From 7f5028cf6190407b7a632b0f30b83187577824cc Mon Sep 17 00:00:00 2001 From: =?utf8?q?Emilio=20L=C3=B3pez?= Date: Mon, 21 Sep 2015 10:38:20 -0300 Subject: [PATCH] sysfs: Support is_visible() on binary attributes MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 introduces a new is_bin_visible() function to implement the same functionality for binary attributes, and updates documentation accordingly. Note that to keep functionality and code similar to that of normal attributes, the mode is now checked as well to ensure it contains only read/write permissions or SYSFS_PREALLOC. Reviewed-by: Guenter Roeck Signed-off-by: Emilio López Acked-by: Greg Kroah-Hartman Signed-off-by: Olof Johansson --- fs/sysfs/group.c | 17 +++++++++++++++-- include/linux/sysfs.h | 18 ++++++++++++++---- 2 files changed, 29 insertions(+), 6 deletions(-) diff --git a/fs/sysfs/group.c b/fs/sysfs/group.c index 39a019936768..51b56e6d9537 100644 --- a/fs/sysfs/group.c +++ b/fs/sysfs/group.c @@ -73,13 +73,26 @@ 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 (i = 0, 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_bin_visible) { + mode = grp->is_bin_visible(kobj, *bin_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; } diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index 9f65758311a4..2f66050d073b 100644 --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -64,10 +64,18 @@ do { \ * a new subdirectory with this name. * @is_visible: Optional: Function to return permissions associated with an * attribute of the group. Will be called repeatedly for each - * attribute in the group. Only read/write permissions as well as - * SYSFS_PREALLOC are accepted. Must return 0 if an attribute is - * not visible. The returned value will replace static permissions - * defined in struct attribute or struct bin_attribute. + * non-binary attribute in the group. Only read/write + * permissions as well as SYSFS_PREALLOC are accepted. Must + * return 0 if an attribute is not visible. The returned value + * will replace static permissions defined in struct attribute. + * @is_bin_visible: + * Optional: Function to return permissions associated with a + * binary attribute of the group. Will be called repeatedly + * for each binary attribute in the group. Only read/write + * permissions as well as SYSFS_PREALLOC are accepted. Must + * return 0 if a binary attribute is not visible. The returned + * value will replace static permissions defined in + * struct bin_attribute. * @attrs: Pointer to NULL terminated list of attributes. * @bin_attrs: Pointer to NULL terminated list of binary attributes. * Either attrs or bin_attrs or both must be provided. @@ -76,6 +84,8 @@ struct attribute_group { const char *name; umode_t (*is_visible)(struct kobject *, struct attribute *, int); + umode_t (*is_bin_visible)(struct kobject *, + struct bin_attribute *, int); struct attribute **attrs; struct bin_attribute **bin_attrs; }; -- 2.20.1