Re: [PATCH 3/5] of: overlay: Master enable switch
Hi Rob,
> On Mar 24, 2015, at 22:25 , Rob Herring wrote:
>
> On Tue, Mar 17, 2015 at 3:30 PM, Pantelis Antoniou
> wrote:
>> Implement a throw once master enable switch to protect against any
>> further overlay applications if the administrator desires so.
>
> sysfs documentation?
>
OK, coming up.
>> Signed-off-by: Pantelis Antoniou
>> ---
>> drivers/of/overlay.c | 66
>> +++-
>> 1 file changed, 65 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
>> index f17f5ef..6688797 100644
>> --- a/drivers/of/overlay.c
>> +++ b/drivers/of/overlay.c
>> @@ -21,6 +21,7 @@
>> #include
>> #include
>> #include
>> +#include
>>
>> #include "of_private.h"
>>
>> @@ -55,6 +56,9 @@ struct of_overlay {
>>struct kobject kobj;
>> };
>>
>> +/* master enable switch; once set to 0 can't be re-enabled */
>> +static atomic_t ov_enable = ATOMIC_INIT(1);
>> +
>> static int of_overlay_apply_one(struct of_overlay *ov,
>>struct device_node *target, const struct device_node
>> *overlay);
>>
>> @@ -345,6 +349,60 @@ static struct kobj_type of_overlay_ktype = {
>>
>> static struct kset *ov_kset;
>>
>> +static ssize_t enable_read(struct file *filp, struct kobject *kobj,
>> + struct bin_attribute *bin_attr, char *buf,
>> + loff_t offset, size_t count)
>> +{
>> + char tbuf[3];
>> +
>> + if (offset < 0)
>> + return -EINVAL;
>> +
>> + if (offset >= sizeof(tbuf))
>> + return 0;
>> +
>> + if (count > sizeof(tbuf) - offset)
>> + count = sizeof(tbuf) - offset;
>> +
>> + /* fill in temp */
>> + tbuf[0] = '0' + atomic_read(_enable);
>> + tbuf[1] = '\n';
>> + tbuf[2] = '\0';
>> +
>> + /* copy to buffer */
>> + memcpy(buf, tbuf + offset, count);
>> +
>> + return count;
>> +}
>> +
>> +static ssize_t enable_write(struct file *filp, struct kobject *kobj,
>> + struct bin_attribute *bin_attr, char *buf,
>> + loff_t off, size_t count)
>> +{
>> + int new_enable;
>> +
>> + if (off != 0 || (buf[0] != '0' && buf[1] != '1'))
>
> Is buf[1] correct here?
>
Nope.
>> + return -EINVAL;
>> +
>> + new_enable = buf[0] - '0';
>> + if (new_enable != 0 && new_enable != 1)
>
> Make unsigned just "if (new_enable > 1)”.
>
OK.
>> + return -EINVAL;
>> +
>> + /* NOP for same value */
>> + if (new_enable == atomic_read(_enable))
>> + return count;
>> +
>> + /* if we've disabled it, no going back */
>> + if (atomic_read(_enable) == 0)
>> + return -EPERM;
>> +
>> + atomic_set(_enable, new_enable);
>> + return count;
>> +}
>> +
>> +/* just a single char + '\n' + '\0' */
>> +static BIN_ATTR_RW(enable, 3);
>> +
>> /**
>> * of_overlay_create() - Create and apply an overlay
>> * @tree: Device node containing all the overlays
>> @@ -360,6 +418,10 @@ int of_overlay_create(struct device_node *tree)
>>struct of_overlay *ov;
>>int err, id;
>>
>> + /* administratively disabled */
>> + if (!atomic_read(_enable))
>> + return -EPERM;
>> +
>>/* allocate the overlay structure */
>>ov = kzalloc(sizeof(*ov), GFP_KERNEL);
>>if (ov == NULL)
>> @@ -596,5 +658,7 @@ int of_overlay_init(void)
>>if (!ov_kset)
>>return -ENOMEM;
>>
>> - return 0;
>> + rc = sysfs_create_bin_file(_kset->kobj, _attr_enable);
>> + WARN(rc, "%s: error adding enable attribute\n", __func__);
>> + return rc;
>> }
>> --
>> 1.7.12
Regards
— Pantelis
--
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Re: [PATCH 3/5] of: overlay: Master enable switch
Hi Rob,
On Mar 24, 2015, at 22:25 , Rob Herring robherri...@gmail.com wrote:
On Tue, Mar 17, 2015 at 3:30 PM, Pantelis Antoniou
pantelis.anton...@konsulko.com wrote:
Implement a throw once master enable switch to protect against any
further overlay applications if the administrator desires so.
sysfs documentation?
