X-Git-Url: https://git.saurik.com/apple/xnu.git/blobdiff_plain/43866e378188c25dd1e2208016ab3cbeb086ae6c..5c9f46613a83ebfc29a5b1f099448259e96a98f0:/bsd/kern/posix_sem.c diff --git a/bsd/kern/posix_sem.c b/bsd/kern/posix_sem.c index 56b920a4f..9dc882363 100644 --- a/bsd/kern/posix_sem.c +++ b/bsd/kern/posix_sem.c @@ -1,16 +1,19 @@ /* - * Copyright (c) 2000-2002 Apple Computer, Inc. All rights reserved. + * Copyright (c) 2000-2007 Apple Inc. All rights reserved. * - * @APPLE_LICENSE_HEADER_START@ - * - * Copyright (c) 1999-2003 Apple Computer, Inc. All Rights Reserved. + * @APPLE_OSREFERENCE_LICENSE_HEADER_START@ * * This file contains Original Code and/or Modifications of Original Code * as defined in and that are subject to the Apple Public Source License * Version 2.0 (the 'License'). You may not use this file except in - * compliance with the License. Please obtain a copy of the License at - * http://www.opensource.apple.com/apsl/ and read it before using this - * file. + * compliance with the License. The rights granted to you under the License + * may not be used to create, or enable the creation or redistribution of, + * unlawful or unlicensed copies of an Apple operating system, or to + * circumvent, violate, or enable the circumvention or violation of, any + * terms of an Apple operating system software license agreement. + * + * Please obtain a copy of the License at + * http://www.opensource.apple.com/apsl/ and read it before using this file. * * The Original Code and all software distributed under the License are * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER @@ -20,14 +23,14 @@ * Please see the License for the specific language governing rights and * limitations under the License. * - * @APPLE_LICENSE_HEADER_END@ + * @APPLE_OSREFERENCE_LICENSE_HEADER_END@ */ /* * Copyright (c) 1990, 1996-1998 Apple Computer, Inc. * All Rights Reserved. */ /* - * posix_shm.c : Support for POSIX semaphore APIs + * posix_sem.c : Support for POSIX semaphore APIs * * File: posix_sem.c * Author: Ananthakrishna Ramesh @@ -37,16 +40,22 @@ * Created for MacOSX * */ +/* + * NOTICE: This file was modified by SPARTA, Inc. in 2005 to introduce + * support for mandatory and extensible security protections. This notice + * is included in support of clause 2.2 (b) of the Apple Public License, + * Version 2.0. + */ #include #include #include #include -#include +#include #include #include -#include -#include +#include +#include #include #include #include @@ -54,14 +63,34 @@ #include #include #include +#include +#include + +#if CONFIG_MACF +#include +#include +#endif + +#include + #include #include #include #include +#include +#include #include #include #include + +#define f_flag f_fglob->fg_flag +#define f_type f_fglob->fg_ops->fo_type +#define f_msgcount f_fglob->fg_msgcount +#define f_cred f_fglob->fg_cred +#define f_ops f_fglob->fg_ops +#define f_offset f_fglob->fg_offset +#define f_data f_fglob->fg_data #define PSEMNAMLEN 31 /* maximum name segment length we bother with */ struct pseminfo { @@ -71,8 +100,10 @@ struct pseminfo { uid_t psem_uid; gid_t psem_gid; char psem_name[PSEMNAMLEN + 1]; /* segment name */ - void * psem_semobject; - struct proc * sem_proc; + semaphore_t psem_semobject; + struct label * psem_label; + pid_t psem_creator_pid; + uint64_t psem_creator_uniqueid; }; #define PSEMINFO_NULL (struct pseminfo *)0 @@ -93,6 +124,10 @@ struct psemcache { }; #define PSEMCACHE_NULL (struct psemcache *)0 +#define PSEMCACHE_NOTFOUND (0) +#define PSEMCACHE_FOUND (-1) +#define PSEMCACHE_NEGATIVE (ENOENT) + struct psemstats { long goodhits; /* hits that we can really use */ long neghits; /* negative hits that we can use */ @@ -105,7 +140,7 @@ struct psemstats { struct psemname { char *psem_nameptr; /* pointer to looked up name */ long psem_namelen; /* length of looked up component */ - u_long psem_hash; /* hash value of looked up name */ + u_int32_t psem_hash; /* hash value of looked up name */ }; struct psemnode { @@ -123,23 +158,70 @@ struct psemnode { LIST_HEAD(psemhashhead, psemcache) *psemhashtbl; /* Hash Table */ u_long psemhash; /* size of hash table - 1 */ long psemnument; /* number of cache entries allocated */ +long posix_sem_max = 10000; /* tunable for max POSIX semaphores */ + /* 10000 limits to ~1M of memory */ +SYSCTL_NODE(_kern, KERN_POSIX, posix, CTLFLAG_RW | CTLFLAG_LOCKED, 0, "Posix"); +SYSCTL_NODE(_kern_posix, OID_AUTO, sem, CTLFLAG_RW | CTLFLAG_LOCKED, 0, "Semaphores"); +SYSCTL_LONG (_kern_posix_sem, OID_AUTO, max, CTLFLAG_RW | CTLFLAG_LOCKED, &posix_sem_max, "max"); + struct psemstats psemstats; /* cache effectiveness statistics */ -static int psem_cache_search __P((struct pseminfo **, - struct psemname *, struct psemcache **)); +static int psem_access(struct pseminfo *pinfo, int mode, kauth_cred_t cred); +static int psem_cache_search(struct pseminfo **, + struct psemname *, struct psemcache **); +static int psem_delete(struct pseminfo * pinfo); + +static int psem_read (struct fileproc *fp, struct uio *uio, + int flags, vfs_context_t ctx); +static int psem_write (struct fileproc *fp, struct uio *uio, + int flags, vfs_context_t ctx); +static int psem_ioctl (struct fileproc *fp, u_long com, + caddr_t data, vfs_context_t ctx); +static int psem_select (struct fileproc *fp, int which, void *wql, vfs_context_t ctx); +static int psem_closefile (struct fileglob *fp, vfs_context_t ctx); +static int psem_unlink_internal(struct pseminfo *pinfo, struct psemcache *pcache); + +static int psem_kqfilter (struct fileproc *fp, struct knote *kn, + struct kevent_internal_s *kev, vfs_context_t ctx); + +static const struct fileops psemops = { + .fo_type = DTYPE_PSXSEM, + .fo_read = psem_read, + .fo_write = psem_write, + .fo_ioctl = psem_ioctl, + .fo_select = psem_select, + .fo_close = psem_closefile, + .fo_kqfilter = psem_kqfilter, + .fo_drain = NULL, +}; + +static lck_grp_t *psx_sem_subsys_lck_grp; +static lck_grp_attr_t *psx_sem_subsys_lck_grp_attr; +static lck_attr_t *psx_sem_subsys_lck_attr; +static lck_mtx_t psx_sem_subsys_mutex; + +#define PSEM_SUBSYS_LOCK() lck_mtx_lock(& psx_sem_subsys_mutex) +#define PSEM_SUBSYS_UNLOCK() lck_mtx_unlock(& psx_sem_subsys_mutex) +#define PSEM_SUBSYS_ASSERT_HELD() LCK_MTX_ASSERT(&psx_sem_subsys_mutex, LCK_MTX_ASSERT_OWNED) + + +static int psem_cache_add(struct pseminfo *psemp, struct psemname *pnp, struct psemcache *pcp); +static void psem_cache_delete(struct psemcache *pcp); +int psem_cache_purge_all(proc_t); + + +/* Initialize the mutex governing access to the posix sem subsystem */ +__private_extern__ void +psem_lock_init( void ) +{ + + psx_sem_subsys_lck_grp_attr = lck_grp_attr_alloc_init(); -static int psem_read __P((struct file *fp, struct uio *uio, - struct ucred *cred, int flags, struct proc *p)); -static int psem_write __P((struct file *fp, struct uio *uio, - struct ucred *cred, int flags, struct proc *p)); -static int psem_ioctl __P((struct file *fp, u_long com, - caddr_t data, struct proc *p)); -static int psem_select __P((struct file *fp, int which, void *wql, - struct proc *p)); -static int psem_closefile __P((struct file *fp, struct