search for: hwrng_attr_available_show

...(struct device *dev, return -ERESTARTSYS; if (current_rng) name = current_rng->name; - ret = snprintf(buf, PAGE_SIZE, "%s\n", name); mutex_unlock(&rng_mutex); + ret = snprintf(buf, PAGE_SIZE, "%s\n", name); return ret; } @@ -284,19 +285,19 @@ static ssize_t hwrng_attr_available_show(struct device *dev, ssize_t ret = 0; struct hwrng *rng; + buf[0] = '\0'; err = mutex_lock_interruptible(&rng_mutex); if (err) return -ERESTARTSYS; - buf[0] = '\0'; list_for_each_entry(rng, &rng_list, list) { strncat(buf, rng->name, PAGE_SIZE - ret - 1);...

...(struct device *dev, return -ERESTARTSYS; if (current_rng) name = current_rng->name; - ret = snprintf(buf, PAGE_SIZE, "%s\n", name); mutex_unlock(&rng_mutex); + ret = snprintf(buf, PAGE_SIZE, "%s\n", name); return ret; } @@ -284,19 +285,19 @@ static ssize_t hwrng_attr_available_show(struct device *dev, ssize_t ret = 0; struct hwrng *rng; + buf[0] = '\0'; err = mutex_lock_interruptible(&rng_mutex); if (err) return -ERESTARTSYS; - buf[0] = '\0'; list_for_each_entry(rng, &rng_list, list) { strncat(buf, rng->name, PAGE_SIZE - ret - 1);...

...mutex_unlock(&rng_mutex); > + ret = snprintf(buf, PAGE_SIZE, "%s\n", name); I'm not sure this is safe. Name is just a pointer. What if the hwrng gets unregistered after unlock and just before the snprintf? > return ret; > } > @@ -284,19 +284,19 @@ static ssize_t hwrng_attr_available_show(struct device *dev, > ssize_t ret = 0; > struct hwrng *rng; > > + buf[0] = '\0'; > err = mutex_lock_interruptible(&rng_mutex); > if (err) > return -ERESTARTSYS; > - buf[0] = '\0'; > list_for_each_entry(rng, &rng_list, list) { >...

...mutex_unlock(&rng_mutex); > + ret = snprintf(buf, PAGE_SIZE, "%s\n", name); I'm not sure this is safe. Name is just a pointer. What if the hwrng gets unregistered after unlock and just before the snprintf? > return ret; > } > @@ -284,19 +284,19 @@ static ssize_t hwrng_attr_available_show(struct device *dev, > ssize_t ret = 0; > struct hwrng *rng; > > + buf[0] = '\0'; > err = mutex_lock_interruptible(&rng_mutex); > if (err) > return -ERESTARTSYS; > - buf[0] = '\0'; > list_for_each_entry(rng, &rng_list, list) { >...

...rng) > name = current_rng->name; > - ret = snprintf(buf, PAGE_SIZE, "%s\n", name); > mutex_unlock(&rng_mutex); > + ret = snprintf(buf, PAGE_SIZE, "%s\n", name); This looks OK... > > return ret; > } > @@ -284,19 +285,19 @@ static ssize_t hwrng_attr_available_show(struct device *dev, > ssize_t ret = 0; > struct hwrng *rng; > > + buf[0] = '\0'; > err = mutex_lock_interruptible(&rng_mutex); > if (err) > return -ERESTARTSYS; > > - buf[0] = '\0'; > list_for_each_entry(rng, &rng_list, list) { &g...

...rng) > name = current_rng->name; > - ret = snprintf(buf, PAGE_SIZE, "%s\n", name); > mutex_unlock(&rng_mutex); > + ret = snprintf(buf, PAGE_SIZE, "%s\n", name); This looks OK... > > return ret; > } > @@ -284,19 +285,19 @@ static ssize_t hwrng_attr_available_show(struct device *dev, > ssize_t ret = 0; > struct hwrng *rng; > > + buf[0] = '\0'; > err = mutex_lock_interruptible(&rng_mutex); > if (err) > return -ERESTARTSYS; > > - buf[0] = '\0'; > list_for_each_entry(rng, &rng_list, list) { &g...

If we read hwrng by long-running dd process, it takes too much cpu time. When we check hwrng attributes from sysfs by cat, it gets stuck. The problem can only be reproduced with non-smp guest with slow backend. This patchset changed hwrng core to always delay 10 jiffies, cat process have chance to execute protected code, the problem is resolved. Thanks. Amos Kong (2): virtio-rng cleanup: move

If we read hwrng by long-running dd process, it takes too much cpu time. When we check hwrng attributes from sysfs by cat, it gets stuck. The problem can only be reproduced with non-smp guest with slow backend. This patchset changed hwrng core to always delay 10 jiffies, cat process have chance to execute protected code, the problem is resolved. Thanks. Amos Kong (2): virtio-rng cleanup: move

On Wed, Jul 09, 2014 at 06:38:22PM +0530, Amit Shah wrote: > On (Wed) 09 Jul 2014 [07:53:17], Jason Cooper wrote: > > On Sat, Jul 05, 2014 at 11:04:52AM +0530, Amit Shah wrote: > > > Commit d9e7972619334 "hwrng: add randomness to system from rng sources" > > > added a call to rng_get_data() from the hwrng_register() function. > > > However, some rng

