1 files changed, 617 insertions, 0 deletions

diff --git a/sys/kern/sysv_shm.c b/sys/kern/sysv_shm.c
new file mode 100644
index 0000000..a6c2dfe
--- /dev/null
+++ b/sys/kern/sysv_shm.c
@@ -0,0 +1,617 @@
+/*	$Id: sysv_shm.c,v 1.39 1998/10/13 08:24:40 dg Exp $ */
+/*	$NetBSD: sysv_shm.c,v 1.23 1994/07/04 23:25:12 glass Exp $	*/
+
+/*
+ * Copyright (c) 1994 Adam Glass and Charles Hannum.  All rights reserved.
+ *
+ * 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.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *	This product includes software developed by Adam Glass and Charles
+ *	Hannum.
+ * 4. The names of the authors may not be used to endorse or promote products
+ *    derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``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 AUTHORS 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.
+ */
+
+#include "opt_compat.h"
+#include "opt_rlimit.h"
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/sysproto.h>
+#include <sys/kernel.h>
+#include <sys/shm.h>
+#include <sys/proc.h>
+#include <sys/malloc.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/sysent.h>
+
+#include <vm/vm.h>
+#include <vm/vm_param.h>
+#include <vm/vm_prot.h>
+#include <sys/lock.h>
+#include <vm/pmap.h>
+#include <vm/vm_object.h>
+#include <vm/vm_map.h>
+#include <vm/vm_page.h>
+#include <vm/vm_pager.h>
+#include <vm/vm_inherit.h>
+
+#ifndef _SYS_SYSPROTO_H_
+struct shmat_args;
+extern int shmat __P((struct proc *p, struct shmat_args *uap));
+struct shmctl_args;
+extern int shmctl __P((struct proc *p, struct shmctl_args *uap));
+struct shmdt_args;
+extern int shmdt __P((struct proc *p, struct shmdt_args *uap));
+struct shmget_args;
+extern int shmget __P((struct proc *p, struct shmget_args *uap));
+#endif
+
+static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments");
+
+static void shminit __P((void *));
+SYSINIT(sysv_shm, SI_SUB_SYSV_SHM, SI_ORDER_FIRST, shminit, NULL)
+
+struct oshmctl_args;
+static int oshmctl __P((struct proc *p, struct oshmctl_args *uap));
+static int shmget_allocate_segment __P((struct proc *p, struct shmget_args *uap, int mode));
+static int shmget_existing __P((struct proc *p, struct shmget_args *uap, int mode, int segnum));
+
+/* XXX casting to (sy_call_t *) is bogus, as usual. */
+static sy_call_t *shmcalls[] = {
+	(sy_call_t *)shmat, (sy_call_t *)oshmctl,
+	(sy_call_t *)shmdt, (sy_call_t *)shmget,
+	(sy_call_t *)shmctl
+};
+
+#define	SHMSEG_FREE     	0x0200
+#define	SHMSEG_REMOVED  	0x0400
+#define	SHMSEG_ALLOCATED	0x0800
+#define	SHMSEG_WANTED		0x1000
+
+static int shm_last_free, shm_nused, shm_committed;
+struct shmid_ds	*shmsegs;
+
+struct shm_handle {
+	/* vm_offset_t kva; */
+	vm_object_t shm_object;
+};
+
+struct shmmap_state {
+	vm_offset_t va;
+	int shmid;
+};
+
+static void shm_deallocate_segment __P((struct shmid_ds *));
+static int shm_find_segment_by_key __P((key_t));
+static struct shmid_ds *shm_find_segment_by_shmid __P((int));
+static int shm_delete_mapping __P((struct proc *, struct shmmap_state *));
+
+static int
+shm_find_segment_by_key(key)
+	key_t key;
+{
+	int i;
+
+	for (i = 0; i < shminfo.shmmni; i++)
