diff options
| -rw-r--r-- | include/linux/sched.h | 2 | ||||
| -rw-r--r-- | include/uapi/linux/prctl.h | 8 | ||||
| -rw-r--r-- | kernel/sched/core_sched.c | 114 | ||||
| -rw-r--r-- | kernel/sys.c | 5 | ||||
| -rw-r--r-- | tools/include/uapi/linux/prctl.h | 8 |
5 files changed, 137 insertions, 0 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index fba47e52e482..c7e7d50e2fdc 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -2182,6 +2182,8 @@ const struct cpumask *sched_trace_rd_span(struct root_domain *rd); #ifdef CONFIG_SCHED_CORE extern void sched_core_free(struct task_struct *tsk); extern void sched_core_fork(struct task_struct *p); +extern int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, + unsigned long uaddr); #else static inline void sched_core_free(struct task_struct *tsk) { } static inline void sched_core_fork(struct task_struct *p) { } diff --git a/include/uapi/linux/prctl.h b/include/uapi/linux/prctl.h index 18a9f59dc067..967d9c55323d 100644 --- a/include/uapi/linux/prctl.h +++ b/include/uapi/linux/prctl.h @@ -259,4 +259,12 @@ struct prctl_mm_map { #define PR_PAC_SET_ENABLED_KEYS 60 #define PR_PAC_GET_ENABLED_KEYS 61 +/* Request the scheduler to share a core */ +#define PR_SCHED_CORE 62 +# define PR_SCHED_CORE_GET 0 +# define PR_SCHED_CORE_CREATE 1 /* create unique core_sched cookie */ +# define PR_SCHED_CORE_SHARE_TO 2 /* push core_sched cookie to pid */ +# define PR_SCHED_CORE_SHARE_FROM 3 /* pull core_sched cookie to pid */ +# define PR_SCHED_CORE_MAX 4 + #endif /* _LINUX_PRCTL_H */ diff --git a/kernel/sched/core_sched.c b/kernel/sched/core_sched.c index dcbbeaefaaa3..9a80e9a474c0 100644 --- a/kernel/sched/core_sched.c +++ b/kernel/sched/core_sched.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-only +#include <linux/prctl.h> #include "sched.h" /* @@ -113,3 +114,116 @@ void sched_core_free(struct task_struct *p) { sched_core_put_cookie(p->core_cookie); } + +static void __sched_core_set(struct task_struct *p, unsigned long cookie) +{ + cookie = sched_core_get_cookie(cookie); + cookie = sched_core_update_cookie(p, cookie); + sched_core_put_cookie(cookie); +} + +/* Called from prctl interface: PR_SCHED_CORE */ +int sched_core_share_pid(unsigned int cmd, pid_t pid, enum pid_type type, + unsigned long uaddr) +{ + unsigned long cookie = 0, id = 0; + struct task_struct *task, *p; + struct pid *grp; + int err = 0; + + if (!static_branch_likely(&sched_smt_present)) + return -ENODEV; + + if (type > PIDTYPE_PGID || cmd >= PR_SCHED_CORE_MAX || pid < 0 || + (cmd != PR_SCHED_CORE_GET && uaddr)) + return -EINVAL; + + rcu_read_lock(); + if (pid == 0) { + task = current; + } else { + task = find_task_by_vpid(pid); + if (!task) { + rcu_read_unlock(); + return -ESRCH; + } + } + get_task_struct(task); + rcu_read_unlock(); + + /* + * Check if this process has the right to modify the specified + * process. Use the regular "ptrace_may_access()" checks. + */ + if (!ptrace_may_access(task, PTRACE_MODE_READ_REALCREDS)) { + err = -EPERM; + goto out; + } + + switch (cmd) { + case PR_SCHED_CORE_GET: + if (type != PIDTYPE_PID || uaddr & 7) { + err = -EINVAL; + goto out; + } + cookie = sched_core_clone_cookie(task); + if (cookie) { + /* XXX improve ? */ + ptr_to_hashval((void *)cookie, &id); + } + err = put_user(id, (u64 __user *)uaddr); + goto out; + + case PR_SCHED_CORE_CREATE: + cookie = sched_core_alloc_cookie(); + if (!cookie) { + err = -ENOMEM; + goto out; + } + break; + + case PR_SCHED_CORE_SHARE_TO: + cookie = sched_core_clone_cookie(current); + break; + + case PR_SCHED_CORE_SHARE_FROM: + if (type != PIDTYPE_PID) { + err = -EINVAL; + goto out; + } + cookie = sched_core_clone_cookie(task); + __sched_core_set(current, cookie); + goto out; + + default: + err = -EINVAL; + goto out; + }; + + if (type == PIDTYPE_PID) { + __sched_core_set(task, cookie); + goto out; + } + + read_lock(&tasklist_lock); + grp = task_pid_type(task, type); + + do_each_pid_thread(grp, type, p) { + if (!ptrace_may_access(p, PTRACE_MODE_READ_REALCREDS)) { + err = -EPERM; + goto out_tasklist; + } + } while_each_pid_thread(grp, type, p); + + do_each_pid_thread(grp, type, p) { + __sched_core_set(p, cookie); + } while_each_pid_thread(grp, type, p); +out_tasklist: + read_unlock(&tasklist_lock); + +out: + sched_core_put_cookie(cookie); + put_task_struct(task); + return err; +} + diff --git a/kernel/sys.c b/kernel/sys.c index 3a583a29815f..9de46a4bf492 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -2550,6 +2550,11 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, error = set_syscall_user_dispatch(arg2, arg3, arg4, (char __user *) arg5); break; +#ifdef CONFIG_SCHED_CORE + case PR_SCHED_CORE: + error = sched_core_share_pid(arg2, arg3, arg4, arg5); + break; +#endif default: error = -EINVAL; break; diff --git a/tools/include/uapi/linux/prctl.h b/tools/include/uapi/linux/prctl.h index 18a9f59dc067..967d9c55323d 100644 --- a/tools/include/uapi/linux/prctl.h +++ b/tools/include/uapi/linux/prctl.h @@ -259,4 +259,12 @@ struct prctl_mm_map { #define PR_PAC_SET_ENABLED_KEYS 60 #define PR_PAC_GET_ENABLED_KEYS 61 +/* Request the scheduler to share a core */ +#define PR_SCHED_CORE 62 +# define PR_SCHED_CORE_GET 0 +# define PR_SCHED_CORE_CREATE 1 /* create unique core_sched cookie */ +# define PR_SCHED_CORE_SHARE_TO 2 /* push core_sched cookie to pid */ +# define PR_SCHED_CORE_SHARE_FROM 3 /* pull core_sched cookie to pid */ +# define PR_SCHED_CORE_MAX 4 + #endif /* _LINUX_PRCTL_H */ |