Commit 2f79136b authored by Bart Van Assche's avatar Bart Van Assche Committed by Jens Axboe

bfq: Check kstrtoul() return value

Make sysfs writes fail for invalid numbers instead of storing
uninitialized data copied from the stack. This patch removes
all uninitialized_var() occurrences from the BFQ source code.
Acked-by: default avatarPaolo Valente <paolo.valente@linaro.org>
Signed-off-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent dfb79af5
......@@ -4802,13 +4802,15 @@ static ssize_t bfq_var_show(unsigned int var, char *page)
return sprintf(page, "%u\n", var);
}
static void bfq_var_store(unsigned long *var, const char *page)
static int bfq_var_store(unsigned long *var, const char *page)
{
unsigned long new_val;
int ret = kstrtoul(page, 10, &new_val);
if (ret == 0)
*var = new_val;
if (ret)
return ret;
*var = new_val;
return 0;
}
#define SHOW_FUNCTION(__FUNC, __VAR, __CONV) \
......@@ -4849,8 +4851,12 @@ static ssize_t \
__FUNC(struct elevator_queue *e, const char *page, size_t count) \
{ \
struct bfq_data *bfqd = e->elevator_data; \
unsigned long uninitialized_var(__data); \
bfq_var_store(&__data, (page)); \
unsigned long __data; \
int ret; \
\
ret = bfq_var_store(&__data, (page)); \
if (ret) \
return ret; \
if (__data < (MIN)) \
__data = (MIN); \
else if (__data > (MAX)) \
......@@ -4877,8 +4883,12 @@ STORE_FUNCTION(bfq_slice_idle_store, &bfqd->bfq_slice_idle, 0, INT_MAX, 2);
static ssize_t __FUNC(struct elevator_queue *e, const char *page, size_t count)\
{ \
struct bfq_data *bfqd = e->elevator_data; \
unsigned long uninitialized_var(__data); \
bfq_var_store(&__data, (page)); \
unsigned long __data; \
int ret; \
\
ret = bfq_var_store(&__data, (page)); \
if (ret) \
return ret; \
if (__data < (MIN)) \
__data = (MIN); \
else if (__data > (MAX)) \
......@@ -4894,9 +4904,12 @@ static ssize_t bfq_max_budget_store(struct elevator_queue *e,
const char *page, size_t count)
{
struct bfq_data *bfqd = e->elevator_data;
unsigned long uninitialized_var(__data);
unsigned long __data;
int ret;
bfq_var_store(&__data, (page));
ret = bfq_var_store(&__data, (page));
if (ret)
return ret;
if (__data == 0)
bfqd->bfq_max_budget = bfq_calc_max_budget(bfqd);
......@@ -4919,9 +4932,12 @@ static ssize_t bfq_timeout_sync_store(struct elevator_queue *e,
const char *page, size_t count)
{
struct bfq_data *bfqd = e->elevator_data;
unsigned long uninitialized_var(__data);
unsigned long __data;
int ret;
bfq_var_store(&__data, (page));
ret = bfq_var_store(&__data, (page));
if (ret)
return ret;
if (__data < 1)
__data = 1;
......@@ -4939,9 +4955,12 @@ static ssize_t bfq_strict_guarantees_store(struct elevator_queue *e,
const char *page, size_t count)
{
struct bfq_data *bfqd = e->elevator_data;
unsigned long uninitialized_var(__data);
unsigned long __data;
int ret;
bfq_var_store(&__data, (page));
ret = bfq_var_store(&__data, (page));
if (ret)
return ret;
if (__data > 1)
__data = 1;
......@@ -4958,9 +4977,12 @@ static ssize_t bfq_low_latency_store(struct elevator_queue *e,
const char *page, size_t count)
{
struct bfq_data *bfqd = e->elevator_data;
unsigned long uninitialized_var(__data);
unsigned long __data;
int ret;
bfq_var_store(&__data, (page));
ret = bfq_var_store(&__data, (page));
if (ret)
return ret;
if (__data > 1)
__data = 1;
......
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