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sysv_shm.c revision 1.46
      1  1.46     perry /*	$NetBSD: sysv_shm.c,v 1.46 1998/08/04 04:03:16 perry Exp $	*/
      2  1.22       cgd 
      3  1.11   hpeyerl /*
      4  1.17   mycroft  * Copyright (c) 1994 Adam Glass and Charles Hannum.  All rights reserved.
      5  1.11   hpeyerl  *
      6  1.11   hpeyerl  * Redistribution and use in source and binary forms, with or without
      7  1.11   hpeyerl  * modification, are permitted provided that the following conditions
      8  1.11   hpeyerl  * are met:
      9  1.11   hpeyerl  * 1. Redistributions of source code must retain the above copyright
     10  1.11   hpeyerl  *    notice, this list of conditions and the following disclaimer.
     11  1.17   mycroft  * 2. Redistributions in binary form must reproduce the above copyright
     12  1.17   mycroft  *    notice, this list of conditions and the following disclaimer in the
     13  1.17   mycroft  *    documentation and/or other materials provided with the distribution.
     14  1.17   mycroft  * 3. All advertising materials mentioning features or use of this software
     15  1.17   mycroft  *    must display the following acknowledgement:
     16  1.17   mycroft  *	This product includes software developed by Adam Glass and Charles
     17  1.17   mycroft  *	Hannum.
     18  1.17   mycroft  * 4. The names of the authors may not be used to endorse or promote products
     19  1.11   hpeyerl  *    derived from this software without specific prior written permission.
     20  1.11   hpeyerl  *
     21  1.17   mycroft  * THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
     22  1.17   mycroft  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     23  1.17   mycroft  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     24  1.17   mycroft  * IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY DIRECT, INDIRECT,
     25  1.17   mycroft  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     26  1.17   mycroft  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     27  1.17   mycroft  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     28  1.17   mycroft  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     29  1.17   mycroft  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     30  1.17   mycroft  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     31  1.11   hpeyerl  */
     32  1.43       mrg 
     33  1.43       mrg #include "opt_uvm.h"
     34  1.11   hpeyerl 
     35  1.11   hpeyerl #include <sys/types.h>
     36  1.11   hpeyerl #include <sys/param.h>
     37  1.11   hpeyerl #include <sys/kernel.h>
     38  1.11   hpeyerl #include <sys/shm.h>
     39  1.11   hpeyerl #include <sys/proc.h>
     40  1.11   hpeyerl #include <sys/uio.h>
     41  1.11   hpeyerl #include <sys/time.h>
     42  1.11   hpeyerl #include <sys/malloc.h>
     43  1.11   hpeyerl #include <sys/mman.h>
     44  1.11   hpeyerl #include <sys/systm.h>
     45  1.12   mycroft #include <sys/stat.h>
     46  1.11   hpeyerl 
     47  1.26       cgd #include <sys/mount.h>
     48  1.26       cgd #include <sys/syscallargs.h>
     49  1.26       cgd 
     50  1.11   hpeyerl #include <vm/vm.h>
     51  1.42       mrg #ifdef UVM
     52  1.42       mrg #include <uvm/uvm_extern.h>
     53  1.42       mrg #else
     54  1.11   hpeyerl #include <vm/vm_map.h>
     55  1.11   hpeyerl #include <vm/vm_kern.h>
     56  1.42       mrg #endif
     57  1.35  christos 
     58  1.35  christos struct shmid_ds *shm_find_segment_by_shmid __P((int));
     59  1.35  christos 
     60  1.11   hpeyerl /*
     61  1.11   hpeyerl  * Provides the following externally accessible functions:
     62  1.11   hpeyerl  *
     63  1.41   thorpej  * shminit(void);		                 initialization
     64  1.41   thorpej  * shmexit(struct vmspace *)                     cleanup
