Messages in this thread | | | Date | Thu, 30 Jul 2009 19:55:47 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH 1/1] task_struct cleanup: move binfmt field to mm_struct |
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On 07/30, Hiroshi Shimamoto wrote: > > 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.
Looks like a nice patch to me.
Oleg.
> Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> > --- > fs/exec.c | 10 ++++++---- > include/linux/mm_types.h | 2 ++ > include/linux/sched.h | 1 - > kernel/exit.c | 2 -- > kernel/fork.c | 13 +++++++------ > 5 files changed, 15 insertions(+), 13 deletions(-) > > diff --git a/fs/exec.c b/fs/exec.c > index 6751a25..1d9b7a1 100644 > --- a/fs/exec.c > +++ b/fs/exec.c > @@ -1380,10 +1380,12 @@ out_ret: > */ > void set_binfmt(struct linux_binfmt *new) > { > - if (current->binfmt) > - module_put(current->binfmt->module); > + struct mm_struct *mm = current->mm; > + > + if (mm->binfmt) > + module_put(mm->binfmt->module); > > - current->binfmt = new; > + mm->binfmt = new; > if (new) > __module_get(new->module); > } > @@ -1729,7 +1731,7 @@ void do_coredump(long signr, int exit_code, struct pt_regs *regs) > > 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 7acc843..6719040 100644 > --- a/include/linux/mm_types.h > +++ b/include/linux/mm_types.h > @@ -240,6 +240,8 @@ struct mm_struct { > > unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ > > + struct linux_binfmt *binfmt; > + > s8 oom_adj; /* OOM kill score adjustment (bit shift) */ > > cpumask_t cpu_vm_mask; > diff --git a/include/linux/sched.h b/include/linux/sched.h > index 3ab08e4..940b070 100644 > --- a/include/linux/sched.h > +++ b/include/linux/sched.h > @@ -1220,7 +1220,6 @@ struct task_struct { > 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 869dc22..77b01be 100644 > --- a/kernel/exit.c > +++ b/kernel/exit.c > @@ -970,8 +970,6 @@ NORET_TYPE void do_exit(long code) > 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 9b42695..653da52 100644 > --- a/kernel/fork.c > +++ b/kernel/fork.c > @@ -494,6 +494,8 @@ void mmput(struct mm_struct *mm) > spin_unlock(&mmlist_lock); > } > put_swap_token(mm); > + if (mm->binfmt) > + module_put(mm->binfmt->module); > mmdrop(mm); > } > } > @@ -619,9 +621,14 @@ struct mm_struct *dup_mm(struct task_struct *tsk) > 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: > @@ -1013,9 +1020,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, > 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); > @@ -1300,9 +1304,6 @@ bad_fork_cleanup_cgroup: > #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); > -- > 1.6.3.3 >
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