xref: /src/sys/compat/linux/common/linux_sched.c

/*	$NetBSD: linux_sched.c,v 1.62 2010/07/01 02:38:29 rmind Exp $	*/

/*-
 * Copyright (c) 1999 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
 * NASA Ames Research Center; by Matthias Scheler.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * Linux compatibility module. Try to deal with scheduler related syscalls.
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: linux_sched.c,v 1.62 2010/07/01 02:38:29 rmind Exp $");

#include <sys/param.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/malloc.h>
#include <sys/syscallargs.h>
#include <sys/wait.h>
#include <sys/kauth.h>
#include <sys/ptrace.h>
#include <sys/types.h>

#include <sys/cpu.h>

#include <compat/linux/common/linux_types.h>
#include <compat/linux/common/linux_signal.h>
#include <compat/linux/common/linux_machdep.h> /* For LINUX_NPTL */
#include <compat/linux/common/linux_emuldata.h>
#include <compat/linux/common/linux_ipc.h>
#include <compat/linux/common/linux_sem.h>
#include <compat/linux/common/linux_exec.h>

#include <compat/linux/linux_syscallargs.h>

#include <compat/linux/common/linux_sched.h>

int
linux_sys_clone(struct lwp *l, const struct linux_sys_clone_args *uap, register_t *retval)
{
	/* {
		syscallarg(int) flags;
		syscallarg(void *) stack;
#ifdef LINUX_NPTL
		syscallarg(void *) parent_tidptr;
		syscallarg(void *) child_tidptr;
#endif
	} */
	int flags, sig;
	int error;
	struct proc *p;
#ifdef LINUX_NPTL
	struct linux_emuldata *led;
#endif

	/*
	 * We don't support the Linux CLONE_PID or CLONE_PTRACE flags.
	 */
	if (SCARG(uap, flags) & (LINUX_CLONE_PID|LINUX_CLONE_PTRACE))
		return (EINVAL);

	/*
	 * Thread group implies shared signals. Shared signals
	 * imply shared VM. This matches what Linux kernel does.
	 */
	if (SCARG(uap, flags) & LINUX_CLONE_THREAD
	    && (SCARG(uap, flags) & LINUX_CLONE_SIGHAND) == 0)
		return (EINVAL);
	if (SCARG(uap, flags) & LINUX_CLONE_SIGHAND
	    && (SCARG(uap, flags) & LINUX_CLONE_VM) == 0)
		return (EINVAL);

	flags = 0;

	if (SCARG(uap, flags) & LINUX_CLONE_VM)
		flags |= FORK_SHAREVM;
	if (SCARG(uap, flags) & LINUX_CLONE_FS)
		flags |= FORK_SHARECWD;
	if (SCARG(uap, flags) & LINUX_CLONE_FILES)
		flags |= FORK_SHAREFILES;
	if (SCARG(uap, flags) & LINUX_CLONE_SIGHAND)
		flags |= FORK_SHARESIGS;
	if (SCARG(uap, flags) & LINUX_CLONE_VFORK)
		flags |= FORK_PPWAIT;

	sig = SCARG(uap, flags) & LINUX_CLONE_CSIGNAL;
	if (sig < 0 || sig >= LINUX__NSIG)
		return (EINVAL);
	sig = linux_to_native_signo[sig];

#ifdef LINUX_NPTL
	led = (struct linux_emuldata *)l->l_proc->p_emuldata;

	led->parent_tidptr = SCARG(uap, parent_tidptr);
	led->child_tidptr = SCARG(uap, child_tidptr);
	led->clone_flags = SCARG(uap, flags);
#endif /* LINUX_NPTL */

	/*
	 * Note that Linux does not provide a portable way of specifying
	 * the stack area; the caller must know if the stack grows up
	 * or down.  So, we pass a stack size of 0, so that the code
	 * that makes this adjustment is a noop.
	 */
	if ((error = fork1(l, flags, sig, SCARG(uap, stack), 0,
	    NULL, NULL, retval, &p)) != 0)
		return error;

