| Message ID | 1499076204-18547-3-git-send-email-freude@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Herbert Xu |
| Headers | show |
Hi Harald, On 3 July 2017 at 15:33, Harald Freudenberger <freude@linux.vnet.ibm.com> wrote: > When a user chooses a rng source via sysfs > attribute this rng should be sticky, even > when other sources with better quality to > register. This patch introduces a simple way > to remember the user's choise. > > Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> > --- > drivers/char/hw_random/core.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c > index e9dda16..ffd4e36 100644 > --- a/drivers/char/hw_random/core.c > +++ b/drivers/char/hw_random/core.c > @@ -28,6 +28,8 @@ > #define RNG_MODULE_NAME "hw_random" > > static struct hwrng *current_rng; > +/* the current rng has been explicitly chosen by user via sysfs */ > +static int cur_rng_set_by_user; > static struct task_struct *hwrng_fill; > /* list of registered rngs, sorted decending by quality */ > static LIST_HEAD(rng_list); > @@ -304,6 +306,7 @@ static ssize_t hwrng_attr_current_store(struct device *dev, > list_for_each_entry(rng, &rng_list, list) { > if (sysfs_streq(rng->name, buf)) { > err = 0; > + cur_rng_set_by_user = 1; > if (rng != current_rng) > err = set_current_rng(rng); > break; > @@ -444,10 +447,12 @@ int hwrng_register(struct hwrng *rng) > > old_rng = current_rng; > err = 0; > - if (!old_rng || (rng->quality > old_rng->quality)) { > + if (!old_rng || > + (!cur_rng_set_by_user && rng->quality > old_rng->quality)) { > /* > * Set new rng as current as the new rng source > - * provides better entropy quality. > + * provides better entropy quality and was not > + * chosen by userspace. > */ > err = set_current_rng(rng); > if (err) > @@ -479,6 +484,7 @@ void hwrng_unregister(struct hwrng *rng) > list_del(&rng->list); > if (current_rng == rng) { > drop_current_rng(); > + cur_rng_set_by_user = 0; > /* rng_list is sorted by quality, use the best (=first) one */ > if (!list_empty(&rng_list)) { > struct hwrng *new_rng; > -- > 2.7.4 > Looks good to me. Reviewed-by: PrasannaKumar Muralidharan <prasannatsmkumar@gmail.com>. Regards, PrasannaKumar
diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index e9dda16..ffd4e36 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -28,6 +28,8 @@ #define RNG_MODULE_NAME "hw_random" static struct hwrng *current_rng; +/* the current rng has been explicitly chosen by user via sysfs */ +static int cur_rng_set_by_user; static struct task_struct *hwrng_fill; /* list of registered rngs, sorted decending by quality */ static LIST_HEAD(rng_list); @@ -304,6 +306,7 @@ static ssize_t hwrng_attr_current_store(struct device *dev, list_for_each_entry(rng, &rng_list, list) { if (sysfs_streq(rng->name, buf)) { err = 0; + cur_rng_set_by_user = 1; if (rng != current_rng) err = set_current_rng(rng); break; @@ -444,10 +447,12 @@ int hwrng_register(struct hwrng *rng) old_rng = current_rng; err = 0; - if (!old_rng || (rng->quality > old_rng->quality)) { + if (!old_rng || + (!cur_rng_set_by_user && rng->quality > old_rng->quality)) { /* * Set new rng as current as the new rng source - * provides better entropy quality. + * provides better entropy quality and was not + * chosen by userspace. */ err = set_current_rng(rng); if (err) @@ -479,6 +484,7 @@ void hwrng_unregister(struct hwrng *rng) list_del(&rng->list); if (current_rng == rng) { drop_current_rng(); + cur_rng_set_by_user = 0; /* rng_list is sorted by quality, use the best (=first) one */ if (!list_empty(&rng_list)) { struct hwrng *new_rng;
When a user chooses a rng source via sysfs attribute this rng should be sticky, even when other sources with better quality to register. This patch introduces a simple way to remember the user's choise. Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> --- drivers/char/hw_random/core.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)