coredump: elf_core_dump: skip kernel threads

linux_binfmt->core_dump() runs before the process does exit_aio(), this
means that we can hit the kernel thread which shares the same ->mm.
Afaics, nothing really bad can happen, but perhaps it makes sense to fix
this minor bug.

It is sad we have to iterate over all threads in system and use
GFP_ATOMIC.  Hopefully we can kill theses ugly do_each_thread()s, but this
needs some nontrivial changes in mm_struct and do_coredump.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Oleg Nesterov 2008-07-25 01:47:40 -07:00 committed by Linus Torvalds
parent 15b9f360c0
commit 24d5288f06
2 changed files with 9 additions and 0 deletions

View file

@ -1520,6 +1520,9 @@ static int fill_note_info(struct elfhdr *elf, int phdrs,
rcu_read_lock();
do_each_thread(g, p)
if (p->mm == dump_task->mm) {
if (p->flags & PF_KTHREAD)
continue;
t = kzalloc(offsetof(struct elf_thread_core_info,
notes[info->thread_notes]),
GFP_ATOMIC);
@ -1724,6 +1727,9 @@ static int fill_note_info(struct elfhdr *elf, int phdrs,
rcu_read_lock();
do_each_thread(g, p)
if (current->mm == p->mm && current != p) {
if (p->flags & PF_KTHREAD)
continue;
ets = kzalloc(sizeof(*ets), GFP_ATOMIC);
if (!ets) {
rcu_read_unlock();

View file

@ -1626,6 +1626,9 @@ static int elf_fdpic_core_dump(long signr, struct pt_regs *regs,
rcu_read_lock();
do_each_thread(g,p)
if (current->mm == p->mm && current != p) {
if (p->flags & PF_KTHREAD)
continue;
tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
if (!tmp) {
rcu_read_unlock();