     65  1.41   thorpej  * shmfork(struct vmspace *, struct vmspace *)   fork handling
     66  1.11   hpeyerl  * shmsys(arg1, arg2, arg3, arg4);         shm{at,ctl,dt,get}(arg2, arg3, arg4)
     67  1.11   hpeyerl  *
     68  1.11   hpeyerl  * Structures:
     69  1.11   hpeyerl  * shmsegs (an array of 'struct shmid_ds')
     70  1.11   hpeyerl  * per proc array of 'struct shmmap_state'
     71  1.11   hpeyerl  */
     72  1.12   mycroft 
     73  1.16   mycroft #define	SHMSEG_FREE     	0x0200
     74  1.16   mycroft #define	SHMSEG_REMOVED  	0x0400
     75  1.16   mycroft #define	SHMSEG_ALLOCATED	0x0800
     76  1.16   mycroft #define	SHMSEG_WANTED		0x1000
     77  1.11   hpeyerl 
     78  1.11   hpeyerl int shm_last_free, shm_nused, shm_committed;
     79  1.11   hpeyerl 
     80  1.11   hpeyerl struct shm_handle {
     81  1.42       mrg #ifdef UVM
     82  1.42       mrg 	struct uvm_object *shm_object;
     83  1.42       mrg #else
     84  1.39  drochner 	vm_object_t shm_object;
     85  1.42       mrg #endif
     86  1.11   hpeyerl };
     87  1.11   hpeyerl 
     88  1.11   hpeyerl struct shmmap_state {
     89  1.11   hpeyerl 	vm_offset_t va;
     90  1.11   hpeyerl 	int shmid;
     91  1.11   hpeyerl };
     92  1.11   hpeyerl 
     93  1.35  christos static int shm_find_segment_by_key __P((key_t));
     94  1.12   mycroft static void shm_deallocate_segment __P((struct shmid_ds *));
     95  1.41   thorpej static int shm_delete_mapping __P((struct vmspace *, struct shmmap_state *));
     96  1.35  christos static int shmget_existing __P((struct proc *, struct sys_shmget_args *,
     97  1.35  christos 				int, int, register_t *));
     98  1.35  christos static int shmget_allocate_segment __P((struct proc *, struct sys_shmget_args *,
     99  1.35  christos 					int, register_t *));
    100  1.11   hpeyerl 
    101  1.12   mycroft static int
    102  1.12   mycroft shm_find_segment_by_key(key)
    103  1.11   hpeyerl 	key_t key;
    104  1.11   hpeyerl {
    105  1.11   hpeyerl 	int i;
    106  1.11   hpeyerl 
    107  1.12   mycroft 	for (i = 0; i < shminfo.shmmni; i++)
    108  1.12   mycroft 		if ((shmsegs[i].shm_perm.mode & SHMSEG_ALLOCATED) &&
    109  1.12   mycroft 		    shmsegs[i].shm_perm.key == key)
    110  1.12   mycroft 			return i;
    111  1.11   hpeyerl 	return -1;
    112  1.11   hpeyerl }
    113  1.11   hpeyerl 
    114  1.28  christos struct shmid_ds *
    115  1.15   mycroft shm_find_segment_by_shmid(shmid)
    116  1.11   hpeyerl 	int shmid;
    117  1.11   hpeyerl {
    118  1.11   hpeyerl 	int segnum;
    119  1.11   hpeyerl 	struct shmid_ds *shmseg;
    120  1.11   hpeyerl 
    121  1.11   hpeyerl 	segnum = IPCID_TO_IX(shmid);
    122  1.12   mycroft 	if (segnum < 0 || segnum >= shminfo.shmmni)
    123  1.11   hpeyerl 		return NULL;
    124  1.11   hpeyerl 	shmseg = &shmsegs[segnum];
    125  1.12   mycroft 	if ((shmseg->shm_perm.mode & (SHMSEG_ALLOCATED | SHMSEG_REMOVED))
    126  1.12   mycroft 	    != SHMSEG_ALLOCATED ||
    127  1.12   mycroft 	    shmseg->shm_perm.seq != IPCID_TO_SEQ(shmid))
    128  1.11   hpeyerl 		return NULL;
    129  1.11   hpeyerl 	return shmseg;
    130  1.11   hpeyerl }
    131  1.11   hpeyerl 
    132  1.12   mycroft static void
    133  1.12   mycroft shm_deallocate_segment(shmseg)
    134  1.12   mycroft 	struct shmid_ds *shmseg;
    135  1.12   mycroft {
    136  1.12   mycroft 	struct shm_handle *shm_handle;
    137  1.14   mycroft 	size_t size;
    138  1.12   mycroft 
    139  1.12   mycroft 	shm_handle = shmseg->shm_internal;
    140  1.14   mycroft 	size = (shmseg->shm_segsz + CLOFSET) & ~CLOFSET;
    141  1.42       mrg #ifdef UVM
    142  1.42       mrg 	uao_detach(shm_handle->shm_object);
    143  1.42       mrg #else
    144  1.39  drochner 	vm_object_deallocate(shm_handle->shm_object);
    145  1.42       mrg #endif
    146  1.12   mycroft 	free((caddr_t)shm_handle, M_SHM);
