The remoteproc framework provides sysfs interfaces for changing
the firmware name and for starting/stopping a remote processor
through the sysfs files 'state' and 'firmware'. The 'recovery'
sysfs file can also be used similarly to control the error recovery
state machine of a remoteproc. These interfaces are currently
allowed irrespective of how the remoteprocs were booted (like
remoteproc self auto-boot, remoteproc client-driven boot etc).
These interfaces can adversely affect a remoteproc and its clients
especially when a remoteproc is being controlled by a remoteproc
client driver(s). Also, not all remoteproc drivers may want to
support the sysfs interfaces by default.
Add support to deny the sysfs state/firmware/recovery change by
introducing a state flag 'deny_sysfs_ops' that the individual
remoteproc drivers can set based on their usage needs. The default
behavior is to allow the sysfs operations as before.
Implement attribute_group->is_visible() to hide the sysfs
state/firmware/recovery entries when deny_sysfs_ops flag is set.
Signed-off-by: Puranjay Mohan <[email protected]>
---
Changes in v3->v4:
Use mode = 0444 in rproc_is_visible() to make the sysfs entries
read-only when the deny_sysfs_ops flag is set.
---
drivers/remoteproc/remoteproc_sysfs.c | 18 +++++++++++++++++-
include/linux/remoteproc.h | 2 ++
2 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
index ea8b89f97d7b..da2d0eecfa44 100644
--- a/drivers/remoteproc/remoteproc_sysfs.c
+++ b/drivers/remoteproc/remoteproc_sysfs.c
@@ -230,6 +230,21 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr,
}
static DEVICE_ATTR_RO(name);
+static umode_t rproc_is_visible(struct kobject *kobj, struct attribute *attr,
+ int n)
+{
+ struct device *dev = kobj_to_dev(kobj);
+ struct rproc *rproc = to_rproc(dev);
+ umode_t mode = attr->mode;
+
+ if (rproc->deny_sysfs_ops && (attr == &dev_attr_recovery.attr ||
+ attr == &dev_attr_firmware.attr ||
+ attr == &dev_attr_state.attr))
+ mode = 0444;
+
+ return mode;
+}
+
static struct attribute *rproc_attrs[] = {
&dev_attr_coredump.attr,
&dev_attr_recovery.attr,
@@ -240,7 +255,8 @@ static struct attribute *rproc_attrs[] = {
};
static const struct attribute_group rproc_devgroup = {
- .attrs = rproc_attrs
+ .attrs = rproc_attrs,
+ .is_visible = rproc_is_visible,
};
static const struct attribute_group *rproc_devgroups[] = {
diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
index e0600e1e5c17..3849c66ce38f 100644
--- a/include/linux/remoteproc.h
+++ b/include/linux/remoteproc.h
@@ -523,6 +523,7 @@ struct rproc_dump_segment {
* @table_sz: size of @cached_table
* @has_iommu: flag to indicate if remote processor is behind an MMU
* @auto_boot: flag to indicate if remote processor should be auto-started
+ * @deny_sysfs_ops: flag to not permit sysfs operations on state, firmware and recovery
* @dump_segments: list of segments in the firmware
* @nb_vdev: number of vdev currently handled by rproc
* @elf_class: firmware ELF class
@@ -562,6 +563,7 @@ struct rproc {
size_t table_sz;
bool has_iommu;
bool auto_boot;
+ bool deny_sysfs_ops;
struct list_head dump_segments;
int nb_vdev;
u8 elf_class;
--
2.17.1
Hi Puranjay,
On Wed, Feb 09, 2022 at 02:33:41PM +0530, Puranjay Mohan wrote:
> The remoteproc framework provides sysfs interfaces for changing
> the firmware name and for starting/stopping a remote processor
> through the sysfs files 'state' and 'firmware'. The 'recovery'
> sysfs file can also be used similarly to control the error recovery
> state machine of a remoteproc. These interfaces are currently
> allowed irrespective of how the remoteprocs were booted (like
> remoteproc self auto-boot, remoteproc client-driven boot etc).
