[PATCH v2] platform/x86: dell-laptop: Allocate buffer on heap rather than globally

From: Mario Limonciello
Date: Wed Jan 31 2018 - 12:48:28 EST

There is no longer a need for the buffer to be defined in
first 4GB physical address space.

Furthermore there may be race conditions with multiple different functions
working on a module wide buffer causing incorrect results.

Fixes: 549b4930f057658dc50d8010e66219233119a4d8
Suggested-by: Pali Rohar <pali.rohar@xxxxxxxxx>
Signed-off-by: Mario Limonciello <mario.limonciello@xxxxxxxx>
---
drivers/platform/x86/dell-laptop.c | 188 ++++++++++++++++++++-----------------
1 file changed, 103 insertions(+), 85 deletions(-)

diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/dell-laptop.c
index fc2dfc8..a7b1419 100644
--- a/drivers/platform/x86/dell-laptop.c
+++ b/drivers/platform/x86/dell-laptop.c
@@ -78,7 +78,6 @@ static struct platform_driver platform_driver = {
}
};

-static struct calling_interface_buffer *buffer;
static struct platform_device *platform_device;
static struct backlight_device *dell_backlight_device;
static struct rfkill *wifi_rfkill;
@@ -322,7 +321,8 @@ static const struct dmi_system_id dell_quirks[] __initconst = {
{ }
};

-static void dell_set_arguments(u32 arg0, u32 arg1, u32 arg2, u32 arg3)
+static void dell_fill_request(struct calling_interface_buffer *buffer,
+ u32 arg0, u32 arg1, u32 arg2, u32 arg3)
{
memset(buffer, 0, sizeof(struct calling_interface_buffer));
buffer->input[0] = arg0;
@@ -331,7 +331,8 @@ static void dell_set_arguments(u32 arg0, u32 arg1, u32 arg2, u32 arg3)
buffer->input[3] = arg3;
}

-static int dell_send_request(u16 class, u16 select)
+static int dell_send_request(struct calling_interface_buffer *buffer,
+ u16 class, u16 select)
{
int ret;

@@ -468,21 +469,22 @@ static int dell_rfkill_set(void *data, bool blocked)
int disable = blocked ? 1 : 0;
unsigned long radio = (unsigned long)data;
int hwswitch_bit = (unsigned long)data - 1;
+ struct calling_interface_buffer buffer;
int hwswitch;
int status;
int ret;

- dell_set_arguments(0, 0, 0, 0);
- ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
+ dell_fill_request(&buffer, 0, 0, 0, 0);
+ ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
if (ret)
return ret;
- status = buffer->output[1];
+ status = buffer.output[1];

- dell_set_arguments(0x2, 0, 0, 0);
- ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
+ dell_fill_request(&buffer, 0x2, 0, 0, 0);
+ ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
if (ret)
return ret;
- hwswitch = buffer->output[1];
+ hwswitch = buffer.output[1];

/* If the hardware switch controls this radio, and the hardware
switch is disabled, always disable the radio */
@@ -490,8 +492,8 @@ static int dell_rfkill_set(void *data, bool blocked)
(status & BIT(0)) && !(status & BIT(16)))
disable = 1;

- dell_set_arguments(1 | (radio<<8) | (disable << 16), 0, 0, 0);
- ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
+ dell_fill_request(&buffer, 1 | (radio<<8) | (disable << 16), 0, 0, 0);
+ ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
return ret;
}

@@ -500,9 +502,11 @@ static void dell_rfkill_update_sw_state(struct rfkill *rfkill, int radio,
{
if (status & BIT(0)) {
/* Has hw-switch, sync sw_state to BIOS */
+ struct calling_interface_buffer buffer;
int block = rfkill_blocked(rfkill);
- dell_set_arguments(1 | (radio << 8) | (block << 16), 0, 0, 0);
- dell_send_request(CLASS_INFO, SELECT_RFKILL);
+ dell_fill_request(&buffer,
+ 1 | (radio << 8) | (block << 16), 0, 0, 0);
+ dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
} else {
/* No hw-switch, sync BIOS state to sw_state */
rfkill_set_sw_state(rfkill, !!(status & BIT(radio + 16)));
@@ -519,21 +523,22 @@ static void dell_rfkill_update_hw_state(struct rfkill *rfkill, int radio,
static void dell_rfkill_query(struct rfkill *rfkill, void *data)
{
int radio = ((unsigned long)data & 0xF);
+ struct calling_interface_buffer buffer;
int hwswitch;
int status;
int ret;