    147  1.12   mycroft 	shmseg->shm_internal = NULL;
    148  1.14   mycroft 	shm_committed -= btoc(size);
    149  1.12   mycroft 	shmseg->shm_perm.mode = SHMSEG_FREE;
    150  1.25   mycroft 	shm_nused--;
    151  1.12   mycroft }
    152  1.12   mycroft 
    153  1.12   mycroft static int
    154  1.41   thorpej shm_delete_mapping(vm, shmmap_s)
    155  1.41   thorpej 	struct vmspace *vm;
    156  1.11   hpeyerl 	struct shmmap_state *shmmap_s;
    157  1.11   hpeyerl {
    158  1.12   mycroft 	struct shmid_ds *shmseg;
    159  1.12   mycroft 	int segnum, result;
    160  1.14   mycroft 	size_t size;
    161  1.11   hpeyerl 
    162  1.12   mycroft 	segnum = IPCID_TO_IX(shmmap_s->shmid);
    163  1.12   mycroft 	shmseg = &shmsegs[segnum];
    164  1.14   mycroft 	size = (shmseg->shm_segsz + CLOFSET) & ~CLOFSET;
    165  1.42       mrg #ifdef UVM
    166  1.45   thorpej 	result = uvm_deallocate(&vm->vm_map, shmmap_s->va, size);
    167  1.42       mrg #else
    168  1.41   thorpej 	result = vm_map_remove(&vm->vm_map,
    169  1.40  drochner 			       shmmap_s->va, shmmap_s->va + size);
    170  1.42       mrg #endif
    171  1.11   hpeyerl 	if (result != KERN_SUCCESS)
    172  1.11   hpeyerl 		return EINVAL;
    173  1.12   mycroft 	shmmap_s->shmid = -1;
    174  1.11   hpeyerl 	shmseg->shm_dtime = time.tv_sec;
    175  1.12   mycroft 	if ((--shmseg->shm_nattch <= 0) &&
    176  1.11   hpeyerl 	    (shmseg->shm_perm.mode & SHMSEG_REMOVED)) {
    177  1.12   mycroft 		shm_deallocate_segment(shmseg);
    178  1.12   mycroft 		shm_last_free = segnum;
    179  1.11   hpeyerl 	}
    180  1.11   hpeyerl 	return 0;
    181  1.11   hpeyerl }
    182  1.11   hpeyerl 
    183  1.12   mycroft int
    184  1.33   mycroft sys_shmdt(p, v, retval)
    185  1.11   hpeyerl 	struct proc *p;
    186  1.32   thorpej 	void *v;
    187  1.32   thorpej 	register_t *retval;
    188  1.32   thorpej {
    189  1.33   mycroft 	struct sys_shmdt_args /* {
    190  1.44    kleink 		syscallarg(const void *) shmaddr;
    191  1.32   thorpej 	} */ *uap = v;
    192  1.12   mycroft 	struct shmmap_state *shmmap_s;
    193  1.11   hpeyerl 	int i;
    194  1.11   hpeyerl 
    195  1.12   mycroft 	shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
    196  1.38  christos 	if (shmmap_s == NULL)
    197  1.38  christos 		return EINVAL;
    198  1.38  christos 
    199  1.12   mycroft 	for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
    200  1.12   mycroft 		if (shmmap_s->shmid != -1 &&
    201  1.26       cgd 		    shmmap_s->va == (vm_offset_t)SCARG(uap, shmaddr))
    202  1.12   mycroft 			break;
    203  1.11   hpeyerl 	if (i == shminfo.shmseg)
    204  1.11   hpeyerl 		return EINVAL;
    205  1.41   thorpej 	return shm_delete_mapping(p->p_vmspace, shmmap_s);
    206  1.11   hpeyerl }
    207  1.11   hpeyerl 
    208  1.12   mycroft int
    209  1.33   mycroft sys_shmat(p, v, retval)
    210  1.11   hpeyerl 	struct proc *p;
    211  1.32   thorpej 	void *v;
    212  1.32   thorpej 	register_t *retval;
    213  1.32   thorpej {
    214  1.33   mycroft 	struct sys_shmat_args /* {
    215  1.26       cgd 		syscallarg(int) shmid;
    216  1.44    kleink 		syscallarg(const void *) shmaddr;
    217  1.35  christos 		syscallarg(int) shmflg;
    218  1.32   thorpej 	} */ *uap = v;
    219  1.12   mycroft 	int error, i, flags;
    220  1.12   mycroft 	struct ucred *cred = p->p_ucred;
    221  1.11   hpeyerl 	struct shmid_ds *shmseg;
    222  1.11   hpeyerl 	struct shmmap_state *shmmap_s = NULL;
    223  1.39  drochner 	struct shm_handle *shm_handle;
    224  1.11   hpeyerl 	vm_offset_t attach_va;
    225  1.11   hpeyerl 	vm_prot_t prot;
    226  1.11   hpeyerl 	vm_size_t size;
    227  1.39  drochner 	int rv;
    228  1.11   hpeyerl 
    229  1.12   mycroft 	shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm;
    230  1.12   mycroft 	if (shmmap_s == NULL) {
