Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-26 06:02:05 +00:00
Code Issues Packages Projects Releases Wiki Activity

ptrace_check_attach: remove unneeded ->signal != NULL check

Browse Source 
It is not possible to see the PT_PTRACED task without ->signal/sighand under
tasklist_lock, release_task() does ptrace_unlink() first.  If the task was
already released before, ptrace_attach() can't succeed and set PT_PTRACED.
Remove this check.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
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 2008-02-08 04:19:00 -08:00 committed by Linus Torvalds
parent 34a1738f7d
commit c0c0b649d6
1 changed files with 5 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
kernel/ptrace.c
View File

@ -99,9 +99,12 @@ int ptrace_check_attach(struct task_struct *child, int kill)
* be changed by us so it's not changing right after this. * be changed by us so it's not changing right after this.
*/ */
read_lock(&tasklist_lock); read_lock(&tasklist_lock);
if ((child->ptrace & PT_PTRACED) && child->parent == current && if ((child->ptrace & PT_PTRACED) && child->parent == current) {
child->signal != NULL) {
ret = 0; ret = 0;
/*
* child->sighand can't be NULL, release_task()
* does ptrace_unlink() before __exit_signal().
*/
spin_lock_irq(&child->sighand->siglock); spin_lock_irq(&child->sighand->siglock);
if (task_is_stopped(child)) if (task_is_stopped(child))
child->state = TASK_TRACED; child->state = TASK_TRACED;