extern int max_threads;
extern int sysrq_enabled;
extern int core_uses_pid;
+extern int suid_dumpable;
extern char core_pattern[];
extern int cad_pid;
extern int pid_max;
extern int sysctl_ieee_emulation_warnings;
#endif
extern int sysctl_userprocess_debug;
+extern int spin_retry;
#endif
extern int sysctl_hz_timer;
#ifdef CONFIG_UNIX98_PTYS
extern ctl_table pty_table[];
#endif
+#ifdef CONFIG_INOTIFY
+extern ctl_table inotify_table[];
+#endif
#ifdef HAVE_ARCH_PICK_MMAP_LAYOUT
int sysctl_legacy_va_layout;
extern struct proc_dir_entry *proc_sys_root;
-static void register_proc_table(ctl_table *, struct proc_dir_entry *);
+static void register_proc_table(ctl_table *, struct proc_dir_entry *, void *);
static void unregister_proc_table(ctl_table *, struct proc_dir_entry *);
#endif
.mode = 0555,
.child = dev_table,
},
+
{ .ctl_name = 0 }
};
.mode = 0644,
.proc_handler = &proc_dointvec,
},
-
+#if defined(CONFIG_ARCH_S390)
+ {
+ .ctl_name = KERN_SPIN_RETRY,
+ .procname = "spin_retry",
+ .data = &spin_retry,
+ .maxlen = sizeof (int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
+#endif
{ .ctl_name = 0 }
};
.mode = 0644,
.proc_handler = &proc_dointvec,
},
+#ifdef CONFIG_INOTIFY
+ {
+ .ctl_name = FS_INOTIFY,
+ .procname = "inotify",
+ .mode = 0555,
+ .child = inotify_table,
+ },
+#endif
#endif
+ {
+ .ctl_name = KERN_SETUID_DUMPABLE,
+ .procname = "suid_dumpable",
+ .data = &suid_dumpable,
+ .maxlen = sizeof(int),
+ .mode = 0644,
+ .proc_handler = &proc_dointvec,
+ },
{ .ctl_name = 0 }
};
static ctl_table dev_table[] = {
{ .ctl_name = 0 }
-};
+};
extern void init_irq_proc (void);
+static DEFINE_SPINLOCK(sysctl_lock);
+
+/* called under sysctl_lock */
+static int use_table(struct ctl_table_header *p)
+{
+ if (unlikely(p->unregistering))
+ return 0;
+ p->used++;
+ return 1;
+}
+
+/* called under sysctl_lock */
+static void unuse_table(struct ctl_table_header *p)
+{
+ if (!--p->used)
+ if (unlikely(p->unregistering))
+ complete(p->unregistering);
+}
+
+/* called under sysctl_lock, will reacquire if has to wait */
+static void start_unregistering(struct ctl_table_header *p)
+{
+ /*
+ * if p->used is 0, nobody will ever touch that entry again;
+ * we'll eliminate all paths to it before dropping sysctl_lock
+ */
+ if (unlikely(p->used)) {
+ struct completion wait;
+ init_completion(&wait);
+ p->unregistering = &wait;
+ spin_unlock(&sysctl_lock);
+ wait_for_completion(&wait);
+ spin_lock(&sysctl_lock);
+ }
+ /*
+ * do not remove from the list until nobody holds it; walking the
+ * list in do_sysctl() relies on that.
