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Commit 83914441 authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

coredump: elf_core_dump: use core_state->dumper list 



Kill the nasty rcu_read_lock() + do_each_thread() loop, use the list
encoded in mm->core_state instead, s/GFP_ATOMIC/GFP_KERNEL/.

This patch allows futher cleanups in binfmt_elf.c, in particular we can
kill the parallel info->threads list.

Signed-off-by: default avatarOleg Nesterov <oleg@tv-sign.ru>
Acked-by: default avatarRoland McGrath <roland@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent b564daf8

fs/binfmt_elf.c

+32 −45
Original line number Diff line number Diff line
@@ -1478,7 +1478,7 @@ static int fill_note_info(struct elfhdr *elf, int phdrs, 
	const struct user_regset_view *view = task_user_regset_view(dump_task);

	struct elf_thread_core_info *t;

	struct elf_prpsinfo *psinfo;

	struct task_struct *g, *p;

	struct core_thread *ct;

	unsigned int i;



	info->size = 0;
@@ -1517,21 +1517,15 @@ static int fill_note_info(struct elfhdr *elf, int phdrs, 
	/*

	 * Allocate a structure for each thread.

	 */

	rcu_read_lock();

	do_each_thread(g, p)

		if (p->mm == dump_task->mm) {

			if (p->flags & PF_KTHREAD)

				continue;



	for (ct = &dump_task->mm->core_state->dumper; ct; ct = ct->next) {

		t = kzalloc(offsetof(struct elf_thread_core_info,

				     notes[info->thread_notes]),

				    GFP_ATOMIC);

			if (unlikely(!t)) {

				rcu_read_unlock();

			    GFP_KERNEL);

		if (unlikely(!t))

			return 0;

			}

			t->task = p;

			if (p == dump_task || !info->thread) {



		t->task = ct->task;

		if (ct->task == dump_task || !info->thread) {

			t->next = info->thread;

			info->thread = t;

		} else {
@@ -1543,8 +1537,6 @@ static int fill_note_info(struct elfhdr *elf, int phdrs, 
			info->thread->next = t;

		}

	}

	while_each_thread(g, p);

	rcu_read_unlock();



	/*

	 * Now fill in each thread's information.
@@ -1691,7 +1683,6 @@ static int fill_note_info(struct elfhdr *elf, int phdrs, 
{

#define	NUM_NOTES	6

	struct list_head *t;

	struct task_struct *g, *p;



	info->notes = NULL;

	info->prstatus = NULL;
@@ -1723,23 +1714,19 @@ static int fill_note_info(struct elfhdr *elf, int phdrs, 


	info->thread_status_size = 0;

	if (signr) {

		struct core_thread *ct;

		struct elf_thread_status *ets;

		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();

		for (ct = current->mm->core_state->dumper.next;

						ct; ct = ct->next) {

			ets = kzalloc(sizeof(*ets), GFP_KERNEL);

			if (!ets)

				return 0;

				}

				ets->thread = p;



			ets->thread = ct->task;

			list_add(&ets->list, &info->thread_list);

		}

		while_each_thread(g, p);

		rcu_read_unlock();



		list_for_each(t, &info->thread_list) {

			int sz;