Date: Sat, 4 Apr 2015 07:59:08 +0000 (UTC) From: Konstantin Belousov <kib@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-10@freebsd.org Subject: svn commit: r281066 - stable/10/sys/kern Message-ID: <201504040759.t347x8IO094091@svn.freebsd.org>
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Author: kib Date: Sat Apr 4 07:59:07 2015 New Revision: 281066 URL: https://svnweb.freebsd.org/changeset/base/281066 Log: MFC r280323: Somewhat modernize the SysV shm code. MFC r280325 (by cognet): Fix warning for !MAC case. Modified: stable/10/sys/kern/sysv_shm.c Directory Properties: stable/10/ (props changed) Modified: stable/10/sys/kern/sysv_shm.c ============================================================================== --- stable/10/sys/kern/sysv_shm.c Sat Apr 4 07:56:04 2015 (r281065) +++ stable/10/sys/kern/sysv_shm.c Sat Apr 4 07:59:07 2015 (r281066) @@ -109,7 +109,6 @@ static int shmget_existing(struct thread #define SHMSEG_FREE 0x0200 #define SHMSEG_REMOVED 0x0400 #define SHMSEG_ALLOCATED 0x0800 -#define SHMSEG_WANTED 0x1000 static int shm_last_free, shm_nused, shmalloced; vm_size_t shm_committed; @@ -122,8 +121,7 @@ struct shmmap_state { static void shm_deallocate_segment(struct shmid_kernel *); static int shm_find_segment_by_key(key_t); -static struct shmid_kernel *shm_find_segment_by_shmid(int); -static struct shmid_kernel *shm_find_segment_by_shmidx(int); +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); @@ -181,13 +179,17 @@ SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_ 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, - NULL, 0, sysctl_shmsegs, "", +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) - key_t key; +shm_find_segment_by_key(key_t key) { int i; @@ -198,46 +200,34 @@ shm_find_segment_by_key(key) 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_by_shmid(int shmid) +shm_find_segment(int arg, bool is_shmid) { - int segnum; struct shmid_kernel *shmseg; + int segnum; - segnum = IPCID_TO_IX(shmid); + 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) || - shmseg->u.shm_perm.seq != IPCID_TO_SEQ(shmid)) - return (NULL); - return (shmseg); -} - -static struct shmid_kernel * -shm_find_segment_by_shmidx(int segnum) -{ - struct shmid_kernel *shmseg; - - 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(shmseg) - struct shmid_kernel *shmseg; +shm_deallocate_segment(struct shmid_kernel *shmseg) { vm_size_t size; - GIANT_REQUIRED; + SYSVSHM_ASSERT_LOCKED(); vm_object_deallocate(shmseg->object); shmseg->object = NULL; @@ -261,9 +251,11 @@ shm_delete_mapping(struct vmspace *vm, s int segnum, result; vm_size_t size; - GIANT_REQUIRED; - + 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); @@ -279,138 +271,110 @@ shm_delete_mapping(struct vmspace *vm, s return (0); } -#ifndef _SYS_SYSPROTO_H_ -struct shmdt_args { - const void *shmaddr; -}; -#endif -int -sys_shmdt(td, uap) - struct thread *td; - struct shmdt_args *uap; +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 i; - int error = 0; + int error, i; + SYSVSHM_ASSERT_LOCKED(); if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC)) return (ENOSYS); - mtx_lock(&Giant); shmmap_s = p->p_vmspace->vm_shm; - if (shmmap_s == NULL) { - error = EINVAL; - goto done2; - } + if (shmmap_s == NULL) + return (EINVAL); for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) { if (shmmap_s->shmid != -1 && - shmmap_s->va == (vm_offset_t)uap->shmaddr) { + shmmap_s->va == (vm_offset_t)shmaddr) { break; } } - if (i == shminfo.shmseg) { - error = EINVAL; - goto done2; - } + 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) - goto done2; + return (error); #endif error = shm_delete_mapping(p->p_vmspace, shmmap_s); -done2: - mtx_unlock(&Giant); return (error); } #ifndef _SYS_SYSPROTO_H_ -struct shmat_args { - int shmid; +struct shmdt_args { const void *shmaddr; - int shmflg; }; #endif int -kern_shmat(td, shmid, shmaddr, shmflg) - struct thread *td; - int shmid; - const void *shmaddr; - int shmflg; +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; - int i; struct shmid_kernel *shmseg; struct shmmap_state *shmmap_s = NULL; vm_offset_t attach_va; vm_prot_t prot; vm_size_t size; - int rv; - int error = 0; + int error, i, rv; + SYSVSHM_ASSERT_LOCKED(); if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC)) return (ENOSYS); - mtx_lock(&Giant); shmmap_s = p->p_vmspace->vm_shm; if (shmmap_s == NULL) { shmmap_s = malloc(shminfo.shmseg * sizeof(struct shmmap_state), M_SHM, M_WAITOK); - - /* - * If malloc() above sleeps, the Giant lock is - * temporarily dropped, which allows another thread to - * allocate shmmap_state and set vm_shm. Recheck - * vm_shm and free the new shmmap_state if another one - * is already allocated. - */ - if (p->p_vmspace->vm_shm != NULL) { - free(shmmap_s, M_SHM); - shmmap_s = p->p_vmspace->vm_shm; - } else { - for (i = 0; i < shminfo.shmseg; i++) - shmmap_s[i].shmid = -1; - p->p_vmspace->vm_shm = shmmap_s; - } - } - shmseg = shm_find_segment_by_shmid(shmid); - if (shmseg == NULL) { - error = EINVAL; - goto done2; + 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) - goto done2; + if (error != 0) + return (error); #ifdef MAC error = mac_sysvshm_check_shmat(td->td_ucred, shmseg, shmflg); if (error != 0) - goto done2; + return (error); #endif for (i = 0; i < shminfo.shmseg; i++) { if (shmmap_s->shmid == -1) break; shmmap_s++; } - if (i >= shminfo.shmseg) { - error = EMFILE; - goto done2; - } + 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) { - if (shmflg & SHM_RND) { + 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) { + else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0) attach_va = (vm_offset_t)shmaddr; - } else { - error = EINVAL; - goto done2; - } + else + return (EINVAL); } else { /* * This is just a hint to vm_map_find() about where to @@ -428,8 +392,7 @@ kern_shmat(td, shmid, shmaddr, shmflg) VMFS_OPTIMAL_SPACE, prot, prot, MAP_INHERIT_SHARE); if (rv != KERN_SUCCESS) { vm_object_deallocate(shmseg->object); - error = ENOMEM; - goto done2; + return (ENOMEM); } shmmap_s->va = attach_va; @@ -438,34 +401,49 @@ kern_shmat(td, shmid, shmaddr, shmflg) shmseg->u.shm_atime = time_second; shmseg->u.shm_nattch++; td->td_retval[0] = attach_va; -done2: - mtx_unlock(&Giant); return (error); } int -sys_shmat(td, uap) - struct thread *td; - struct shmat_args *uap; +kern_shmat(struct thread *td, int shmid, const void *shmaddr, int shmflg) { - return kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg); + int error; + + SYSVSHM_LOCK(); + error = kern_shmat_locked(td, shmid, shmaddr, shmflg); + SYSVSHM_UNLOCK(); + return (error); } -int -kern_shmctl(td, shmid, cmd, buf, bufsz) - struct thread *td; +#ifndef _SYS_SYSPROTO_H_ +struct shmat_args { int shmid; - int cmd; - void *buf; - size_t *bufsz; + 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) { - int error = 0; 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); - mtx_lock(&Giant); + error = 0; switch (cmd) { /* * It is possible that kern_shmctl is being called from the Linux ABI @@ -481,9 +459,8 @@ kern_shmctl(td, shmid, cmd, buf, bufsz) if (bufsz) *bufsz = sizeof(shminfo); td->td_retval[0] = shmalloced; - goto done2; + return (0); 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 ? */ @@ -491,56 +468,50 @@ kern_shmctl(td, shmid, cmd, buf, bufsz) 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) + if (bufsz != NULL) *bufsz = sizeof(shm_info); td->td_retval[0] = shmalloced; - goto done2; + return (0); } } - if (cmd == SHM_STAT) - shmseg = shm_find_segment_by_shmidx(shmid); - else - shmseg = shm_find_segment_by_shmid(shmid); - if (shmseg == NULL) { - error = EINVAL; - goto done2; - } + 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) - goto done2; + return (error); #endif switch (cmd) { case SHM_STAT: case IPC_STAT: error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); - if (error) - goto done2; + if (error != 0) + return (error); memcpy(buf, &shmseg->u, sizeof(struct shmid_ds)); - if (bufsz) + if (bufsz != NULL) *bufsz = sizeof(struct shmid_ds); - if (cmd == SHM_STAT) - td->td_retval[0] = IXSEQ_TO_IPCID(shmid, shmseg->u.shm_perm); + if (cmd == SHM_STAT) { + td->td_retval[0] = IXSEQ_TO_IPCID(shmid, + shmseg->u.shm_perm); + } break; - case IPC_SET: { - struct shmid_ds *shmid; - - shmid = (struct shmid_ds *)buf; + case IPC_SET: + shmidp = (struct shmid_ds *)buf; error = ipcperm(td, &shmseg->u.shm_perm, IPC_M); - if (error) - goto done2; - shmseg->u.shm_perm.uid = shmid->shm_perm.uid; - shmseg->u.shm_perm.gid = shmid->shm_perm.gid; + 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) | - (shmid->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) - goto done2; + 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) { @@ -556,11 +527,21 @@ kern_shmctl(td, shmid, cmd, buf, bufsz) error = EINVAL; break; } -done2: - mtx_unlock(&Giant); 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; @@ -569,9 +550,7 @@ struct shmctl_args { }; #endif int -sys_shmctl(td, uap) - struct thread *td; - struct shmctl_args *uap; +sys_shmctl(struct thread *td, struct shmctl_args *uap) { int error = 0; struct shmid_ds buf; @@ -613,28 +592,18 @@ done: static int -shmget_existing(td, uap, mode, segnum) - struct thread *td; - struct shmget_args *uap; - int mode; - int segnum; +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 (shmseg->u.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->u.shm_perm.mode |= SHMSEG_WANTED; - error = tsleep(shmseg, PLOCK | PCATCH, "shmget", 0); - if (error) - return (error); - return (EAGAIN); - } if ((uap->shmflg & (IPC_CREAT | IPC_EXCL)) == (IPC_CREAT | IPC_EXCL)) return (EEXIST); #ifdef MAC @@ -649,18 +618,15 @@ shmget_existing(td, uap, mode, segnum) } static int -shmget_allocate_segment(td, uap, mode) - struct thread *td; - struct shmget_args *uap; - int mode; +shmget_allocate_segment(struct thread *td, struct shmget_args *uap, int mode) { - int i, segnum, shmid; - size_t size; struct ucred *cred = td->td_ucred; struct shmid_kernel *shmseg; vm_object_t shm_object; + int i, segnum; + size_t size; - GIANT_REQUIRED; + SYSVSHM_ASSERT_LOCKED(); if (uap->size < shminfo.shmmin || uap->size > shminfo.shmmax) return (EINVAL); @@ -681,6 +647,8 @@ shmget_allocate_segment(td, uap, mode) 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); @@ -695,15 +663,7 @@ shmget_allocate_segment(td, uap, mode) } PROC_UNLOCK(td->td_proc); #endif - /* - * In case we sleep in malloc(), mark the segment present but deleted - * so that noone else tries to create the same key. - */ - shmseg->u.shm_perm.mode = SHMSEG_ALLOCATED | SHMSEG_REMOVED; - shmseg->u.shm_perm.key = uap->key; - shmseg->u.shm_perm.seq = (shmseg->u.shm_perm.seq + 1) & 0x7fff; - shmid = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); - + /* * We make sure that we have allocated a pager before we need * to. @@ -728,8 +688,9 @@ shmget_allocate_segment(td, uap, mode) 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 = (shmseg->u.shm_perm.mode & SHMSEG_WANTED) | - (mode & ACCESSPERMS) | SHMSEG_ALLOCATED; + 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; @@ -741,15 +702,8 @@ shmget_allocate_segment(td, uap, mode) shmseg->u.shm_ctime = time_second; shm_committed += btoc(size); shm_nused++; - if (shmseg->u.shm_perm.mode & SHMSEG_WANTED) { - /* - * Somebody else wanted this key while we were asleep. Wake - * them up now. - */ - shmseg->u.shm_perm.mode &= ~SHMSEG_WANTED; - wakeup(shmseg); - } - td->td_retval[0] = shmid; + td->td_retval[0] = IXSEQ_TO_IPCID(segnum, shmseg->u.shm_perm); + return (0); } @@ -761,54 +715,52 @@ struct shmget_args { }; #endif int -sys_shmget(td, uap) - struct thread *td; - struct shmget_args *uap; +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); - mtx_lock(&Giant); mode = uap->shmflg & ACCESSPERMS; - if (uap->key != IPC_PRIVATE) { - again: + 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) { + if (segnum >= 0) error = shmget_existing(td, uap, mode, segnum); - if (error == EAGAIN) - goto again; - goto done2; - } - if ((uap->shmflg & IPC_CREAT) == 0) { + else if ((uap->shmflg & IPC_CREAT) == 0) error = ENOENT; - goto done2; - } + else + error = shmget_allocate_segment(td, uap, mode); } - error = shmget_allocate_segment(td, uap, mode); -done2: - mtx_unlock(&Giant); + SYSVSHM_UNLOCK(); return (error); } static void -shmfork_myhook(p1, p2) - struct proc *p1, *p2; +shmfork_myhook(struct proc *p1, struct proc *p2) { struct shmmap_state *shmmap_s; size_t size; int i; - mtx_lock(&Giant); + 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) + 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++; - mtx_unlock(&Giant); + } + } + SYSVSHM_UNLOCK(); } static void @@ -817,14 +769,15 @@ shmexit_myhook(struct vmspace *vm) struct shmmap_state *base, *shm; int i; - if ((base = vm->vm_shm) != NULL) { + base = vm->vm_shm; + if (base != NULL) { vm->vm_shm = NULL; - mtx_lock(&Giant); + SYSVSHM_LOCK(); for (i = 0, shm = base; i < shminfo.shmseg; i++, shm++) { if (shm->shmid != -1) shm_delete_mapping(vm, shm); } - mtx_unlock(&Giant); + SYSVSHM_UNLOCK(); free(base, M_SHM); } } @@ -832,8 +785,10 @@ shmexit_myhook(struct vmspace *vm) static void shmrealloc(void) { - int i; struct shmid_kernel *newsegs; + int i; + + SYSVSHM_ASSERT_LOCKED(); if (shmalloced >= shminfo.shmmni) return; @@ -891,7 +846,7 @@ static struct syscall_helper_data shm32_ #endif static int -shminit() +shminit(void) { int i, error; @@ -925,6 +880,7 @@ shminit() shm_last_free = 0; shm_nused = 0; shm_committed = 0; + sx_init(&sysvshmsx, "sysvshmsx"); shmexit_hook = &shmexit_myhook; shmfork_hook = &shmfork_myhook; @@ -940,7 +896,7 @@ shminit() } static int -shmunload() +shmunload(void) { int i; @@ -967,14 +923,19 @@ shmunload() free(shmsegs, M_SHM); shmexit_hook = NULL; shmfork_hook = NULL; + sx_destroy(&sysvshmsx); return (0); } static int sysctl_shmsegs(SYSCTL_HANDLER_ARGS) { + int error; - return (SYSCTL_OUT(req, shmsegs, shmalloced * sizeof(shmsegs[0]))); + SYSVSHM_LOCK(); + error = SYSCTL_OUT(req, shmsegs, shmalloced * sizeof(shmsegs[0])); + SYSVSHM_UNLOCK(); + return (error); } #if defined(__i386__) && (defined(COMPAT_FREEBSD4) || defined(COMPAT_43)) @@ -1006,21 +967,22 @@ oshmctl(struct thread *td, struct oshmct if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC)) return (ENOSYS); - mtx_lock(&Giant); - shmseg = shm_find_segment_by_shmid(uap->shmid); + SYSVSHM_LOCK(); + shmseg = shm_find_segment(uap->shmid, true); if (shmseg == NULL) { - error = EINVAL; - goto done2; + SYSVSHM_UNLOCK(); + return (error); } switch (uap->cmd) { case IPC_STAT: error = ipcperm(td, &shmseg->u.shm_perm, IPC_R); - if (error) - goto done2; + if (error != 0) + break; #ifdef MAC - error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd); + error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, + uap->cmd); if (error != 0) - goto done2; + break; #endif ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm); outbuf.shm_segsz = shmseg->u.shm_segsz; @@ -1032,15 +994,12 @@ oshmctl(struct thread *td, struct oshmct outbuf.shm_ctime = shmseg->u.shm_ctime; outbuf.shm_handle = shmseg->object; error = copyout(&outbuf, uap->ubuf, sizeof(outbuf)); - if (error) - goto done2; break; default: error = freebsd7_shmctl(td, (struct freebsd7_shmctl_args *)uap); break; } -done2: - mtx_unlock(&Giant); + SYSVSHM_UNLOCK(); return (error); #else return (EINVAL); @@ -1054,27 +1013,27 @@ static sy_call_t *shmcalls[] = { (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(td, uap) - struct thread *td; - /* XXX actually varargs. */ - struct shmsys_args /* { - int which; - int a2; - int a3; - int a4; - } */ *uap; +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 >= sizeof(shmcalls)/sizeof(shmcalls[0])) + if (uap->which < 0 || uap->which >= nitems(shmcalls)) return (EINVAL); - mtx_lock(&Giant); + SYSVSHM_LOCK(); error = (*shmcalls[uap->which])(td, &uap->a2); - mtx_unlock(&Giant); + SYSVSHM_UNLOCK(); return (error); } @@ -1315,9 +1274,7 @@ struct freebsd7_shmctl_args { }; #endif int -freebsd7_shmctl(td, uap) - struct thread *td; - struct freebsd7_shmctl_args *uap; +freebsd7_shmctl(struct thread *td, struct freebsd7_shmctl_args *uap) { int error = 0; struct shmid_ds_old old;
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