| Message ID | 20201121030156.22857-3-s-anna@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | remoteproc sysfs fixes/improvements | expand |
On Fri 20 Nov 21:01 CST 2020, Suman Anna 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. > This makes sense, but can't we implement attribute_group->is_visible to simply hide these entries from userspace instead of leaving them "broken"? Regards, Bjorn > Signed-off-by: Suman Anna <s-anna@ti.com> > --- > v2: revised to account for the 'recovery' sysfs file as well, patch > description updated accordingly > v1: https://patchwork.kernel.org/project/linux-remoteproc/patch/20180915003725.17549-5-s-anna@ti.com/ > > drivers/remoteproc/remoteproc_sysfs.c | 12 ++++++++++++ > include/linux/remoteproc.h | 2 ++ > 2 files changed, 14 insertions(+) > > diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c > index bd2950a246c9..3fd18a71c188 100644 > --- a/drivers/remoteproc/remoteproc_sysfs.c > +++ b/drivers/remoteproc/remoteproc_sysfs.c > @@ -49,6 +49,10 @@ static ssize_t recovery_store(struct device *dev, > { > struct rproc *rproc = to_rproc(dev); > > + /* restrict sysfs operations if not allowed by remoteproc drivers */ > + if (rproc->deny_sysfs_ops) > + return -EPERM; > + > if (sysfs_streq(buf, "enabled")) { > /* change the flag and begin the recovery process if needed */ > rproc->recovery_disabled = false; > @@ -158,6 +162,10 @@ static ssize_t firmware_store(struct device *dev, > char *p; > int err, len = count; > > + /* restrict sysfs operations if not allowed by remoteproc drivers */ > + if (rproc->deny_sysfs_ops) > + return -EPERM; > + > err = mutex_lock_interruptible(&rproc->lock); > if (err) { > dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, err); > @@ -225,6 +233,10 @@ static ssize_t state_store(struct device *dev, > struct rproc *rproc = to_rproc(dev); > int ret = 0; > > + /* restrict sysfs operations if not allowed by remoteproc drivers */ > + if (rproc->deny_sysfs_ops) > + return -EPERM; > + > if (sysfs_streq(buf, "start")) { > if (rproc->state == RPROC_RUNNING) > return -EBUSY; > diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h > index 3fa3ba6498e8..dbc3767f7d0e 100644 > --- a/include/linux/remoteproc.h > +++ b/include/linux/remoteproc.h > @@ -508,6 +508,7 @@ struct rproc_dump_segment { > * @has_iommu: flag to indicate if remote processor is behind an MMU > * @auto_boot: flag to indicate if remote processor should be auto-started > * @autonomous: true if an external entity has booted the remote processor > + * @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 > * @char_dev: character device of the rproc > @@ -545,6 +546,7 @@ struct rproc { > bool has_iommu; > bool auto_boot; > bool autonomous; > + bool deny_sysfs_ops; > struct list_head dump_segments; > int nb_vdev; > u8 elf_class; > -- > 2.28.0 >
On 11/20/20 9:38 PM, Bjorn Andersson wrote: > On Fri 20 Nov 21:01 CST 2020, Suman Anna 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. >> > > This makes sense, but can't we implement attribute_group->is_visible to > simply hide these entries from userspace instead of leaving them > "broken"? I would have to look into that, but can that be changed dynamically? Also, note that the enforcement is only on the writes/stores which impact the state-machine, but not the reads/shows. For PRU usecases, we will be setting this dynamically. regards Suman > > Regards, > Bjorn > >> Signed-off-by: Suman Anna <s-anna@ti.com> >> --- >> v2: revised to account for the 'recovery' sysfs file as well, patch >> description updated accordingly >> v1: https://patchwork.kernel.org/project/linux-remoteproc/patch/20180915003725.17549-5-s-anna@ti.com/ >> >> drivers/remoteproc/remoteproc_sysfs.c | 12 ++++++++++++ >> include/linux/remoteproc.h | 2 ++ >> 2 files changed, 14 