/* $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. */ /*- * Copyright (c) 2003-2005 McAfee, Inc. * All rights reserved. * * This software was developed for the FreeBSD Project in part by McAfee * Research, the Security Research Division of McAfee, Inc under DARPA/SPAWAR * contract N66001-01-C-8035 ("CBOSS"), as part of the DARPA CHATS research * program. * * 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. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 AUTHOR OR CONTRIBUTORS 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 __FBSDID("$FreeBSD$"); #include "opt_compat.h" #include "opt_sysvipc.h" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include FEATURE(sysv_shm, "System V shared memory segments support"); static MALLOC_DEFINE(M_SHM, "shm", "SVID compatible shared memory segments"); 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); #define SHMSEG_FREE 0x0200 #define SHMSEG_REMOVED 0x0400 #define SHMSEG_ALLOCATED 0x0800 static int shm_last_free, shm_nused, shmalloced; vm_size_t shm_committed; static struct shmid_kernel *shmsegs; struct shmmap_state { vm_offset_t va; int shmid; }; static void shm_deallocate_segment(struct shmid_kernel *); static int shm_find_segment_by_key(key_t); static struct shmid_kernel *shm_find_segment(int, bool); static int shm_delete_mapping(struct vmspace *vm, struct shmmap_state *); static void shmrealloc(void); static int shminit(void); static int sysvshm_modload(struct module *, int, void *); static int shmunload(void); static void shmexit_myhook(struct vmspace *vm); static void shmfork_myhook(struct proc *p1, struct proc *p2); static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS); /* * Tuneable values. */ #ifndef SHMMAXPGS #define SHMMAXPGS 131072 /* 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; static int shm_allow_removed; SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmax, CTLFLAG_RW, &shminfo.shmmax, 0, "Maximum shared memory segment size"); SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmin, CTLFLAG_RW, &shminfo.shmmin, 0, "Minimum shared memory segment size"); SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmmni, CTLFLAG_RDTUN, &shminfo.shmmni, 0, "Number of shared memory identifiers"); SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmseg, CTLFLAG_RDTUN, &shminfo.shmseg, 0, "Number of segments per process"); SYSCTL_ULONG(_kern_ipc, OID_AUTO, shmall, CTLFLAG_RW, &shminfo.shmall, 0, "Maximum number of pages available for shared memory"); SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RW, &shm_use_phys, 0, "Enable/Disable locking of shared memory pages in core"); SYSCTL_INT(_kern_ipc, OID_AUTO, shm_allow_removed, CTLFLAG_RW, &shm_allow_removed, 0, "Enable/Disable attachment to attached segments marked for removal"); SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLTYPE_OPAQUE | CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, 0, sysctl_shmsegs, "", "Current number of shared memory segments allocated"); static struct sx sysvshmsx; #define SYSVSHM_LOCK() sx_xlock(&sysvshmsx) #define SYSVSHM_UNLOCK() sx_xunlock(&sysvshmsx) #define SYSVSHM_ASSERT_LOCKED() sx_assert(&sysvshmsx, SA_XLOCKED) static int shm_find_segment_by_key(key_t key) { int i; for (i = 0; i < shmalloced; i++) if ((shmsegs[i].u.shm_perm.mode & SHMSEG_ALLOCATED) && shmsegs[i].u.shm_perm.key == key) return (i); return (-1); } /* * Finds segment either by shmid if is_shmid is true, or by segnum if * is_shmid is false. */ static struct shmid_kernel * shm_find_segment(int arg, bool is_shmid) { struct shmid_kernel *shmseg; int segnum; segnum = is_shmid ? IPCID_TO_IX(arg) : arg; if (segnum < 0 || segnum >= shmalloced) return (NULL); shmseg = &shmsegs[segnum]; if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 || (!shm_allow_removed && (shmseg->u.shm_perm.mode & SHMSEG_REMOVED) != 0) || (is_shmid && shmseg->u.shm_perm.seq != IPCID_TO_SEQ(arg))) return (NULL); return (shmseg); } static void shm_deallocate_segment(struct shmid_kernel *shmseg) { vm_size_t size; SYSVSHM_ASSERT_LOCKED(); vm_object_deallocate(shmseg->object); shmseg->object = NULL; size = round_page(shmseg->u.shm_segsz); shm_committed -= btoc(size); shm_nused--; shmseg->u.shm_perm.mode = SHMSEG_FREE; #ifdef MAC mac_sysvshm_cleanup(shmseg); #endif racct_sub_cred(shmseg->cred, RACCT_NSHM, 1); racct_sub_cred(shmseg->cred, RACCT_SHMSIZE, size); crfree(shmseg->cred); shmseg->cred = NULL; } static int shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s) { struct shmid_kernel *shmseg; int segnum, result; vm_size_t size; SYSVSHM_ASSERT_LOCKED(); segnum = IPCID_TO_IX(shmmap_s->shmid); KASSERT(segnum >= 0 && segnum < shmalloced, ("segnum %d shmalloced %d", segnum, shmalloced)); shmseg = &shmsegs[segnum]; size = round_page(shmseg->u.shm_segsz); result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size); if (result != KERN_SUCCESS) return (EINVAL); shmmap_s->shmid = -1; shmseg->u.shm_dtime = time_second; if ((--shmseg->u.shm_nattch <= 0) && (shmseg->u.shm_perm.mode & SHMSEG_REMOVED)) { shm_deallocate_segment(shmseg); shm_last_free = segnum; } return (0); } static int kern_shmdt_locked(struct thread *td, const void *shmaddr) { struct proc *p = td->td_proc; struct shmmap_state *shmmap_s; #ifdef MAC struct shmid_kernel *shmsegptr; #endif int error, i; SYSVSHM_ASSERT_LOCKED(); if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC)) return (ENOSYS); shmmap_s = 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)shmaddr) { break; } } if (i == shminfo.shmseg) return (EINVAL); #ifdef MAC shmsegptr = &shmsegs[IPCID_TO_IX(shmmap_s->shmid)]; error = mac_sysvshm_check_shmdt(td->td_ucred, shmsegptr); if (error != 0) return (error); #endif error = shm_delete_mapping(p->p_vmspace, shmmap_s); return (error); } #ifndef _SYS_SYSPROTO_H_ struct shmdt_args { const void *shmaddr; }; #endif int sys_shmdt(struct thread *td, struct shmdt_args *uap) { int error; SYSVSHM_LOCK(); error = kern_shmdt_locked(td, uap->shmaddr); SYSVSHM_UNLOCK(); return (error); } static int kern_shmat_locked(struct thread *td, int shmid, const void *shmaddr, int shmflg) { struct proc *p = td->td_proc; struct shmid_kernel *shmseg; struct shmmap_state *shmmap_s; vm_offset_t attach_va; vm_prot_t prot; vm_size_t size; int error, i, rv; SYSVSHM_ASSERT_LOCKED(); if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC)) return (ENOSYS); shmmap_s = p->p_vmspace->vm_shm; if (shmmap_s == NULL) { shmmap_s = malloc(shminfo.shmseg * sizeof(struct shmmap_state), M_SHM, M_WAITOK); for (i = 0; i < shminfo.shmseg; i++) shmmap_s[i].shmid = -1; KASSERT(p->p_vmspace->vm_shm == NULL, ("raced")); p->p_vmspace->vm_shm = shmmap_s; } shmseg = shm_find_segment(shmid, true); if (shmseg == NULL) return (EINVAL); error = ipcperm(td, &shmseg->u.shm_perm, (shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W); if (error != 0) return (error); #ifdef MAC error = mac_sysvshm_check_shmat(td->td_ucred, shmseg, shmflg); if (error != 0) return (error); #endif 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->u.shm_segsz); prot = VM_PROT_READ; if ((shmflg & SHM_RDONLY) == 0) prot |= VM_PROT_WRITE; if (shmaddr != NULL) { if ((shmflg & SHM_RND) != 0) attach_va = (vm_offset_t)shmaddr & ~(SHMLBA-1); else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0) attach_va = (vm_offset_t)shmaddr; else return (EINVAL); } else { /* * This is just a hint to vm_map_find() about where to * put it. */ PROC_LOCK(p); attach_va = round_page((vm_offset_t)p->p_vmspace->vm_daddr + lim_max(p, RLIMIT_DATA)); PROC_UNLOCK(p); } vm_object_reference(shmseg->object); rv = vm_map_find(&p->p_vmspace->vm_map, shmseg->object, 0, &attach_va, size, 0, shmaddr != NULL ? VMFS_NO_SPACE : VMFS_OPTIMAL_SPACE, prot, prot, MAP_INHERIT_SHARE); if (rv != KERN_SUCCESS) { vm_object_deallocate(shmseg->object); return (ENOMEM); } shmmap_s->va = attach_va; shmmap_s->shmid = shmid; shmseg->u.shm_lpid = p->p_pid; shmseg->u.shm_atime = time_second; shmseg->u.shm_nattch++; td->td_retval[0] = attach_va; return (error); } int kern_shmat(struct thread *td, int shmid, const void *shmaddr, int shmflg) { int error; SYSVSHM_LOCK(); error = kern_shmat_locked(td, shmid, shmaddr, shmflg); SYSVSHM_UNLOCK(); return (error); } #ifndef _SYS_SYSPROTO_H_ struct shmat_args { int shmid; const void *shmaddr; int shmflg; }; #endif int sys_shmat(struct thread *td, struct shmat_args *uap) { return (kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg)); } static int kern_shmctl_locked(struct thread *td, int shmid, int cmd, void *buf, size_t *bufsz) { struct shmid_kernel *shmseg; struct shmid_ds *shmidp; struct shm_info shm_info; int error; SYSVSHM_ASSERT_LOCKED(); if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC)) return (ENOSYS); error = 0; switch (cmd) { /* * It is possible that kern_shmctl is being called from the Linux ABI * layer, in which case, we will need to implement IPC_INFO. It should * be noted that other shmctl calls will be funneled through here for * Linix binaries as well. * * NB: The Linux ABI layer will convert this data to structure(s) more * consistent with the Linux ABI. */ case IPC_INFO: memcpy(buf, &shminfo, sizeof(shminfo)); if (bufsz) *bufsz = sizeof(shminfo); td->td_retval[0] = shmalloced; return (0); case 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 ? */ memcpy(buf, &shm_info, sizeof(shm_info)); if (bufsz != NULL) *bufsz = sizeof(shm_info); td->td_retval[0] = shmalloced; return (0); } } shmseg = shm_find_segment(shmid, cmd != SHM_STAT); if (shmseg == NULL) return (EINVAL); #ifdef MAC error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, cmd); if (error != 0) return (error); #endif switch (cmd) { case SHM_STAT: case IPC_STAT: error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); if (error != 0) return (error); memcpy(buf, &shmseg->u, sizeof(struct shmid_ds)); if (bufsz != NULL) *bufsz = sizeof(struct shmid_ds); if (cmd == SHM_STAT) { td->td_retval[0] = IXSEQ_TO_IPCID(shmid, shmseg->u.shm_perm); } break; case IPC_SET: shmidp = (struct shmid_ds *)buf; error = ipcperm(td, &shmseg->u.shm_perm, IPC_M); if (error != 0) return (error); shmseg->u.shm_perm.uid = shmidp->shm_perm.uid; shmseg->u.shm_perm.gid = shmidp->shm_perm.gid; shmseg->u.shm_perm.mode = (shmseg->u.shm_perm.mode & ~ACCESSPERMS) | (shmidp->shm_perm.mode & ACCESSPERMS); shmseg->u.shm_ctime = time_second; break; case IPC_RMID: error = ipcperm(td, &shmseg->u.shm_perm, IPC_M); if (error != 0) return (error); shmseg->u.shm_perm.key = IPC_PRIVATE; shmseg->u.shm_perm.mode |= SHMSEG_REMOVED; if (shmseg->u.shm_nattch <= 0) { shm_deallocate_segment(shmseg); shm_last_free = IPCID_TO_IX(shmid); } break; #if 0 case SHM_LOCK: case SHM_UNLOCK: #endif default: error = EINVAL; break; } return (error); } int kern_shmctl(struct thread *td, int shmid, int cmd, void *buf, size_t *bufsz) { int error; SYSVSHM_LOCK(); error = kern_shmctl_locked(td, shmid, cmd, buf, bufsz); SYSVSHM_UNLOCK(); return (error); } #ifndef _SYS_SYSPROTO_H_ struct shmctl_args { int shmid; int cmd; struct shmid_ds *buf; }; #endif int sys_shmctl(struct thread *td, struct shmctl_args *uap) { int error = 0; struct shmid_ds buf; size_t bufsz; /* * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support * Linux binaries. If we see the call come through the FreeBSD ABI, * return an error back to the user since we do not to support this. */ if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || uap->cmd == SHM_STAT) return (EINVAL); /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ if (uap->cmd == IPC_SET) { if ((error = copyin(uap->buf, &buf, sizeof(struct shmid_ds)))) goto done; } error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); if (error) goto done; /* Cases in which we need to copyout */ switch (uap->cmd) { case IPC_STAT: error = copyout(&buf, uap->buf, bufsz); break; } done: if (error) { /* Invalidate the return value */ td->td_retval[0] = -1; } return (error); } static int shmget_existing(struct thread *td, struct shmget_args *uap, int mode, int segnum) { struct shmid_kernel *shmseg; #ifdef MAC int error; #endif SYSVSHM_ASSERT_LOCKED(); KASSERT(segnum >= 0 && segnum < shmalloced, ("segnum %d shmalloced %d", segnum, shmalloced)); shmseg = &shmsegs[segnum]; if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL)) return (EEXIST); #ifdef MAC error = mac_sysvshm_check_shmget(td->td_ucred, shmseg, uap->shmflg); if (error != 0) return (error); #endif if (uap->size != 0 && uap->size > shmseg->u.shm_segsz) return (EINVAL); td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); return (0); } static int shmget_allocate_segment(struct thread *td, struct shmget_args *uap, int mode) { struct ucred *cred = td->td_ucred; struct shmid_kernel *shmseg; vm_object_t shm_object; int i, segnum; size_t size; SYSVSHM_ASSERT_LOCKED(); 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].u.shm_perm.mode & SHMSEG_FREE) break; if (i == shmalloced) return (ENOSPC); segnum = i; } else { segnum = shm_last_free; shm_last_free = -1; } KASSERT(segnum >= 0 && segnum < shmalloced, ("segnum %d shmalloced %d", segnum, shmalloced)); shmseg = &shmsegs[segnum]; #ifdef RACCT PROC_LOCK(td->td_proc); if (racct_add(td->td_proc, RACCT_NSHM, 1)) { PROC_UNLOCK(td->td_proc); return (ENOSPC); } if (racct_add(td->td_proc, RACCT_SHMSIZE, size)) { racct_sub(td->td_proc, RACCT_NSHM, 1); PROC_UNLOCK(td->td_proc); return (ENOMEM); } PROC_UNLOCK(td->td_proc); #endif /* * We make sure that we have allocated a pager before we need * to. */ shm_object = vm_pager_allocate(shm_use_phys ? OBJT_PHYS : OBJT_SWAP, 0, size, VM_PROT_DEFAULT, 0, cred); if (shm_object == NULL) { #ifdef RACCT PROC_LOCK(td->td_proc); racct_sub(td->td_proc, RACCT_NSHM, 1); racct_sub(td->td_proc, RACCT_SHMSIZE, size); PROC_UNLOCK(td->td_proc); #endif return (ENOMEM); } shm_object->pg_color = 0; VM_OBJECT_WLOCK(shm_object); vm_object_clear_flag(shm_object, OBJ_ONEMAPPING); vm_object_set_flag(shm_object, OBJ_COLORED | OBJ_NOSPLIT); VM_OBJECT_WUNLOCK(shm_object); shmseg->object = shm_object; shmseg->u.shm_perm.cuid = shmseg->u.shm_perm.uid = cred->cr_uid; shmseg->u.shm_perm.cgid = shmseg->u.shm_perm.gid = cred->cr_gid; shmseg->u.shm_perm.mode = (mode & ACCESSPERMS) | SHMSEG_ALLOCATED; shmseg->u.shm_perm.key = uap->key; shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff; shmseg->cred = crhold(cred); shmseg->u.shm_segsz = uap->size; shmseg->u.shm_cpid = td->td_proc->p_pid; shmseg->u.shm_lpid = shmseg->u.shm_nattch = 0; shmseg->u.shm_atime = shmseg->u.shm_dtime = 0; #ifdef MAC mac_sysvshm_create(cred, shmseg); #endif shmseg->u.shm_ctime = time_second; shm_committed += btoc(size); shm_nused++; td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); return (0); } #ifndef _SYS_SYSPROTO_H_ struct shmget_args { key_t key; size_t size; int shmflg; }; #endif int sys_shmget(struct thread *td, struct shmget_args *uap) { int segnum, mode; int error; if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC)) return (ENOSYS); mode = uap->shmflg & ACCESSPERMS; SYSVSHM_LOCK(); if (uap->key == IPC_PRIVATE) { error = shmget_allocate_segment(td, uap, mode); } else { segnum = shm_find_segment_by_key(uap->key); if (segnum >= 0) error = shmget_existing(td, uap, mode, segnum); else if ((uap->shmflg & IPC_CREAT) == 0) error = ENOENT; else error = shmget_allocate_segment(td, uap, mode); } SYSVSHM_UNLOCK(); return (error); } static void shmfork_myhook(struct proc *p1, struct proc *p2) { struct shmmap_state *shmmap_s; size_t size; int i; SYSVSHM_LOCK(); size = shminfo.shmseg * sizeof(struct shmmap_state); shmmap_s = malloc(size, M_SHM, M_WAITOK); bcopy(p1->p_vmspace->vm_shm, shmmap_s, size); p2->p_vmspace->vm_shm = shmmap_s; for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) { if (shmmap_s->shmid != -1) { KASSERT(IPCID_TO_IX(shmmap_s->shmid) >= 0 && IPCID_TO_IX(shmmap_s->shmid) < shmalloced, ("segnum %d shmalloced %d", IPCID_TO_IX(shmmap_s->shmid), shmalloced)); shmsegs[IPCID_TO_IX(shmmap_s->shmid)].u.shm_nattch++; } } SYSVSHM_UNLOCK(); } static void shmexit_myhook(struct vmspace *vm) { struct shmmap_state *base, *shm; int i; base = vm->vm_shm; if (base != NULL) { vm->vm_shm = NULL; SYSVSHM_LOCK(); for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) { if (shm->shmid != -1) shm_delete_mapping(vm, shm); } SYSVSHM_UNLOCK(); free(base, M_SHM); } } static void shmrealloc(void) { struct shmid_kernel *newsegs; int i; SYSVSHM_ASSERT_LOCKED(); if (shmalloced >= shminfo.shmmni) return; newsegs = malloc(shminfo.shmmni * sizeof(*newsegs), M_SHM, M_WAITOK); for (i = 0; i < shmalloced; i++) bcopy(&shmsegs[i], &newsegs[i], sizeof(newsegs[0])); for (; i < shminfo.shmmni; i++) { shmsegs[i].u.shm_perm.mode = SHMSEG_FREE; shmsegs[i].u.shm_perm.seq = 0; #ifdef MAC mac_sysvshm_init(&shmsegs[i]); #endif } free(shmsegs, M_SHM); shmsegs = newsegs; shmalloced = shminfo.shmmni; } static struct syscall_helper_data shm_syscalls[] = { SYSCALL_INIT_HELPER(shmat), SYSCALL_INIT_HELPER(shmctl), SYSCALL_INIT_HELPER(shmdt), SYSCALL_INIT_HELPER(shmget), #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) SYSCALL_INIT_HELPER_COMPAT(freebsd7_shmctl), #endif #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) SYSCALL_INIT_HELPER(shmsys), #endif SYSCALL_INIT_LAST }; #ifdef COMPAT_FREEBSD32 #include #include #include #include #include #include static struct syscall_helper_data shm32_syscalls[] = { SYSCALL32_INIT_HELPER_COMPAT(shmat), SYSCALL32_INIT_HELPER_COMPAT(shmdt), SYSCALL32_INIT_HELPER_COMPAT(shmget), SYSCALL32_INIT_HELPER(freebsd32_shmsys), SYSCALL32_INIT_HELPER(freebsd32_shmctl), #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) SYSCALL32_INIT_HELPER(freebsd7_freebsd32_shmctl), #endif SYSCALL_INIT_LAST }; #endif static int shminit(void) { int i, error; #ifndef BURN_BRIDGES if (TUNABLE_ULONG_FETCH("kern.ipc.shmmaxpgs", &shminfo.shmall) != 0) printf("kern.ipc.shmmaxpgs is now called kern.ipc.shmall!\n"); #endif TUNABLE_ULONG_FETCH("kern.ipc.shmall", &shminfo.shmall); if (!TUNABLE_ULONG_FETCH("kern.ipc.shmmax", &shminfo.shmmax)) { /* Initialize shmmax dealing with possible overflow. */ for (i = PAGE_SIZE; i > 0; i--) { shminfo.shmmax = shminfo.shmall * i; if (shminfo.shmmax >= shminfo.shmall) break; } } TUNABLE_ULONG_FETCH("kern.ipc.shmmin", &shminfo.shmmin); TUNABLE_ULONG_FETCH("kern.ipc.shmmni", &shminfo.shmmni); TUNABLE_ULONG_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); for (i = 0; i < shmalloced; i++) { shmsegs[i].u.shm_perm.mode = SHMSEG_FREE; shmsegs[i].u.shm_perm.seq = 0; #ifdef MAC mac_sysvshm_init(&shmsegs[i]); #endif } shm_last_free = 0; shm_nused = 0; shm_committed = 0; sx_init(&sysvshmsx, "sysvshmsx"); shmexit_hook = &shmexit_myhook; shmfork_hook = &shmfork_myhook; error = syscall_helper_register(shm_syscalls); if (error != 0) return (error); #ifdef COMPAT_FREEBSD32 error = syscall32_helper_register(shm32_syscalls); if (error != 0) return (error); #endif return (0); } static int shmunload(void) { int i; if (shm_nused > 0) return (EBUSY); #ifdef COMPAT_FREEBSD32 syscall32_helper_unregister(shm32_syscalls); #endif syscall_helper_unregister(shm_syscalls); for (i = 0; i < shmalloced; i++) { #ifdef MAC mac_sysvshm_destroy(&shmsegs[i]); #endif /* * Objects might be still mapped into the processes * address spaces. Actual free would happen on the * last mapping destruction. */ if (shmsegs[i].u.shm_perm.mode != SHMSEG_FREE) vm_object_deallocate(shmsegs[i].object); } free(shmsegs, M_SHM); shmexit_hook = NULL; shmfork_hook = NULL; sx_destroy(&sysvshmsx); return (0); } static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS) { int error; SYSVSHM_LOCK(); error = SYSCTL_OUT(req, shmsegs, shmalloced * sizeof(shmsegs[0])); SYSVSHM_UNLOCK(); return (error); } #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) struct oshmid_ds { struct ipc_perm_old shm_perm; /* operation perms */ int shm_segsz; /* size of segment (bytes) */ u_short shm_cpid; /* pid, creator */ u_short 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(struct thread *td, struct oshmctl_args *uap) { #ifdef COMPAT_43 int error = 0; struct shmid_kernel *shmseg; struct oshmid_ds outbuf; if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC)) return (ENOSYS); if (uap->cmd != IPC_STAT) { return (freebsd7_shmctl(td, (struct freebsd7_shmctl_args *)uap)); } SYSVSHM_LOCK(); shmseg = shm_find_segment(uap->shmid, true); if (shmseg == NULL) { SYSVSHM_UNLOCK(); return (EINVAL); } error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); if (error != 0) { SYSVSHM_UNLOCK(); return (error); } #ifdef MAC error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd); if (error != 0) { SYSVSHM_UNLOCK(); return (error); } #endif ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm); outbuf.shm_segsz = shmseg->u.shm_segsz; outbuf.shm_cpid = shmseg->u.shm_cpid; outbuf.shm_lpid = shmseg->u.shm_lpid; outbuf.shm_nattch = shmseg->u.shm_nattch; outbuf.shm_atime = shmseg->u.shm_atime; outbuf.shm_dtime = shmseg->u.shm_dtime; outbuf.shm_ctime = shmseg->u.shm_ctime; outbuf.shm_handle = shmseg->object; SYSVSHM_UNLOCK(); error = copyout(&outbuf, uap->ubuf, sizeof(outbuf)); return (error); #else return (EINVAL); #endif } /* XXX casting to (sy_call_t *) is bogus, as usual. */ static sy_call_t *shmcalls[] = { (sy_call_t *)sys_shmat, (sy_call_t *)oshmctl, (sy_call_t *)sys_shmdt, (sy_call_t *)sys_shmget, (sy_call_t *)freebsd7_shmctl }; #ifndef _SYS_SYSPROTO_H_ /* XXX actually varargs. */ struct shmsys_args { int which; int a2; int a3; int a4; }; #endif int sys_shmsys(struct thread *td, struct shmsys_args *uap) { int error; if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC)) return (ENOSYS); if (uap->which < 0 || uap->which >= nitems(shmcalls)) return (EINVAL); error = (*shmcalls[uap->which])(td, &uap->a2); return (error); } #endif /* i386 && (COMPAT_FREEBSD4 || COMPAT_43) */ #ifdef COMPAT_FREEBSD32 int freebsd32_shmsys(struct thread *td, struct freebsd32_shmsys_args *uap) { #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) switch (uap->which) { case 0: { /* shmat */ struct shmat_args ap; ap.shmid = uap->a2; ap.shmaddr = PTRIN(uap->a3); ap.shmflg = uap->a4; return (sysent[SYS_shmat].sy_call(td, &ap)); } case 2: { /* shmdt */ struct shmdt_args ap; ap.shmaddr = PTRIN(uap->a2); return (sysent[SYS_shmdt].sy_call(td, &ap)); } case 3: { /* shmget */ struct shmget_args ap; ap.key = uap->a2; ap.size = uap->a3; ap.shmflg = uap->a4; return (sysent[SYS_shmget].sy_call(td, &ap)); } case 4: { /* shmctl */ struct freebsd7_freebsd32_shmctl_args ap; ap.shmid = uap->a2; ap.cmd = uap->a3; ap.buf = PTRIN(uap->a4); return (freebsd7_freebsd32_shmctl(td, &ap)); } case 1: /* oshmctl */ default: return (EINVAL); } #else return (nosys(td, NULL)); #endif } #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) int freebsd7_freebsd32_shmctl(struct thread *td, struct freebsd7_freebsd32_shmctl_args *uap) { int error = 0; union { struct shmid_ds shmid_ds; struct shm_info shm_info; struct shminfo shminfo; } u; union { struct shmid_ds32_old shmid_ds32; struct shm_info32 shm_info32; struct shminfo32 shminfo32; } u32; size_t sz; if (uap->cmd == IPC_SET) { if ((error = copyin(uap->buf, &u32.shmid_ds32, sizeof(u32.shmid_ds32)))) goto done; freebsd32_ipcperm_old_in(&u32.shmid_ds32.shm_perm, &u.shmid_ds.shm_perm); CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); CP(u32.shmid_ds32, u.shmid_ds, shm_atime); CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); } error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); if (error) goto done; /* Cases in which we need to copyout */ switch (uap->cmd) { case IPC_INFO: CP(u.shminfo, u32.shminfo32, shmmax); CP(u.shminfo, u32.shminfo32, shmmin); CP(u.shminfo, u32.shminfo32, shmmni); CP(u.shminfo, u32.shminfo32, shmseg); CP(u.shminfo, u32.shminfo32, shmall); error = copyout(&u32.shminfo32, uap->buf, sizeof(u32.shminfo32)); break; case SHM_INFO: CP(u.shm_info, u32.shm_info32, used_ids); CP(u.shm_info, u32.shm_info32, shm_rss); CP(u.shm_info, u32.shm_info32, shm_tot); CP(u.shm_info, u32.shm_info32, shm_swp); CP(u.shm_info, u32.shm_info32, swap_attempts); CP(u.shm_info, u32.shm_info32, swap_successes); error = copyout(&u32.shm_info32, uap->buf, sizeof(u32.shm_info32)); break; case SHM_STAT: case IPC_STAT: freebsd32_ipcperm_old_out(&u.shmid_ds.shm_perm, &u32.shmid_ds32.shm_perm); if (u.shmid_ds.shm_segsz > INT32_MAX) u32.shmid_ds32.shm_segsz = INT32_MAX; else CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); CP(u.shmid_ds, u32.shmid_ds32, shm_atime); CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); u32.shmid_ds32.shm_internal = 0; error = copyout(&u32.shmid_ds32, uap->buf, sizeof(u32.shmid_ds32)); break; } done: if (error) { /* Invalidate the return value */ td->td_retval[0] = -1; } return (error); } #endif int freebsd32_shmctl(struct thread *td, struct freebsd32_shmctl_args *uap) { int error = 0; union { struct shmid_ds shmid_ds; struct shm_info shm_info; struct shminfo shminfo; } u; union { struct shmid_ds32 shmid_ds32; struct shm_info32 shm_info32; struct shminfo32 shminfo32; } u32; size_t sz; if (uap->cmd == IPC_SET) { if ((error = copyin(uap->buf, &u32.shmid_ds32, sizeof(u32.shmid_ds32)))) goto done; freebsd32_ipcperm_in(&u32.shmid_ds32.shm_perm, &u.shmid_ds.shm_perm); CP(u32.shmid_ds32, u.shmid_ds, shm_segsz); CP(u32.shmid_ds32, u.shmid_ds, shm_lpid); CP(u32.shmid_ds32, u.shmid_ds, shm_cpid); CP(u32.shmid_ds32, u.shmid_ds, shm_nattch); CP(u32.shmid_ds32, u.shmid_ds, shm_atime); CP(u32.shmid_ds32, u.shmid_ds, shm_dtime); CP(u32.shmid_ds32, u.shmid_ds, shm_ctime); } error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&u, &sz); if (error) goto done; /* Cases in which we need to copyout */ switch (uap->cmd) { case IPC_INFO: CP(u.shminfo, u32.shminfo32, shmmax); CP(u.shminfo, u32.shminfo32, shmmin); CP(u.shminfo, u32.shminfo32, shmmni); CP(u.shminfo, u32.shminfo32, shmseg); CP(u.shminfo, u32.shminfo32, shmall); error = copyout(&u32.shminfo32, uap->buf, sizeof(u32.shminfo32)); break; case SHM_INFO: CP(u.shm_info, u32.shm_info32, used_ids); CP(u.shm_info, u32.shm_info32, shm_rss); CP(u.shm_info, u32.shm_info32, shm_tot); CP(u.shm_info, u32.shm_info32, shm_swp); CP(u.shm_info, u32.shm_info32, swap_attempts); CP(u.shm_info, u32.shm_info32, swap_successes); error = copyout(&u32.shm_info32, uap->buf, sizeof(u32.shm_info32)); break; case SHM_STAT: case IPC_STAT: freebsd32_ipcperm_out(&u.shmid_ds.shm_perm, &u32.shmid_ds32.shm_perm); if (u.shmid_ds.shm_segsz > INT32_MAX) u32.shmid_ds32.shm_segsz = INT32_MAX; else CP(u.shmid_ds, u32.shmid_ds32, shm_segsz); CP(u.shmid_ds, u32.shmid_ds32, shm_lpid); CP(u.shmid_ds, u32.shmid_ds32, shm_cpid); CP(u.shmid_ds, u32.shmid_ds32, shm_nattch); CP(u.shmid_ds, u32.shmid_ds32, shm_atime); CP(u.shmid_ds, u32.shmid_ds32, shm_dtime); CP(u.shmid_ds, u32.shmid_ds32, shm_ctime); error = copyout(&u32.shmid_ds32, uap->buf, sizeof(u32.shmid_ds32)); break; } done: if (error) { /* Invalidate the return value */ td->td_retval[0] = -1; } return (error); } #endif #if defined(COMPAT_FREEBSD4) || defined(COMPAT_FREEBSD5) || \ defined(COMPAT_FREEBSD6) || defined(COMPAT_FREEBSD7) #ifndef CP #define CP(src, dst, fld) do { (dst).fld = (src).fld; } while (0) #endif #ifndef _SYS_SYSPROTO_H_ struct freebsd7_shmctl_args { int shmid; int cmd; struct shmid_ds_old *buf; }; #endif int freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap) { int error = 0; struct shmid_ds_old old; struct shmid_ds buf; size_t bufsz; /* * The only reason IPC_INFO, SHM_INFO, SHM_STAT exists is to support * Linux binaries. If we see the call come through the FreeBSD ABI, * return an error back to the user since we do not to support this. */ if (uap->cmd == IPC_INFO || uap->cmd == SHM_INFO || uap->cmd == SHM_STAT) return (EINVAL); /* IPC_SET needs to copyin the buffer before calling kern_shmctl */ if (uap->cmd == IPC_SET) { if ((error = copyin(uap->buf, &old, sizeof(old)))) goto done; ipcperm_old2new(&old.shm_perm, &buf.shm_perm); CP(old, buf, shm_segsz); CP(old, buf, shm_lpid); CP(old, buf, shm_cpid); CP(old, buf, shm_nattch); CP(old, buf, shm_atime); CP(old, buf, shm_dtime); CP(old, buf, shm_ctime); } error = kern_shmctl(td, uap->shmid, uap->cmd, (void *)&buf, &bufsz); if (error) goto done; /* Cases in which we need to copyout */ switch (uap->cmd) { case IPC_STAT: ipcperm_new2old(&buf.shm_perm, &old.shm_perm); if (buf.shm_segsz > INT_MAX) old.shm_segsz = INT_MAX; else CP(buf, old, shm_segsz); CP(buf, old, shm_lpid); CP(buf, old, shm_cpid); if (buf.shm_nattch > SHRT_MAX) old.shm_nattch = SHRT_MAX; else CP(buf, old, shm_nattch); CP(buf, old, shm_atime); CP(buf, old, shm_dtime); CP(buf, old, shm_ctime); old.shm_internal = NULL; error = copyout(&old, uap->buf, sizeof(old)); break; } done: if (error) { /* Invalidate the return value */ td->td_retval[0] = -1; } return (error); } #endif /* COMPAT_FREEBSD4 || COMPAT_FREEBSD5 || COMPAT_FREEBSD6 || COMPAT_FREEBSD7 */ static int sysvshm_modload(struct module *module, int cmd, void *arg) { int error = 0; switch (cmd) { case MOD_LOAD: error = shminit(); if (error != 0) shmunload(); 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 }; DECLARE_MODULE(sysvshm, sysvshm_mod, SI_SUB_SYSV_SHM, SI_ORDER_FIRST); MODULE_VERSION(sysvshm, 1);