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| author | Peter Zijlstra <peterz@infradead.org> | 2022-05-03 23:57:47 +0300 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2022-05-11 22:37:06 +0300 |
| commit | 31cae1eaae4fd65095ad6a3659db467bc3c2599e (patch) | |
| tree | 55d58c2a6149e34b41ff4d1b9888f96e3c9d2a2d /include/linux/sched/jobctl.h | |
| parent | 5b4197cb287daf3cfd008fbf8682a1d6f4b13c0b (diff) | |
| download | linux-31cae1eaae4fd65095ad6a3659db467bc3c2599e.tar.xz | |
sched,signal,ptrace: Rework TASK_TRACED, TASK_STOPPED state
Currently ptrace_stop() / do_signal_stop() rely on the special states
TASK_TRACED and TASK_STOPPED resp. to keep unique state. That is, this
state exists only in task->__state and nowhere else.
There's two spots of bother with this:
- PREEMPT_RT has task->saved_state which complicates matters,
meaning task_is_{traced,stopped}() needs to check an additional
variable.
- An alternative freezer implementation that itself relies on a
special TASK state would loose TASK_TRACED/TASK_STOPPED and will
result in misbehaviour.
As such, add additional state to task->jobctl to track this state
outside of task->__state.
NOTE: this doesn't actually fix anything yet, just adds extra state.
--EWB
* didn't add a unnecessary newline in signal.h
* Update t->jobctl in signal_wake_up and ptrace_signal_wake_up
instead of in signal_wake_up_state. This prevents the clearing
of TASK_STOPPED and TASK_TRACED from getting lost.
* Added warnings if JOBCTL_STOPPED or JOBCTL_TRACED are not cleared
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20220421150654.757693825@infradead.org
Tested-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Link: https://lkml.kernel.org/r/20220505182645.497868-12-ebiederm@xmission.com
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Diffstat (limited to 'include/linux/sched/jobctl.h')
| -rw-r--r-- | include/linux/sched/jobctl.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/sched/jobctl.h b/include/linux/sched/jobctl.h index d556c3425963..68876d0a7ef9 100644 --- a/include/linux/sched/jobctl.h +++ b/include/linux/sched/jobctl.h @@ -21,6 +21,9 @@ struct task_struct; #define JOBCTL_TRAP_FREEZE_BIT 23 /* trap for cgroup freezer */ #define JOBCTL_PTRACE_FROZEN_BIT 24 /* frozen for ptrace */ +#define JOBCTL_STOPPED_BIT 26 /* do_signal_stop() */ +#define JOBCTL_TRACED_BIT 27 /* ptrace_stop() */ + #define JOBCTL_STOP_DEQUEUED (1UL << JOBCTL_STOP_DEQUEUED_BIT) #define JOBCTL_STOP_PENDING (1UL << JOBCTL_STOP_PENDING_BIT) #define JOBCTL_STOP_CONSUME (1UL << JOBCTL_STOP_CONSUME_BIT) @@ -31,6 +34,9 @@ struct task_struct; #define JOBCTL_TRAP_FREEZE (1UL << JOBCTL_TRAP_FREEZE_BIT) #define JOBCTL_PTRACE_FROZEN (1UL << JOBCTL_PTRACE_FROZEN_BIT) +#define JOBCTL_STOPPED (1UL << JOBCTL_STOPPED_BIT) +#define JOBCTL_TRACED (1UL << JOBCTL_TRACED_BIT) + #define JOBCTL_TRAP_MASK (JOBCTL_TRAP_STOP | JOBCTL_TRAP_NOTIFY) #define JOBCTL_PENDING_MASK (JOBCTL_STOP_PENDING | JOBCTL_TRAP_MASK) |