insertions(+) >> >> diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c >> index bd2950a246c9..3fd18a71c188 100644 >> --- a/drivers/remoteproc/remoteproc_sysfs.c >> +++ b/drivers/remoteproc/remoteproc_sysfs.c >> @@ -49,6 +49,10 @@ static ssize_t recovery_store(struct device *dev, >> { >> struct rproc *rproc = to_rproc(dev); >> >> + /* restrict sysfs operations if not allowed by remoteproc drivers */ >> + if (rproc->deny_sysfs_ops) >> + return -EPERM; >> + >> if (sysfs_streq(buf, "enabled")) { >> /* change the flag and begin the recovery process if needed */ >> rproc->recovery_disabled = false; >> @@ -158,6 +162,10 @@ static ssize_t firmware_store(struct device *dev, >> char *p; >> int err, len = count; >> >> + /* restrict sysfs operations if not allowed by remoteproc drivers */ >> + if (rproc->deny_sysfs_ops) >> + return -EPERM; >> + >> err = mutex_lock_interruptible(&rproc->lock); >> if (err) { >> dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, err); >> @@ -225,6 +233,10 @@ static ssize_t state_store(struct device *dev, >> struct rproc *rproc = to_rproc(dev); >> int ret = 0; >> >> + /* restrict sysfs operations if not allowed by remoteproc drivers */ >> + if (rproc->deny_sysfs_ops) >> + return -EPERM; >> + >> if (sysfs_streq(buf, "start")) { >> if (rproc->state == RPROC_RUNNING) >> return -EBUSY; >> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h >> index 3fa3ba6498e8..dbc3767f7d0e 100644 >> --- a/include/linux/remoteproc.h >> +++ b/include/linux/remoteproc.h >> @@ -508,6 +508,7 @@ struct rproc_dump_segment { >> * @has_iommu: flag to indicate if remote processor is behind an MMU >> * @auto_boot: flag to indicate if remote processor should be auto-started >> * @autonomous: true if an external entity has booted the remote processor >> + * @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 >> * @char_dev: character device of the rproc >> @@ -545,6 +546,7 @@ struct rproc { >> bool has_iommu; >> bool auto_boot; >> bool autonomous; >> + bool deny_sysfs_ops; >> struct list_head dump_segments; >> int nb_vdev; >> u8 elf_class; >> -- >> 2.28.0 >>
On Fri 20 Nov 21:44 CST 2020, Suman Anna wrote: > On 11/20/20 9:38 PM, Bjorn Andersson wrote: > > On Fri 20 Nov 21:01 CST 2020, Suman Anna 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. > >> > > > > This makes sense, but can't we implement attribute_group->is_visible to > > simply hide these entries from userspace instead of leaving them > > "broken"? > > I would have to look into that, but can that be changed dynamically? > Also, note that the enforcement is only on the writes/stores which impact > the state-machine, but not the reads/shows. > > For PRU usecases, we will be setting this dynamically. > It looks to be dynamic, but I don't know if there's any "caching" involved. Please have a look and let me know. Regards, Bjorn > regards > Suman > > > > > Regards, > > Bjorn > > > >> Signed-off-by: Suman Anna <s-anna@ti.com> > >> --- > >> v2: revised to account for the 'recovery' sysfs file as well, patch > >> description updated accordingly > >> v1: https://patchwork.kernel.org/project/linux-remoteproc/patch/20180915003725.17549-5-s-anna@ti.com/ > >> > >> drivers/remoteproc/remoteproc_sysfs.c | 12 ++++++++++++ > >> include/linux/remoteproc.h | 2 ++ > >> 2 files changed, 14 insertions(+) > >> > >> diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c > >> index bd2950a246c9..3fd18a71c188 100644 > >> --- a/drivers/remoteproc/remoteproc_sysfs.c > >> +++ b/drivers/remoteproc/remoteproc_sysfs.c > >> @@ -49,6 +49,10 @@ static ssize_t recovery_store(struct device *dev, > >> { > >> struct rproc *rproc = to_rproc(dev); > >> > >> + /* restrict sysfs operations if not allowed by remoteproc drivers */ > >> + if (rproc->deny_sysfs_ops) > >> + return -EPERM; > >> + > >> if (sysfs_streq(buf, "enabled")) { > >> /* change