Remove execution domain support

All users of exec_domain are gone, now we can get rid
of that abandoned feature.
To not break existing userspace we keep a dummy
/proc/execdomains file which will always contain
"0-0     Linux                   [kernel]".

Signed-off-by: Richard Weinberger <richard@nod.at>

3 files changed, 1 insertions, 105 deletions

diff --git a/kernel/exec_domain.c b/kernel/exec_domain.c
index 83d4382f5699..b2fb57d6b9b2 100644
--- a/kernel/exec_domain.c
+++ b/kernel/exec_domain.c
@@ -20,13 +20,7 @@
 #include <linux/types.h>
 #include <linux/fs_struct.h>
 
-
 static void default_handler(int, struct pt_regs *);
-
-static struct exec_domain *exec_domains = &default_exec_domain;
-static DEFINE_RWLOCK(exec_domains_lock);
-
-
 static unsigned long ident_map[32] = {
         0,      1,      2,      3,      4,      5,      6,      7,
         8,      9,      10,     11,     12,     13,     14,     15,
@@ -55,94 +49,9 @@ default_handler(int segment, struct pt_regs *regp)
                 send_sig(SIGSEGV, current, 1);
 }
 
-static struct exec_domain *
-lookup_exec_domain(unsigned int personality)
-{
-        unsigned int pers = personality(personality);
-        struct exec_domain *ep;
-
-        read_lock(&exec_domains_lock);
-        for (ep = exec_domains; ep; ep = ep->next) {
-                if (pers >= ep->pers_low && pers <= ep->pers_high)
-                        if (try_module_get(ep->module))
-                                goto out;
-        }
-
-#ifdef CONFIG_MODULES
-        read_unlock(&exec_domains_lock);
-        request_module("personality-%d", pers);
-        read_lock(&exec_domains_lock);
-
-        for (ep = exec_domains; ep; ep = ep->next) {
-                if (pers >= ep->pers_low && pers <= ep->pers_high)
-                        if (try_module_get(ep->module))
-                                goto out;
-        }
-#endif
-
-        ep = &default_exec_domain;
-out:
-        read_unlock(&exec_domains_lock);
-        return ep;
-}
-
-int
-register_exec_domain(struct exec_domain *ep)
-{
-        struct exec_domain      *tmp;
-        int                     err = -EBUSY;
-
-        if (ep == NULL)
-                return -EINVAL;
-
-        if (ep->next != NULL)
-                return -EBUSY;
-
-        write_lock(&exec_domains_lock);
-        for (tmp = exec_domains; tmp; tmp = tmp->next) {
-                if (tmp == ep)
-                        goto out;
-        }
-
-        ep->next = exec_domains;
-        exec_domains = ep;
-        err = 0;
-
-out:
-        write_unlock(&exec_domains_lock);
-        return err;
-}
-EXPORT_SYMBOL(register_exec_domain);
-
-int
-unregister_exec_domain(struct exec_domain *ep)
-{
-        struct exec_domain      **epp;
-
-        epp = &exec_domains;
-        write_lock(&exec_domains_lock);
-        for (epp = &exec_domains; *epp; epp = &(*epp)->next) {
-                if (ep == *epp)
-                        goto unregister;
-        }
-        write_unlock(&exec_domains_lock);
-        return -EINVAL;
-
-unregister:
-        *epp = ep->next;
-        ep->next = NULL;
-        write_unlock(&exec_domains_lock);
-        return 0;
-}
-EXPORT_SYMBOL(unregister_exec_domain);
-
 int __set_personality(unsigned int personality)
 {
-        struct exec_domain *oep = current_thread_info()->exec_domain;
-
-        current_thread_info()->exec_domain = lookup_exec_domain(personality);
         current->personality = personality;
-        module_put(oep->module);
 
         return 0;
 }
@@ -151,14 +60,7 @@ EXPORT_SYMBOL(__set_personality);
 #ifdef CONFIG_PROC_FS
 static int execdomains_proc_show(struct seq_file *m, void *v)
 {
-        struct exec_domain      *ep;
-
-        read_lock(&exec_domains_lock);
-        for (ep = exec_domains; ep; ep = ep->next)
-                seq_printf(m, "%d-%d\t%-16s\t[%s]\n",
-                               ep->pers_low, ep->pers_high, ep->name,
-                               module_name(ep->module));
-        read_unlock(&exec_domains_lock);
+        seq_puts(m, "0-0\tLinux           \t[kernel]\n");
         return 0;
 }
 
diff --git a/kernel/exit.c b/kernel/exit.c
index feff10bbb307..22fcc05dec40 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -756,8 +756,6 @@ void do_exit(long code)
 
         cgroup_exit(tsk);
 
-        module_put(task_thread_info(tsk)->exec_domain->module);
-
         /*
          * FIXME: do that only when needed, using sched_exit tracepoint
          */
diff --git a/kernel/fork.c b/kernel/fork.c
index cf65139615a0..f2c1e7352298 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1279,9 +1279,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
         if (nr_threads >= max_threads)
                 goto bad_fork_cleanup_count;
 
-        if (!try_module_get(task_thread_info(p)->exec_domain->module))
-                goto bad_fork_cleanup_count;
-
         delayacct_tsk_init(p);  /* Must remain after dup_task_struct() */
         p->flags &= ~(PF_SUPERPRIV | PF_WQ_WORKER);
         p->flags |= PF_FORKNOEXEC;
@@ -1590,7 +1587,6 @@ bad_fork_cleanup_threadgroup_lock:
         if (clone_flags & CLONE_THREAD)
                 threadgroup_change_end(current);
         delayacct_tsk_free(p);
-        module_put(task_thread_info(p)->exec_domain->module);
 bad_fork_cleanup_count:
         atomic_dec(&p->cred->user->processes);
         exit_creds(p);