OK, coming up.
Signed-off-by: Pantelis Antoniou pantelis.anton...@konsulko.com
---
drivers/of/overlay.c | 66
+++-
1 file changed, 65 insertions(+), 1 deletion(-)
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index f17f5ef..6688797 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -21,6 +21,7 @@
#include linux/err.h
#include linux/idr.h
#include linux/sysfs.h
+#include linux/atomic.h
#include of_private.h
@@ -55,6 +56,9 @@ struct of_overlay {
struct kobject kobj;
};
+/* master enable switch; once set to 0 can't be re-enabled */
+static atomic_t ov_enable = ATOMIC_INIT(1);
+
static int of_overlay_apply_one(struct of_overlay *ov,
struct device_node *target, const struct device_node
*overlay);
@@ -345,6 +349,60 @@ static struct kobj_type of_overlay_ktype = {
static struct kset *ov_kset;
+static ssize_t enable_read(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr, char *buf,
+ loff_t offset, size_t count)
+{
+ char tbuf[3];
+
+ if (offset 0)
+ return -EINVAL;
+
+ if (offset = sizeof(tbuf))
+ return 0;
+
+ if (count sizeof(tbuf) - offset)
+ count = sizeof(tbuf) - offset;
+
+ /* fill in temp */
+ tbuf[0] = '0' + atomic_read(ov_enable);
+ tbuf[1] = '\n';
+ tbuf[2] = '\0';
+
+ /* copy to buffer */
+ memcpy(buf, tbuf + offset, count);
+
+ return count;
+}
+
+static ssize_t enable_write(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr, char *buf,
+ loff_t off, size_t count)
+{
+ int new_enable;
+
+ if (off != 0 || (buf[0] != '0' buf[1] != '1'))
Is buf[1] correct here?
Nope.
+ return -EINVAL;
+
+ new_enable = buf[0] - '0';
+ if (new_enable != 0 new_enable != 1)
Make unsigned just if (new_enable 1)”.
OK.
+ return -EINVAL;
+
+ /* NOP for same value */
+ if (new_enable == atomic_read(ov_enable))
+ return count;
+
+ /* if we've disabled it, no going back */
+ if (atomic_read(ov_enable) == 0)
+ return -EPERM;
+
+ atomic_set(ov_enable, new_enable);
+ return count;
+}
+
+/* just a single char + '\n' + '\0' */
+static BIN_ATTR_RW(enable, 3);
+
/**
* of_overlay_create() - Create and apply an overlay
* @tree: Device node containing all the overlays
@@ -360,6 +418,10 @@ int of_overlay_create(struct device_node *tree)
struct of_overlay *ov;
int err, id;
+ /* administratively disabled */
+ if (!atomic_read(ov_enable))
+ return -EPERM;
+
/* allocate the overlay structure */
ov = kzalloc(sizeof(*ov), GFP_KERNEL);
if (ov == NULL)
@@ -596,5 +658,7 @@ int of_overlay_init(void)
if (!ov_kset)
return -ENOMEM;
- return 0;
+ rc = sysfs_create_bin_file(ov_kset-kobj, bin_attr_enable);
+ WARN(rc, %s: error adding enable attribute\n, __func__);
+ return rc;
}
--
1.7.12
Regards
— Pantelis
--
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Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/5] of: overlay: Master enable switch
On Tue, Mar 17, 2015 at 3:30 PM, Pantelis Antoniou
wrote:
> Implement a throw once master enable switch to protect against any
> further overlay applications if the administrator desires so.
sysfs documentation?
