| Message ID | 87k0b7v9yk.fsf_-_@email.froward.int.ebiederm.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | ptrace: cleaning up ptrace_stop | expand |
On 2022-04-29 16:46:59 [-0500], Eric W. Biederman wrote: > > The states TASK_STOPPED and TASK_TRACE are special in they can not > handle spurious wake-ups. This plus actively depending upon and > changing the value of tsk->__state causes problems for PREEMPT_RT and > Peter's freezer rewrite. PREEMPT_RT wise, I had to duct tape wait_task_inactive() and remove the preempt-disable section in ptrace_stop() (like previously). This reduces the amount of __state + saved_state checks and looks otherwise stable in light testing. Sebastian
The states TASK_STOPPED and TASK_TRACE are special in they can not handle spurious wake-ups. This plus actively depending upon and changing the value of tsk->__state causes problems for PREEMPT_RT and Peter's freezer rewrite. There are a lot of details we have to get right to sort out the technical challenges and this is my parred back version of the changes that contains just those problems I see good solutions to that I believe are ready. In particular I don't have a solution that is ready for the challenges presented by wait_task_inactive. I hope we can review these changes and then have a firm foundation for the rest of the challenges. There are cleanups to the ptrace support for xtensa, um, and ia64. I have sucked in the first patch of Peter's freezer change as with minor modifications I believe it is ready to go. Eric W. Biederman (12): signal: Rename send_signal send_signal_locked signal: Replace __group_send_sig_info with send_signal_locked ptrace/um: Replace PT_DTRACE with TIF_SINGLESTEP ptrace/xtensa: Replace PT_SINGLESTEP with TIF_SINGLESTEP signal: Use lockdep_assert_held instead of assert_spin_locked ptrace: Reimplement PTRACE_KILL by always sending SIGKILL ptrace: Don't change __state ptrace: Remove arch_ptrace_attach ptrace: Always take siglock in ptrace_resume ptrace: Only return signr from ptrace_stop if it was provided ptrace: Always call schedule in ptrace_stop sched,signal,ptrace: Rework TASK_TRACED, TASK_STOPPED state arch/ia64/include/asm/ptrace.h | 4 -- arch/ia64/kernel/ptrace.c | 57 ---------------- arch/um/include/asm/thread_info.h | 2 + arch/um/kernel/exec.c | 2 +- arch/um/kernel/process.c | 2 +- arch/um/kernel/ptrace.c | 8 +-- arch/um/kernel/signal.c | 4 +- arch/xtensa/kernel/ptrace.c | 4 +- arch/xtensa/kernel/signal.c | 4 +- drivers/tty/tty_jobctrl.c | 4 +- include/linux/ptrace.h | 7 -- include/linux/sched.h | 10 ++- include/linux/sched/jobctl.h | 10 +++ include/linux/sched/signal.h | 23 ++++++- include/linux/signal.h | 3 +- kernel/ptrace.c | 88 +++++++++---------------- kernel/signal.c | 135 +++++++++++++++++--------------------- kernel/time/posix-cpu-timers.c | 6 +- 18 files changed, 145 insertions(+), 228 deletions(-) Eric