diff options
Diffstat (limited to 'sys/kern/sysv_shm.c')
| -rw-r--r-- | sys/kern/sysv_shm.c | 890 |
1 files changed, 890 insertions, 0 deletions
diff --git a/sys/kern/sysv_shm.c b/sys/kern/sysv_shm.c new file mode 100644 index 0000000..85356a0 --- /dev/null +++ b/sys/kern/sysv_shm.c @@ -0,0 +1,890 @@ +/* $FreeBSD$ */ +/* $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_sysvipc.h" + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/kernel.h> +#include <sys/lock.h> +#include <sys/sysctl.h> +#include <sys/shm.h> +#include <sys/proc.h> +#include <sys/malloc.h> +#include <sys/mman.h> +#include <sys/mutex.h> +#include <sys/stat.h> +#include <sys/syscall.h> +#include <sys/sysent.h> +#include <sys/sysproto.h> +#include <sys/jail.h> + +#include <vm/vm.h> +#include <vm/vm_param.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> + +static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments"); + +struct oshmctl_args; +static int oshmctl(struct thread *td, struct oshmctl_args *uap); + +static int shmget_allocate_segment(struct thread *td, + struct shmget_args *uap, int mode); +static int shmget_existing(struct thread *td, 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, shmalloced; +static 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(struct shmid_ds *); +static int shm_find_segment_by_key(key_t); +static struct shmid_ds *shm_find_segment_by_shmid(int); +static struct shmid_ds *shm_find_segment_by_shmidx(int); +static int shm_delete_mapping(struct proc *p, struct shmmap_state *); +static void shmrealloc(void); +static void shminit(void); +static int sysvshm_modload(struct module *, int, void *); +static int shmunload(void); +static void shmexit_myhook(struct proc *p); +static void shmfork_myhook(struct proc *p1, struct proc *p2); +static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS); + +/* + * Tuneable values. + */ +#ifndef SHMMAXPGS +#define SHMMAXPGS 8192 /* Note: sysv shared memory is swap backed. */ +#endif +#ifndef SHMMAX +#define SHMMAX (SHMMAXPGS*PAGE_SIZE) +#endif +#ifndef SHMMIN +#define SHMMIN 1 +#endif +#ifndef SHMMNI +#define SHMMNI 192 +#endif +#ifndef SHMSEG +#define SHMSEG 128 +#endif +#ifndef SHMALL +#define SHMALL (SHMMAXPGS) +#endif + +struct shminfo shminfo = { + SHMMAX, + SHMMIN, + SHMMNI, + SHMSEG, + SHMALL +}; + +static int shm_use_phys; + +SYSCTL_DECL(_kern_ipc); +SYSCTL_INT(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RW, &shminfo.shmmax, 0, ""); +SYSCTL_INT(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RW, &shminfo.shmmin, 0, ""); +SYSCTL_INT(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RD, &shminfo.shmmni, 0, ""); +SYSCTL_INT(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RD, &shminfo.shmseg, 0, ""); +SYSCTL_INT(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RW, &shminfo.shmall, 0, ""); +SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RW, + &shm_use_phys, 0, ""); +SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLFLAG_RD, + NULL, 0, sysctl_shmsegs, "", ""); + +static int +shm_find_segment_by_key(key) + key_t key; +{ + int i; + + for (i = 0; i < shmalloced; 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 >= shmalloced) + 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 struct shmid_ds * +shm_find_segment_by_shmidx(int segnum) +{ + struct shmid_ds *shmseg; + + if (segnum < 0 || segnum >= shmalloced) + return NULL; + shmseg = &shmsegs[segnum]; + if ((shmseg->shm_perm.mode & (SHMSEG_ALLOCATED | SHMSEG_REMOVED)) + != SHMSEG_ALLOCATED ) + return NULL; + return shmseg; +} + +static void +shm_deallocate_segment(shmseg) + struct shmid_ds *shmseg; +{ + struct shm_handle *shm_handle; + size_t size; + + GIANT_REQUIRED; + + 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; + + GIANT_REQUIRED; + + 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 + +/* + * MPSAFE + */ +int +shmdt(td, uap) + struct thread *td; + struct shmdt_args *uap; +{ + struct proc *p = td->td_proc; + struct shmmap_state *shmmap_s; + int i; + int error = 0; + + if (!jail_sysvipc_allowed && jailed(td->td_ucred)) + return (ENOSYS); + mtx_lock(&Giant); + shmmap_s = (struct shmmap_state *)p->p_vmspace->vm_shm; + if (shmmap_s == NULL) { + error = EINVAL; + goto done2; + } + 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) { + error = EINVAL; + goto done2; + } + error = shm_delete_mapping(p, shmmap_s); +done2: + mtx_unlock(&Giant); + return (error); +} + +#ifndef _SYS_SYSPROTO_H_ +struct shmat_args { + int shmid; + void *shmaddr; + int shmflg; +}; +#endif + +/* + * MPSAFE + */ +int +shmat(td, uap) + struct thread *td; + struct shmat_args *uap; +{ + struct proc *p = td->td_proc; + int i, flags; + 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; + int error = 0; + + if (!jail_sysvipc_allowed && jailed(td->td_ucred)) + return (ENOSYS); + mtx_lock(&Giant); + 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) { + error = EINVAL; + goto done2; + } + error = ipcperm(td, &shmseg->shm_perm, + (uap->shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W); + if (error) + goto done2; + for (i = 0; i < shminfo.shmseg; i++) { + if (shmmap_s->shmid == -1) + break; + shmmap_s++; + } + if (i >= shminfo.shmseg) { + error = EMFILE; + goto done2; + } + size = round_page(shmseg->shm_segsz); +#ifdef VM_PROT_READ_IS_EXEC + prot = VM_PROT_READ | VM_PROT_EXECUTE; +#else + prot = VM_PROT_READ; +#endif + 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 { + error = EINVAL; + goto done2; + } + } 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) { + error = ENOMEM; + goto done2; + } + 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++; + td->td_retval[0] = attach_va; +done2: + mtx_unlock(&Giant); + return (error); +} + +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; +}; + +/* + * MPSAFE + */ +static int +oshmctl(td, uap) + struct thread *td; + struct oshmctl_args *uap; +{ +#ifdef COMPAT_43 + int error = 0; + struct shmid_ds *shmseg; + struct oshmid_ds outbuf; + + if (!jail_sysvipc_allowed && jailed(td->td_ucred)) + return (ENOSYS); + mtx_lock(&Giant); + shmseg = shm_find_segment_by_shmid(uap->shmid); + if (shmseg == NULL) { + error = EINVAL; + goto done2; + } + switch (uap->cmd) { + case IPC_STAT: + error = ipcperm(td, &shmseg->shm_perm, IPC_R); + if (error) + goto done2; + 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) + goto done2; + break; + default: + /* XXX casting to (sy_call_t *) is bogus, as usual. */ + error = ((sy_call_t *)shmctl)(td, uap); + break; + } +done2: + mtx_unlock(&Giant); + return (error); +#else + return EINVAL; +#endif +} + +#ifndef _SYS_SYSPROTO_H_ +struct shmctl_args { + int shmid; + int cmd; + struct shmid_ds *buf; +}; +#endif + +/* + * MPSAFE + */ +int +shmctl(td, uap) + struct thread *td; + struct shmctl_args *uap; +{ + int error = 0; + struct shmid_ds inbuf; + struct shmid_ds *shmseg; + + if (!jail_sysvipc_allowed && jailed(td->td_ucred)) + return (ENOSYS); + mtx_lock(&Giant); + switch (uap->cmd) { + case IPC_INFO: + error = copyout( (caddr_t)&shminfo, uap->buf, sizeof( shminfo ) ); + if (error) + goto done2; + td->td_retval[0] = shmalloced; + goto done2; + case SHM_INFO: { + struct shm_info shm_info; + shm_info.used_ids = shm_nused; + shm_info.shm_rss = 0; /*XXX where to get from ? */ + shm_info.shm_tot = 0; /*XXX where to get from ? */ + shm_info.shm_swp = 0; /*XXX where to get from ? */ + shm_info.swap_attempts = 0; /*XXX where to get from ? */ + shm_info.swap_successes = 0; /*XXX where to get from ? */ + error = copyout( (caddr_t)&shm_info, uap->buf, sizeof( shm_info ) ); + if (error) + goto done2; + td->td_retval[0] = shmalloced; + goto done2; + } + } + if( (uap->cmd) == SHM_STAT ) + shmseg = shm_find_segment_by_shmidx(uap->shmid); + else + shmseg = shm_find_segment_by_shmid(uap->shmid); + if (shmseg == NULL) { + error = EINVAL; + goto done2; + } + switch (uap->cmd) { + case SHM_STAT: + case IPC_STAT: + error = ipcperm(td, &shmseg->shm_perm, IPC_R); + if (error) + goto done2; + error = copyout((caddr_t)shmseg, uap->buf, sizeof(inbuf)); + if (error) + goto done2; + else if( (uap->cmd) == SHM_STAT ) + td->td_retval[0] = IXSEQ_TO_IPCID( uap->shmid, shmseg->shm_perm ); + break; + case IPC_SET: + error = ipcperm(td, &shmseg->shm_perm, IPC_M); + if (error) + goto done2; + error = copyin(uap->buf, (caddr_t)&inbuf, sizeof(inbuf)); + if (error) + goto done2; + 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(td, &shmseg->shm_perm, IPC_M); + if (error) + goto done2; + 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: + error = EINVAL; + break; + } +done2: + mtx_unlock(&Giant); + return (error); +} + +#ifndef _SYS_SYSPROTO_H_ +struct shmget_args { + key_t key; + size_t size; + int shmflg; +}; +#endif + +static int +shmget_existing(td, uap, mode, segnum) + struct thread *td; + struct shmget_args *uap; + int mode; + int segnum; +{ + struct shmid_ds *shmseg; + 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; + } + if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL)) + return EEXIST; + error = ipcperm(td, &shmseg->shm_perm, mode); + if (error) + return error; + if (uap->size && uap->size > shmseg->shm_segsz) + return EINVAL; + td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->shm_perm); + return 0; +} + +static int +shmget_allocate_segment(td, uap, mode) + struct thread *td; + struct shmget_args *uap; + int mode; +{ + int i, segnum, shmid, size; + struct ucred *cred = td->td_ucred; + struct shmid_ds *shmseg; + struct shm_handle *shm_handle; + + GIANT_REQUIRED; + + 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) { + shmrealloc(); /* Maybe expand the shmsegs[] array. */ + for (i = 0; i < shmalloced; i++) + if (shmsegs[i].shm_perm.mode & SHMSEG_FREE) + break; + if (i == shmalloced) + return ENOSPC; + 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. + */ + if (shm_use_phys) { + shm_handle->shm_object = + vm_pager_allocate(OBJT_PHYS, 0, size, VM_PROT_DEFAULT, 0); + } else { + 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 = td->td_proc->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); + } + td->td_retval[0] = shmid; + return 0; +} + +/* + * MPSAFE + */ +int +shmget(td, uap) + struct thread *td; + struct shmget_args *uap; +{ + int segnum, mode; + int error; + + if (!jail_sysvipc_allowed && jailed(td->td_ucred)) + return (ENOSYS); + mtx_lock(&Giant); + mode = uap->shmflg & ACCESSPERMS; + if (uap->key != IPC_PRIVATE) { + again: + segnum = shm_find_segment_by_key(uap->key); + if (segnum >= 0) { + error = shmget_existing(td, uap, mode, segnum); + if (error == EAGAIN) + goto again; + goto done2; + } + if ((uap->shmflg & IPC_CREAT) == 0) { + error = ENOENT; + goto done2; + } + } + error = shmget_allocate_segment(td, uap, mode); +done2: + mtx_unlock(&Giant); + return (error); +} + +/* + * MPSAFE + */ +int +shmsys(td, uap) + struct thread *td; + /* XXX actually varargs. */ + struct shmsys_args /* { + u_int which; + int a2; + int a3; + int a4; + } */ *uap; +{ + int error; + + if (!jail_sysvipc_allowed && jailed(td->td_ucred)) + return (ENOSYS); + if (uap->which >= sizeof(shmcalls)/sizeof(shmcalls[0])) + return (EINVAL); + mtx_lock(&Giant); + error = (*shmcalls[uap->which])(td, &uap->a2); + mtx_unlock(&Giant); + return (error); +} + +static void +shmfork_myhook(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++; +} + +static void +shmexit_myhook(p) + struct proc *p; +{ + struct shmmap_state *shmmap_s; + int i; + + GIANT_REQUIRED; + + 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; +} + +static void +shmrealloc(void) +{ + int i; + struct shmid_ds *newsegs; + + if (shmalloced >= shminfo.shmmni) + return; + + newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK); + if (newsegs == NULL) + return; + for (i = 0; i < shmalloced; i++) + bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0])); + for (; i < shminfo.shmmni; i++) { + shmsegs[i].shm_perm.mode = SHMSEG_FREE; + shmsegs[i].shm_perm.seq = 0; + } + free(shmsegs, M_SHM); + shmsegs = newsegs; + shmalloced = shminfo.shmmni; +} + +static void +shminit() +{ + int i; + + TUNABLE_INT_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall); + shminfo.shmmax = shminfo.shmall * PAGE_SIZE; + TUNABLE_INT_FETCH("kern.ipc.shmmin", &shminfo.shmmin); + TUNABLE_INT_FETCH("kern.ipc.shmmni", &shminfo.shmmni); + TUNABLE_INT_FETCH("kern.ipc.shmseg", &shminfo.shmseg); + TUNABLE_INT_FETCH("kern.ipc.shm_use_phys", &shm_use_phys); + + shmalloced = shminfo.shmmni; + shmsegs = malloc(shmalloced * sizeof(shmsegs[0]), M_SHM, M_WAITOK); + if (shmsegs == NULL) + panic("cannot allocate initial memory for sysvshm"); + for (i = 0; i < shmalloced; i++) { + shmsegs[i].shm_perm.mode = SHMSEG_FREE; + shmsegs[i].shm_perm.seq = 0; + } + shm_last_free = 0; + shm_nused = 0; + shm_committed = 0; + shmexit_hook = &shmexit_myhook; + shmfork_hook = &shmfork_myhook; +} + +static int +shmunload() +{ + + if (shm_nused > 0) + return (EBUSY); + + free(shmsegs, M_SHM); + shmexit_hook = NULL; + shmfork_hook = NULL; + return (0); +} + +static int +sysctl_shmsegs(SYSCTL_HANDLER_ARGS) +{ + + return (SYSCTL_OUT(req, shmsegs, shmalloced * sizeof(shmsegs[0]))); +} + +static int +sysvshm_modload(struct module *module, int cmd, void *arg) +{ + int error = 0; + + switch (cmd) { + case MOD_LOAD: + shminit(); + break; + case MOD_UNLOAD: + error = shmunload(); + break; + case MOD_SHUTDOWN: + break; + default: + error = EINVAL; + break; + } + return (error); +} + +static moduledata_t sysvshm_mod = { + "sysvshm", + &sysvshm_modload, + NULL +}; + +SYSCALL_MODULE_HELPER(shmsys); +SYSCALL_MODULE_HELPER(shmat); +SYSCALL_MODULE_HELPER(shmctl); +SYSCALL_MODULE_HELPER(shmdt); +SYSCALL_MODULE_HELPER(shmget); + +DECLARE_MODULE(sysvshm, sysvshm_mod, + SI_SUB_SYSV_SHM, SI_ORDER_FIRST); +MODULE_VERSION(sysvshm, 1); |