- dell_set_arguments(0, 0, 0, 0);
- ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
- status = buffer->output[1];
+ dell_fill_request(&buffer, 0, 0, 0, 0);
+ ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
+ status = buffer.output[1];

if (ret != 0 || !(status & BIT(0))) {
return;
}

- dell_set_arguments(0, 0x2, 0, 0);
- ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
- hwswitch = buffer->output[1];
+ dell_fill_request(&buffer, 0, 0x2, 0, 0);
+ ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
+ hwswitch = buffer.output[1];

if (ret != 0)
return;
@@ -550,22 +555,23 @@ static struct dentry *dell_laptop_dir;

static int dell_debugfs_show(struct seq_file *s, void *data)
{
+ struct calling_interface_buffer buffer;
int hwswitch_state;
int hwswitch_ret;
int status;
int ret;

- dell_set_arguments(0, 0, 0, 0);
- ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
+ dell_fill_request(&buffer, 0, 0, 0, 0);
+ ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
if (ret)
return ret;
- status = buffer->output[1];
+ status = buffer.output[1];

- dell_set_arguments(0, 0x2, 0, 0);
- hwswitch_ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
+ dell_fill_request(&buffer, 0, 0x2, 0, 0);
+ hwswitch_ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
if (hwswitch_ret)
return hwswitch_ret;
- hwswitch_state = buffer->output[1];
+ hwswitch_state = buffer.output[1];

seq_printf(s, "return:\t%d\n", ret);
seq_printf(s, "status:\t0x%X\n", status);
@@ -646,22 +652,23 @@ static const struct file_operations dell_debugfs_fops = {

static void dell_update_rfkill(struct work_struct *ignored)
{
+ struct calling_interface_buffer buffer;
int hwswitch = 0;
int status;
int ret;

- dell_set_arguments(0, 0, 0, 0);
- ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
- status = buffer->output[1];
+ dell_fill_request(&buffer, 0, 0, 0, 0);
+ ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
+ status = buffer.output[1];

if (ret != 0)
return;

- dell_set_arguments(0, 0x2, 0, 0);
- ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
+ dell_fill_request(&buffer, 0, 0x2, 0, 0);
+ ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);

if (ret == 0 && (status & BIT(0)))
- hwswitch = buffer->output[1];
+ hwswitch = buffer.output[1];

if (wifi_rfkill) {
dell_rfkill_update_hw_state(wifi_rfkill, 1, status, hwswitch);
@@ -719,6 +726,7 @@ static struct notifier_block dell_laptop_rbtn_notifier = {

static int __init dell_setup_rfkill(void)
{
+ struct calling_interface_buffer buffer;
int status, ret, whitelisted;
const char *product;

@@ -734,9 +742,9 @@ static int __init dell_setup_rfkill(void)
if (!force_rfkill && !whitelisted)
return 0;

- dell_set_arguments(0, 0, 0, 0);
- ret = dell_send_request(CLASS_INFO, SELECT_RFKILL);
- status = buffer->output[1];
+ dell_fill_request(&buffer, 0, 0, 0, 0);
+ ret = dell_send_request(&buffer, CLASS_INFO, SELECT_RFKILL);
+ status = buffer.output[1];

/* dell wireless info smbios call is not supported */
if (ret != 0)
@@ -889,6 +897,7 @@ static void dell_cleanup_rfkill(void)

static int dell_send_intensity(struct backlight_device *bd)
{
+ struct calling_interface_buffer buffer;
struct calling_interface_token *token;
int ret;

@@ -896,17 +905,21 @@ static int dell_send_intensity(struct backlight_device *bd)
if (!token)
return -ENODEV;

- dell_set_arguments(token->location, bd->props.brightness, 0, 0);
+ dell_fill_request(&buffer,
+ token->location, bd->props.brightness, 0, 0);
if (power_supply_is_system_supplied() > 0)
- ret = dell_send_request(CLASS_TOKEN_WRITE, SELECT_TOKEN_AC);
+ ret = dell_send_request(&buffer,
+ CLASS_TOKEN_WRITE, SELECT_TOKEN_AC);
else
- ret = dell_send_request(CLASS_TOKEN_WRITE, SELECT_TOKEN_BAT);
+ ret = dell_send_request(&buffer,
+ CLASS_TOKEN_WRITE, SELECT_TOKEN_BAT);

return ret;
}

static int dell_get_intensity(struct backlight_device *bd)
{
+ struct calling_interface_buffer buffer;
struct calling_interface_token *token;
int ret;

@@ -914,14 +927,17 @@ static int dell_get_intensity(struct backlight_device *bd)
if (!token)
return -ENODEV;