> Signed-off-by: Pantelis Antoniou
> ---
> drivers/of/overlay.c | 66
> +++-
> 1 file changed, 65 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
> index f17f5ef..6688797 100644
> --- a/drivers/of/overlay.c
> +++ b/drivers/of/overlay.c
> @@ -21,6 +21,7 @@
> #include
> #include
> #include
> +#include
>
> #include "of_private.h"
>
> @@ -55,6 +56,9 @@ struct of_overlay {
> struct kobject kobj;
> };
>
> +/* master enable switch; once set to 0 can't be re-enabled */
> +static atomic_t ov_enable = ATOMIC_INIT(1);
> +
> static int of_overlay_apply_one(struct of_overlay *ov,
> struct device_node *target, const struct device_node
> *overlay);
>
> @@ -345,6 +349,60 @@ static struct kobj_type of_overlay_ktype = {
>
> static struct kset *ov_kset;
>
> +static ssize_t enable_read(struct file *filp, struct kobject *kobj,
> + struct bin_attribute *bin_attr, char *buf,
> + loff_t offset, size_t count)
> +{
> + char tbuf[3];
> +
> + if (offset < 0)
> + return -EINVAL;
> +
> + if (offset >= sizeof(tbuf))
> + return 0;
> +
> + if (count > sizeof(tbuf) - offset)
> + count = sizeof(tbuf) - offset;
> +
> + /* fill in temp */
> + tbuf[0] = '0' + atomic_read(_enable);
> + tbuf[1] = '\n';
> + tbuf[2] = '\0';
> +
> + /* copy to buffer */
> + memcpy(buf, tbuf + offset, count);
> +
> + return count;
> +}
> +
> +static ssize_t enable_write(struct file *filp, struct kobject *kobj,
> + struct bin_attribute *bin_attr, char *buf,
> + loff_t off, size_t count)
> +{
> + int new_enable;
> +
> + if (off != 0 || (buf[0] != '0' && buf[1] != '1'))
Is buf[1] correct here?
> + return -EINVAL;
> +
> + new_enable = buf[0] - '0';
> + if (new_enable != 0 && new_enable != 1)
Make unsigned just "if (new_enable > 1)".
> + return -EINVAL;
> +
> + /* NOP for same value */
> + if (new_enable == atomic_read(_enable))
> + return count;
> +
> + /* if we've disabled it, no going back */
> + if (atomic_read(_enable) == 0)
> + return -EPERM;
> +
> + atomic_set(_enable, new_enable);
> + return count;
> +}
> +
> +/* just a single char + '\n' + '\0' */
> +static BIN_ATTR_RW(enable, 3);
> +
> /**
> * of_overlay_create() - Create and apply an overlay
> * @tree: Device node containing all the overlays
> @@ -360,6 +418,10 @@ int of_overlay_create(struct device_node *tree)
> struct of_overlay *ov;
> int err, id;
>
> + /* administratively disabled */
> + if (!atomic_read(_enable))
> + return -EPERM;
> +
> /* allocate the overlay structure */
> ov = kzalloc(sizeof(*ov), GFP_KERNEL);
> if (ov == NULL)
> @@ -596,5 +658,7 @@ int of_overlay_init(void)
> if (!ov_kset)
> return -ENOMEM;
>
> - return 0;
> + rc = sysfs_create_bin_file(_kset->kobj, _attr_enable);
> + WARN(rc, "%s: error adding enable attribute\n", __func__);
> + return rc;
> }
> --
> 1.7.12
>
--
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Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH 3/5] of: overlay: Master enable switch
On Tue, Mar 17, 2015 at 3:30 PM, Pantelis Antoniou
pantelis.anton...@konsulko.com wrote:
Implement a throw once master enable switch to protect against any
further overlay applications if the administrator desires so.
sysfs documentation?
Signed-off-by: Pantelis Antoniou pantelis.anton...@konsulko.com
---
drivers/of/overlay.c | 66
+++-
1 file changed, 65 insertions(+), 1 deletion(-)
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index f17f5ef..6688797 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -21,6 +21,7 @@
#include linux/err.h
#include linux/idr.h
#include linux/sysfs.h
+#include linux/atomic.h
#include of_private.h
@@ -55,6 +56,9 @@ struct of_overlay {
struct kobject kobj;
};
+/* master enable switch; once set to 0 can't be re-enabled */
+static atomic_t ov_enable = ATOMIC_INIT(1);
+
static int of_overlay_apply_one(struct of_overlay *ov,
struct device_node *target, const struct device_node
*overlay);
@@ -345,6 +349,60 @@ static struct kobj_type of_overlay_ktype = {
static struct kset *ov_kset;
+static ssize_t enable_read(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr, char *buf,
+ loff_t offset, size_t count)
+{
+ char tbuf[3];
+
+ if (offset 0)
+ return -EINVAL;
+
+ if (offset = sizeof(tbuf))
+ return 0;
+
+ if (count sizeof(tbuf) - offset)
+ count = sizeof(tbuf) - offset;
+
+ /* fill in temp */
+ tbuf[0] = '0' + atomic_read(ov_enable);
+ tbuf[1] = '\n';
+ tbuf[2] = '\0';
+
+ /* copy to buffer */
+ memcpy(buf, tbuf + offset, count);
+
+ return count;
+}
+
+static ssize_t enable_write(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr, char *buf,
+ loff_t off, size_t count)
+{
+ int new_enable;
+
+ if (off != 0 || (buf[0] != '0' buf[1] != '1'))
Is buf[1] correct here?