> These interfaces can adversely affect a remoteproc and its clients
> especially when a remoteproc is being controlled by a remoteproc
> client driver(s). Also, not all remoteproc drivers may want to
> support the sysfs interfaces by default.
>
> Add support to deny the sysfs state/firmware/recovery change by
> introducing a state flag 'deny_sysfs_ops' that the individual
> remoteproc drivers can set based on their usage needs. The default
> behavior is to allow the sysfs operations as before.
>
> Implement attribute_group->is_visible() to hide the sysfs
> state/firmware/recovery entries when deny_sysfs_ops flag is set.
>
> Signed-off-by: Puranjay Mohan <[email protected]>
> ---
> Changes in v3->v4:
> Use mode = 0444 in rproc_is_visible() to make the sysfs entries
> read-only when the deny_sysfs_ops flag is set.
> ---
> drivers/remoteproc/remoteproc_sysfs.c | 18 +++++++++++++++++-
> include/linux/remoteproc.h | 2 ++
> 2 files changed, 19 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
> index ea8b89f97d7b..da2d0eecfa44 100644
> --- a/drivers/remoteproc/remoteproc_sysfs.c
> +++ b/drivers/remoteproc/remoteproc_sysfs.c
> @@ -230,6 +230,21 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr,
> }
> static DEVICE_ATTR_RO(name);
>
> +static umode_t rproc_is_visible(struct kobject *kobj, struct attribute *attr,
> + int n)
> +{
> + struct device *dev = kobj_to_dev(kobj);
> + struct rproc *rproc = to_rproc(dev);
> + umode_t mode = attr->mode;
> +
> + if (rproc->deny_sysfs_ops && (attr == &dev_attr_recovery.attr ||
> + attr == &dev_attr_firmware.attr ||
> + attr == &dev_attr_state.attr))
I was wondering if we should also add coredump to this group to make it an all
or nothing option (name is already read only).
> + mode = 0444;
Much better.
> +
> + return mode;
> +}
> +
> static struct attribute *rproc_attrs[] = {
> &dev_attr_coredump.attr,
> &dev_attr_recovery.attr,
> @@ -240,7 +255,8 @@ static struct attribute *rproc_attrs[] = {
> };
>
> static const struct attribute_group rproc_devgroup = {
> - .attrs = rproc_attrs
> + .attrs = rproc_attrs,
> + .is_visible = rproc_is_visible,
> };
>
> static const struct attribute_group *rproc_devgroups[] = {
> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
> index e0600e1e5c17..3849c66ce38f 100644
> --- a/include/linux/remoteproc.h
> +++ b/include/linux/remoteproc.h
> @@ -523,6 +523,7 @@ struct rproc_dump_segment {
> * @table_sz: size of @cached_table
> * @has_iommu: flag to indicate if remote processor is behind an MMU
> * @auto_boot: flag to indicate if remote processor should be auto-started
> + * @deny_sysfs_ops: flag to not permit sysfs operations on state, firmware and recovery
> * @dump_segments: list of segments in the firmware
> * @nb_vdev: number of vdev currently handled by rproc
> * @elf_class: firmware ELF class
> @@ -562,6 +563,7 @@ struct rproc {
> size_t table_sz;
> bool has_iommu;
> bool auto_boot;
> + bool deny_sysfs_ops;
Wouldn't "sysfs_read_only" make more sense?
With or without the above and for this set:
Reviewed-by: Mathieu Poirier <[email protected]>
> struct list_head dump_segments;
> int nb_vdev;
> u8 elf_class;
> --
> 2.17.1
>
Hi Mathieu,
On 11/02/22 00:18, Mathieu Poirier wrote:
> Hi Puranjay,
>
> On Wed, Feb 09, 2022 at 02:33:41PM +0530, Puranjay Mohan wrote:
>> The remoteproc framework provides sysfs interfaces for changing
>> the firmware name and for starting/stopping a remote processor
>> through the sysfs files 'state' and 'firmware'. The 'recovery'
>> sysfs file can also be used similarly to control the error recovery
>> state machine of a remoteproc. These interfaces are currently
>> allowed irrespective of how the remoteprocs were booted (like
>> remoteproc self auto-boot, remoteproc client-driven boot etc).
