task_struct cleanup: move binfmt field to mm_struct
Because the binfmt is not different between threads in the same process,
it can be moved from task_struct to mm_struct. And binfmt moudle is
handled per mm_struct instead of task_struct.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Acked-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/exec.c b/fs/exec.c
index 6dc92c3..d49be6b 100644
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -1397,10 +1397,12 @@
void set_binfmt(struct linux_binfmt *new)
{
- if (current->binfmt)
- module_put(current->binfmt->module);
+ struct mm_struct *mm = current->mm;
- current->binfmt = new;
+ if (mm->binfmt)
+ module_put(mm->binfmt->module);
+
+ mm->binfmt = new;
if (new)
__module_get(new->module);
}
@@ -1770,7 +1772,7 @@
audit_core_dumps(signr);
- binfmt = current->binfmt;
+ binfmt = mm->binfmt;
if (!binfmt || !binfmt->core_dump)
goto fail;
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 6b7029a..21d6aa4 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -240,6 +240,8 @@
unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
+ struct linux_binfmt *binfmt;
+
cpumask_t cpu_vm_mask;
/* Architecture-specific MM context */
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 811cd96..8a16f6d 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1271,7 +1271,6 @@
struct mm_struct *mm, *active_mm;
/* task state */
- struct linux_binfmt *binfmt;
int exit_state;
int exit_code, exit_signal;
int pdeath_signal; /* The signal sent when the parent dies */
diff --git a/kernel/exit.c b/kernel/exit.c
index 6c75ff83..5859f59 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -976,8 +976,6 @@
disassociate_ctty(1);
module_put(task_thread_info(tsk)->exec_domain->module);
- if (tsk->binfmt)
- module_put(tsk->binfmt->module);
proc_exit_connector(tsk);
diff --git a/kernel/fork.c b/kernel/fork.c
index e49f181..266c6af 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -518,6 +518,8 @@
spin_unlock(&mmlist_lock);
}
put_swap_token(mm);
+ if (mm->binfmt)
+ module_put(mm->binfmt->module);
mmdrop(mm);
}
}
@@ -643,9 +645,14 @@
mm->hiwater_rss = get_mm_rss(mm);
mm->hiwater_vm = mm->total_vm;
+ if (mm->binfmt && !try_module_get(mm->binfmt->module))
+ goto free_pt;
+
return mm;
free_pt:
+ /* don't put binfmt in mmput, we haven't got module yet */
+ mm->binfmt = NULL;
mmput(mm);
fail_nomem:
@@ -1037,9 +1044,6 @@
if (!try_module_get(task_thread_info(p)->exec_domain->module))
goto bad_fork_cleanup_count;
- if (p->binfmt && !try_module_get(p->binfmt->module))
- goto bad_fork_cleanup_put_domain;
-
p->did_exec = 0;
delayacct_tsk_init(p); /* Must remain after dup_task_struct() */
copy_flags(clone_flags, p);
@@ -1327,9 +1331,6 @@
#endif
cgroup_exit(p, cgroup_callbacks_done);
delayacct_tsk_free(p);
- if (p->binfmt)
- module_put(p->binfmt->module);
-bad_fork_cleanup_put_domain:
module_put(task_thread_info(p)->exec_domain->module);
bad_fork_cleanup_count:
atomic_dec(&p->cred->user->processes);
