = -EINVAL;
+ goto exit;
+ }

i = 0;
ok = 1;
@@ -248,6 +287,8 @@ static ssize_t led_rgb_store(struct device *dev, struct device_attribute *attr,

} while (*buf);

+exit:
+ kfree(msg);
return (ok && i == 0) ? count : -EINVAL;
}

@@ -261,42 +302,55 @@ static ssize_t sequence_show(struct device *dev,
{
struct ec_params_lightbar *param;
struct ec_response_lightbar *resp;
- struct cros_ec_command msg = INIT_MSG(param, resp);
+ struct cros_ec_command *msg;
int ret;
struct cros_ec_device *ec = dev_get_drvdata(dev);

- param = (struct ec_params_lightbar *)msg.outdata;
+ msg = alloc_lightbar_cmd_msg();
+ if (!msg)
+ return -ENOMEM;
+
+ param = (struct ec_params_lightbar *)msg->data;
param->cmd = LIGHTBAR_CMD_GET_SEQ;
ret = lb_throttle();
if (ret)
- return ret;
+ goto exit;

- ret = cros_ec_cmd_xfer(ec, &msg);
+ ret = cros_ec_cmd_xfer(ec, msg);
if (ret < 0)
- return ret;
+ goto exit;

- if (msg.result != EC_RES_SUCCESS)
- return scnprintf(buf, PAGE_SIZE,
- "ERROR: EC returned %d\n", msg.result);
+ if (msg->result != EC_RES_SUCCESS) {
+ ret = scnprintf(buf, PAGE_SIZE,
+ "ERROR: EC returned %d\n", msg->result);
+ goto exit;
+ }

- resp = (struct ec_response_lightbar *)msg.indata;
+ resp = (struct ec_response_lightbar *)msg->data;
if (resp->get_seq.num >= ARRAY_SIZE(seqname))
- return scnprintf(buf, PAGE_SIZE, "%d\n", resp->get_seq.num);
+ ret = scnprintf(buf, PAGE_SIZE, "%d\n", resp->get_seq.num);
else
- return scnprintf(buf, PAGE_SIZE, "%s\n",
- seqname[resp->get_seq.num]);
+ ret = scnprintf(buf, PAGE_SIZE, "%s\n",
+ seqname[resp->get_seq.num]);
+
+exit:
+ kfree(msg);
+ return ret;
}

static ssize_t sequence_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct ec_params_lightbar *param;
- struct ec_response_lightbar *resp;
- struct cros_ec_command msg = INIT_MSG(param, resp);
+ struct cros_ec_command *msg;
unsigned int num;
int ret, len;
struct cros_ec_device *ec = dev_get_drvdata(dev);

+ msg = alloc_lightbar_cmd_msg();
+ if (!msg)
+ return -ENOMEM;
+
for (len = 0; len < count; len++)
if (!isalnum(buf[len]))
break;
@@ -311,18 +365,18 @@ static ssize_t sequence_store(struct device *dev, struct device_attribute *attr,
return ret;
}

- param = (struct ec_params_lightbar *)msg.outdata;
+ param = (struct ec_params_lightbar *)msg->data;
param->cmd = LIGHTBAR_CMD_SEQ;
param->seq.num = num;
ret = lb_throttle();
if (ret)
return ret;

- ret = cros_ec_cmd_xfer(ec, &msg);
+ ret = cros_ec_cmd_xfer(ec, msg);
if (ret < 0)
return ret;

- if (msg.result != EC_RES_SUCCESS)
+ if (msg->result != EC_RES_SUCCESS)
return -EINVAL;

return count;
diff --git a/drivers/platform/chrome/cros_ec_lpc.c b/drivers/platform/chrome/cros_ec_lpc.c
index ea75af35c995..214ae7fef984 100644
--- a/drivers/platform/chrome/cros_ec_lpc.c
+++ b/drivers/platform/chrome/cros_ec_lpc.c
@@ -73,8 +73,8 @@ static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,

