> Il giorno 30 ago 2017, alle ore 20:42, Bart Van Assche > <[email protected]> ha scritto: > > 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. > > Signed-off-by: Bart Van Assche <[email protected]> > Cc: Paolo Valente <[email protected]>
Acked-by: Paolo Valente <[email protected]> > --- > block/bfq-iosched.c | 52 +++++++++++++++++++++++++++++++++++++--------------- > 1 file changed, 37 insertions(+), 15 deletions(-) > > diff --git a/block/bfq-iosched.c b/block/bfq-iosched.c > index 8c11c2e827a5..cf92f16eb5f2 100644 > --- a/block/bfq-iosched.c > +++ b/block/bfq-iosched.c > @@ -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; > -- > 2.14.1 >
