[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 <oleg@tv-sign.ru>
Acked-By: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Oleg Nesterov 2006-09-29 02:00:25 -07:00 committed by Linus Torvalds
parent 486ccb05fd
commit bce9a234ce
1 changed files with 3 additions and 4 deletions

View File

@ -1597,20 +1597,19 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
if (signr) { if (signr) {
struct elf_thread_status *tmp; struct elf_thread_status *tmp;
read_lock(&tasklist_lock); rcu_read_lock();
do_each_thread(g,p) do_each_thread(g,p)
if (current->mm == p->mm && current != p) { if (current->mm == p->mm && current != p) {
tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC); tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
if (!tmp) { if (!tmp) {
read_unlock(&tasklist_lock); rcu_read_unlock();
goto cleanup; goto cleanup;
} }
INIT_LIST_HEAD(&tmp->list);
tmp->thread = p; tmp->thread = p;
list_add(&tmp->list, &thread_list); list_add(&tmp->list, &thread_list);
} }
while_each_thread(g,p); while_each_thread(g,p);
read_unlock(&tasklist_lock); rcu_read_unlock();
list_for_each(t, &thread_list) { list_for_each(t, &thread_list) {
struct elf_thread_status *tmp; struct elf_thread_status *tmp;
int sz; int sz;