the flag and begin the recovery process if needed */ > >> rproc->recovery_disabled = false; > >> @@ -158,6 +162,10 @@ static ssize_t firmware_store(struct device *dev, > >> char *p; > >> int err, len = count; > >> > >> + /* restrict sysfs operations if not allowed by remoteproc drivers */ > >> + if (rproc->deny_sysfs_ops) > >> + return -EPERM; > >> + > >> err = mutex_lock_interruptible(&rproc->lock); > >> if (err) { > >> dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, err); > >> @@ -225,6 +233,10 @@ static ssize_t state_store(struct device *dev, > >> struct rproc *rproc = to_rproc(dev); > >> int ret = 0; > >> > >> + /* restrict sysfs operations if not allowed by remoteproc drivers */ > >> + if (rproc->deny_sysfs_ops) > >> + return -EPERM; > >> + > >> if (sysfs_streq(buf, "start")) { > >> if (rproc->state == RPROC_RUNNING) > >> return -EBUSY; > >> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h > >> index 3fa3ba6498e8..dbc3767f7d0e 100644 > >> --- a/include/linux/remoteproc.h > >> +++ b/include/linux/remoteproc.h > >> @@ -508,6 +508,7 @@ struct rproc_dump_segment { > >> * @has_iommu: flag to indicate if remote processor is behind an MMU > >> * @auto_boot: flag to indicate if remote processor should be auto-started > >> * @autonomous: true if an external entity has booted the remote processor > >> + * @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 > >> * @char_dev: character device of the rproc > >> @@ -545,6 +546,7 @@ struct rproc { > >> bool has_iommu; > >> bool auto_boot; > >> bool autonomous; > >> + bool deny_sysfs_ops; > >> struct list_head dump_segments; > >> int nb_vdev; > >> u8 elf_class; > >> -- > >> 2.28.0 > >> >
On 11/21/20 11:33 PM, Bjorn Andersson wrote: > On Fri 20 Nov 21:44 CST 2020, Suman Anna wrote: > >> On 11/20/20 9:38 PM, Bjorn Andersson wrote: >>> On Fri 20 Nov 21:01 CST 2020, Suman Anna 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. >>>> >>> >>> This makes sense, but can't we implement attribute_group->is_visible to >>> simply hide these entries from userspace instead of leaving them >>> "broken"? >> >> I would have to look into that, but can that be changed dynamically? >> Also, note that the enforcement is only on the writes/stores which impact >> the state-machine, but not the reads/shows. >> >> For PRU usecases, we will be setting this dynamically. >> > > It looks to be dynamic, but I don't know if there's any "caching" > involved. Please have a look and let me know. OK, will do. I can only check the week after though. regards Suman > > Regards, > Bjorn > >> regards >> Suman >> >>> >>> Regards, >>> Bjorn >>> >>>> Signed-off-by: Suman Anna <s-anna@ti.com> >>>> --- >>>> v2: revised to account for the 'recovery' sysfs file as well, patch >>>> description updated accordingly >>>> v1: https://patchwork.kernel.org/project/linux-remoteproc/patch/20180915003725.17549-5-s-anna@ti.com/ >>>> >>>> drivers/remoteproc/remoteproc_sysfs.c | 12 ++++++++++++ >>>> include/linux/remoteproc.h | 2 ++ >>>> 2 files changed, 14 insertions(+) >>>> >>>> diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c >>>> index bd2950a246c9..3fd18a71c188 100644 >>>> --- a/drivers/remoteproc/remoteproc_sysfs.c >>>> +++ b/drivers/remoteproc/remoteproc_sysfs.c >>>> @@ -49,6 +49,10 @@ static ssize_t recovery_store(struct device *dev, >>>> { >>>> struct rproc *rproc = to_rproc(dev); >>>> >>>> + /* restrict sysfs operations if not allowed by remoteproc drivers */ >>>> + if (rproc->deny_sysfs_ops) >>>> + return -EPERM; >>>> + >>>> if (sysfs_streq(buf, "enabled")) { >>>> /* change the flag and begin the recovery process if needed */ >>>> rproc->recovery_disabled = false; >>>> @@ -158,6 +162,10 @@ static ssize_t firmware_store(struct device *dev, >>>> char *p; >>>> int err, len = count; >>>> >>>> + /* restrict sysfs