lkml.org 
[lkml]   [2008]   [Jun]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] coredump: elf_core_dump: skip kernel threads
On 06/19, Roland McGrath wrote:
>
> Perhaps a little prettier like this:
>
> --- a/fs/binfmt_elf.c
> +++ b/fs/binfmt_elf.c
> @@ -1469,6 +1469,12 @@ static int fill_thread_core_info(struct
> return 1;
> }
>
> +static bool is_dump_thread(struct task_struct *dump_task,
> + struct task_struct *thread)
> +{
> + return !(thread->flags & PF_KTHREAD) && thread->mm == dump_task->mm;
> +}
> +
> static int fill_note_info(struct elfhdr *elf, int phdrs,
> struct elf_note_info *info,
> long signr, struct pt_regs *regs)
> @@ -1518,7 +1524,7 @@ static int fill_note_info(struct elfhdr
> */
> rcu_read_lock();
> do_each_thread(g, p)
> - if (p->mm == dump_task->mm) {
> + if (is_dump_thread(dump_task, p)) {
> t = kzalloc(offsetof(struct elf_thread_core_info,
> notes[info->thread_notes]),
> GFP_ATOMIC);

Agreed.

> > 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.
>
> Agreed, and twice at that (coredump_wait). But this is something more to
> consider for the future, and I wouldn't worry about it right now.

In most cases coredump_wait() doesn't need to do for_each_process().

And I think there are other reasons to kill these do_each_thread()s.
We can simplify the code and make the coredumping process visible to
oom_kill. I sent the preparatory patches.

Oleg.



\
 
 \ /
  Last update: 2008-06-28 15:37    [W:0.040 / U:0.132 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site