/* Copy data and update checksum */
for (i = 0; i < msg->outsize; i++) {
- outb(msg->outdata[i], EC_LPC_ADDR_HOST_PARAM + i);
- csum += msg->outdata[i];
+ outb(msg->data[i], EC_LPC_ADDR_HOST_PARAM + i);
+ csum += msg->data[i];
}

/* Finalize checksum and write args */
@@ -119,8 +119,8 @@ static int cros_ec_cmd_xfer_lpc(struct cros_ec_device *ec,

/* Read response and update checksum */
for (i = 0; i < args.data_size; i++) {
- msg->indata[i] = inb(EC_LPC_ADDR_HOST_PARAM + i);
- csum += msg->indata[i];
+ msg->data[i] = inb(EC_LPC_ADDR_HOST_PARAM + i);
+ csum += msg->data[i];
}

/* Verify checksum */
diff --git a/drivers/platform/chrome/cros_ec_sysfs.c b/drivers/platform/chrome/cros_ec_sysfs.c
index fb62ab6cc659..78ba82d670cb 100644
--- a/drivers/platform/chrome/cros_ec_sysfs.c
+++ b/drivers/platform/chrome/cros_ec_sysfs.c
@@ -29,6 +29,7 @@
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/printk.h>
+#include <linux/slab.h>
#include <linux/stat.h>
#include <linux/types.h>
#include <linux/uaccess.h>
@@ -66,14 +67,19 @@ static ssize_t store_ec_reboot(struct device *dev,
{"hibernate", EC_REBOOT_HIBERNATE, 0},
{"at-shutdown", -1, EC_REBOOT_FLAG_ON_AP_SHUTDOWN},
};
- struct cros_ec_command msg = { 0 };
- struct ec_params_reboot_ec *param =
- (struct ec_params_reboot_ec *)msg.outdata;
+ struct cros_ec_command *msg;
+ struct ec_params_reboot_ec *param;
int got_cmd = 0, offset = 0;
int i;
int ret;
struct cros_ec_device *ec = dev_get_drvdata(dev);

+ msg = kmalloc(sizeof(*msg) + sizeof(*param), GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
+ param = (struct ec_params_reboot_ec *)msg->data;
+
param->flags = 0;
while (1) {
/* Find word to start scanning */
@@ -100,19 +106,26 @@ static ssize_t store_ec_reboot(struct device *dev,
offset++;
}

- if (!got_cmd)
- return -EINVAL;
-
- msg.command = EC_CMD_REBOOT_EC;
- msg.outsize = sizeof(param);
- ret = cros_ec_cmd_xfer(ec, &msg);
- if (ret < 0)
- return ret;
- if (msg.result != EC_RES_SUCCESS) {
- dev_dbg(ec->dev, "EC result %d\n", msg.result);
- return -EINVAL;
+ if (!got_cmd) {
+ count = -EINVAL;
+ goto exit;
}

+ msg->version = 0;
+ msg->command = EC_CMD_REBOOT_EC;
+ msg->outsize = sizeof(*param);
+ msg->insize = 0;
+ ret = cros_ec_cmd_xfer(ec, msg);
+ if (ret < 0) {
+ count = ret;
+ goto exit;
+ }
+ if (msg->result != EC_RES_SUCCESS) {
+ dev_dbg(ec->dev, "EC result %d\n", msg->result);
+ count = -EINVAL;
+ }
+exit:
+ kfree(msg);
return count;
}

@@ -123,22 +136,32 @@ static ssize_t show_ec_version(struct device *dev,
struct ec_response_get_version *r_ver;
struct ec_response_get_chip_info *r_chip;
struct ec_response_board_version *r_board;
- struct cros_ec_command msg = { 0 };
+ struct cros_ec_command *msg;
int ret;
int count = 0;
struct cros_ec_device *ec = dev_get_drvdata(dev);