operations if not allowed by remoteproc drivers */ >>>> + if (rproc->deny_sysfs_ops) >>>> + return -EPERM; >>>> + >>>> err = mutex_lock_interruptible(&rproc->lock); >>>> if (err) { >>>> dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, err); >>>> @@ -225,6 +233,10 @@ static ssize_t state_store(struct device *dev, >>>> struct rproc *rproc = to_rproc(dev); >>>> int ret = 0; >>>> >>>> + /* restrict sysfs operations if not allowed by remoteproc drivers */ >>>> + if (rproc->deny_sysfs_ops) >>>> + return -EPERM; >>>> + >>>> if (sysfs_streq(buf, "start")) { >>>> if (rproc->state == RPROC_RUNNING) >>>> return -EBUSY; >>>> diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h >>>> index 3fa3ba6498e8..dbc3767f7d0e 100644 >>>> --- a/include/linux/remoteproc.h >>>> +++ b/include/linux/remoteproc.h >>>> @@ -508,6 +508,7 @@ struct rproc_dump_segment { >>>> * @has_iommu: flag to indicate if remote processor is behind an MMU >>>> * @auto_boot: flag to indicate if remote processor should be auto-started >>>> * @autonomous: true if an external entity has booted the remote processor >>>> + * @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 >>>> * @char_dev: character device of the rproc >>>> @@ -545,6 +546,7 @@ struct rproc { >>>> bool has_iommu; >>>> bool auto_boot; >>>> bool autonomous; >>>> + bool deny_sysfs_ops; >>>> struct list_head dump_segments; >>>> int nb_vdev; >>>> u8 elf_class; >>>> -- >>>> 2.28.0 >>>> >>
diff --git a/drivers/remoteproc/remoteproc_sysfs.c b/drivers/remoteproc/remoteproc_sysfs.c index bd2950a246c9..3fd18a71c188 100644 --- a/drivers/remoteproc/remoteproc_sysfs.c +++ b/drivers/remoteproc/remoteproc_sysfs.c @@ -49,6 +49,10 @@ static ssize_t recovery_store(struct device *dev, { struct rproc *rproc = to_rproc(dev); + /* restrict sysfs operations if not allowed by remoteproc drivers */ + if (rproc->deny_sysfs_ops) + return -EPERM; + if (sysfs_streq(buf, "enabled")) { /* change the flag and begin the recovery process if needed */ rproc->recovery_disabled = false; @@ -158,6 +162,10 @@ static ssize_t firmware_store(struct device *dev, char *p; int err, len = count; + /* restrict sysfs operations if not allowed by remoteproc drivers */ + if (rproc->deny_sysfs_ops) + return -EPERM; + err = mutex_lock_interruptible(&rproc->lock); if (err) { dev_err(dev, "can't lock rproc %s: %d\n", rproc->name, err); @@ -225,6 +233,10 @@ static ssize_t state_store(struct device *dev, struct rproc *rproc = to_rproc(dev); int ret = 0; + /* restrict sysfs operations if not allowed by remoteproc drivers */ + if (rproc->deny_sysfs_ops) + return -EPERM; + if (sysfs_streq(buf, "start")) { if (rproc->state == RPROC_RUNNING) return -EBUSY; diff --git a/include/linux/remoteproc.h b/include/linux/remoteproc.h index 3fa3ba6498e8..dbc3767f7d0e 100644 --- a/include/linux/remoteproc.h +++ b/include/linux/remoteproc.h @@ -508,6 +508,7 @@ struct rproc_dump_segment { * @has_iommu: flag to indicate if remote processor is behind an MMU * @auto_boot: flag to indicate if remote processor should be auto-started * @autonomous: true if an external entity has booted the remote processor + * @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 * @char_dev: character device of the rproc @@ -545,6 +546,7 @@ struct rproc { bool has_iommu; bool auto_boot; bool autonomous; + bool deny_sysfs_ops; struct list_head dump_segments; int nb_vdev; u8 elf_class;
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. Signed-off-by: Suman Anna <s-anna@ti.com> --- v2: revised to account for the 'recovery' sysfs file as well, patch description updated accordingly v1: https://patchwork.kernel.org/project/linux-remoteproc/patch/20180915003725.17549-5-s-anna@ti.com/ drivers/remoteproc/remoteproc_sysfs.c | 12 ++++++++++++ include/linux/remoteproc.h | 2 ++ 2 files changed, 14 insertions(+)