[PATCH 5/5] sysfs: Reject with a warning invalid uses of tagged directories.
From: Eric W. Biederman <hidden>
Date: 2011-10-13 08:02:22
Also in:
lkml
Subsystem:
driver core, kobjects, debugfs and sysfs, filesystems (vfs and infrastructure), the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Alexander Viro, Christian Brauner, Linus Torvalds
sysfs is a core piece of ifrastructure that many people use and few people have all of the rules in their head on how to use it correctly. Add warnings for people using tagged directories improperly to that any misuses can be caught and diagnosed quickly. A single inexpensive test in sysfs_find_dirent is almost sufficient to catch all possible misuses. An additional warning is needed in sysfs_add_dirent so that we actually fail when attempting to add an untagged dirent in a tagged directory. Signed-off-by: Eric W. Biederman <redacted> --- fs/sysfs/dir.c | 14 ++++++++++++++ fs/sysfs/file.c | 3 --- 2 files changed, 14 insertions(+), 3 deletions(-)
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 352d26d..26f370a 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c@@ -384,6 +384,13 @@ int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd) { struct sysfs_inode_attrs *ps_iattr; + if (!!sysfs_ns_type(acxt->parent_sd) != !!sd->s_ns) { + WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n", + sysfs_ns_type(acxt->parent_sd)? "required": "invalid", + acxt->parent_sd->s_name, sd->s_name); + return -EINVAL; + } + if (sysfs_find_dirent(acxt->parent_sd, sd->s_ns, sd->s_name)) return -EEXIST;
@@ -542,6 +549,13 @@ struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd, { struct sysfs_dirent *sd; + if (!!sysfs_ns_type(parent_sd) != !!ns) { + WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n", + sysfs_ns_type(parent_sd)? "required": "invalid", + parent_sd->s_name, name); + return NULL; + } + for (sd = parent_sd->s_dir.children; sd; sd = sd->s_sibling) { if (sd->s_ns != ns) continue;
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 07c1b4e..d4e6080 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c@@ -466,9 +466,6 @@ void sysfs_notify(struct kobject *k, const char *dir, const char *attr) mutex_lock(&sysfs_mutex); if (sd && dir) - /* Only directories are tagged, so no need to pass - * a tag explicitly. - */ sd = sysfs_find_dirent(sd, NULL, dir); if (sd && attr) sd = sysfs_find_dirent(sd, NULL, attr);
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1.7.2.5