+		if ((shmsegs[i].shm_perm.mode & SHMSEG_ALLOCATED) &&
+		    shmsegs[i].shm_perm.key == key)
+			return i;
+	return -1;
+}
+
+static struct shmid_ds *
+shm_find_segment_by_shmid(shmid)
+	int shmid;
+{
+	int segnum;
+	struct shmid_ds *shmseg;
+
+	segnum = IPCID_TO_IX(shmid);
+	if (segnum < 0 || segnum >= shminfo.shmmni)
+		return NULL;
+	shmseg = &shmsegs[segnum];
+	if ((shmseg->shm_perm.mode & (SHMSEG_ALLOCATED | SHMSEG_REMOVED))
+	    != SHMSEG_ALLOCATED ||
+	    shmseg->shm_perm.seq != IPCID_TO_SEQ(shmid))
+		return NULL;
+	return shmseg;
+}
+
+static void
+shm_deallocate_segment(shmseg)
+	struct shmid_ds *shmseg;
+{
+	struct shm_handle *shm_handle;
+	size_t size;
+
+	shm_handle = shmseg->shm_internal;
+	vm_object_deallocate(shm_handle->shm_object);
+	free((caddr_t)shm_handle, M_SHM);
+	shmseg->shm_internal = NULL;
+	size = round_page(shmseg->shm_segsz);
+	shm_committed -= btoc(size);
+	shm_nused--;
+	shmseg->shm_perm.mode = SHMSEG_FREE;
+}
+
+static int
+shm_delete_mapping(p, shmmap_s)
+	struct proc *p;
+	struct shmmap_state *shmmap_s;
+{
+	struct shmid_ds *shmseg;
+	int segnum, result;
+	size_t size;
+
+	segnum = IPCID_TO_IX(shmmap_s->shmid);
+	shmseg = &shmsegs[segnum];
+	size = round_page(shmseg->shm_segsz);
+	result = vm_map_remove(&p->p_vmspace->vm_map, shmmap_s->va, shmmap_s->va + size);
+	if (result != KERN_SUCCESS)
+		return EINVAL;
+	shmmap_s->shmid = -1;
+	shmseg->shm_dtime = time_second;
+	if ((--shmseg->shm_nattch <= 0) &&
+	    (shmseg->shm_perm.mode & SHMSEG_REMOVED)) {
+		shm_deallocate_segment(shmseg);
+		shm_last_free = segnum;
+	}
+	return 0;
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct shmdt_args {
+	void *shmaddr;
+};
+#endif
+
+int
+shmdt(p, uap)
+	struct proc *p;
+	struct shmdt_args *uap;
+{
+	struct shmmap_state *shmmap_s;
+	int i;
+
+	shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
+ 	if (shmmap_s == NULL)
+ 	    return EINVAL;
+	for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
+		if (shmmap_s->shmid != -1 &&
+		    shmmap_s->va == (vm_offset_t)uap->shmaddr)
+			break;
+	if (i == shminfo.shmseg)
+		return EINVAL;
+	return shm_delete_mapping(p, shmmap_s);
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct shmat_args {
+	int shmid;
+	void *shmaddr;
+	int shmflg;
+};
+#endif
+
+int
+shmat(p, uap)
+	struct proc *p;
+	struct shmat_args *uap;
+{
+	int error, i, flags;
+	struct ucred *cred = p->p_ucred;
+	struct shmid_ds *shmseg;
+	struct shmmap_state *shmmap_s = NULL;
+	struct shm_handle *shm_handle;
+	vm_offset_t attach_va;
+	vm_prot_t prot;
+	vm_size_t size;
+	int rv;
+
+	shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
+	if (shmmap_s == NULL) {
+		size = shminfo.shmseg * sizeof(struct shmmap_state);
+		shmmap_s = malloc(size, M_SHM, M_WAITOK);
+		for (i = 0; i < shminfo.shmseg; i++)
+			shmmap_s[i].shmid = -1;
+		p->p_vmspace->vm_shm = (caddr_t)shmmap_s;
+	}
+	shmseg = shm_find_segment_by_shmid(uap->shmid);
+	if (shmseg == NULL)
+		return EINVAL;
+	error = ipcperm(cred, &shmseg->shm_perm,
+	    (uap->shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
+	if (error)
+		return error;
+	for (i = 0; i < shminfo.shmseg; i++) {