    231  1.12   mycroft 		size = shminfo.shmseg * sizeof(struct shmmap_state);
    232  1.12   mycroft 		shmmap_s = malloc(size, M_SHM, M_WAITOK);
    233  1.18       cgd 		for (i = 0; i < shminfo.shmseg; i++)
    234  1.18       cgd 			shmmap_s[i].shmid = -1;
    235  1.12   mycroft 		p->p_vmspace->vm_shm = (caddr_t)shmmap_s;
    236  1.12   mycroft 	}
    237  1.26       cgd 	shmseg = shm_find_segment_by_shmid(SCARG(uap, shmid));
    238  1.11   hpeyerl 	if (shmseg == NULL)
    239  1.11   hpeyerl 		return EINVAL;
    240  1.35  christos 	error = ipcperm(cred, &shmseg->shm_perm,
    241  1.35  christos 		    (SCARG(uap, shmflg) & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
    242  1.35  christos 	if (error)
    243  1.12   mycroft 		return error;
    244  1.12   mycroft 	for (i = 0; i < shminfo.shmseg; i++) {
    245  1.12   mycroft 		if (shmmap_s->shmid == -1)
    246  1.12   mycroft 			break;
    247  1.12   mycroft 		shmmap_s++;
    248  1.11   hpeyerl 	}
    249  1.12   mycroft 	if (i >= shminfo.shmseg)
    250  1.12   mycroft 		return EMFILE;
    251  1.14   mycroft 	size = (shmseg->shm_segsz + CLOFSET) & ~CLOFSET;
    252  1.12   mycroft 	prot = VM_PROT_READ;
    253  1.26       cgd 	if ((SCARG(uap, shmflg) & SHM_RDONLY) == 0)
    254  1.12   mycroft 		prot |= VM_PROT_WRITE;
    255  1.12   mycroft 	flags = MAP_ANON | MAP_SHARED;
    256  1.26       cgd 	if (SCARG(uap, shmaddr)) {
    257  1.12   mycroft 		flags |= MAP_FIXED;
    258  1.26       cgd 		if (SCARG(uap, shmflg) & SHM_RND)
    259  1.26       cgd 			attach_va =
    260  1.26       cgd 			    (vm_offset_t)SCARG(uap, shmaddr) & ~(SHMLBA-1);
    261  1.26       cgd 		else if (((vm_offset_t)SCARG(uap, shmaddr) & (SHMLBA-1)) == 0)
    262  1.26       cgd 			attach_va = (vm_offset_t)SCARG(uap, shmaddr);
    263  1.11   hpeyerl 		else
    264  1.14   mycroft 			return EINVAL;
    265  1.12   mycroft 	} else {
    266  1.20   mycroft 		/* This is just a hint to vm_mmap() about where to put it. */
    267  1.31       cgd 		attach_va =
    268  1.31       cgd 		    round_page(p->p_vmspace->vm_taddr + MAXTSIZ + MAXDSIZ);
    269  1.11   hpeyerl 	}
    270  1.39  drochner 	shm_handle = shmseg->shm_internal;
    271  1.42       mrg #ifdef UVM
    272  1.42       mrg 	uao_reference(shm_handle->shm_object);
    273  1.42       mrg 	rv = uvm_map(&p->p_vmspace->vm_map, &attach_va, size,
    274  1.42       mrg 		     shm_handle->shm_object, 0,
    275  1.42       mrg 		     UVM_MAPFLAG(prot, prot, UVM_INH_SHARE,
    276  1.42       mrg 				 UVM_ADV_RANDOM, 0));
    277  1.42       mrg 	if (rv != KERN_SUCCESS) {
    278  1.42       mrg 	    return ENOMEM;
    279  1.42       mrg 	}
    280  1.42       mrg #else
    281  1.39  drochner 	vm_object_reference(shm_handle->shm_object);
    282  1.39  drochner 	rv = vm_map_find(&p->p_vmspace->vm_map, shm_handle->shm_object,
    283  1.39  drochner 		0, &attach_va, size, (flags & MAP_FIXED)?0:1);
    284  1.39  drochner 	if (rv != KERN_SUCCESS) {
    285  1.39  drochner 		return ENOMEM;
    286  1.39  drochner 	}
    287  1.39  drochner 	vm_map_protect(&p->p_vmspace->vm_map, attach_va, attach_va + size,
    288  1.39  drochner 		       prot, 0);
    289  1.39  drochner 	vm_map_inherit(&p->p_vmspace->vm_map,
    290  1.39  drochner 		attach_va, attach_va + size, VM_INHERIT_SHARE);
    291  1.42       mrg #endif
    292  1.39  drochner 
    293  1.12   mycroft 	shmmap_s->va = attach_va;
    294  1.26       cgd 	shmmap_s->shmid = SCARG(uap, shmid);
    295  1.11   hpeyerl 	shmseg->shm_lpid = p->p_pid;
    296  1.11   hpeyerl 	shmseg->shm_atime = time.tv_sec;
    297  1.11   hpeyerl 	shmseg->shm_nattch++;
    298  1.12   mycroft 	*retval = attach_va;
    299  1.11   hpeyerl 	return 0;
    300  1.11   hpeyerl }
    301  1.11   hpeyerl 
    302  1.12   mycroft int
    303  1.33   mycroft sys_shmctl(p, v, retval)