On Wed, Jul 09, 2014 at 06:38:22PM +0530, Amit Shah wrote: > On (Wed) 09 Jul 2014 [07:53:17], Jason Cooper wrote: > > On Sat, Jul 05, 2014 at 11:04:52AM +0530, Amit Shah wrote: > > > Commit d9e7972619334 "hwrng: add randomness to system from rng sources" > > > added a call to rng_get_data() from the hwrng_register() function. > > > However, some rng

...es, bytes_read); + + kfree(bytes); } static inline int hwrng_init(struct hwrng *rng) @@ -84,7 +95,7 @@ static inline int hwrng_init(struct hwrng *rng) if (ret) return ret; - add_early_randomness(rng); + add_early_randomness(rng, 0); return ret; } @@ -281,18 +292,54 @@ static ssize_t hwrng_attr_available_show(struct device *dev, return ret; } +/* + * seed the kernel's entropy pool from the current hwrng. + * + * 'echo "n" >rng_seed_kernel', where n >= 0. + * n = 0: default size added (16 bytes) + * 0 < n <= 256: n bytes added. + * n > 256: 256 bytes added....

...es, bytes_read); + + kfree(bytes); } static inline int hwrng_init(struct hwrng *rng) @@ -84,7 +95,7 @@ static inline int hwrng_init(struct hwrng *rng) if (ret) return ret; - add_early_randomness(rng); + add_early_randomness(rng, 0); return ret; } @@ -281,18 +292,54 @@ static ssize_t hwrng_attr_available_show(struct device *dev, return ret; } +/* + * seed the kernel's entropy pool from the current hwrng. + * + * 'echo "n" >rng_seed_kernel', where n >= 0. + * n = 0: default size added (16 bytes) + * 0 < n <= 256: n bytes added. + * n > 256: 256 bytes added....

If we read hwrng by long-running dd process, it takes too much cpu time and almost hold the mutex lock. When we check hwrng attributes from sysfs by cat, it gets stuck in waiting the lock releaseing. The problem can only be reproduced with non-smp guest with slow backend. This patchset resolves the issue by changing rng_dev_read() to always schedule 10 jiffies after release mutex lock, then cat

If we read hwrng by long-running dd process, it takes too much cpu time and almost hold the mutex lock. When we check hwrng attributes from sysfs by cat, it gets stuck in waiting the lock releaseing. The problem can only be reproduced with non-smp guest with slow backend. This patchset resolves the issue by changing rng_dev_read() to always schedule 10 jiffies after release mutex lock, then cat

...(struct device *dev, return -ERESTARTSYS; if (current_rng) name = current_rng->name; - ret = snprintf(buf, PAGE_SIZE, "%s\n", name); mutex_unlock(&rng_mutex); + ret = snprintf(buf, PAGE_SIZE, "%s\n", name); return ret; } @@ -284,19 +285,19 @@ static ssize_t hwrng_attr_available_show(struct device *dev, ssize_t ret = 0; struct hwrng *rng; + buf[0] = '\0'; err = mutex_lock_interruptible(&rng_mutex); if (err) return -ERESTARTSYS; - buf[0] = '\0'; list_for_each_entry(rng, &rng_list, list) { strncat(buf, rng->name, PAGE_SIZE - ret - 1);...

...(struct device *dev, return -ERESTARTSYS; if (current_rng) name = current_rng->name; - ret = snprintf(buf, PAGE_SIZE, "%s\n", name); mutex_unlock(&rng_mutex); + ret = snprintf(buf, PAGE_SIZE, "%s\n", name); return ret; } @@ -284,19 +284,19 @@ static ssize_t hwrng_attr_available_show(struct device *dev, ssize_t ret = 0; struct hwrng *rng; + buf[0] = '\0'; err = mutex_lock_interruptible(&rng_mutex); if (err) return -ERESTARTSYS; - buf[0] = '\0'; list_for_each_entry(rng, &rng_list, list) { strncat(buf, rng->name, PAGE_SIZE - ret - 1);...

...(struct device *dev, return -ERESTARTSYS; if (current_rng) name = current_rng->name; - ret = snprintf(buf, PAGE_SIZE, "%s\n", name); mutex_unlock(&rng_mutex); + ret = snprintf(buf, PAGE_SIZE, "%s\n", name); return ret; } @@ -284,19 +284,19 @@ static ssize_t hwrng_attr_available_show(struct device *dev, ssize_t ret = 0; struct hwrng *rng; + buf[0] = '\0'; err = mutex_lock_interruptible(&rng_mutex); if (err) return -ERESTARTSYS; - buf[0] = '\0'; list_for_each_entry(rng, &rng_list, list) { strncat(buf, rng->name, PAGE_SIZE - ret - 1);...

...; - ret = snprintf(buf, PAGE_SIZE, "%s\n", name); > > mutex_unlock(&rng_mutex); > > + ret = snprintf(buf, PAGE_SIZE, "%s\n", name); > > This looks OK... > > > > > return ret; > > } > > @@ -284,19 +285,19 @@ static ssize_t hwrng_attr_available_show(struct device *dev, > > ssize_t ret = 0; > > struct hwrng *rng; > > > > + buf[0] = '\0'; > > err = mutex_lock_interruptible(&rng_mutex); > > if (err) > > return -ERESTARTSYS; > > > > - buf[0] = '\0'; > >...