+		if (shmmap_s->shmid == -1)
+			break;
+		shmmap_s++;
+	}
+	if (i >= shminfo.shmseg)
+		return EMFILE;
+	size = round_page(shmseg->shm_segsz);
+	prot = VM_PROT_READ;
+	if ((uap->shmflg & SHM_RDONLY) == 0)
+		prot |= VM_PROT_WRITE;
+	flags = MAP_ANON | MAP_SHARED;
+	if (uap->shmaddr) {
+		flags |= MAP_FIXED;
+		if (uap->shmflg & SHM_RND)
+			attach_va = (vm_offset_t)uap->shmaddr & ~(SHMLBA-1);
+		else if (((vm_offset_t)uap->shmaddr & (SHMLBA-1)) == 0)
+			attach_va = (vm_offset_t)uap->shmaddr;
+		else
+			return EINVAL;
+	} else {
+		/* This is just a hint to vm_map_find() about where to put it. */
+		attach_va = round_page((vm_offset_t)p->p_vmspace->vm_taddr + MAXTSIZ + MAXDSIZ);
+	}
+
+	shm_handle = shmseg->shm_internal;
+	vm_object_reference(shm_handle->shm_object);
+	rv = vm_map_find(&p->p_vmspace->vm_map, shm_handle->shm_object,
+		0, &attach_va, size, (flags & MAP_FIXED)?0:1, prot, prot, 0);
+	if (rv != KERN_SUCCESS) {
+		return ENOMEM;
+	}
+	vm_map_inherit(&p->p_vmspace->vm_map,
+		attach_va, attach_va + size, VM_INHERIT_SHARE);
+
+	shmmap_s->va = attach_va;
+	shmmap_s->shmid = uap->shmid;
+	shmseg->shm_lpid = p->p_pid;
+	shmseg->shm_atime = time_second;
+	shmseg->shm_nattch++;
+	p->p_retval[0] = attach_va;
+	return 0;
+}
+
+struct oshmid_ds {
+	struct	ipc_perm shm_perm;	/* operation perms */
+	int	shm_segsz;		/* size of segment (bytes) */
+	ushort	shm_cpid;		/* pid, creator */
+	ushort	shm_lpid;		/* pid, last operation */
+	short	shm_nattch;		/* no. of current attaches */
+	time_t	shm_atime;		/* last attach time */
+	time_t	shm_dtime;		/* last detach time */
+	time_t	shm_ctime;		/* last change time */
+	void	*shm_handle;		/* internal handle for shm segment */
+};
+
+struct oshmctl_args {
+	int shmid;
+	int cmd;
+	struct oshmid_ds *ubuf;
+};
+
+static int
+oshmctl(p, uap)
+	struct proc *p;
+	struct oshmctl_args *uap;
+{
+#ifdef COMPAT_43
+	int error;
+	struct ucred *cred = p->p_ucred;
+	struct shmid_ds *shmseg;
+	struct oshmid_ds outbuf;
+
+	shmseg = shm_find_segment_by_shmid(uap->shmid);
+	if (shmseg == NULL)
+		return EINVAL;
+	switch (uap->cmd) {
+	case IPC_STAT:
+		error = ipcperm(cred, &shmseg->shm_perm, IPC_R);
+		if (error)
+			return error;
+		outbuf.shm_perm = shmseg->shm_perm;
+		outbuf.shm_segsz = shmseg->shm_segsz;
+		outbuf.shm_cpid = shmseg->shm_cpid;
+		outbuf.shm_lpid = shmseg->shm_lpid;
+		outbuf.shm_nattch = shmseg->shm_nattch;
+		outbuf.shm_atime = shmseg->shm_atime;
+		outbuf.shm_dtime = shmseg->shm_dtime;
+		outbuf.shm_ctime = shmseg->shm_ctime;
+		outbuf.shm_handle = shmseg->shm_internal;
+		error = copyout((caddr_t)&outbuf, uap->ubuf, sizeof(outbuf));
+		if (error)
+			return error;
+		break;
+	default:
+		/* XXX casting to (sy_call_t *) is bogus, as usual. */
+		return ((sy_call_t *)shmctl)(p, uap);
+	}
+	return 0;
+#else
+	return EINVAL;
+#endif
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct shmctl_args {
+	int shmid;
+	int cmd;
+	struct shmid_ds *buf;
+};
+#endif
+
+int
+shmctl(p, uap)
+	struct proc *p;
+	struct shmctl_args *uap;
+{
+	int error;
+	struct ucred *cred = p->p_ucred;
+	struct shmid_ds inbuf;
+	struct shmid_ds *shmseg;
+