    304  1.11   hpeyerl 	struct proc *p;
    305  1.32   thorpej 	void *v;
    306  1.32   thorpej 	register_t *retval;
    307  1.32   thorpej {
    308  1.33   mycroft 	struct sys_shmctl_args /* {
    309  1.26       cgd 		syscallarg(int) shmid;
    310  1.26       cgd 		syscallarg(int) cmd;
    311  1.26       cgd 		syscallarg(struct shmid_ds *) buf;
    312  1.32   thorpej 	} */ *uap = v;
    313  1.35  christos 	int error;
    314  1.12   mycroft 	struct ucred *cred = p->p_ucred;
    315  1.11   hpeyerl 	struct shmid_ds inbuf;
    316  1.11   hpeyerl 	struct shmid_ds *shmseg;
    317  1.11   hpeyerl 
    318  1.26       cgd 	shmseg = shm_find_segment_by_shmid(SCARG(uap, shmid));
    319  1.11   hpeyerl 	if (shmseg == NULL)
    320  1.11   hpeyerl 		return EINVAL;
    321  1.26       cgd 	switch (SCARG(uap, cmd)) {
    322  1.11   hpeyerl 	case IPC_STAT:
    323  1.35  christos 		if ((error = ipcperm(cred, &shmseg->shm_perm, IPC_R)) != 0)
    324  1.11   hpeyerl 			return error;
    325  1.35  christos 		error = copyout((caddr_t)shmseg, SCARG(uap, buf),
    326  1.35  christos 				sizeof(inbuf));
    327  1.35  christos 		if (error)
    328  1.11   hpeyerl 			return error;
    329  1.11   hpeyerl 		break;
    330  1.11   hpeyerl 	case IPC_SET:
    331  1.35  christos 		if ((error = ipcperm(cred, &shmseg->shm_perm, IPC_M)) != 0)
    332  1.13   mycroft 			return error;
    333  1.35  christos 		error = copyin(SCARG(uap, buf), (caddr_t)&inbuf,
    334  1.35  christos 			       sizeof(inbuf));
    335  1.35  christos 		if (error)
    336  1.11   hpeyerl 			return error;
    337  1.11   hpeyerl 		shmseg->shm_perm.uid = inbuf.shm_perm.uid;
    338  1.11   hpeyerl 		shmseg->shm_perm.gid = inbuf.shm_perm.gid;
    339  1.12   mycroft 		shmseg->shm_perm.mode =
    340  1.12   mycroft 		    (shmseg->shm_perm.mode & ~ACCESSPERMS) |
    341  1.12   mycroft 		    (inbuf.shm_perm.mode & ACCESSPERMS);
    342  1.12   mycroft 		shmseg->shm_ctime = time.tv_sec;
    343  1.11   hpeyerl 		break;
    344  1.11   hpeyerl 	case IPC_RMID:
    345  1.35  christos 		if ((error = ipcperm(cred, &shmseg->shm_perm, IPC_M)) != 0)
    346  1.13   mycroft 			return error;
    347  1.12   mycroft 		shmseg->shm_perm.key = IPC_PRIVATE;
    348  1.12   mycroft 		shmseg->shm_perm.mode |= SHMSEG_REMOVED;
    349  1.12   mycroft 		if (shmseg->shm_nattch <= 0) {
    350  1.12   mycroft 			shm_deallocate_segment(shmseg);
    351  1.26       cgd 			shm_last_free = IPCID_TO_IX(SCARG(uap, shmid));
    352  1.11   hpeyerl 		}
    353  1.11   hpeyerl 		break;
    354  1.11   hpeyerl 	case SHM_LOCK:
    355  1.11   hpeyerl 	case SHM_UNLOCK:
    356  1.11   hpeyerl 	default:
    357  1.11   hpeyerl 		return EINVAL;
    358  1.11   hpeyerl 	}
    359  1.11   hpeyerl 	return 0;
    360  1.11   hpeyerl }
    361  1.11   hpeyerl 
    362  1.12   mycroft static int
    363  1.12   mycroft shmget_existing(p, uap, mode, segnum, retval)
    364  1.11   hpeyerl 	struct proc *p;
    365  1.33   mycroft 	struct sys_shmget_args /* {
    366  1.26       cgd 		syscallarg(key_t) key;
    367  1.44    kleink 		syscallarg(size_t) size;
    368  1.35  christos 		syscallarg(int) shmflg;
    369  1.26       cgd 	} */ *uap;
    370  1.11   hpeyerl 	int mode;
    371  1.11   hpeyerl 	int segnum;
    372  1.26       cgd 	register_t *retval;
    373  1.11   hpeyerl {
    374  1.12   mycroft 	struct shmid_ds *shmseg;
    375  1.12   mycroft 	struct ucred *cred = p->p_ucred;
    376  1.11   hpeyerl 	int error;
    377  1.11   hpeyerl 
    378  1.11   hpeyerl 	shmseg = &shmsegs[segnum];
    379  1.16   mycroft 	if (shmseg->shm_perm.mode & SHMSEG_REMOVED) {
    380  1.16   mycroft 		/*
    381  1.16   mycroft 		 * This segment is in the process of being allocated.  Wait
    382  1.16   mycroft 		 * until it's done, and look the key up again (in case the
    383  1.16   mycroft 		 * allocation failed or it was freed).