>> These interfaces can adversely affect a remoteproc and its clients
>> especially when a remoteproc is being controlled by a remoteproc
>> client driver(s). Also, not all remoteproc drivers may want to
>> support the sysfs interfaces by default.
>>
>> Add support to deny the sysfs state/firmware/recovery change by
>> introducing a state flag 'deny_sysfs_ops' that the individual
>> remoteproc drivers can set based on their usage needs. The default
>> behavior is to allow the sysfs operations as before.
>>
>> Implement attribute_group->is_visible() to hide the sysfs
>> state/firmware/recovery entries when deny_sysfs_ops flag is set.
>>
>> Signed-off-by: Puranjay Mohan <[email protected]>
>> ---
>> Changes in v3->v4:
>> Use mode = 0444 in rproc_is_visible() to make the sysfs entries
>> read-only when the deny_sysfs_ops flag is set.
>> ---
>> drivers/remoteproc/remoteproc_sysfs.c | 18 +++++++++++++++++-
>> include/linux/remoteproc.h | 2 ++
>> 2 files changed, 19 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c
>> index ea8b89f97d7b..da2d0eecfa44 100644
>> --- a/drivers/remoteproc/remoteproc_sysfs.c
>> +++ b/drivers/remoteproc/remoteproc_sysfs.c
>> @@ -230,6 +230,21 @@ static ssize_t name_show(struct device *dev, struct device_attribute *attr,
>> }
>> static DEVICE_ATTR_RO(name);
>>
>> +static umode_t rproc_is_visible(struct kobject *kobj, struct attribute *attr,
>> + int n)
>> +{
>> + struct device *dev = kobj_to_dev(kobj);
>> + struct rproc *rproc = to_rproc(dev);
>> + umode_t mode = attr->mode;
>> +
>> + if (rproc->deny_sysfs_ops && (attr == &dev_attr_recovery.attr ||
>> + attr == &dev_attr_firmware.attr ||
>> + attr == &dev_attr_state.attr))
>
> I was wondering if we should also add coredump to this group to make it an all
> or nothing option (name is already read only).
I have sent a v5 where I have added coredump to this.
>
>> + mode = 0444;
>
> Much better.
>
>> +
>> + return mode;
>> +}
>> +
>> static struct attribute *rproc_attrs[] = {
>> &dev_attr_coredump.attr,
>> &dev_attr_recovery.attr,
>> @@ -240,7 +255,8 @@ static struct attribute *rproc_attrs[] = {
>> };
>>
>> static const struct attribute_group rproc_devgroup = {
>> - .attrs = rproc_attrs
>> + .attrs = rproc_attrs,
>> + .is_visible = rproc_is_visible,
>> };
>>
>> static const struct attribute_group *rproc_devgroups[] = {
>> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h
>> index e0600e1e5c17..3849c66ce38f 100644
>> --- a/include/linux/remoteproc.h
>> +++ b/include/linux/remoteproc.h
>> @@ -523,6 +523,7 @@ struct rproc_dump_segment {
>> * @table_sz: size of @cached_table
>> * @has_iommu: flag to indicate if remote processor is behind an MMU
>> * @auto_boot: flag to indicate if remote processor should be auto-started
>> + * @deny_sysfs_ops: flag to not permit sysfs operations on state, firmware and recovery
>> * @dump_segments: list of segments in the firmware
>> * @nb_vdev: number of vdev currently handled by rproc
>> * @elf_class: firmware ELF class
>> @@ -562,6 +563,7 @@ struct rproc {
>> size_t table_sz;
>> bool has_iommu;
>> bool auto_boot;
>> + bool deny_sysfs_ops;
>
> Wouldn't "sysfs_read_only" make more sense?
I agree, I have renamed it to sysfs_read_only in v5 patch
>
>
> With or without the above and for this set:
>
> Reviewed-by: Mathieu Poirier <[email protected]>
Thanks.
Puranjay Mohan
>
>> struct list_head dump_segments;
>> int nb_vdev;
>> u8 elf_class;
>> --
>> 2.17.1
>>