+ msg = kmalloc(sizeof(*msg) + EC_HOST_PARAM_SIZE, GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
/* Get versions. RW may change. */
- msg.command = EC_CMD_GET_VERSION;
- msg.insize = sizeof(*r_ver);
- ret = cros_ec_cmd_xfer(ec, &msg);
- if (ret < 0)
- return ret;
- if (msg.result != EC_RES_SUCCESS)
- return scnprintf(buf, PAGE_SIZE,
- "ERROR: EC returned %d\n", msg.result);
+ msg->version = 0;
+ msg->command = EC_CMD_GET_VERSION;
+ msg->insize = sizeof(*r_ver);
+ msg->outsize = 0;
+ ret = cros_ec_cmd_xfer(ec, msg);
+ if (ret < 0) {
+ count = ret;
+ goto exit;
+ }
+ if (msg->result != EC_RES_SUCCESS) {
+ count = scnprintf(buf, PAGE_SIZE,
+ "ERROR: EC returned %d\n", msg->result);
+ goto exit;
+ }

- r_ver = (struct ec_response_get_version *)msg.indata;
+ r_ver = (struct ec_response_get_version *)msg->data;
/* Strings should be null-terminated, but let's be sure. */
r_ver->version_string_ro[sizeof(r_ver->version_string_ro) - 1] = '\0';
r_ver->version_string_rw[sizeof(r_ver->version_string_rw) - 1] = '\0';
@@ -152,33 +175,33 @@ static ssize_t show_ec_version(struct device *dev,
image_names[r_ver->current_image] : "?"));

/* Get build info. */
- msg.command = EC_CMD_GET_BUILD_INFO;
- msg.insize = sizeof(msg.indata);
- ret = cros_ec_cmd_xfer(ec, &msg);
+ msg->command = EC_CMD_GET_BUILD_INFO;
+ msg->insize = EC_HOST_PARAM_SIZE;
+ ret = cros_ec_cmd_xfer(ec, msg);
if (ret < 0)
count += scnprintf(buf + count, PAGE_SIZE - count,
"Build info: XFER ERROR %d\n", ret);
- else if (msg.result != EC_RES_SUCCESS)
+ else if (msg->result != EC_RES_SUCCESS)
count += scnprintf(buf + count, PAGE_SIZE - count,
- "Build info: EC error %d\n", msg.result);
+ "Build info: EC error %d\n", msg->result);
else {
- msg.indata[sizeof(msg.indata) - 1] = '\0';
+ msg->data[sizeof(msg->data) - 1] = '\0';
count += scnprintf(buf + count, PAGE_SIZE - count,
- "Build info: %s\n", msg.indata);
+ "Build info: %s\n", msg->data);
}

/* Get chip info. */
- msg.command = EC_CMD_GET_CHIP_INFO;
- msg.insize = sizeof(*r_chip);
- ret = cros_ec_cmd_xfer(ec, &msg);
+ msg->command = EC_CMD_GET_CHIP_INFO;
+ msg->insize = sizeof(*r_chip);
+ ret = cros_ec_cmd_xfer(ec, msg);
if (ret < 0)
count += scnprintf(buf + count, PAGE_SIZE - count,
"Chip info: XFER ERROR %d\n", ret);
- else if (msg.result != EC_RES_SUCCESS)
+ else if (msg->result != EC_RES_SUCCESS)
count += scnprintf(buf + count, PAGE_SIZE - count,
- "Chip info: EC error %d\n", msg.result);
+ "Chip info: EC error %d\n", msg->result);
else {
- r_chip = (struct ec_response_get_chip_info *)msg.indata;
+ r_chip = (struct ec_response_get_chip_info *)msg->data;

r_chip->vendor[sizeof(r_chip->vendor) - 1] = '\0';
r_chip->name[sizeof(r_chip->name) - 1] = '\0';
@@ -192,23 +215,25 @@ static ssize_t show_ec_version(struct device *dev,
}