+ */
+ list_del_init(&p->ctl_entry);
+}
+
void __init sysctl_init(void)
{
#ifdef CONFIG_PROC_FS
- register_proc_table(root_table, proc_sys_root);
+ register_proc_table(root_table, proc_sys_root, &root_table_header);
init_irq_proc();
#endif
}
void __user *newval, size_t newlen)
{
struct list_head *tmp;
+ int error = -ENOTDIR;
if (nlen <= 0 || nlen >= CTL_MAXNAME)
return -ENOTDIR;
if (!oldlenp || get_user(old_len, oldlenp))
return -EFAULT;
}
+ spin_lock(&sysctl_lock);
tmp = &root_table_header.ctl_entry;
do {
struct ctl_table_header *head =
list_entry(tmp, struct ctl_table_header, ctl_entry);
void *context = NULL;
- int error = parse_table(name, nlen, oldval, oldlenp,
+
+ if (!use_table(head))
+ continue;
+
+ spin_unlock(&sysctl_lock);
+
+ error = parse_table(name, nlen, oldval, oldlenp,
newval, newlen, head->ctl_table,
&context);
- if (context)
- kfree(context);
+ kfree(context);
+
+ spin_lock(&sysctl_lock);
+ unuse_table(head);
if (error != -ENOTDIR)
- return error;
- tmp = tmp->next;
- } while (tmp != &root_table_header.ctl_entry);
- return -ENOTDIR;
+ break;
+ } while ((tmp = tmp->next) != &root_table_header.ctl_entry);
+ spin_unlock(&sysctl_lock);
+ return error;
}
asmlinkage long sys_sysctl(struct __sysctl_args __user *args)
return NULL;
tmp->ctl_table = table;
INIT_LIST_HEAD(&tmp->ctl_entry);
+ tmp->used = 0;
+ tmp->unregistering = NULL;
+ spin_lock(&sysctl_lock);
if (insert_at_head)
list_add(&tmp->ctl_entry, &root_table_header.ctl_entry);
else
list_add_tail(&tmp->ctl_entry, &root_table_header.ctl_entry);
+ spin_unlock(&sysctl_lock);
#ifdef CONFIG_PROC_FS
- register_proc_table(table, proc_sys_root);
+ register_proc_table(table, proc_sys_root, tmp);
#endif
return tmp;
}
*/
void unregister_sysctl_table(struct ctl_table_header * header)
{
- list_del(&header->ctl_entry);
+ might_sleep();
+ spin_lock(&sysctl_lock);
+ start_unregistering(header);
#ifdef CONFIG_PROC_FS
unregister_proc_table(header->ctl_table, proc_sys_root);
#endif
+ spin_unlock(&sysctl_lock);
kfree(header);
}
#ifdef CONFIG_PROC_FS
/* Scan the sysctl entries in table and add them all into /proc */
-static void register_proc_table(ctl_table * table, struct proc_dir_entry *root)
+static void register_proc_table(ctl_table * table, struct proc_dir_entry *root, void *set)
{
struct proc_dir_entry *de;
int len;
de = create_proc_entry(table->procname, mode, root);
if (!de)
continue;
+ de->set = set;
de->data = (void *) table;
if (table->proc_handler)
de->proc_fops = &proc_sys_file_operations;
}
table->de = de;
if (de->mode & S_IFDIR)
- register_proc_table(table->child, de);
+ register_proc_table(table->child, de, set);
}
}
continue;
}
+ /*
+ * In any case, mark the entry as goner; we'll keep it
+ * around if it's busy, but we'll know to do nothing with
+ * its fields. We are under sysctl_lock here.
+ */
+ de->data = NULL;
+
/* Don't unregister proc entries that are still being used.. */
if (atomic_read(&de->count))
continue;
size_t count, loff_t *ppos)
{
int op;
- struct proc_dir_entry *de;
+ struct proc_dir_entry *de = PDE(file->f_dentry->d_inode);
struct ctl_table *table;
size_t res;
- ssize_t error;
+ ssize_t error = -ENOTDIR;
- de = PDE(file->f_dentry->d_inode);
- if (!de || !de->data)
- return -ENOTDIR;
- table = (struct ctl_table *) de->data;
- if (!table || !table->proc_handler)
- return -ENOTDIR;
- op = (write ? 002 : 004);
- if (ctl_perm(table, op))
- return -EPERM;
-
- res = count;
-
- error = (*table->proc_handler) (table, write, file, buf, &res, ppos);
- if (error)
- return error;
- return res;
+ spin_lock(&sysctl_lock);
+ if (de && de->data && use_table(de->set)) {
+ /*
+ * at that point we know that sysctl was not unregistered
+ * and won't be until we finish
+ */
+ spin_unlock(&sysctl_lock);
+ table = (struct ctl_table *) de->data;
+ if (!table || !table->proc_handler)
+ goto out;
+ error = -EPERM;
+ op = (write ? 002 : 004);
+ if (ctl_perm(table, op))
+ goto out;
+
+ /* careful: calling conventions are nasty here */
+ res = count;
+ error = (*table->proc_handler)(table, write, file,
+ buf, &res, ppos);
+ if (!error)
+ error = res;
+ out:
+ spin_lock(&sysctl_lock);
+ unuse_table(de->set);
+ }
+ spin_unlock(&sysctl_lock);
+ return error;
}
static int proc_opensys(struct inode *inode, struct file *file)
projects / karo-tx-linux.git / blobdiff