#ifdef LINUX_NPTL
	if ((SCARG(uap, flags) & LINUX_CLONE_SETTLS) != 0)
		return linux_init_thread_area(l, LIST_FIRST(&p->p_lwps));
#endif /* LINUX_NPTL */

	return 0;
}

/*
 * linux realtime priority
 *
 * - SCHED_RR and SCHED_FIFO tasks have priorities [1,99].
 *
 * - SCHED_OTHER tasks don't have realtime priorities.
 *   in particular, sched_param::sched_priority is always 0.
 */

#define	LINUX_SCHED_RTPRIO_MIN	1
#define	LINUX_SCHED_RTPRIO_MAX	99

static int
sched_linux2native(int linux_policy, struct linux_sched_param *linux_params,
    int *native_policy, struct sched_param *native_params)
{

	switch (linux_policy) {
	case LINUX_SCHED_OTHER:
		if (native_policy != NULL) {
			*native_policy = SCHED_OTHER;
		}
		break;

	case LINUX_SCHED_FIFO:
		if (native_policy != NULL) {
			*native_policy = SCHED_FIFO;
		}
		break;

	case LINUX_SCHED_RR:
		if (native_policy != NULL) {
			*native_policy = SCHED_RR;
		}
		break;

	default:
		return EINVAL;
	}

	if (linux_params != NULL) {
		int prio = linux_params->sched_priority;

		KASSERT(native_params != NULL);

		if (linux_policy == LINUX_SCHED_OTHER) {
			if (prio != 0) {
				return EINVAL;
			}
			native_params->sched_priority = PRI_NONE; /* XXX */
		} else {
			if (prio < LINUX_SCHED_RTPRIO_MIN ||
			    prio > LINUX_SCHED_RTPRIO_MAX) {
				return EINVAL;
			}
			native_params->sched_priority =
			    (prio - LINUX_SCHED_RTPRIO_MIN)
			    * (SCHED_PRI_MAX - SCHED_PRI_MIN)
			    / (LINUX_SCHED_RTPRIO_MAX - LINUX_SCHED_RTPRIO_MIN)
			    + SCHED_PRI_MIN;
		}
	}

	return 0;
}

static int
sched_native2linux(int native_policy, struct sched_param *native_params,
    int *linux_policy, struct linux_sched_param *linux_params)
{

	switch (native_policy) {
	case SCHED_OTHER:
		if (linux_policy != NULL) {
			*linux_policy = LINUX_SCHED_OTHER;
		}
		break;

	case SCHED_FIFO:
		if (linux_policy != NULL) {
			*linux_policy = LINUX_SCHED_FIFO;
		}
		break;

	case SCHED_RR:
		if (linux_policy != NULL) {
			*linux_policy = LINUX_SCHED_RR;
		}
		break;

	default:
		panic("%s: unknown policy %d\n", __func__, native_policy);
	}

	if (native_params != NULL) {
		int prio = native_params->sched_priority;

		KASSERT(prio >= SCHED_PRI_MIN);
		KASSERT(prio <= SCHED_PRI_MAX);
		KASSERT(linux_params != NULL);

#ifdef DEBUG_LINUX
		printf("native2linux: native: policy %d, priority %d\n",
		    native_policy, prio);
#endif

		if (native_policy == SCHED_OTHER) {
			linux_params->sched_priority = 0;
		} else {
			linux_params->sched_priority =
			    (prio - SCHED_PRI_MIN)
			    * (LINUX_SCHED_RTPRIO_MAX - LINUX_SCHED_RTPRIO_MIN)
			    / (SCHED_PRI_MAX - SCHED_PRI_MIN)
			    + LINUX_SCHED_RTPRIO_MIN;
		}
#ifdef DEBUG_LINUX
		printf("native2linux: linux: policy %d, priority %d\n",
		    -1, linux_params->sched_priority);
#endif
	}

