From 83914441f94c6f2cd468ca97365f6c34f418706e Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Fri, 25 Jul 2008 01:47:45 -0700 Subject: [PATCH] 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: Oleg Nesterov Acked-by: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/binfmt_elf.c | 77 ++++++++++++++++++++----------------------------- 1 file changed, 32 insertions(+), 45 deletions(-) diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c index bad7d8770d72..88d180306cf9 100644 --- a/fs/binfmt_elf.c +++ b/fs/binfmt_elf.c @@ -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; @@ -1517,34 +1517,26 @@ 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; - - t = kzalloc(offsetof(struct elf_thread_core_info, - notes[info->thread_notes]), - GFP_ATOMIC); - if (unlikely(!t)) { - rcu_read_unlock(); - return 0; - } - t->task = p; - if (p == dump_task || !info->thread) { - t->next = info->thread; - info->thread = t; - } else { - /* - * Make sure to keep the original task at - * the head of the list. - */ - t->next = info->thread->next; - info->thread->next = t; - } + 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_KERNEL); + if (unlikely(!t)) + return 0; + + t->task = ct->task; + if (ct->task == dump_task || !info->thread) { + t->next = info->thread; + info->thread = t; + } else { + /* + * Make sure to keep the original task at + * the head of the list. + */ + t->next = info->thread->next; + 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(); - return 0; - } - ets->thread = p; - list_add(&ets->list, &info->thread_list); - } - while_each_thread(g, p); - 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 = ct->task; + list_add(&ets->list, &info->thread_list); + } + list_for_each(t, &info->thread_list) { int sz; -- 2.20.1