+ return -EINVAL;
+
+ new_enable = buf[0] - '0';
+ if (new_enable != 0 new_enable != 1)
Make unsigned just if (new_enable 1).
+ return -EINVAL;
+
+ /* NOP for same value */
+ if (new_enable == atomic_read(ov_enable))
+ return count;
+
+ /* if we've disabled it, no going back */
+ if (atomic_read(ov_enable) == 0)
+ return -EPERM;
+
+ atomic_set(ov_enable, new_enable);
+ return count;
+}
+
+/* just a single char + '\n' + '\0' */
+static BIN_ATTR_RW(enable, 3);
+
/**
* of_overlay_create() - Create and apply an overlay
* @tree: Device node containing all the overlays
@@ -360,6 +418,10 @@ int of_overlay_create(struct device_node *tree)
struct of_overlay *ov;
int err, id;
+ /* administratively disabled */
+ if (!atomic_read(ov_enable))
+ return -EPERM;
+
/* allocate the overlay structure */
ov = kzalloc(sizeof(*ov), GFP_KERNEL);
if (ov == NULL)
@@ -596,5 +658,7 @@ int of_overlay_init(void)
if (!ov_kset)
return -ENOMEM;
- return 0;
+ rc = sysfs_create_bin_file(ov_kset-kobj, bin_attr_enable);
+ WARN(rc, %s: error adding enable attribute\n, __func__);
+ return rc;
}
--
1.7.12
--
To unsubscribe from this list: send the line unsubscribe linux-kernel in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH 3/5] of: overlay: Master enable switch
Implement a throw once master enable switch to protect against any
further overlay applications if the administrator desires so.
Signed-off-by: Pantelis Antoniou
---
drivers/of/overlay.c | 66 +++-
1 file changed, 65 insertions(+), 1 deletion(-)
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index f17f5ef..6688797 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -21,6 +21,7 @@
#include
#include
#include
+#include
#include "of_private.h"
@@ -55,6 +56,9 @@ struct of_overlay {
struct kobject kobj;
};
+/* master enable switch; once set to 0 can't be re-enabled */
+static atomic_t ov_enable = ATOMIC_INIT(1);
+
static int of_overlay_apply_one(struct of_overlay *ov,
struct device_node *target, const struct device_node *overlay);
@@ -345,6 +349,60 @@ static struct kobj_type of_overlay_ktype = {
static struct kset *ov_kset;
+static ssize_t enable_read(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr, char *buf,
+ loff_t offset, size_t count)
+{
+ char tbuf[3];
+
+ if (offset < 0)
+ return -EINVAL;
+
+ if (offset >= sizeof(tbuf))
+ return 0;
+
+ if (count > sizeof(tbuf) - offset)
+ count = sizeof(tbuf) - offset;
+
+ /* fill in temp */
+ tbuf[0] = '0' + atomic_read(_enable);
+ tbuf[1] = '\n';
+ tbuf[2] = '\0';
+
+ /* copy to buffer */
+ memcpy(buf, tbuf + offset, count);
+
+ return count;
+}
+
+static ssize_t enable_write(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr, char *buf,
+ loff_t off, size_t count)
+{
+ int new_enable;
+
+ if (off != 0 || (buf[0] != '0' && buf[1] != '1'))
+ return -EINVAL;
+
+ new_enable = buf[0] - '0';
+ if (new_enable != 0 && new_enable != 1)
+ return -EINVAL;
+
+ /* NOP for same value */
+ if (new_enable == atomic_read(_enable))
+ return count;
+
+ /* if we've disabled it, no going back */
+ if (atomic_read(_enable) == 0)
+ return -EPERM;
+
+ atomic_set(_enable, new_enable);
+ return count;
+}
+
+/* just a single char + '\n' + '\0' */
+static BIN_ATTR_RW(enable, 3);
+
/**
* of_overlay_create() - Create and apply an overlay
* @tree: Device node containing all the overlays
@@ -360,6 +418,10 @@ int of_overlay_create(struct device_node *tree)
struct of_overlay *ov;
int err, id;
+ /* administratively disabled */
+ if (!atomic_read(_enable))
+ return -EPERM;
+
/* allocate the overlay structure */
ov = kzalloc(sizeof(*ov), GFP_KERNEL);
if (ov == NULL)
@@ -596,5 +658,7 @@ int of_overlay_init(void)
if (!ov_kset)
return -ENOMEM;
- return 0;
+ rc = sysfs_create_bin_file(_kset->kobj, _attr_enable);
+ WARN(rc, "%s: error adding enable attribute\n", __func__);
+ return rc;
}
--
1.7.12
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[PATCH 3/5] of: overlay: Master enable switch
Implement a throw once master enable switch to protect against any
further overlay applications if the administrator desires so.
