[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-Id: <1305301580-9924-1-git-send-email-tj@kernel.org>
Date: Fri, 13 May 2011 17:46:11 +0200
From: Tejun Heo <tj@...nel.org>
To: oleg@...hat.com, jan.kratochvil@...hat.com,
vda.linux@...glemail.com
Cc: linux-kernel@...r.kernel.org, torvalds@...ux-foundation.org,
akpm@...ux-foundation.org, indan@....nu, bdonlan@...il.com
Subject: [PATCHSET ptrace] ptrace: prepare for PTRACE_SEIZE/INTERRUPT
Hello,
This patchset is extension of preparation patches extracted from
"ptrace: implement PTRACE_SEIZE/INTERRUPT and group stop notification"
patchset[1].
Trivial and reviewed ones are collected at the beginning so that they
can be applied to the ptrace tree. The latter half concentrates on
improving TRAPPING handling without actually implementing any new
ptrace request.
This patchset makes the following changes to TRAPPING wait.
* TRAPPING is cleared when an action which requires cancellation
happens and the fallback clearing at the end of do_signal_stop() is
removed. This doesn't require adding any extra callsite to
clear_trapping() explicitly. Jobctl flag clearing automatically
handles cancellation of TRAPPING.
* Instead of signal->wait_chldexit, bit waitqueue is used. This
removes the unnecessary complexity and dependency on parent/child
hierarchy of TRAPPING wait. Note that this removes the wrong wait
queue bug Oleg pointed out in wait_trapping().
* TRAPPING wait is moved from PTRACE_ATTACH to wait_task_stopped() and
ptrace_check_attach(). In both cases, TRAPPING uses
restart_syscall() to retry. This simplifies the code and combined
with the next change makes TRAPPING much safer.
* TRAPPING now uses interruptible sleep. This makes it way safer even
if we get something wrong - at least, the tracer can be easily
killed no matter what. Also, this makes TRAPPING wait behave just
like other syscall retries and mixing TRAPPING waits with freezing
becomes much easier.
Other than making the transient TASK_RUNNING during TRAPPING visible
through /proc and using automatically restarted interruptible sleep,
this patchset doesn't make userland visible changes.
This patchset contains the following nine patches.
0001-job-control-reorganize-wait_task_stopped.patch
0002-job-control-rename-signal-group_stop-and-flags-to-jo.patch
0003-ptrace-ptrace_check_attach-rename-kill-to-ignore_sta.patch
0004-ptrace-relocate-set_current_state-TASK_TRACED-in-ptr.patch
0005-job-control-introduce-JOBCTL_PENDING_MASK-and-task_c.patch
0006-job-control-make-task_clear_jobctl_pending-clear-TRA.patch
0007-ptrace-use-bit_waitqueue-for-TRAPPING-instead-of-wai.patch
0008-ptrace-move-JOBCTL_TRAPPING-wait-to-wait-2-and-ptrac.patch
0009-ptrace-make-TRAPPING-wait-interruptible.patch
0001-0004 are reviewed or mostly trivial prep patches.
0005-0006 move clearing of TRAPPING to the actions requiring it.
0007 makes TRAPPING wait use bit waitqueue.
0008-0009 moves TRAPPING wait to wait(2) and ptrace_check_attach() and
makes it interruptible.
This patchset is on top of the current ptrace branch[2] - 40ae717d1e
"ptrace: fix signal->wait_chldexit usage in
task_clear_group_stop_trapping()" and is availble in the following git
branch.
git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc.git review-ptrace-seize-prep
diffstat follows.
fs/exec.c | 2
include/linux/ptrace.h | 3 -
include/linux/sched.h | 19 ++++--
kernel/exit.c | 46 +++++++++++++---
kernel/ptrace.c | 92 ++++++++++++++++++++++++++++-----
kernel/signal.c | 134 +++++++++++++++++++++++++------------------------
6 files changed, 200 insertions(+), 96 deletions(-)
Thanks.
--
tejun
[1] http://thread.gmane.org/gmane.linux.kernel/1136930
[2] git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc.git ptrace
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists