/*
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* Copyright (C) 2013 Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License as
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* published by the Free Software Foundation; either version 2 of the
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* License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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*/
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#include <linux/list.h>
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#include <linux/err.h>
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#include <cobalt/kernel/lock.h>
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#include <cobalt/kernel/heap.h>
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#include <cobalt/kernel/tree.h>
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#include "internal.h"
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#include "sem.h"
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#include "thread.h"
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#include <trace/events/cobalt-posix.h>
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DEFINE_PRIVATE_XNLOCK(named_sem_lock);
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struct cobalt_named_sem {
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struct cobalt_sem *sem;
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struct cobalt_sem_shadow __user *usem;
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unsigned int refs;
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struct xnid id;
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};
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static struct cobalt_named_sem *
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sem_search(struct cobalt_process *process, xnhandle_t handle)
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{
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struct xnid *i;
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i = xnid_fetch(&process->usems, handle);
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if (i == NULL)
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return NULL;
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return container_of(i, struct cobalt_named_sem, id);
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}
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static struct cobalt_sem_shadow __user *
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sem_open(struct cobalt_process *process,
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struct cobalt_sem_shadow __user *ushadow,
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struct filename *filename, int oflags, mode_t mode,
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unsigned int value)
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{
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const char *name = filename->name;
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struct cobalt_sem_shadow shadow;
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struct cobalt_named_sem *u, *v;
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struct cobalt_sem *sem;
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xnhandle_t handle;
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spl_t s;
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int rc;
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if (name[0] != '/' || name[1] == '\0')
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return ERR_PTR(-EINVAL);
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retry_bind:
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rc = xnregistry_bind(&name[1], XN_NONBLOCK, XN_RELATIVE, &handle);
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switch (rc) {
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case 0:
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/* Found */
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if ((oflags & (O_CREAT | O_EXCL)) == (O_CREAT | O_EXCL))
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return ERR_PTR(-EEXIST);
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xnlock_get_irqsave(&named_sem_lock, s);
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u = sem_search(process, handle);
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if (u) {
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++u->refs;
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xnlock_put_irqrestore(&named_sem_lock, s);
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return u->usem;
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}
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xnlock_put_irqrestore(&named_sem_lock, s);
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xnlock_get_irqsave(&nklock, s);
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sem = xnregistry_lookup(handle, NULL);
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if (sem && sem->magic != COBALT_SEM_MAGIC) {
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xnlock_put_irqrestore(&nklock, s);
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return ERR_PTR(-EINVAL);
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}
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if (sem) {
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++sem->refs;
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xnlock_put_irqrestore(&nklock, s);
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} else {
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xnlock_put_irqrestore(&nklock, s);
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goto retry_bind;
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}
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__cobalt_sem_shadow_init(sem, COBALT_NAMED_SEM_MAGIC, &shadow);
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break;
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case -EWOULDBLOCK:
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/* Not found */
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if ((oflags & O_CREAT) == 0)
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return ERR_PTR(-ENOENT);
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shadow.magic = 0;
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sem = __cobalt_sem_init(&name[1], &shadow,
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SEM_PSHARED | SEM_NAMED, value);
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if (IS_ERR(sem)) {
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rc = PTR_ERR(sem);
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if (rc == -EEXIST)
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goto retry_bind;
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return ERR_PTR(rc);
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}
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sem->pathname = filename;
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handle = shadow.handle;
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break;
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default:
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return ERR_PTR(rc);
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}
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if (cobalt_copy_to_user(ushadow, &shadow, sizeof(shadow))) {
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__cobalt_sem_destroy(handle);
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return ERR_PTR(-EFAULT);
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}
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u = xnmalloc(sizeof(*u));
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if (u == NULL) {
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__cobalt_sem_destroy(handle);
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return ERR_PTR(-ENOMEM);
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}
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u->sem = sem;
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u->usem = ushadow;
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u->refs = 1;
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xnlock_get_irqsave(&named_sem_lock, s);
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v = sem_search(process, handle);
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if (v) {
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++v->refs;
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xnlock_put_irqrestore(&named_sem_lock, s);
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xnlock_get_irqsave(&nklock, s);
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--sem->refs;
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xnlock_put_irqrestore(&nklock, s);
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putname(filename);
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xnfree(u);
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u = v;
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} else {
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xnid_enter(&process->usems, &u->id, handle);
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xnlock_put_irqrestore(&named_sem_lock, s);
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}
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trace_cobalt_psem_open(name, handle, oflags, mode, value);
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return u->usem;
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}
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static int sem_close(struct cobalt_process *process, xnhandle_t handle)
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{
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struct cobalt_named_sem *u;
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spl_t s;
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int err;
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xnlock_get_irqsave(&named_sem_lock, s);
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u = sem_search(process, handle);
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if (u == NULL) {
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err = -ENOENT;
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goto err_unlock;
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}
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if (--u->refs) {
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err = 0;
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goto err_unlock;
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}
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xnid_remove(&process->usems, &u->id);
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xnlock_put_irqrestore(&named_sem_lock, s);
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__cobalt_sem_destroy(handle);
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xnfree(u);
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return 1;
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err_unlock:
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xnlock_put_irqrestore(&named_sem_lock, s);
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return err;
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}
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struct cobalt_sem_shadow __user *
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__cobalt_sem_open(struct cobalt_sem_shadow __user *usm,
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const char __user *u_name,
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int oflags, mode_t mode, unsigned int value)
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{
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struct cobalt_process *process;
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struct filename *filename;
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process = cobalt_current_process();
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if (process == NULL)
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return ERR_PTR(-EPERM);
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filename = getname(u_name);
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if (IS_ERR(filename))
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return ERR_CAST(filename);
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usm = sem_open(process, usm, filename, oflags, mode, value);
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if (IS_ERR(usm)) {
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trace_cobalt_psem_open_failed(filename->name, oflags, mode,
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value, PTR_ERR(usm));
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putname(filename);
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}
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return usm;
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}
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COBALT_SYSCALL(sem_open, lostage,
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(struct cobalt_sem_shadow __user *__user *u_addrp,
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const char __user *u_name,
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int oflags, mode_t mode, unsigned int value))
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{
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struct cobalt_sem_shadow __user *usm;
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if (__xn_get_user(usm, u_addrp))
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return -EFAULT;
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usm = __cobalt_sem_open(usm, u_name, oflags, mode, value);
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if (IS_ERR(usm))
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return PTR_ERR(usm);
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return __xn_put_user(usm, u_addrp) ? -EFAULT : 0;
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}
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COBALT_SYSCALL(sem_close, lostage,
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(struct cobalt_sem_shadow __user *usm))
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{
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struct cobalt_process *process;
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xnhandle_t handle;
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process = cobalt_current_process();
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if (process == NULL)
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return -EPERM;
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handle = cobalt_get_handle_from_user(&usm->handle);
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trace_cobalt_psem_close(handle);
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return sem_close(process, handle);
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}
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static inline int sem_unlink(const char *name)
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{
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xnhandle_t handle;
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int ret;
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if (name[0] != '/')
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return -EINVAL;
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ret = xnregistry_bind(name + 1, XN_NONBLOCK, XN_RELATIVE, &handle);
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if (ret == -EWOULDBLOCK)
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return -ENOENT;
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if (__cobalt_sem_destroy(handle) == -EBUSY)
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xnregistry_unlink(xnregistry_key(handle));
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return 0;
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}
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COBALT_SYSCALL(sem_unlink, lostage,
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(const char __user *u_name))
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{
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struct filename *filename;
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int ret;
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filename = getname(u_name);
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if (IS_ERR(filename))
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return PTR_ERR(filename);
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trace_cobalt_psem_unlink(filename->name);
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ret = sem_unlink(filename->name);
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putname(filename);
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return ret;
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}
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static void reclaim_named_sem(void *arg, struct xnid *i)
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{
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struct cobalt_process *process = arg;
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struct cobalt_named_sem *u;
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u = container_of(i, struct cobalt_named_sem, id);
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u->refs = 1;
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sem_close(process, xnid_key(i));
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}
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void cobalt_nsem_reclaim(struct cobalt_process *process)
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{
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xntree_cleanup(&process->usems, process, reclaim_named_sem);
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}
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