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      1 /*	$NetBSD: shm.h,v 1.56 2024/05/12 10:34:56 rillig Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1999 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
      9  * NASA Ames Research Center.
     10  *
     11  * Redistribution and use in source and binary forms, with or without
     12  * modification, are permitted provided that the following conditions
     13  * are met:
     14  * 1. Redistributions of source code must retain the above copyright
     15  *    notice, this list of conditions and the following disclaimer.
     16  * 2. Redistributions in binary form must reproduce the above copyright
     17  *    notice, this list of conditions and the following disclaimer in the
     18  *    documentation and/or other materials provided with the distribution.
     19  *
     20  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     21  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     22  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     23  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     24  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     30  * POSSIBILITY OF SUCH DAMAGE.
     31  */
     32 
     33 /*
     34  * Copyright (c) 1994 Adam Glass
     35  * All rights reserved.
     36  *
     37  * Redistribution and use in source and binary forms, with or without
     38  * modification, are permitted provided that the following conditions
     39  * are met:
     40  * 1. Redistributions of source code must retain the above copyright
     41  *    notice, this list of conditions and the following disclaimer.
     42  * 2. Redistributions in binary form must reproduce the above copyright
     43  *    notice, this list of conditions and the following disclaimer in the
     44  *    documentation and/or other materials provided with the distribution.
     45  * 3. All advertising materials mentioning features or use of this software
     46  *    must display the following acknowledgement:
     47  *      This product includes software developed by Adam Glass.
     48  * 4. The name of the author may not be used to endorse or promote products
     49  *    derived from this software without specific prior written permission
     50  *
     51  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     52  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     53  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     54  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     55  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     56  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     57  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     58  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     59  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     60  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     61  */
     62 
     63 /*
     64  * As defined+described in "X/Open System Interfaces and Headers"
     65  *                         Issue 4, p. XXX
     66  */
     67 
     68 #ifndef _SYS_SHM_H_
     69 #define _SYS_SHM_H_
     70 
     71 #include <sys/cdefs.h>
     72 #include <sys/featuretest.h>
     73 
     74 #include <sys/ipc.h>
     75 
     76 #define	SHM_RDONLY	010000	/* Attach read-only (else read-write) */
     77 #define	SHM_RND		020000	/* Round attach address to SHMLBA */
     78 #ifdef _KERNEL
     79 #define _SHM_RMLINGER	040000	/* Attach even if segment removed */
     80 #endif
     81 
     82 /* Segment low boundary address multiple */
     83 #if defined(_KERNEL) || defined(_STANDALONE) || defined(_MODULE)
     84 #define	SHMLBA		PAGE_SIZE
     85 #else
     86 /*
     87  * SHMLBA uses libc's internal __sysconf() to retrieve the machine's
     88  * page size. The value of _SC_PAGESIZE is 28 -- we hard code it so we do not
     89  * need to include unistd.h
     90  */
     91 __BEGIN_DECLS
     92 long __sysconf(int);
     93 __END_DECLS
     94 #define	SHMLBA		(__sysconf(28))
     95 #endif
     96 
     97 typedef unsigned int	shmatt_t;
     98 
     99 struct shmid_ds {
    100 	struct ipc_perm	shm_perm;	/* operation permission structure */
    101 	size_t		shm_segsz;	/* size of segment in bytes */
    102 	pid_t		shm_lpid;	/* process ID of last shm operation */
    103 	pid_t		shm_cpid;	/* process ID of creator */
    104 	shmatt_t	shm_nattch;	/* number of current attaches */
    105 	time_t		shm_atime;	/* time of last shmat() */
    106 	time_t		shm_dtime;	/* time of last shmdt() */
    107 	time_t		shm_ctime;	/* time of last change by shmctl() */
    108 
    109 	/*
    110 	 * These members are private and used only in the internal
    111 	 * implementation of this interface.
    112 	 */
    113 	void		*_shm_internal;
    114 };
    115 
    116 #if defined(_NETBSD_SOURCE)
    117 /*
    118  * Some systems (e.g. HP-UX) take these as the second (cmd) arg to shmctl().