    384  1.16   mycroft 		 */
    385  1.16   mycroft 		shmseg->shm_perm.mode |= SHMSEG_WANTED;
    386  1.35  christos 		error = tsleep((caddr_t)shmseg, PLOCK | PCATCH, "shmget", 0);
    387  1.35  christos 		if (error)
    388  1.16   mycroft 			return error;
    389  1.16   mycroft 		return EAGAIN;
    390  1.16   mycroft 	}
    391  1.35  christos 	if ((error = ipcperm(cred, &shmseg->shm_perm, mode)) != 0)
    392  1.11   hpeyerl 		return error;
    393  1.26       cgd 	if (SCARG(uap, size) && SCARG(uap, size) > shmseg->shm_segsz)
    394  1.11   hpeyerl 		return EINVAL;
    395  1.37  christos 	if ((SCARG(uap, shmflg) & (IPC_CREAT | IPC_EXCL)) ==
    396  1.26       cgd 	    (IPC_CREAT | IPC_EXCL))
    397  1.12   mycroft 		return EEXIST;
    398  1.11   hpeyerl 	*retval = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
    399  1.11   hpeyerl 	return 0;
    400  1.11   hpeyerl }
    401  1.11   hpeyerl 
    402  1.14   mycroft static int
    403  1.14   mycroft shmget_allocate_segment(p, uap, mode, retval)
    404  1.14   mycroft 	struct proc *p;
    405  1.33   mycroft 	struct sys_shmget_args /* {
    406  1.26       cgd 		syscallarg(key_t) key;
    407  1.44    kleink 		syscallarg(size_t) size;
    408  1.35  christos 		syscallarg(int) shmflg;
    409  1.26       cgd 	} */ *uap;
    410  1.14   mycroft 	int mode;
    411  1.26       cgd 	register_t *retval;
    412  1.14   mycroft {
    413  1.39  drochner 	int i, segnum, shmid, size;
    414  1.14   mycroft 	struct ucred *cred = p->p_ucred;
    415  1.14   mycroft 	struct shmid_ds *shmseg;
    416  1.14   mycroft 	struct shm_handle *shm_handle;
    417  1.42       mrg #ifndef UVM
    418  1.39  drochner 	vm_pager_t pager;
    419  1.42       mrg #endif
    420  1.40  drochner 	int error = 0;
    421  1.14   mycroft 
    422  1.26       cgd 	if (SCARG(uap, size) < shminfo.shmmin ||
    423  1.26       cgd 	    SCARG(uap, size) > shminfo.shmmax)
    424  1.14   mycroft 		return EINVAL;
    425  1.14   mycroft 	if (shm_nused >= shminfo.shmmni) /* any shmids left? */
    426  1.14   mycroft 		return ENOSPC;
    427  1.26       cgd 	size = (SCARG(uap, size) + CLOFSET) & ~CLOFSET;
    428  1.14   mycroft 	if (shm_committed + btoc(size) > shminfo.shmall)
    429  1.14   mycroft 		return ENOMEM;
    430  1.14   mycroft 	if (shm_last_free < 0) {
    431  1.14   mycroft 		for (i = 0; i < shminfo.shmmni; i++)
    432  1.14   mycroft 			if (shmsegs[i].shm_perm.mode & SHMSEG_FREE)
    433  1.14   mycroft 				break;
    434  1.14   mycroft 		if (i == shminfo.shmmni)
    435  1.14   mycroft 			panic("shmseg free count inconsistent");
    436  1.14   mycroft 		segnum = i;
    437  1.14   mycroft 	} else  {
    438  1.14   mycroft 		segnum = shm_last_free;
    439  1.14   mycroft 		shm_last_free = -1;
    440  1.14   mycroft 	}
    441  1.14   mycroft 	shmseg = &shmsegs[segnum];
    442  1.14   mycroft 	/*
    443  1.14   mycroft 	 * In case we sleep in malloc(), mark the segment present but deleted
    444  1.14   mycroft 	 * so that noone else tries to create the same key.
