Commit 756d5282 authored by Gustavo A. R. Silva's avatar Gustavo A. R. Silva Committed by Alexandre Belloni
Browse files

rtc: s5m: Remove VLA usage 

In preparation to enabling -Wvla, remove VLAs and replace them
with fixed-length arrays instead.

>From a security viewpoint, the use of Variable Length Arrays can be
a vector for stack overflow attacks. Also, in general, as the code
evolves it is easy to lose track of how big a VLA can get. Thus, we
can end up having segfaults that are hard to debug.

Also, fixed as part of the directive to remove all VLAs from
the kernel: https://lkml.org/lkml/2018/3/7/621



Signed-off-by: default avatarGustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: default avatarKrzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: default avatarAlexandre Belloni <alexandre.belloni@bootlin.com>
parent 4a681243

drivers/rtc/rtc-s5m.c

+8 −6
Original line number Diff line number Diff line
@@ -47,6 +47,8 @@ enum { 
	RTC_MONTH,

	RTC_YEAR1,

	RTC_YEAR2,

	/* Make sure this is always the last enum name. */

	RTC_MAX_NUM_TIME_REGS

};



/*
@@ -378,7 +380,7 @@ static void s5m8763_tm_to_data(struct rtc_time *tm, u8 *data) 
static int s5m_rtc_read_time(struct device *dev, struct rtc_time *tm)

{

	struct s5m_rtc_info *info = dev_get_drvdata(dev);

	u8 data[info->regs->regs_count];

	u8 data[RTC_MAX_NUM_TIME_REGS];

	int ret;



	if (info->regs->read_time_udr_mask) {
@@ -424,7 +426,7 @@ static int s5m_rtc_read_time(struct device *dev, struct rtc_time *tm) 
static int s5m_rtc_set_time(struct device *dev, struct rtc_time *tm)

{

	struct s5m_rtc_info *info = dev_get_drvdata(dev);

	u8 data[info->regs->regs_count];

	u8 data[RTC_MAX_NUM_TIME_REGS];

	int ret = 0;



	switch (info->device_type) {
@@ -461,7 +463,7 @@ static int s5m_rtc_set_time(struct device *dev, struct rtc_time *tm) 
static int s5m_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm)

{

	struct s5m_rtc_info *info = dev_get_drvdata(dev);

	u8 data[info->regs->regs_count];

	u8 data[RTC_MAX_NUM_TIME_REGS];

	unsigned int val;

	int ret, i;
@@ -511,7 +513,7 @@ static int s5m_rtc_read_alarm(struct device *dev, struct rtc_wkalrm *alrm) 


static int s5m_rtc_stop_alarm(struct s5m_rtc_info *info)

{

	u8 data[info->regs->regs_count];

	u8 data[RTC_MAX_NUM_TIME_REGS];

	int ret, i;

	struct rtc_time tm;
@@ -556,7 +558,7 @@ static int s5m_rtc_stop_alarm(struct s5m_rtc_info *info) 
static int s5m_rtc_start_alarm(struct s5m_rtc_info *info)

{

	int ret;

	u8 data[info->regs->regs_count];

	u8 data[RTC_MAX_NUM_TIME_REGS];

	u8 alarm0_conf;

	struct rtc_time tm;
@@ -609,7 +611,7 @@ static int s5m_rtc_start_alarm(struct s5m_rtc_info *info) 
static int s5m_rtc_set_alarm(struct device *dev, struct rtc_wkalrm *alrm)

{

	struct s5m_rtc_info *info = dev_get_drvdata(dev);

	u8 data[info->regs->regs_count];

	u8 data[RTC_MAX_NUM_TIME_REGS];

	int ret;



	switch (info->device_type) {

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