| Message ID | 0954fe1d-e0ff-6b35-6d2d-96901cad6503@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Superseded |
| Delegated to: | Herbert Xu |
| Headers | show |
Hi Harald, > Here is an updated version with just showing 0 or 1 in the new sysfs > attribute file: > ========== cut ========== > From: Harald Freudenberger <freude@linux.vnet.ibm.com> > Date: Mon, 3 Jul 2017 10:19:22 +0200 > Subject: [PATCH 3/3] crypto: hwrng add sysfs attribute to show user selected > rng > > This patch introduces a new sysfs attribute file 'rng_selected' > which shows if the current rng has been chosen by userspace. > > If a rng source is chosen by user via echo some valid string > to rng_current there should be a way to signal this choice to > userspace. The new attribute file 'rng_selected' shows '1' for > user selecte rng and '0' otherwise. > > Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> > --- > drivers/char/hw_random/core.c | 21 ++++++++++++++++----- > 1 file changed, 16 insertions(+), 5 deletions(-) > > diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c > index ffd4e36..2b4c7f6 100644 > --- a/drivers/char/hw_random/core.c > +++ b/drivers/char/hw_random/core.c > @@ -28,8 +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; > +/* the rng explicitly selected by user via sysfs */ > +static struct hwrng *selected_rng; > static struct task_struct *hwrng_fill; > /* list of registered rngs, sorted decending by quality */ > static LIST_HEAD(rng_list); > @@ -306,7 +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; > + selected_rng = rng; > if (rng != current_rng) > err = set_current_rng(rng); > break; > @@ -355,16 +355,27 @@ static ssize_t hwrng_attr_available_show(struct device *dev, > return strlen(buf); > } > > +static ssize_t hwrng_attr_selected_show(struct device *dev, > + struct device_attribute *attr, > + char *buf) > +{ > + return snprintf(buf, PAGE_SIZE, "%d\n", selected_rng ? 1 : 0); > +} > + > static DEVICE_ATTR(rng_current, S_IRUGO | S_IWUSR, > hwrng_attr_current_show, > hwrng_attr_current_store); > static DEVICE_ATTR(rng_available, S_IRUGO, > hwrng_attr_available_show, > NULL); > +static DEVICE_ATTR(rng_selected, S_IRUGO, > + hwrng_attr_selected_show, > + NULL); > > static struct attribute *rng_dev_attrs[] = { > &dev_attr_rng_current.attr, > &dev_attr_rng_available.attr, > + &dev_attr_rng_selected.attr, > NULL > }; > > @@ -448,7 +459,7 @@ int hwrng_register(struct hwrng *rng) > old_rng = current_rng; > err = 0; > if (!old_rng || > - (!cur_rng_set_by_user && rng->quality > old_rng->quality)) { > + (!selected_rng && rng->quality > old_rng->quality)) { > /* > * Set new rng as current as the new rng source > * provides better entropy quality and was not > @@ -484,7 +495,7 @@ void hwrng_unregister(struct hwrng *rng) > list_del(&rng->list); > if (current_rng == rng) { > drop_current_rng(); > - cur_rng_set_by_user = 0; > + selected_rng = NULL; > /* rng_list is sorted by quality, use the best (=first) one */ > if (!list_empty(&rng_list)) { > struct hwrng *new_rng; > -- > 2.7.4 > ========== cut ========== > Nice to see quick turn around time. Why not just use the cur_rng_set_by_user instead of selected_rng? This way patch 3 won't change things that patch 2 introduced and patch 3 will become much smaller. Also I feel folding patch 3 and 2 will make sense as both are related to user selected rng. Regards, PrasannaKumar
========== cut ========== From: Harald Freudenberger <freude@linux.vnet.ibm.com> Date: Mon, 3 Jul 2017 10:19:22 +0200 Subject: [PATCH 3/3] crypto: hwrng add sysfs attribute to show user selected rng This patch introduces a new sysfs attribute file 'rng_selected' which shows if the current rng has been chosen by userspace. If a rng source is chosen by user via echo some valid string to rng_current there should be a way to signal this choice to userspace. The new attribute file 'rng_selected' shows '1' for user selecte rng and '0' otherwise. Signed-off-by: Harald Freudenberger <freude@linux.vnet.ibm.com> --- drivers/char/hw_random/core.c | 21 ++++++++++++++++----- 1 file changed, 16 insertions(+), 5 deletions(-) diff --git a/drivers/char/hw_random/core.c b/drivers/char/hw_random/core.c index ffd4e36..2b4c7f6 100644 --- a/drivers/char/hw_random/core.c +++ b/drivers/char/hw_random/core.c @@ -28,8 +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; +/* the rng explicitly selected by user via sysfs */ +static struct hwrng *selected_rng; static struct task_struct *hwrng_fill; /* list of registered rngs, sorted decending by quality */ static LIST_HEAD(rng_list); @@ -306,7 +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; + selected_rng = rng; if (rng != current_rng) err = set_current_rng(rng); break; @@ -355,16 +355,27 @@ static ssize_t hwrng_attr_available_show(struct device *dev, return strlen(buf); } +static ssize_t hwrng_attr_selected_show(struct device *dev, + struct device_attribute *attr, + char *buf) +{ + return snprintf(buf, PAGE_SIZE, "%d\n", selected_rng ? 1 : 0); +} + static DEVICE_ATTR(rng_current, S_IRUGO | S_IWUSR, hwrng_attr_current_show, hwrng_attr_current_store); static DEVICE_ATTR(rng_available, S_IRUGO, hwrng_attr_available_show, NULL); +static DEVICE_ATTR(rng_selected, S_IRUGO, + hwrng_attr_selected_show, + NULL); static struct attribute *rng_dev_attrs[] = { &dev_attr_rng_current.attr, &dev_attr_rng_available.attr, + &dev_attr_rng_selected.attr, NULL }; @@ -448,7 +459,7 @@ int hwrng_register(struct hwrng *rng) old_rng = current_rng; err = 0; if (!old_rng || - (!cur_rng_set_by_user && rng->quality > old_rng->quality)) { + (!selected_rng && rng->quality > old_rng->quality)) { /* * Set new rng as current as the new rng source * provides better entropy quality and was not @@ -484,7 +495,7 @@ void hwrng_unregister(struct hwrng *rng) list_del(&rng->list); if (current_rng == rng) { drop_current_rng(); - cur_rng_set_by_user = 0; + selected_rng = NULL; /* rng_list is sorted by quality, use the best (=first) one */ if (!list_empty(&rng_list)) { struct hwrng *new_rng;