From b092062cb6d799fa3504c5975cbb1b05c8b67d6d Mon Sep 17 00:00:00 2001 From: "Christian Brauner (Amutable)" Date: Wed, 20 May 2026 23:48:53 +0200 Subject: exec: introduce struct task_exec_state Introduce struct task_exec_state, a per-task RCU-protected structure that holds the dumpable mode and the user namespace and stays attached to the task for its full lifetime. task_exec_state_rcu() is the canonical reader: asserts RCU or task_lock is held, WARNs on a NULL state, returns the rcu_dereference()'d pointer. Reviewed-by: Jann Horn Link: https://patch.msgid.link/20260520-work-task_exec_state-v3-2-69f895bc1385@kernel.org Signed-off-by: Christian Brauner (Amutable) --- include/linux/sched.h | 2 ++ include/linux/sched/exec_state.h | 31 +++++++++++++++++++++++++++++++ 2 files changed, 33 insertions(+) create mode 100644 include/linux/sched/exec_state.h (limited to 'include/linux') diff --git a/include/linux/sched.h b/include/linux/sched.h index ee06cba5c6f5..6674dbf960b5 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -962,6 +962,8 @@ struct task_struct { struct mm_struct *mm; struct mm_struct *active_mm; + struct task_exec_state __rcu *exec_state; + int exit_state; int exit_code; int exit_signal; diff --git a/include/linux/sched/exec_state.h b/include/linux/sched/exec_state.h new file mode 100644 index 000000000000..dc5a795cbfe2 --- /dev/null +++ b/include/linux/sched/exec_state.h @@ -0,0 +1,31 @@ +// SPDX-License-Identifier: GPL-2.0 +/* Copyright (c) 2026 Christian Brauner */ +#ifndef _LINUX_SCHED_EXEC_STATE_H +#define _LINUX_SCHED_EXEC_STATE_H + +#include +#include +#include +#include +#include + +struct task_exec_state { + refcount_t count; + enum task_dumpable dumpable; + struct user_namespace *user_ns; + struct rcu_head rcu; +}; + +struct task_exec_state *alloc_task_exec_state(struct user_namespace *user_ns); +void put_task_exec_state(struct task_exec_state *exec_state); +struct task_exec_state *task_exec_state_rcu(const struct task_struct *tsk); +struct task_exec_state *task_exec_state_replace(struct task_struct *tsk, + struct task_exec_state *exec_state); +void task_exec_state_set_dumpable(enum task_dumpable value); +enum task_dumpable task_exec_state_get_dumpable(struct task_struct *task); +int task_exec_state_copy(struct task_struct *tsk); +void __init exec_state_init(void); + +DEFINE_FREE(put_task_exec_state, struct task_exec_state *, put_task_exec_state(_T)) + +#endif /* _LINUX_SCHED_EXEC_STATE_H */ -- cgit v1.2.3