Signed-off-by: Pantelis Antoniou pantelis.anton...@konsulko.com
---
drivers/of/overlay.c | 66 +++-
1 file changed, 65 insertions(+), 1 deletion(-)
diff --git a/drivers/of/overlay.c b/drivers/of/overlay.c
index f17f5ef..6688797 100644
--- a/drivers/of/overlay.c
+++ b/drivers/of/overlay.c
@@ -21,6 +21,7 @@
#include linux/err.h
#include linux/idr.h
#include linux/sysfs.h
+#include linux/atomic.h
#include of_private.h
@@ -55,6 +56,9 @@ struct of_overlay {
struct kobject kobj;
};
+/* master enable switch; once set to 0 can't be re-enabled */
+static atomic_t ov_enable = ATOMIC_INIT(1);
+
static int of_overlay_apply_one(struct of_overlay *ov,
struct device_node *target, const struct device_node *overlay);
@@ -345,6 +349,60 @@ static struct kobj_type of_overlay_ktype = {
static struct kset *ov_kset;
+static ssize_t enable_read(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr, char *buf,
+ loff_t offset, size_t count)
+{
+ char tbuf[3];
+
+ if (offset 0)
+ return -EINVAL;
+
+ if (offset = sizeof(tbuf))
+ return 0;
+
+ if (count sizeof(tbuf) - offset)
+ count = sizeof(tbuf) - offset;
+
+ /* fill in temp */
+ tbuf[0] = '0' + atomic_read(ov_enable);
+ tbuf[1] = '\n';
+ tbuf[2] = '\0';
+
+ /* copy to buffer */
+ memcpy(buf, tbuf + offset, count);
+
+ return count;
+}
+
+static ssize_t enable_write(struct file *filp, struct kobject *kobj,
+ struct bin_attribute *bin_attr, char *buf,
+ loff_t off, size_t count)
+{
+ int new_enable;
+
+ if (off != 0 || (buf[0] != '0' buf[1] != '1'))
+ return -EINVAL;
+
+ new_enable = buf[0] - '0';
+ if (new_enable != 0 new_enable != 1)
+ return -EINVAL;
+
+ /* NOP for same value */
+ if (new_enable == atomic_read(ov_enable))
+ return count;
+
+ /* if we've disabled it, no going back */
+ if (atomic_read(ov_enable) == 0)
+ return -EPERM;
+
+ atomic_set(ov_enable, new_enable);
+ return count;
+}
+
+/* just a single char + '\n' + '\0' */
+static BIN_ATTR_RW(enable, 3);
+
/**
* of_overlay_create() - Create and apply an overlay
* @tree: Device node containing all the overlays
@@ -360,6 +418,10 @@ int of_overlay_create(struct device_node *tree)
struct of_overlay *ov;
int err, id;
+ /* administratively disabled */
+ if (!atomic_read(ov_enable))
+ return -EPERM;
+
/* allocate the overlay structure */
ov = kzalloc(sizeof(*ov), GFP_KERNEL);
if (ov == NULL)
@@ -596,5 +658,7 @@ int of_overlay_init(void)
if (!ov_kset)
return -ENOMEM;
- return 0;
+ rc = sysfs_create_bin_file(ov_kset-kobj, bin_attr_enable);
+ WARN(rc, %s: error adding enable attribute\n, __func__);
+ return rc;
}
--
1.7.12
--
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the body of a message to majord...@vger.kernel.org
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