[PATCH 1/3] sysfs: Fix is_visible() support for binary attributes

From: Emilio LÃpez
Date: Tue Sep 08 2015 - 08:09:01 EST


According to the sysfs header file:

"The returned value will replace static permissions defined in
struct attribute or struct bin_attribute."

but this isn't the case, as is_visible is only called on
struct attribute only. This patch adds the code paths required
to support is_visible() on binary attributes.

Signed-off-by: Emilio LÃpez <emilio.lopez@xxxxxxxxxxxxxxx>
---
fs/sysfs/group.c | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)

diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c
index 39a0199..eb6996a 100644
--- a/fs/sysfs/group.c
+++ b/fs/sysfs/group.c
@@ -37,10 +37,10 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj,
{
struct attribute *const *attr;
struct bin_attribute *const *bin_attr;
- int error = 0, i;
+ int error = 0, i = 0;

if (grp->attrs) {
- for (i = 0, attr = grp->attrs; *attr && !error; i++, attr++) {
+ for (attr = grp->attrs; *attr && !error; i++, attr++) {
umode_t mode = (*attr)->mode;

/*
@@ -73,13 +73,27 @@ static int create_files(struct kernfs_node *parent, struct kobject *kobj,
}

if (grp->bin_attrs) {
- for (bin_attr = grp->bin_attrs; *bin_attr; bin_attr++) {
+ for (bin_attr = grp->bin_attrs; *bin_attr; i++, bin_attr++) {
+ umode_t mode = (*bin_attr)->attr.mode;
+
if (update)
kernfs_remove_by_name(parent,
(*bin_attr)->attr.name);
+ if (grp->is_visible) {
+ mode = grp->is_visible(kobj,
+ &(*bin_attr)->attr, i);
+ if (!mode)
+ continue;
+ }
+
+ WARN(mode & ~(SYSFS_PREALLOC | 0664),
+ "Attribute %s: Invalid permissions 0%o\n",
+ (*bin_attr)->attr.name, mode);
+
+ mode &= SYSFS_PREALLOC | 0664;
error = sysfs_add_file_mode_ns(parent,
&(*bin_attr)->attr, true,
- (*bin_attr)->attr.mode, NULL);
+ mode, NULL);
if (error)
break;
}
--
2.1.4

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