- dell_set_arguments(token->location, 0, 0, 0);
+ dell_fill_request(&buffer, token->location, 0, 0, 0);
if (power_supply_is_system_supplied() > 0)
- ret = dell_send_request(CLASS_TOKEN_READ, SELECT_TOKEN_AC);
+ ret = dell_send_request(&buffer,
+ CLASS_TOKEN_READ, SELECT_TOKEN_AC);
else
- ret = dell_send_request(CLASS_TOKEN_READ, SELECT_TOKEN_BAT);
+ ret = dell_send_request(&buffer,
+ CLASS_TOKEN_READ, SELECT_TOKEN_BAT);

if (ret == 0)
- ret = buffer->output[1];
+ ret = buffer.output[1];
+
return ret;
}

@@ -1186,31 +1202,33 @@ static enum led_brightness kbd_led_level;

static int kbd_get_info(struct kbd_info *info)
{
+ struct calling_interface_buffer buffer;
u8 units;
int ret;

- dell_set_arguments(0, 0, 0, 0);
- ret = dell_send_request(CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT);
+ dell_fill_request(&buffer, 0, 0, 0, 0);
+ ret = dell_send_request(&buffer,
+ CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT);
if (ret)
return ret;

- info->modes = buffer->output[1] & 0xFFFF;
- info->type = (buffer->output[1] >> 24) & 0xFF;
- info->triggers = buffer->output[2] & 0xFF;
- units = (buffer->output[2] >> 8) & 0xFF;
- info->levels = (buffer->output[2] >> 16) & 0xFF;
+ info->modes = buffer.output[1] & 0xFFFF;
+ info->type = (buffer.output[1] >> 24) & 0xFF;
+ info->triggers = buffer.output[2] & 0xFF;
+ units = (buffer.output[2] >> 8) & 0xFF;
+ info->levels = (buffer.output[2] >> 16) & 0xFF;

if (quirks && quirks->kbd_led_levels_off_1 && info->levels)
info->levels--;

if (units & BIT(0))
- info->seconds = (buffer->output[3] >> 0) & 0xFF;
+ info->seconds = (buffer.output[3] >> 0) & 0xFF;
if (units & BIT(1))
- info->minutes = (buffer->output[3] >> 8) & 0xFF;
+ info->minutes = (buffer.output[3] >> 8) & 0xFF;
if (units & BIT(2))
- info->hours = (buffer->output[3] >> 16) & 0xFF;
+ info->hours = (buffer.output[3] >> 16) & 0xFF;
if (units & BIT(3))
- info->days = (buffer->output[3] >> 24) & 0xFF;
+ info->days = (buffer.output[3] >> 24) & 0xFF;

return ret;
}
@@ -1270,31 +1288,34 @@ static int kbd_set_level(struct kbd_state *state, u8 level)

static int kbd_get_state(struct kbd_state *state)
{
+ struct calling_interface_buffer buffer;
int ret;

- dell_set_arguments(0x1, 0, 0, 0);
- ret = dell_send_request(CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT);
+ dell_fill_request(&buffer, 0, 0, 0, 0);
+ ret = dell_send_request(&buffer,
+ CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT);
if (ret)
return ret;

- state->mode_bit = ffs(buffer->output[1] & 0xFFFF);
+ state->mode_bit = ffs(buffer.output[1] & 0xFFFF);
if (state->mode_bit != 0)
state->mode_bit--;

- state->triggers = (buffer->output[1] >> 16) & 0xFF;
- state->timeout_value = (buffer->output[1] >> 24) & 0x3F;
- state->timeout_unit = (buffer->output[1] >> 30) & 0x3;
- state->als_setting = buffer->output[2] & 0xFF;
- state->als_value = (buffer->output[2] >> 8) & 0xFF;
- state->level = (buffer->output[2] >> 16) & 0xFF;
- state->timeout_value_ac = (buffer->output[2] >> 24) & 0x3F;
- state->timeout_unit_ac = (buffer->output[2] >> 30) & 0x3;
+ state->triggers = (buffer.output[1] >> 16) & 0xFF;
+ state->timeout_value = (buffer.output[1] >> 24) & 0x3F;
+ state->timeout_unit = (buffer.output[1] >> 30) & 0x3;
+ state->als_setting = buffer.output[2] & 0xFF;
+ state->als_value = (buffer.output[2] >> 8) & 0xFF;
+ state->level = (buffer.output[2] >> 16) & 0xFF;
+ state->timeout_value_ac = (buffer.output[2] >> 24) & 0x3F;
+ state->timeout_unit_ac = (buffer.output[2] >> 30) & 0x3;