	return 0;
}

int
linux_sys_sched_setparam(struct lwp *l, const struct linux_sys_sched_setparam_args *uap, register_t *retval)
{
	/* {
		syscallarg(linux_pid_t) pid;
		syscallarg(const struct linux_sched_param *) sp;
	} */
	int error, policy;
	struct linux_sched_param lp;
	struct sched_param sp;

	if (SCARG(uap, pid) < 0 || SCARG(uap, sp) == NULL) {
		error = EINVAL;
		goto out;
	}

	error = copyin(SCARG(uap, sp), &lp, sizeof(lp));
	if (error)
		goto out;

	/* We need the current policy in Linux terms. */
	error = do_sched_getparam(SCARG(uap, pid), 0, &policy, NULL);
	if (error)
		goto out;
	error = sched_native2linux(policy, NULL, &policy, NULL);
	if (error)
		goto out;

	error = sched_linux2native(policy, &lp, &policy, &sp);
	if (error)
		goto out;

	error = do_sched_setparam(SCARG(uap, pid), 0, policy, &sp);
	if (error)
		goto out;

 out:
	return error;
}

int
linux_sys_sched_getparam(struct lwp *l, const struct linux_sys_sched_getparam_args *uap, register_t *retval)
{
	/* {
		syscallarg(linux_pid_t) pid;
		syscallarg(struct linux_sched_param *) sp;
	} */
	struct linux_sched_param lp;
	struct sched_param sp;
	int error, policy;

	if (SCARG(uap, pid) < 0 || SCARG(uap, sp) == NULL) {
		error = EINVAL;
		goto out;
	}

	error = do_sched_getparam(SCARG(uap, pid), 0, &policy, &sp);
	if (error)
		goto out;
#ifdef DEBUG_LINUX
	printf("getparam: native: policy %d, priority %d\n",
	    policy, sp.sched_priority);
#endif

	error = sched_native2linux(policy, &sp, NULL, &lp);
	if (error)
		goto out;
#ifdef DEBUG_LINUX
	printf("getparam: linux: policy %d, priority %d\n",
	    policy, lp.sched_priority);
#endif

	error = copyout(&lp, SCARG(uap, sp), sizeof(lp));
	if (error)
		goto out;

 out:
	return error;
}

int
linux_sys_sched_setscheduler(struct lwp *l, const struct linux_sys_sched_setscheduler_args *uap, register_t *retval)
{
	/* {
		syscallarg(linux_pid_t) pid;
		syscallarg(int) policy;
		syscallarg(cont struct linux_sched_param *) sp;
	} */
	int error, policy;
	struct linux_sched_param lp;
	struct sched_param sp;

	if (SCARG(uap, pid) < 0 || SCARG(uap, sp) == NULL) {
		error = EINVAL;
		goto out;
	}

	error = copyin(SCARG(uap, sp), &lp, sizeof(lp));
	if (error)
		goto out;
#ifdef DEBUG_LINUX
	printf("setscheduler: linux: policy %d, priority %d\n",
	    SCARG(uap, policy), lp.sched_priority);
#endif

	error = sched_linux2native(SCARG(uap, policy), &lp, &policy, &sp);
	if (error)
		goto out;
#ifdef DEBUG_LINUX
	printf("setscheduler: native: policy %d, priority %d\n",
	    policy, sp.sched_priority);
#endif

	error = do_sched_setparam(SCARG(uap, pid), 0, policy, &sp);
	if (error)
		goto out;

 out:
	return error;
}

int
linux_sys_sched_getscheduler(struct lwp *l, const struct linux_sys_sched_getscheduler_args *uap, register_t *retval)
{
	/* {
		syscallarg(linux_pid_t) pid;
	} */
	int error, policy;

	*retval = -1;

	error = do_sched_getparam(SCARG(uap, pid), 0, &policy, NULL);
	if (error)
		goto out;

	error = sched_native2linux(policy, NULL, &policy, NULL);
	if (error)
		goto out;

