Remove execution domain support
Richard Weinberger [Mon, 30 Mar 2015 06:14:16 +0000 (08:14 +0200)]
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>
(cherry picked from commit 973f911f55a0e510dd6db8bbb29cd82ff138d3c0)

Change-Id: I79f174db866f149c4393441d7b51941725bfe7f0

kernel/exec_domain.c
kernel/exit.c
kernel/fork.c

index 0dbeae3..b31cceb 100644 (file)
 #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,
@@ -55,92 +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);
-}
-
-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;
-}
-
 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;
 }
@@ -148,14 +59,7 @@ int __set_personality(unsigned int 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;
 }
 
index 33fde71..5f28bb7 100644 (file)
@@ -819,9 +819,8 @@ void do_exit(long code)
 
        cgroup_exit(tsk, 1);
 
-       module_put(task_thread_info(tsk)->exec_domain->module);
-
        proc_exit_connector(tsk);
+
        /*
         * FIXME: do that only when needed, using sched_exit tracepoint
         */
index d481cb9..c308d12 100644 (file)
@@ -1286,9 +1286,6 @@ 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;
-
        p->did_exec = 0;
        delayacct_tsk_init(p);  /* Must remain after dup_task_struct() */
        copy_flags(clone_flags, p);
@@ -1600,7 +1597,6 @@ bad_fork_cleanup_cgroup:
                threadgroup_change_end(current);
        cgroup_exit(p, 0);
        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);