return ret;
}

static int kbd_set_state(struct kbd_state *state)
{
+ struct calling_interface_buffer buffer;
int ret;
u32 input1;
u32 input2;
@@ -1307,8 +1328,9 @@ static int kbd_set_state(struct kbd_state *state)
input2 |= (state->level & 0xFF) << 16;
input2 |= (state->timeout_value_ac & 0x3F) << 24;
input2 |= (state->timeout_unit_ac & 0x3) << 30;
- dell_set_arguments(0x2, input1, input2, 0);
- ret = dell_send_request(CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT);
+ dell_fill_request(&buffer, 0x2, input1, input2, 0);
+ ret = dell_send_request(&buffer,
+ CLASS_KBD_BACKLIGHT, SELECT_KBD_BACKLIGHT);

return ret;
}
@@ -1335,6 +1357,7 @@ static int kbd_set_state_safe(struct kbd_state *state, struct kbd_state *old)

static int kbd_set_token_bit(u8 bit)
{
+ struct calling_interface_buffer buffer;
struct calling_interface_token *token;
int ret;

@@ -1345,14 +1368,15 @@ static int kbd_set_token_bit(u8 bit)
if (!token)
return -EINVAL;

- dell_set_arguments(token->location, token->value, 0, 0);
- ret = dell_send_request(CLASS_TOKEN_WRITE, SELECT_TOKEN_STD);
+ dell_fill_request(&buffer, token->location, token->value, 0, 0);
+ ret = dell_send_request(&buffer, CLASS_TOKEN_WRITE, SELECT_TOKEN_STD);

return ret;
}

static int kbd_get_token_bit(u8 bit)
{
+ struct calling_interface_buffer buffer;
struct calling_interface_token *token;
int ret;
int val;
@@ -1364,9 +1388,9 @@ static int kbd_get_token_bit(u8 bit)
if (!token)
return -EINVAL;

- dell_set_arguments(token->location, 0, 0, 0);
- ret = dell_send_request(CLASS_TOKEN_READ, SELECT_TOKEN_STD);
- val = buffer->output[1];
+ dell_fill_request(&buffer, token->location, 0, 0, 0);
+ ret = dell_send_request(&buffer, CLASS_TOKEN_READ, SELECT_TOKEN_STD);
+ val = buffer.output[1];

if (ret)
return ret;
@@ -2102,6 +2126,7 @@ static struct notifier_block dell_laptop_notifier = {

int dell_micmute_led_set(int state)
{
+ struct calling_interface_buffer buffer;
struct calling_interface_token *token;

if (state == 0)
@@ -2114,8 +2139,8 @@ int dell_micmute_led_set(int state)
if (!token)
return -ENODEV;

- dell_set_arguments(token->location, token->value, 0, 0);
- dell_send_request(CLASS_TOKEN_WRITE, SELECT_TOKEN_STD);
+ dell_fill_request(&buffer, token->location, token->value, 0, 0);
+ dell_send_request(&buffer, CLASS_TOKEN_WRITE, SELECT_TOKEN_STD);

return state;
}
@@ -2146,13 +2171,6 @@ static int __init dell_init(void)
if (ret)
goto fail_platform_device2;

- buffer = kzalloc(sizeof(struct calling_interface_buffer), GFP_KERNEL);
- if (!buffer) {
- ret = -ENOMEM;
- goto fail_buffer;
- }
-
-
ret = dell_setup_rfkill();

if (ret) {
@@ -2177,10 +2195,13 @@ static int __init dell_init(void)

token = dell_smbios_find_token(BRIGHTNESS_TOKEN);
if (token) {
- dell_set_arguments(token->location, 0, 0, 0);
- ret = dell_send_request(CLASS_TOKEN_READ, SELECT_TOKEN_AC);
+ struct calling_interface_buffer buffer;
+
+ dell_fill_request(&buffer, token->location, 0, 0, 0);
+ ret = dell_send_request(&buffer,
+ CLASS_TOKEN_READ, SELECT_TOKEN_AC);
if (ret)
- max_intensity = buffer->output[3];
+ max_intensity = buffer.output[3];
}

if (max_intensity) {
@@ -2214,8 +2235,6 @@ static int __init dell_init(void)
fail_get_brightness:
backlight_device_unregister(dell_backlight_device);
fail_backlight:
- kfree(buffer);
-fail_buffer:
dell_cleanup_rfkill();
fail_rfkill:
platform_device_del(platform_device);
@@ -2235,7 +2254,6 @@ static void __exit dell_exit(void)
touchpad_led_exit();
kbd_led_exit();
backlight_device_unregister(dell_backlight_device);
- kfree(buffer);
dell_cleanup_rfkill();
if (platform_device) {
platform_device_unregister(platform_device);
--
2.7.4