	*retval = policy;

 out:
	return error;
}

int
linux_sys_sched_yield(struct lwp *l, const void *v, register_t *retval)
{

	yield();
	return 0;
}

int
linux_sys_sched_get_priority_max(struct lwp *l, const struct linux_sys_sched_get_priority_max_args *uap, register_t *retval)
{
	/* {
		syscallarg(int) policy;
	} */

	switch (SCARG(uap, policy)) {
	case LINUX_SCHED_OTHER:
		*retval = 0;
		break;
	case LINUX_SCHED_FIFO:
	case LINUX_SCHED_RR:
		*retval = LINUX_SCHED_RTPRIO_MAX;
		break;
	default:
		return EINVAL;
	}

	return 0;
}

int
linux_sys_sched_get_priority_min(struct lwp *l, const struct linux_sys_sched_get_priority_min_args *uap, register_t *retval)
{
	/* {
		syscallarg(int) policy;
	} */

	switch (SCARG(uap, policy)) {
	case LINUX_SCHED_OTHER:
		*retval = 0;
		break;
	case LINUX_SCHED_FIFO:
	case LINUX_SCHED_RR:
		*retval = LINUX_SCHED_RTPRIO_MIN;
		break;
	default:
		return EINVAL;
	}

	return 0;
}

#ifndef __m68k__
/* Present on everything but m68k */
int
linux_sys_exit_group(struct lwp *l, const struct linux_sys_exit_group_args *uap, register_t *retval)
{
#ifdef LINUX_NPTL
	/* {
		syscallarg(int) error_code;
	} */
	struct proc *p = l->l_proc;
	struct linux_emuldata *led = p->p_emuldata;
	struct linux_emuldata *e;

	if (led->s->flags & LINUX_LES_USE_NPTL) {

#ifdef DEBUG_LINUX
		printf("%s:%d, led->s->refs = %d\n", __func__, __LINE__,
		    led->s->refs);
#endif

		/*
		 * The calling thread is supposed to kill all threads
		 * in the same thread group (i.e. all threads created
		 * via clone(2) with CLONE_THREAD flag set).
		 *
		 * If there is only one thread, things are quite simple
		 */
		if (led->s->refs == 1)
			return sys_exit(l, (const void *)uap, retval);

#ifdef DEBUG_LINUX
		printf("%s:%d\n", __func__, __LINE__);
#endif

		mutex_enter(proc_lock);
		led->s->flags |= LINUX_LES_INEXITGROUP;
		led->s->xstat = W_EXITCODE(SCARG(uap, error_code), 0);

		/*
		 * Kill all threads in the group. The emulation exit hook takes
		 * care of hiding the zombies and reporting the exit code
		 * properly.
		 */
      		LIST_FOREACH(e, &led->s->threads, threads) {
			if (e->proc == p)
				continue;

#ifdef DEBUG_LINUX
			printf("%s: kill PID %d\n", __func__, e->proc->p_pid);
#endif
			psignal(e->proc, SIGKILL);
		}

		/* Now, kill ourselves */
		psignal(p, SIGKILL);
		mutex_exit(proc_lock);

		return 0;

	}
#endif /* LINUX_NPTL */

	return sys_exit(l, (const void *)uap, retval);
}
#endif /* !__m68k__ */

#ifdef LINUX_NPTL
int
linux_sys_set_tid_address(struct lwp *l, const struct linux_sys_set_tid_address_args *uap, register_t *retval)
{
	/* {
		syscallarg(int *) tidptr;
	} */
	struct linux_emuldata *led;

	led = (struct linux_emuldata *)l->l_proc->p_emuldata;
	led->clear_tid = SCARG(uap, tid);

	led->s->flags |= LINUX_LES_USE_NPTL;

	*retval = l->l_proc->p_pid;

	return 0;
}

/* ARGUSED1 */
int
linux_sys_gettid(struct lwp *l, const void *v, register_t *retval)
{
	/* The Linux kernel does it exactly that way */
	*retval = l->l_proc->p_pid;
	return 0;
}