/* Get board version */
- msg.command = EC_CMD_GET_BOARD_VERSION;
- msg.insize = sizeof(*r_board);
- ret = cros_ec_cmd_xfer(ec, &msg);
+ msg->command = EC_CMD_GET_BOARD_VERSION;
+ msg->insize = sizeof(*r_board);
+ ret = cros_ec_cmd_xfer(ec, msg);
if (ret < 0)
count += scnprintf(buf + count, PAGE_SIZE - count,
"Board version: XFER ERROR %d\n", ret);
- else if (msg.result != EC_RES_SUCCESS)
+ else if (msg->result != EC_RES_SUCCESS)
count += scnprintf(buf + count, PAGE_SIZE - count,
- "Board version: EC error %d\n", msg.result);
+ "Board version: EC error %d\n", msg->result);
else {
- r_board = (struct ec_response_board_version *)msg.indata;
+ r_board = (struct ec_response_board_version *)msg->data;

count += scnprintf(buf + count, PAGE_SIZE - count,
"Board version: %d\n",
r_board->board_version);
}

+exit:
+ kfree(msg);
return count;
}

@@ -216,27 +241,38 @@ static ssize_t show_ec_flashinfo(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ec_response_flash_info *resp;
- struct cros_ec_command msg = { 0 };
+ struct cros_ec_command *msg;
int ret;
struct cros_ec_device *ec = dev_get_drvdata(dev);

+ msg = kmalloc(sizeof(*msg) + sizeof(*resp), GFP_KERNEL);
+ if (!msg)
+ return -ENOMEM;
+
/* The flash info shouldn't ever change, but ask each time anyway. */
- msg.command = EC_CMD_FLASH_INFO;
- msg.insize = sizeof(*resp);
- ret = cros_ec_cmd_xfer(ec, &msg);
+ msg->version = 0;
+ msg->command = EC_CMD_FLASH_INFO;
+ msg->insize = sizeof(*resp);
+ msg->outsize = 0;
+ ret = cros_ec_cmd_xfer(ec, msg);
if (ret < 0)
- return ret;
- if (msg.result != EC_RES_SUCCESS)
- return scnprintf(buf, PAGE_SIZE,
- "ERROR: EC returned %d\n", msg.result);
-
- resp = (struct ec_response_flash_info *)msg.indata;
-
- return scnprintf(buf, PAGE_SIZE,
- "FlashSize %d\nWriteSize %d\n"
- "EraseSize %d\nProtectSize %d\n",
- resp->flash_size, resp->write_block_size,
- resp->erase_block_size, resp->protect_block_size);
+ goto exit;
+ if (msg->result != EC_RES_SUCCESS) {
+ ret = scnprintf(buf, PAGE_SIZE,
+ "ERROR: EC returned %d\n", msg->result);
+ goto exit;
+ }
+
+ resp = (struct ec_response_flash_info *)msg->data;
+
+ ret = scnprintf(buf, PAGE_SIZE,
+ "FlashSize %d\nWriteSize %d\n"
+ "EraseSize %d\nProtectSize %d\n",
+ resp->flash_size, resp->write_block_size,
+ resp->erase_block_size, resp->protect_block_size);
+exit:
+ kfree(msg);
+ return ret;
}

/* Module initialization */
diff --git a/include/linux/mfd/cros_ec.h b/include/linux/mfd/cros_ec.h
index 14cf522123dd..7eee38abd02a 100644
--- a/include/linux/mfd/cros_ec.h
+++ b/include/linux/mfd/cros_ec.h
@@ -42,8 +42,7 @@ enum {
* @outsize: Outgoing length in bytes
* @insize: Max number of bytes to accept from EC
* @result: EC's response to the command (separate from communication failure)
- * @outdata: Outgoing data to EC
- * @indata: Where to put the incoming data from EC
+ * @data: Where to put the incoming data from EC and outgoing data to EC
*/
struct cros_ec_command {
uint32_t version;
@@ -51,8 +50,7 @@ struct cros_ec_command {
uint32_t outsize;
uint32_t insize;
uint32_t result;
- uint8_t outdata[EC_PROTO2_MAX_PARAM_SIZE];
- uint8_t indata[EC_PROTO2_MAX_PARAM_SIZE];
+ uint8_t data[0];
};

/**
--
2.1.4