    445  1.14   mycroft 	 */
    446  1.14   mycroft 	shmseg->shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED;
    447  1.26       cgd 	shmseg->shm_perm.key = SCARG(uap, key);
    448  1.14   mycroft 	shmseg->shm_perm.seq = (shmseg->shm_perm.seq + 1) & 0x7fff;
    449  1.14   mycroft 	shm_handle = (struct shm_handle *)
    450  1.14   mycroft 	    malloc(sizeof(struct shm_handle), M_SHM, M_WAITOK);
    451  1.14   mycroft 	shmid = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm);
    452  1.39  drochner 
    453  1.42       mrg 
    454  1.42       mrg #ifdef UVM
    455  1.42       mrg 	shm_handle->shm_object = uao_create(size, 0);
    456  1.42       mrg #else
    457  1.39  drochner 	shm_handle->shm_object = vm_object_allocate(size);
    458  1.39  drochner 	if (shm_handle->shm_object == NULL) {
    459  1.40  drochner 		/* XXX cannot happen */
    460  1.40  drochner 		error = ENOMEM;
    461  1.40  drochner 		goto out;
    462  1.39  drochner 	}
    463  1.39  drochner 	/*
    464  1.39  drochner 	 * We make sure that we have allocated a pager before we need
    465  1.39  drochner 	 * to.
    466  1.39  drochner 	 */
    467  1.39  drochner 	pager = vm_pager_allocate(PG_DFLT, 0, size, VM_PROT_DEFAULT, 0);
    468  1.39  drochner 	if (pager == NULL) {
    469  1.40  drochner 		error = ENOMEM;
    470  1.40  drochner 		goto out;
    471  1.14   mycroft 	}
    472  1.39  drochner 	vm_object_setpager(shm_handle->shm_object, pager, 0, 0);
    473  1.42       mrg #endif
    474  1.42       mrg 
    475  1.14   mycroft 	shmseg->shm_internal = shm_handle;
    476  1.14   mycroft 	shmseg->shm_perm.cuid = shmseg->shm_perm.uid = cred->cr_uid;
    477  1.14   mycroft 	shmseg->shm_perm.cgid = shmseg->shm_perm.gid = cred->cr_gid;
    478  1.16   mycroft 	shmseg->shm_perm.mode = (shmseg->shm_perm.mode & SHMSEG_WANTED) |
    479  1.16   mycroft 	    (mode & ACCESSPERMS) | SHMSEG_ALLOCATED;
    480  1.26       cgd 	shmseg->shm_segsz = SCARG(uap, size);
    481  1.14   mycroft 	shmseg->shm_cpid = p->p_pid;
    482  1.14   mycroft 	shmseg->shm_lpid = shmseg->shm_nattch = 0;
    483  1.14   mycroft 	shmseg->shm_atime = shmseg->shm_dtime = 0;
    484  1.14   mycroft 	shmseg->shm_ctime = time.tv_sec;
    485  1.14   mycroft 	shm_committed += btoc(size);
    486  1.14   mycroft 	shm_nused++;
    487  1.40  drochner 
    488  1.42       mrg #ifndef UVM
    489  1.40  drochner out:
    490  1.40  drochner 	if (error) {
    491  1.40  drochner 		if (shm_handle->shm_object != NULL)
    492  1.40  drochner 			vm_object_deallocate(shm_handle->shm_object);
    493  1.40  drochner 		free(shm_handle, M_SHM);
    494  1.40  drochner 		shmseg->shm_perm.mode = (shmseg->shm_perm.mode & SHMSEG_WANTED)
    495  1.40  drochner 		    | SHMSEG_FREE;
    496  1.40  drochner 	} else
    497  1.42       mrg #endif
    498  1.40  drochner 		*retval = shmid;
    499  1.16   mycroft 	if (shmseg->shm_perm.mode & SHMSEG_WANTED) {
    500  1.16   mycroft 		/*
    501  1.16   mycroft 		 * Somebody else wanted this key while we were asleep.  Wake
    502  1.16   mycroft 		 * them up now.