#ifdef LINUX_NPTL
/* ARGUSED1 */
int
linux_sys_getpid(struct lwp *l, const void *v, register_t *retval)
{
	struct linux_emuldata *led = l->l_proc->p_emuldata;

	if (led->s->flags & LINUX_LES_USE_NPTL) {
		/* The Linux kernel does it exactly that way */
		*retval = led->s->group_pid;
	} else {
		*retval = l->l_proc->p_pid;
	}

	return 0;
}

/* ARGUSED1 */
int
linux_sys_getppid(struct lwp *l, const void *v, register_t *retval)
{
	struct proc *p = l->l_proc;
	struct linux_emuldata *led = p->p_emuldata;
	struct proc *glp;
	struct proc *pp;

	mutex_enter(proc_lock);
	if (led->s->flags & LINUX_LES_USE_NPTL) {

		/* Find the thread group leader's parent */
		glp = proc_find(led->s->group_pid);
		if (glp == NULL) {
			/* Maybe panic... */
			printf("linux_sys_getppid: missing group leader PID"
			    " %d\n", led->s->group_pid);
			mutex_exit(proc_lock);
			return -1;
		}
		pp = glp->p_pptr;

		/* If this is a Linux process too, return thread group PID */
		if (pp->p_emul == p->p_emul) {
			struct linux_emuldata *pled;

			pled = pp->p_emuldata;
			*retval = pled->s->group_pid;
		} else {
			*retval = pp->p_pid;
		}

	} else {
		*retval = p->p_pptr->p_pid;
	}
	mutex_exit(proc_lock);

	return 0;
}
#endif /* LINUX_NPTL */

int
linux_sys_sched_getaffinity(struct lwp *l, const struct linux_sys_sched_getaffinity_args *uap, register_t *retval)
{
	/* {
		syscallarg(pid_t) pid;
		syscallarg(unsigned int) len;
		syscallarg(unsigned long *) mask;
	} */
	int error, size, nb = ncpu;
	unsigned long *c, *data;
	proc_t *p;

	/* Unlike Linux, dynamically calculate cpu mask size */
	size = sizeof(long) * ((ncpu + LONG_BIT - 1) / LONG_BIT);
	if (SCARG(uap, len) < size)
		return EINVAL;

	/* XXX: Pointless check.  TODO: Actually implement this. */
	mutex_enter(proc_lock);
	p = proc_find(SCARG(uap, pid));
	mutex_exit(proc_lock);
	if (p == NULL) {
		return ESRCH;
	}

	/*
	 * return the actual number of CPU, tag all of them as available
	 * The result is a mask, the first CPU being in the least significant
	 * bit.
	 */
	data = kmem_zalloc(size, KM_SLEEP);
	c = data;
	while (nb > LONG_BIT) {
		*c++ = ~0UL;
		nb -= LONG_BIT;
	}
	if (nb)
		*c = (1 << ncpu) - 1;

	error = copyout(data, SCARG(uap, mask), size);
	kmem_free(data, size);

	*retval = size;
	return error;

}

int
linux_sys_sched_setaffinity(struct lwp *l, const struct linux_sys_sched_setaffinity_args *uap, register_t *retval)
{
	/* {
		syscallarg(pid_t) pid;
		syscallarg(unsigned int) len;
		syscallarg(unsigned long *) mask;
	} */
	proc_t *p;

	/* XXX: Pointless check.  TODO: Actually implement this. */
	mutex_enter(proc_lock);
	p = proc_find(SCARG(uap, pid));
	mutex_exit(proc_lock);
	if (p == NULL) {
		return ESRCH;
	}

	/* Let's ignore it */
#ifdef DEBUG_LINUX
	printf("linux_sys_sched_setaffinity\n");
#endif
	return 0;
};
#endif /* LINUX_NPTL */