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authorJeff Layton <jlayton@redhat.com>2012-10-10 15:25:28 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2012-10-12 20:14:55 -0400
commit91a27b2a756784714e924e5e854b919273082d26 (patch)
tree3913246b7d6e62703ec915f481e3a7159393f0f0 /kernel
parent8e377d15078a501c4da98471f56396343c407d92 (diff)
downloadvexpress-lsk-91a27b2a756784714e924e5e854b919273082d26.tar.gz
vfs: define struct filename and have getname() return it
getname() is intended to copy pathname strings from userspace into a kernel buffer. The result is just a string in kernel space. It would however be quite helpful to be able to attach some ancillary info to the string. For instance, we could attach some audit-related info to reduce the amount of audit-related processing needed. When auditing is enabled, we could also call getname() on the string more than once and not need to recopy it from userspace. This patchset converts the getname()/putname() interfaces to return a struct instead of a string. For now, the struct just tracks the string in kernel space and the original userland pointer for it. Later, we'll add other information to the struct as it becomes convenient. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/acct.c4
-rw-r--r--kernel/auditsc.c64
2 files changed, 37 insertions, 31 deletions
diff --git a/kernel/acct.c b/kernel/acct.c
index 5be01017d30..08354195eec 100644
--- a/kernel/acct.c
+++ b/kernel/acct.c
@@ -260,10 +260,10 @@ SYSCALL_DEFINE1(acct, const char __user *, name)
return -EPERM;
if (name) {
- char *tmp = getname(name);
+ struct filename *tmp = getname(name);
if (IS_ERR(tmp))
return (PTR_ERR(tmp));
- error = acct_on(tmp);
+ error = acct_on(tmp->name);
putname(tmp);
} else {
struct bsd_acct_struct *acct;
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index d147585e9ef..d4d82319eed 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -103,28 +103,29 @@ struct audit_cap_data {
* we don't let putname() free it (instead we free all of the saved
* pointers at syscall exit time).
*
- * Further, in fs/namei.c:path_lookup() we store the inode and device. */
+ * Further, in fs/namei.c:path_lookup() we store the inode and device.
+ */
struct audit_names {
- struct list_head list; /* audit_context->names_list */
- const char *name;
- unsigned long ino;
- dev_t dev;
- umode_t mode;
- kuid_t uid;
- kgid_t gid;
- dev_t rdev;
- u32 osid;
- struct audit_cap_data fcap;
- unsigned int fcap_ver;
- int name_len; /* number of name's characters to log */
- unsigned char type; /* record type */
- bool name_put; /* call __putname() for this name */
+ struct list_head list; /* audit_context->names_list */
+ struct filename *name;
+ unsigned long ino;
+ dev_t dev;
+ umode_t mode;
+ kuid_t uid;
+ kgid_t gid;
+ dev_t rdev;
+ u32 osid;
+ struct audit_cap_data fcap;
+ unsigned int fcap_ver;
+ int name_len; /* number of name's characters to log */
+ unsigned char type; /* record type */
+ bool name_put; /* call __putname() for this name */
/*
* This was an allocated audit_names and not from the array of
* names allocated in the task audit context. Thus this name
* should be freed on syscall exit
*/
- bool should_free;
+ bool should_free;
};
struct audit_aux_data {
@@ -996,7 +997,7 @@ static inline void audit_free_names(struct audit_context *context)
context->ino_count);
list_for_each_entry(n, &context->names_list, list) {
printk(KERN_ERR "names[%d] = %p = %s\n", i,
- n->name, n->name ?: "(null)");
+ n->name, n->name->name ?: "(null)");
}
dump_stack();
return;
@@ -1553,7 +1554,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
case AUDIT_NAME_FULL:
/* log the full path */
audit_log_format(ab, " name=");
- audit_log_untrustedstring(ab, n->name);
+ audit_log_untrustedstring(ab, n->name->name);
break;
case 0:
/* name was specified as a relative path and the
@@ -1563,7 +1564,7 @@ static void audit_log_name(struct audit_context *context, struct audit_names *n,
default:
/* log the name's directory component */
audit_log_format(ab, " name=");
- audit_log_n_untrustedstring(ab, n->name,
+ audit_log_n_untrustedstring(ab, n->name->name,
n->name_len);
}
} else
@@ -2026,7 +2027,7 @@ static struct audit_names *audit_alloc_name(struct audit_context *context,
* Add a name to the list of audit names for this context.
* Called from fs/namei.c:getname().
*/
-void __audit_getname(const char *name)
+void __audit_getname(struct filename *name)
{
struct audit_context *context = current->audit_context;
struct audit_names *n;
@@ -2040,6 +2041,11 @@ void __audit_getname(const char *name)
return;
}
+#if AUDIT_DEBUG
+ /* The filename _must_ have a populated ->name */
+ BUG_ON(!name->name);
+#endif
+
n = audit_alloc_name(context, AUDIT_TYPE_UNKNOWN);
if (!n)
return;
@@ -2059,7 +2065,7 @@ void __audit_getname(const char *name)
* then we delay the putname until syscall exit.
* Called from include/linux/fs.h:putname().
*/
-void audit_putname(const char *name)
+void audit_putname(struct filename *name)
{
struct audit_context *context = current->audit_context;
@@ -2074,7 +2080,7 @@ void audit_putname(const char *name)
list_for_each_entry(n, &context->names_list, list)
printk(KERN_ERR "name[%d] = %p = %s\n", i,
- n->name, n->name ?: "(null)");
+ n->name, n->name->name ?: "(null)");
}
#endif
__putname(name);
@@ -2088,8 +2094,8 @@ void audit_putname(const char *name)
" put_count=%d\n",
__FILE__, __LINE__,
context->serial, context->major,
- context->in_syscall, name, context->name_count,
- context->put_count);
+ context->in_syscall, name->name,
+ context->name_count, context->put_count);
dump_stack();
}
}
@@ -2152,7 +2158,7 @@ void __audit_inode(const char *name, const struct dentry *dentry,
list_for_each_entry_reverse(n, &context->names_list, list) {
/* does the name pointer match? */
- if (n->name != name)
+ if (!n->name || n->name->name != name)
continue;
/* match the correct record type */
@@ -2175,7 +2181,7 @@ out_alloc:
return;
out:
if (parent) {
- n->name_len = n->name ? parent_len(n->name) : AUDIT_NAME_FULL;
+ n->name_len = n->name ? parent_len(n->name->name) : AUDIT_NAME_FULL;
n->type = AUDIT_TYPE_PARENT;
} else {
n->name_len = AUDIT_NAME_FULL;
@@ -2220,7 +2226,7 @@ void __audit_inode_child(const struct inode *parent,
continue;
if (n->ino == parent->i_ino &&
- !audit_compare_dname_path(dname, n->name, n->name_len)) {
+ !audit_compare_dname_path(dname, n->name->name, n->name_len)) {
found_parent = n;
break;
}
@@ -2236,8 +2242,8 @@ void __audit_inode_child(const struct inode *parent,
if (found_parent && (n->name != found_parent->name))
continue;
- if (!strcmp(dname, n->name) ||
- !audit_compare_dname_path(dname, n->name,
+ if (!strcmp(dname, n->name->name) ||
+ !audit_compare_dname_path(dname, n->name->name,
found_parent ?
found_parent->name_len :
AUDIT_NAME_FULL)) {