    119  */
    120 #define	SHM_LOCK	3	/* Lock segment in memory. */
    121 #define	SHM_UNLOCK	4	/* Unlock a segment locked by SHM_LOCK. */
    122 #endif /* _NETBSD_SOURCE */
    123 
    124 #if defined(_NETBSD_SOURCE)
    125 /*
    126  * Permission definitions used in shmflag arguments to shmat(2) and shmget(2).
    127  * Provided for source compatibility only; do not use in new code!
    128  */
    129 #define	SHM_R		IPC_R	/* S_IRUSR, R for owner */
    130 #define	SHM_W		IPC_W	/* S_IWUSR, W for owner */
    131 
    132 /*
    133  * System 5 style catch-all structure for shared memory constants that
    134  * might be of interest to user programs.  Do we really want/need this?
    135  */
    136 struct shminfo {
    137 	uint64_t	shmmax;	/* max shared memory segment size (bytes) */
    138 	uint32_t	shmmin;	/* min shared memory segment size (bytes) */
    139 	uint32_t	shmmni;	/* max number of shared memory identifiers */
    140 	uint32_t	shmseg;	/* max shared memory segments per process */
    141 	uint32_t	shmall;	/* max amount of shared memory (pages) */
    142 };
    143 
    144 /* Warning: 64-bit structure padding is needed here */
    145 struct shmid_ds_sysctl {
    146 	struct		ipc_perm_sysctl shm_perm;
    147 	uint64_t	shm_segsz;
    148 	pid_t		shm_lpid;
    149 	pid_t		shm_cpid;
    150 	time_t		shm_atime;
    151 	time_t		shm_dtime;
    152 	time_t		shm_ctime;
    153 	uint32_t	shm_nattch;
    154 };
    155 struct shm_sysctl_info {
    156 	struct	shminfo shminfo;
    157 	struct	shmid_ds_sysctl shmids[1];
    158 };
    159 #endif /* _NETBSD_SOURCE */
    160 
    161 #ifdef _KERNEL
    162 extern struct shminfo shminfo;
    163 extern struct shmid_ds *shmsegs;
    164 extern int shm_nused;
    165 
    166 #define	SHMSEG_FREE		0x0200
    167 #define	SHMSEG_REMOVED		0x0400
    168 #define	SHMSEG_ALLOCATED	0x0800
    169 #define	SHMSEG_WANTED		0x1000
    170 #define	SHMSEG_RMLINGER		0x2000
    171 #define	SHMSEG_WIRED		0x4000
    172 
    173 struct vmspace;
    174 
    175 int	shminit(void);
    176 int	shmfini(void);
    177 void	shmfork(struct vmspace *, struct vmspace *);
    178 void	shmexit(struct vmspace *);
    179 int	shmctl1(struct lwp *, int, int, struct shmid_ds *);
    180 
    181 int	shm_find_segment_perm_by_index(int, struct ipc_perm *);
    182 
    183 extern void (*uvm_shmexit)(struct vmspace *);
    184 extern void (*uvm_shmfork)(struct vmspace *, struct vmspace *);
    185 
    186 #define SYSCTL_FILL_SHM(src, dst) do { \
    187 	SYSCTL_FILL_PERM((src).shm_perm, (dst).shm_perm); \
    188 	(dst).shm_segsz = (src).shm_segsz; \
    189 	(dst).shm_lpid = (src).shm_lpid; \
    190 	(dst).shm_cpid = (src).shm_cpid; \
    191 	(dst).shm_atime = (src).shm_atime; \
    192 	(dst).shm_dtime = (src).shm_dtime; \
    193 	(dst).shm_ctime = (src).shm_ctime; \
    194 	(dst).shm_nattch = (src).shm_nattch; \
    195 } while (0)
    196 
    197 #else /* !_KERNEL */
    198 
    199 __BEGIN_DECLS
    200 void	*shmat(int, const void *, int);
    201 int	shmctl(int, int, struct shmid_ds *) __RENAME(__shmctl50);
    202 int	shmdt(const void *);
    203 int	shmget(key_t, size_t, int);
    204 __END_DECLS
    205 
    206 #endif /* !_KERNEL */
    207 
    208 #endif /* !_SYS_SHM_H_ */
    209