From: Oleg Nesterov <oleg@redhat.com>
To: Tejun Heo <tj@kernel.org>
Cc: linux-kernel@vger.kernel.org, akpm@linux-foundation.org,
torvalds@linux-foundation.org, hch@infradead.org
Subject: Re: [PATCH 5/7] ptrace: kill clone/exec tracehooks
Date: Mon, 20 Jun 2011 22:33:20 +0200 [thread overview]
Message-ID: <20110620203320.GC17157@redhat.com> (raw)
In-Reply-To: <1308322240-8247-6-git-send-email-tj@kernel.org>
On 06/17, Tejun Heo wrote:
>
> At this point, tracehooks aren't useful to mainline kernel and mostly
> just add an extra layer of obfuscation.
Yes, this is true.
> @@ -1481,10 +1481,22 @@ long do_fork(unsigned long clone_flags,
> }
>
> /*
> - * When called from kernel_thread, don't do user tracing stuff.
> + * Determine whether and which event to report to ptracer. When
> + * called from kernel_thread or CLONE_UNTRACED is explicitly
> + * requested, no event is reported; otherwise, report if the event
> + * for the type of forking is enabled.
> */
> - if (likely(user_mode(regs)))
> - trace = tracehook_prepare_clone(clone_flags);
> + if (likely(user_mode(regs)) && !(clone_flags & CLONE_UNTRACED)) {
Off-topic, but I never understood this user_mode() check... OK, a
traced task can call kernel_thread() in kernel, but this used
CLONE_UNTRACED.
> + if (clone_flags & CLONE_VFORK)
> + trace = PTRACE_EVENT_VFORK;
> + else if ((clone_flags & CSIGNAL) != SIGCHLD)
> + trace = PTRACE_EVENT_CLONE;
> + else
> + trace = PTRACE_EVENT_FORK;
> +
> + if (likely(!ptrace_event_enabled(current, trace)))
> + trace = 0;
> + }
As I said am going to apply this all except 6/7, but imho this
deserves a trivial helper anyway.
Oleg.
next prev parent reply other threads:[~2011-06-20 20:35 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-17 14:50 [PATCHSET] ptrace: kill most tracehooks Tejun Heo
2011-06-17 14:50 ` [PATCH 1/7] ptrace: kill task_ptrace() Tejun Heo
2011-06-17 14:50 ` [PATCH 2/7] ptrace: introduce ptrace_event_enabled() and simplify ptrace_event() and tracehook_prepare_clone() Tejun Heo
2011-06-17 14:50 ` [PATCH 3/7] ptrace: move SIGTRAP on exec(2) logic to ptrace_event() Tejun Heo
2011-06-20 20:25 ` Oleg Nesterov
2011-06-21 7:21 ` Tejun Heo
2011-06-21 20:40 ` Oleg Nesterov
2011-06-23 8:58 ` Tejun Heo
2011-06-17 14:50 ` [PATCH 4/7] ptrace: kill trivial tracehooks Tejun Heo
2011-06-17 14:50 ` [PATCH 5/7] ptrace: kill clone/exec tracehooks Tejun Heo
2011-06-20 20:33 ` Oleg Nesterov [this message]
2011-06-21 7:24 ` Tejun Heo
2011-06-17 14:50 ` [PATCH 6/7] ptrace: kill detah tracehooks Tejun Heo
2011-06-20 19:39 ` Oleg Nesterov
2011-06-21 20:23 ` Oleg Nesterov
2011-06-23 9:24 ` Tejun Heo
2011-06-22 21:07 ` [PATCH 0/8] kill task_detached() (Was: ptrace: kill detah tracehooks) Oleg Nesterov
2011-06-22 21:08 ` [PATCH 1/8] make do_notify_parent() return bool Oleg Nesterov
2011-06-23 9:52 ` Tejun Heo
2011-06-22 21:08 ` [PATCH 2/8] kill tracehook_notify_death() Oleg Nesterov
2011-06-23 12:22 ` Tejun Heo
2011-06-23 13:21 ` Oleg Nesterov
2011-06-23 13:27 ` Tejun Heo
2011-06-23 13:28 ` Oleg Nesterov
2011-06-23 17:06 ` Oleg Nesterov
2011-06-25 14:15 ` Tejun Heo
2011-06-26 20:51 ` Oleg Nesterov
2011-06-27 8:24 ` Tejun Heo
2011-06-27 14:21 ` Oleg Nesterov
2011-06-27 14:36 ` Tejun Heo
2011-06-22 21:08 ` [PATCH 3/8] __ptrace_detach: avoid task_detached(), check do_notify_parent() Oleg Nesterov
2011-06-23 13:25 ` Tejun Heo
2011-06-22 21:09 ` [PATCH 4/8] make do_notify_parent() __must_check, update the callers Oleg Nesterov
2011-06-23 13:38 ` Tejun Heo
2011-06-22 21:09 ` [PATCH 5/8] reparent_leader: check EXIT_DEAD instead of task_detached() Oleg Nesterov
2011-06-22 21:09 ` [PATCH 6/8] kill task_detached() Oleg Nesterov
2011-06-22 21:10 ` [PATCH 7/8] do not change dead_task->exit_signal Oleg Nesterov
2011-06-22 21:10 ` [PATCH 8/8] redefine thread_group_leader() as exit_signal >= 0 Oleg Nesterov
2011-06-23 13:56 ` Tejun Heo
2011-06-17 14:50 ` [PATCH 7/7] ptrace: s/tracehook_tracer_task()/ptrace_parent()/ Tejun Heo
2011-06-20 20:16 ` Oleg Nesterov
2011-06-21 11:44 ` John Johansen
2011-06-23 9:14 ` Tejun Heo
2011-06-20 11:16 ` [PATCHSET] ptrace: kill most tracehooks Christoph Hellwig
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