+	shmseg = shm_find_segment_by_shmid(uap->shmid);
+	if (shmseg == NULL)
+		return EINVAL;
+	switch (uap->cmd) {
+	case IPC_STAT:
+		error = ipcperm(cred, &shmseg->shm_perm, IPC_R);
+		if (error)
+			return error;
+		error = copyout((caddr_t)shmseg, uap->buf, sizeof(inbuf));
+		if (error)
+			return error;
+		break;
+	case IPC_SET:
+		error = ipcperm(cred, &shmseg->shm_perm, IPC_M);
+		if (error)
+			return error;
+		error = copyin(uap->buf, (caddr_t)&inbuf, sizeof(inbuf));
+		if (error)
+			return error;
+		shmseg->shm_perm.uid = inbuf.shm_perm.uid;
+		shmseg->shm_perm.gid = inbuf.shm_perm.gid;
+		shmseg->shm_perm.mode =
+		    (shmseg->shm_perm.mode & ~ACCESSPERMS) |
+		    (inbuf.shm_perm.mode & ACCESSPERMS);
+		shmseg->shm_ctime = time_second;
+		break;
+	case IPC_RMID:
+		error = ipcperm(cred, &shmseg->shm_perm, IPC_M);
+		if (error)
+			return error;
+		shmseg->shm_perm.key = IPC_PRIVATE;
+		shmseg->shm_perm.mode |= SHMSEG_REMOVED;
+		if (shmseg->shm_nattch <= 0) {
+			shm_deallocate_segment(shmseg);
+			shm_last_free = IPCID_TO_IX(uap->shmid);
+		}
+		break;
+#if 0
+	case SHM_LOCK:
+	case SHM_UNLOCK:
+#endif
+	default:
+		return EINVAL;
+	}
+	return 0;
+}
+
+#ifndef _SYS_SYSPROTO_H_
+struct shmget_args {
+	key_t key;
+	size_t size;
+	int shmflg;
+};
+#endif
+
+static int
+shmget_existing(p, uap, mode, segnum)
+	struct proc *p;
+	struct shmget_args *uap;
+	int mode;
+	int segnum;
+{
+	struct shmid_ds *shmseg;
+	struct ucred *cred = p->p_ucred;
+	int error;
+
+	shmseg = &shmsegs[segnum];
+	if (shmseg->shm_perm.mode & SHMSEG_REMOVED) {
+		/*
+		 * This segment is in the process of being allocated.  Wait
+		 * until it's done, and look the key up again (in case the
+		 * allocation failed or it was freed).
+		 */
+		shmseg->shm_perm.mode |= SHMSEG_WANTED;
+		error = tsleep((caddr_t)shmseg, PLOCK | PCATCH, "shmget", 0);
+		if (error)
+			return error;
+		return EAGAIN;
+	}
+	error = ipcperm(cred, &shmseg->shm_perm, mode);
+	if (error)
+		return error;
+	if (uap->size && uap->size > shmseg->shm_segsz)
+		return EINVAL;
+       if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL))
+		return EEXIST;
+	p->p_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
+	return 0;
+}
+
+static int
+shmget_allocate_segment(p, uap, mode)
+	struct proc *p;
+	struct shmget_args *uap;
+	int mode;
+{
+	int i, segnum, shmid, size;
+	struct ucred *cred = p->p_ucred;
+	struct shmid_ds *shmseg;
+	struct shm_handle *shm_handle;
+
+	if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax)
+		return EINVAL;
+	if (shm_nused >= shminfo.shmmni) /* any shmids left? */
+		return ENOSPC;
+	size = round_page(uap->size);
+	if (shm_committed + btoc(size) > shminfo.shmall)
+		return ENOMEM;
+	if (shm_last_free < 0) {
+		for (i = 0; i < shminfo.shmmni; i++)
+			if (shmsegs[i].shm_perm.mode & SHMSEG_FREE)
+				break;
+		if (i == shminfo.shmmni)
+			panic("shmseg free count inconsistent");
+		segnum = i;
+	} else  {
+		segnum = shm_last_free;
+		shm_last_free = -1;
+	}
+	shmseg = &shmsegs[segnum];
+	/*
+	 * In case we sleep in malloc(), mark the segment present but deleted
+	 * so that noone else tries to create the same key.