    503  1.16   mycroft 		 */
    504  1.16   mycroft 		shmseg->shm_perm.mode &= ~SHMSEG_WANTED;
    505  1.16   mycroft 		wakeup((caddr_t)shmseg);
    506  1.16   mycroft 	}
    507  1.40  drochner 	return error;
    508  1.14   mycroft }
    509  1.14   mycroft 
    510  1.12   mycroft int
    511  1.33   mycroft sys_shmget(p, v, retval)
    512  1.11   hpeyerl 	struct proc *p;
    513  1.32   thorpej 	void *v;
    514  1.32   thorpej 	register_t *retval;
    515  1.32   thorpej {
    516  1.33   mycroft 	struct sys_shmget_args /* {
    517  1.26       cgd 		syscallarg(key_t) key;
    518  1.26       cgd 		syscallarg(int) size;
    519  1.35  christos 		syscallarg(int) shmflg;
    520  1.32   thorpej 	} */ *uap = v;
    521  1.11   hpeyerl 	int segnum, mode, error;
    522  1.11   hpeyerl 
    523  1.26       cgd 	mode = SCARG(uap, shmflg) & ACCESSPERMS;
    524  1.26       cgd 	if (SCARG(uap, key) != IPC_PRIVATE) {
    525  1.16   mycroft 	again:
    526  1.26       cgd 		segnum = shm_find_segment_by_key(SCARG(uap, key));
    527  1.16   mycroft 		if (segnum >= 0) {
    528  1.16   mycroft 			error = shmget_existing(p, uap, mode, segnum, retval);
    529  1.16   mycroft 			if (error == EAGAIN)
    530  1.16   mycroft 				goto again;
    531  1.16   mycroft 			return error;
    532  1.16   mycroft 		}
    533  1.26       cgd 		if ((SCARG(uap, shmflg) & IPC_CREAT) == 0)
    534  1.14   mycroft 			return ENOENT;
    535  1.11   hpeyerl 	}
    536  1.14   mycroft 	return shmget_allocate_segment(p, uap, mode, retval);
    537  1.11   hpeyerl }
    538  1.11   hpeyerl 
    539  1.12   mycroft void
    540  1.41   thorpej shmfork(vm1, vm2)
    541  1.41   thorpej 	struct vmspace *vm1, *vm2;
    542  1.11   hpeyerl {
    543  1.11   hpeyerl 	struct shmmap_state *shmmap_s;
    544  1.12   mycroft 	size_t size;
    545  1.11   hpeyerl 	int i;
    546  1.11   hpeyerl 
    547  1.41   thorpej 	if (vm1->vm_shm == NULL) {
    548  1.41   thorpej 		vm2->vm_shm = NULL;
    549  1.38  christos 		return;
    550  1.38  christos 	}
    551  1.41   thorpej 
    552  1.12   mycroft 	size = shminfo.shmseg * sizeof(struct shmmap_state);
    553  1.12   mycroft 	shmmap_s = malloc(size, M_SHM, M_WAITOK);
    554  1.46     perry 	memcpy(shmmap_s, vm1->vm_shm, size);
    555  1.41   thorpej 	vm2->vm_shm = (caddr_t)shmmap_s;
    556  1.12   mycroft 	for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
    557  1.12   mycroft 		if (shmmap_s->shmid != -1)
    558  1.11   hpeyerl 			shmsegs[IPCID_TO_IX(shmmap_s->shmid)].shm_nattch++;
    559  1.11   hpeyerl }
    560  1.11   hpeyerl 
    561  1.12   mycroft void
    562  1.41   thorpej shmexit(vm)
    563  1.41   thorpej 	struct vmspace *vm;
    564  1.11   hpeyerl {
    565  1.12   mycroft 	struct shmmap_state *shmmap_s;
    566  1.11   hpeyerl 	int i;
    567  1.11   hpeyerl 
    568  1.41   thorpej 	shmmap_s = (struct shmmap_state *)vm->vm_shm;
    569  1.38  christos 	if (shmmap_s == NULL)
    570  1.38  christos 		return;
    571  1.12   mycroft 	for (i = 0; i < shminfo.shmseg; i++, shmmap_s++)
    572  1.12   mycroft 		if (shmmap_s->shmid != -1)
    573  1.41   thorpej 			shm_delete_mapping(vm, shmmap_s);
    574  1.41   thorpej 	free(vm->vm_shm, M_SHM);
    575  1.41   thorpej 	vm->vm_shm = NULL;
    576  1.11   hpeyerl }
    577  1.11   hpeyerl 
    578  1.12   mycroft void
    579  1.12   mycroft shminit()
    580  1.11   hpeyerl {
    581  1.11   hpeyerl 	int i;
    582  1.24   deraadt 
    583  1.24   deraadt 	shminfo.shmmax *= NBPG;
    584  1.11   hpeyerl 
    585  1.11   hpeyerl 	for (i = 0; i < shminfo.shmmni; i++) {
    586  1.11   hpeyerl 		shmsegs[i].shm_perm.mode = SHMSEG_FREE;
    587  1.11   hpeyerl 		shmsegs[i].shm_perm.seq = 0;
    588  1.11   hpeyerl 	}
    589  1.11   hpeyerl 	shm_last_free = 0;
    590  1.11   hpeyerl 	shm_nused = 0;
    591  1.11   hpeyerl 	shm_committed = 0;
    592  1.11   hpeyerl }
    593