diff options
author | Oleg Nesterov <oleg@redhat.com> | 2009-06-04 19:29:09 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-06-04 21:07:40 -0400 |
commit | edaba2c5334492f82d39ec35637c6dea5176a977 (patch) | |
tree | d05ee0eacdb0c725da8374e9c1f38a4808dfdd2e | |
parent | 08f67461c609ad96bf26732b590569e02e322019 (diff) |
ptrace: revert "ptrace_detach: the wrong wakeup breaks the ERESTARTxxx logic"
Commit 95a3540da9c81a5987be810e1d9a83640a366bd5 ("ptrace_detach: the wrong
wakeup breaks the ERESTARTxxx logic") removed the "extra"
wake_up_process() from ptrace_detach(), but as Jan pointed out this breaks
the compatibility.
I believe the changelog is right and this wake_up() is wrong in many
ways, but GDB assumes that ptrace(PTRACE_DETACH, child, 0, 0) always
wakes up the tracee.
Despite the fact this breaks SIGNAL_STOP_STOPPED/group_stop_count logic,
and despite the fact this wake_up_process() can break another
assumption: PTRACE_DETACH with SIGSTOP should leave the tracee in
TASK_STOPPED case. Because the untraced child can dequeue SIGSTOP and
call do_signal_stop() before ptrace_detach() calls wake_up_process().
Revert this change for now. We need some fixes even if we we want to keep
the current behaviour, but these fixes are not for 2.6.30.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Roland McGrath <roland@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | kernel/ptrace.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 0692ab5a0d67..42c317874cfa 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c | |||
@@ -304,6 +304,8 @@ int ptrace_detach(struct task_struct *child, unsigned int data) | |||
304 | if (child->ptrace) { | 304 | if (child->ptrace) { |
305 | child->exit_code = data; | 305 | child->exit_code = data; |
306 | dead = __ptrace_detach(current, child); | 306 | dead = __ptrace_detach(current, child); |
307 | if (!child->exit_state) | ||
308 | wake_up_process(child); | ||
307 | } | 309 | } |
308 | write_unlock_irq(&tasklist_lock); | 310 | write_unlock_irq(&tasklist_lock); |
309 | 311 | ||