+	 */
+	shmseg->shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED;
+	shmseg->shm_perm.key = uap->key;
+	shmseg->shm_perm.seq = (shmseg->shm_perm.seq + 1) & 0x7fff;
+	shm_handle = (struct shm_handle *)
+	    malloc(sizeof(struct shm_handle), M_SHM, M_WAITOK);
+	shmid = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
+	
+	/*
+	 * We make sure that we have allocated a pager before we need
+	 * to.
+	 */
+	shm_handle->shm_object =
+		vm_pager_allocate(OBJT_SWAP, 0, size, VM_PROT_DEFAULT, 0);
+	vm_object_clear_flag(shm_handle->shm_object, OBJ_ONEMAPPING);
+	vm_object_set_flag(shm_handle->shm_object, OBJ_NOSPLIT);
+
+	shmseg->shm_internal = shm_handle;
+	shmseg->shm_perm.cuid = shmseg->shm_perm.uid = cred->cr_uid;
+	shmseg->shm_perm.cgid = shmseg->shm_perm.gid = cred->cr_gid;
+	shmseg->shm_perm.mode = (shmseg->shm_perm.mode & SHMSEG_WANTED) |
+	    (mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
+	shmseg->shm_segsz = uap->size;
+	shmseg->shm_cpid = p->p_pid;
+	shmseg->shm_lpid = shmseg->shm_nattch = 0;
+	shmseg->shm_atime = shmseg->shm_dtime = 0;
+	shmseg->shm_ctime = time_second;
+	shm_committed += btoc(size);
+	shm_nused++;
+	if (shmseg->shm_perm.mode & SHMSEG_WANTED) {
+		/*
+		 * Somebody else wanted this key while we were asleep.  Wake
+		 * them up now.
+		 */
+		shmseg->shm_perm.mode &= ~SHMSEG_WANTED;
+		wakeup((caddr_t)shmseg);
+	}
+	p->p_retval[0] = shmid;
+	return 0;
+}
+
+int
+shmget(p, uap)
+	struct proc *p;
+	struct shmget_args *uap;
+{
+	int segnum, mode, error;
+
+	mode = uap->shmflg & ACCESSPERMS;
+	if (uap->key != IPC_PRIVATE) {
+	again:
+		segnum = shm_find_segment_by_key(uap->key);
+		if (segnum >= 0) {
+			error = shmget_existing(p, uap, mode, segnum);
+			if (error == EAGAIN)
+				goto again;
+			return error;
+		}
+		if ((uap->shmflg & IPC_CREAT) == 0)
+			return ENOENT;
+	}
+	return shmget_allocate_segment(p, uap, mode);
+}
+
+int
+shmsys(p, uap)
+	struct proc *p;
+	/* XXX actually varargs. */
+	struct shmsys_args /* {
+		u_int	which;
+		int	a2;
+		int	a3;
+		int	a4;
+	} */ *uap;
+{
+
+	if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0]))
+		return EINVAL;
+	return ((*shmcalls[uap->which])(p, &uap->a2));
+}
+
+void
+shmfork(p1, p2)
+	struct proc *p1, *p2;
+{
+	struct shmmap_state *shmmap_s;
+	size_t size;
+	int i;
+
+	size = shminfo.shmseg * sizeof(struct shmmap_state);
+	shmmap_s = malloc(size, M_SHM, M_WAITOK);
+	bcopy((caddr_t)p1->p_vmspace->vm_shm, (caddr_t)shmmap_s, size);
+	p2->p_vmspace->vm_shm = (caddr_t)shmmap_s;
+	for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
+		if (shmmap_s->shmid != -1)
+			shmsegs[IPCID_TO_IX(shmmap_s->shmid)].shm_nattch++;
+}
+
+void
+shmexit(p)
+	struct proc *p;
+{
+	struct shmmap_state *shmmap_s;
+	int i;
+
+	shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
+	for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
+		if (shmmap_s->shmid != -1)
+			shm_delete_mapping(p, shmmap_s);
+	free((caddr_t)p->p_vmspace->vm_shm, M_SHM);
+	p->p_vmspace->vm_shm = NULL;
+}
+
+void
+shminit(dummy)
+	void *dummy;
+{
+	int i;
+	for (i = 0; i < shminfo.shmmni; i++) {
+		shmsegs[i].shm_perm.mode = SHMSEG_FREE;
+		shmsegs[i].shm_perm.seq = 0;
+	}
+	shm_last_free = 0;
+	shm_nused = 0;
+	shm_committed = 0;
+}