From bce9a234ce7d8dddbfcec28e37ea58b5d8f6003d Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 29 Sep 2006 02:00:25 -0700 Subject: [PATCH] [PATCH] elf_fdpic_core_dump: don't take tasklist_lock do_each_thread() is rcu-safe, and all tasks which use this ->mm must sleep in wait_for_completion(&mm->core_done) at this point, so we can use RCU locks. Also, remove unneeded INIT_LIST_HEAD(new) before list_add(new, head). Signed-off-by: Oleg Nesterov Acked-By: David Howells Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/binfmt_elf_fdpic.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/fs/binfmt_elf_fdpic.c b/fs/binfmt_elf_fdpic.c index 2f3365829229..f86d5c9ce5eb 100644 --- a/fs/binfmt_elf_fdpic.c +++ b/fs/binfmt_elf_fdpic.c @@ -1597,20 +1597,19 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs, if (signr) { struct elf_thread_status *tmp; - read_lock(&tasklist_lock); + rcu_read_lock(); do_each_thread(g,p) if (current->mm == p->mm && current != p) { tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC); if (!tmp) { - read_unlock(&tasklist_lock); + rcu_read_unlock(); goto cleanup; } - INIT_LIST_HEAD(&tmp->list); tmp->thread = p; list_add(&tmp->list, &thread_list); } while_each_thread(g,p); - read_unlock(&tasklist_lock); + rcu_read_unlock(); list_for_each(t, &thread_list) { struct elf_thread_status *tmp; int sz; -- 2.20.1