proc *p)); + psx_sem_subsys_lck_grp = lck_grp_alloc_init("posix shared memory", psx_sem_subsys_lck_grp_attr); -struct fileops psemops = - { psem_read, psem_write, psem_ioctl, psem_select, psem_closefile }; + psx_sem_subsys_lck_attr = lck_attr_alloc_init(); + lck_mtx_init(& psx_sem_subsys_mutex, psx_sem_subsys_lck_grp, psx_sem_subsys_lck_attr); +} /* * Lookup an entry in the cache @@ -152,17 +234,15 @@ struct fileops psemops = */ static int -psem_cache_search(psemp, pnp, pcache) - struct pseminfo **psemp; - struct psemname *pnp; - struct psemcache **pcache; +psem_cache_search(struct pseminfo **psemp, struct psemname *pnp, + struct psemcache **pcache) { - register struct psemcache *pcp, *nnp; - register struct psemhashhead *pcpp; + struct psemcache *pcp, *nnp; + struct psemhashhead *pcpp; if (pnp->psem_namelen > PSEMNAMLEN) { psemstats.longnames++; - return (0); + return PSEMCACHE_NOTFOUND; } pcpp = PSEMHASH(pnp); @@ -175,7 +255,7 @@ psem_cache_search(psemp, pnp, pcache) if (pcp == 0) { psemstats.miss++; - return (0); + return PSEMCACHE_NOTFOUND; } /* We found a "positive" match, return the vnode */ @@ -184,7 +264,7 @@ psem_cache_search(psemp, pnp, pcache) /* TOUCH(ncp); */ *psemp = pcp->pseminfo; *pcache = pcp; - return (-1); + return PSEMCACHE_FOUND; } /* @@ -192,41 +272,32 @@ psem_cache_search(psemp, pnp, pcache) * The nc_vpid field records whether this is a whiteout. */ psemstats.neghits++; - return (ENOENT); + return PSEMCACHE_NEGATIVE; } /* * Add an entry to the cache. */ static int -psem_cache_add(psemp, pnp) - struct pseminfo *psemp; - struct psemname *pnp; +psem_cache_add(struct pseminfo *psemp, struct psemname *pnp, struct psemcache *pcp) { - register struct psemcache *pcp; - register struct psemhashhead *pcpp; + struct psemhashhead *pcpp; struct pseminfo *dpinfo; struct psemcache *dpcp; #if DIAGNOSTIC - if (pnp->psem_namelen > NCHNAMLEN) + if (pnp->psem_namelen > PSEMNAMLEN) panic("cache_enter: name too long"); #endif - /* - * We allocate a new entry if we are less than the maximum - * allowed and the one at the front of the LRU list is in use. - * Otherwise we use the one at the front of the LRU list. - */ - pcp = (struct psemcache *)_MALLOC(sizeof(struct psemcache), M_SHM, M_WAITOK); + /* if the entry has already been added by some one else return */ - if (psem_cache_search(&dpinfo, pnp, &dpcp) == -1) { - _FREE(pcp, M_SHM); - return(EEXIST); + if (psem_cache_search(&dpinfo, pnp, &dpcp) == PSEMCACHE_FOUND) { + return EEXIST; } + if (psemnument >= posix_sem_max) + return ENOSPC; psemnument++; - - bzero(pcp, sizeof(struct psemcache)); /* * Fill in cache info, if vp is NULL this is a "negative" cache entry. * For negative entries, we have to record whether it is a whiteout. @@ -239,7 +310,7 @@ psem_cache_add(psemp, pnp) pcpp = PSEMHASH(pnp); #if DIAGNOSTIC { - register struct psemcache *p; + struct psemcache *p; for (p = pcpp->lh_first; p != 0; p = p->psem_hash.le_next) if (p == pcp) @@ -247,21 +318,20 @@ psem_cache_add(psemp, pnp) } #endif LIST_INSERT_HEAD(pcpp, pcp, psem_hash); - return(0); + return 0; } /* * Name cache initialization, from vfs_init() when we are booting */ void -psem_cache_init() +psem_cache_init(void) { - psemhashtbl = hashinit(desiredvnodes, M_SHM, &psemhash); + psemhashtbl = hashinit(posix_sem_max / 2, M_SHM, &psemhash); } static void -psem_cache_delete(pcp) - struct psemcache *pcp; +psem_cache_delete(struct psemcache *pcp) { #if DIAGNOSTIC if (pcp->psem_hash.le_prev == 0) @@ -270,53 +340,60 @@ psem_cache_delete(pcp) panic("namecache purge le_next"); #endif /* DIAGNOSTIC */ LIST_REMOVE(pcp, psem_hash); - pcp->psem_hash.le_prev = 0; + pcp->psem_hash.le_prev = NULL; psemnument--; } /* - * Invalidate a all entries to particular vnode. - * - * We actually just increment the v_id, that will do it. The entries will - * be purged by lookup as they get found. If the v_id wraps around, we - * need to ditch the entire cache, to avoid confusion. No valid vnode will - * ever have (v_id == 0). + * Remove all cached psem entries. Open semaphores (with a positive refcount) + * will continue to exist, but their cache entries tying them to a particular + * name/path will be removed making all future lookups on the name fail. */ -void -psem_cache_purge(void) +int +psem_cache_purge_all(__unused proc_t p) { - struct psemcache *pcp; + struct psemcache *pcp, *tmppcp; struct psemhashhead *pcpp; + int error = 0; + + if (kauth_cred_issuser(kauth_cred_get()) == 0) + return EPERM; + PSEM_SUBSYS_LOCK(); for (pcpp = &psemhashtbl[psemhash]; pcpp >= psemhashtbl; pcpp--) { - while (pcp = pcpp->lh_first) - psem_cache_delete(pcp); + LIST_FOREACH_SAFE(pcp, pcpp, psem_hash, tmppcp) { + assert(pcp->psem_nlen); + /* + * unconditionally unlink the cache entry + */ + error = psem_unlink_internal(pcp->pseminfo, pcp); + if (error) + goto out; + } } -} + assert(psemnument == 0); -struct sem_open_args { - const char *name; - int oflag; - int mode; - int value; -}; +out: + PSEM_SUBSYS_UNLOCK(); + + if (error) + printf("%s: Error %d removing all semaphores: %ld remain!\n", + __func__, error, psemnument); + return error; +} int -sem_open(p, uap, retval) - struct proc *p; - register struct sem_open_args *uap; - register_t *retval; +sem_open(proc_t p, struct sem_open_args *uap, user_addr_t *retval) { - register struct filedesc *fdp = p->p_fd; - register struct file *fp; - register struct vnode *vp; - int flags, i; - struct file *nfp; - int type, indx, error; + size_t i; + int indx, error; struct psemname nd; struct pseminfo *pinfo; - extern struct fileops psemops; - char * pnbuf; + struct fileproc *fp = NULL; + char *pnbuf = NULL; + struct pseminfo *new_pinfo = PSEMINFO_NULL; + struct psemnode *new_pnode = PSEMNODE_NULL; + struct psemcache *pcache = PSEMCACHE_NULL; char * nameptr; char * cp; size_t pathlen, plen; @@ -324,22 +401,32 @@ sem_open(p, uap, retval) int cmode = uap->mode; int value = uap->value; int incache = 0; - struct psemnode * pnode = PSEMNODE_NULL; - struct psemcache * pcache = PSEMCACHE_NULL; - kern_return_t kret = KERN_SUCCESS; - int pinfo_alloc = 0; + struct psemcache *pcp = PSEMCACHE_NULL; + kern_return_t kret = KERN_INVALID_ADDRESS; /* default fail */ + + AUDIT_ARG(fflags, uap->oflag); + AUDIT_ARG(mode, uap->mode); + AUDIT_ARG(value32, uap->value); pinfo = PSEMINFO_NULL; - MALLOC_ZONE(pnbuf, caddr_t, - MAXPATHLEN, M_NAMEI, M_WAITOK); + /* + * Preallocate everything we might need up front to avoid taking + * and dropping the lock, opening us up to race conditions. + */ + MALLOC_ZONE(pnbuf, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK | M_ZERO); + if (pnbuf == NULL) { + error = ENOSPC; + goto bad; + } + pathlen = MAXPATHLEN; - error = copyinstr(uap->name, pnbuf, - MAXPATHLEN, &pathlen); + error = copyinstr(uap->name, pnbuf, MAXPATHLEN, &pathlen); if (error) { goto bad; } - if (pathlen > PSEMNAMLEN) { + AUDIT_ARG(text, pnbuf); + if ( (pathlen > PSEMNAMLEN) ) { error = ENAMETOOLONG; goto bad; } @@ -362,30 +449,92 @@ sem_open(p, uap, retval) nameptr = pnbuf; nd.psem_nameptr = nameptr; nd.psem_namelen = plen; - nd. psem_hash =0; + nd.psem_hash = 0; for (cp = nameptr, i=1; *cp != 0 && i <= plen; i++, cp++) { nd.psem_hash += (unsigned char)*cp * i; } - error = psem_cache_search(&pinfo, &nd, &pcache); + /* + * attempt to allocate a new fp; if unsuccessful, the fp will be + * left unmodified (NULL). + */ + error = falloc(p, &fp, &indx, vfs_context_current()); + if (error) + goto bad; - if (error == ENOENT) { - error = EINVAL; + /* + * We allocate a new entry if we are less than the maximum + * allowed and the one at the front of the LRU list is in use. + * Otherwise we use the one at the front of the LRU list. + */ + MALLOC(pcp, struct psemcache *, sizeof(struct psemcache), M_SHM, M_WAITOK|M_ZERO); + if (pcp == PSEMCACHE_NULL) { + error = ENOMEM; goto bad; + } + MALLOC(new_pinfo, struct pseminfo *, sizeof(struct pseminfo), M_SHM, M_WAITOK|M_ZERO); + if (new_pinfo == NULL) { + error = ENOSPC; + goto bad; } - if (!error) { - incache = 0; - } else - incache = 1; - fmode = FFLAGS(uap->oflag); +#if CONFIG_MACF + mac_posixsem_label_init(new_pinfo); +#endif - if (error = falloc(p, &nfp, &indx)) { + /* + * Provisionally create the semaphore in the new_pinfo; we have to do + * this here to prevent locking later. We use the value of kret to + * signal success or failure, which is why we set its default value + * to KERN_INVALID_ADDRESS, above. + */ + + fmode = FFLAGS(uap->oflag); + + if((fmode & O_CREAT)) { + + if((value < 0) || (value > SEM_VALUE_MAX)) { + error = EINVAL; + goto bad; + } + + kret = semaphore_create(kernel_task, &new_pinfo->psem_semobject, SYNC_POLICY_FIFO, value); + + if (kret != KERN_SUCCESS) { + switch (kret) { + case KERN_RESOURCE_SHORTAGE: + error = ENOMEM; + break; + case KERN_PROTECTION_FAILURE: + error = EACCES; + break; + default: + error = EINVAL; + } + goto bad; + } + } + + MALLOC(new_pnode, struct psemnode *, sizeof(struct psemnode), M_SHM, M_WAITOK|M_ZERO); + if (new_pnode == NULL) { + error = ENOSPC; goto bad; } - fp = nfp; + PSEM_SUBSYS_LOCK(); + error = psem_cache_search(&pinfo, &nd, &pcache); + + if (error == PSEMCACHE_NEGATIVE) { + error = EINVAL; + goto bad_locked; + } + + if (error == PSEMCACHE_FOUND) + incache = 1; + else + incache = 0; + cmode &= ALLPERMS; if (((fmode & (O_CREAT | O_EXCL))==(O_CREAT | O_EXCL)) && incache) { @@ -394,181 +543,220 @@ sem_open(p, uap, retval) if (pinfo->psem_flags & PSEM_INDELETE) { } #endif + AUDIT_ARG(posix_ipc_perm, pinfo->psem_uid, + pinfo->psem_gid, pinfo->psem_mode); error = EEXIST; - goto bad1; + goto bad_locked; } if (((fmode & (O_CREAT | O_EXCL))== O_CREAT) && incache) { /* As per POSIX, O_CREAT has no effect */ fmode &= ~O_CREAT; } - if (fmode & O_CREAT) { - if((value < 0) && (value > SEM_VALUE_MAX)) { - error = EINVAL; - goto bad1; - } - pinfo = (struct pseminfo *)_MALLOC(sizeof(struct pseminfo), M_SHM, M_WAITOK); - bzero(pinfo, sizeof(struct pseminfo)); - pinfo_alloc = 1; + if ( (fmode & O_CREAT) ) { + /* create a new one (commit the allocation) */ + pinfo = new_pinfo; pinfo->psem_flags = PSEM_DEFINED | PSEM_INCREATE; pinfo->psem_usecount = 1; pinfo->psem_mode = cmode; - pinfo->psem_uid = p->p_ucred->cr_uid; - pinfo->psem_gid = p->p_ucred->cr_gid; - kret = semaphore_create(kernel_task, &pinfo->psem_semobject, - SYNC_POLICY_FIFO, value); - if(kret != KERN_SUCCESS) - goto bad3; + pinfo->psem_uid = kauth_getuid(); + pinfo->psem_gid = kauth_getgid(); + bcopy(pnbuf, &pinfo->psem_name[0], PSEMNAMLEN); + pinfo->psem_name[PSEMNAMLEN]= 0; pinfo->psem_flags &= ~PSEM_DEFINED; pinfo->psem_flags |= PSEM_ALLOCATED; - pinfo->sem_proc = p; + pinfo->psem_creator_pid = p->p_pid; + pinfo->psem_creator_uniqueid = p->p_uniqueid; + +#if CONFIG_MACF + error = mac_posixsem_check_create(kauth_cred_get(), nameptr); + if (error) { + goto bad_locked; + } + mac_posixsem_label_associate(kauth_cred_get(), pinfo, nameptr); +#endif } else { /* semaphore should exist as it is without O_CREAT */ if (!incache) { error = ENOENT; - goto bad1; + goto bad_locked; } if( pinfo->psem_flags & PSEM_INDELETE) { error = ENOENT; - goto bad1; + goto bad_locked; } - if (error = psem_access(pinfo, fmode, p->p_ucred, p)) - goto bad1; + AUDIT_ARG(posix_ipc_perm, pinfo->psem_uid, + pinfo->psem_gid, pinfo->psem_mode); +#if CONFIG_MACF + error = mac_posixsem_check_open(kauth_cred_get(), pinfo); + if (error) { + goto bad_locked; + } +#endif + if ( (error = psem_access(pinfo, fmode, kauth_cred_get())) ) { + goto bad_locked; + } } - pnode = (struct psemnode *)_MALLOC(sizeof(struct psemnode), M_SHM, M_WAITOK); - bzero(pnode, sizeof(struct psemnode)); if (!incache) { - if (error = psem_cache_add(pinfo, &nd)) { - goto bad2; + /* if successful, this will consume the pcp */ + if ( (error = psem_cache_add(pinfo, &nd, pcp)) ) { + goto bad_locked; } } pinfo->psem_flags &= ~PSEM_INCREATE; pinfo->psem_usecount++; - pnode->pinfo = pinfo; - fp->f_flag = flags & FMASK; - fp->f_type = DTYPE_PSXSEM; + new_pnode->pinfo = pinfo; + PSEM_SUBSYS_UNLOCK(); + + /* + * if incache, we did not use the new pcp or the new pcp or the + * new . and we must free them. + */ + if (incache) { + FREE(pcp, M_SHM); + pcp = PSEMCACHE_NULL; + if (new_pinfo != PSEMINFO_NULL) { + /* return value ignored - we can't _not_ do this */ + (void)semaphore_destroy(kernel_task, new_pinfo->psem_semobject); +#if CONFIG_MACF + mac_posixsem_label_destroy(new_pinfo); +#endif + FREE(new_pinfo, M_SHM); + new_pinfo = PSEMINFO_NULL; + } + } + + proc_fdlock(p); + fp->f_flag = fmode & FMASK; fp->f_ops = &psemops; - fp->f_data = (caddr_t)pnode; - *fdflags(p, indx) &= ~UF_RESERVED; - *retval = indx; - _FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI); + fp->f_data = (caddr_t)new_pnode; + procfdtbl_releasefd(p, indx, NULL); + fp_drop(p, indx, fp, 1); + proc_fdunlock(p); + + *retval = CAST_USER_ADDR_T(indx); + FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI); return (0); -bad3: - switch (kret) { - case KERN_RESOURCE_SHORTAGE: - error = ENOMEM; - case KERN_PROTECTION_FAILURE: - error = EACCES; - default: - error = EINVAL; - } - goto bad1; -bad2: - _FREE(pnode, M_SHM); - if (pinfo_alloc) - _FREE(pinfo, M_SHM); -bad1: - fdrelse(p, indx); - ffree(nfp); +bad_locked: + PSEM_SUBSYS_UNLOCK(); bad: - _FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI); + if (pcp != PSEMCACHE_NULL) + FREE(pcp, M_SHM); + + if (new_pnode != PSEMNODE_NULL) + FREE(new_pnode, M_SHM); + + if (fp != NULL) + fp_free(p, indx, fp); + + if (new_pinfo != PSEMINFO_NULL) { + /* + * kret signals whether or not we successfully created a + * Mach semaphore for this semaphore; if so, we need to + * destroy it here. + */ + if (kret == KERN_SUCCESS) { + /* return value ignored - we can't _not_ do this */ + (void)semaphore_destroy(kernel_task, new_pinfo->psem_semobject); + } +#if CONFIG_MACF + mac_posixsem_label_destroy(new_pinfo); +#endif + FREE(new_pinfo, M_SHM); + } + + if (pnbuf != NULL) + FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI); return (error); } -int -psem_access(pinfo, mode, cred, p) - struct pseminfo *pinfo; - int mode; - struct ucred *cred; - struct proc *p; +/* + * XXX This code is repeated in several places + */ +static int +psem_access(struct pseminfo *pinfo, int mode, kauth_cred_t cred) { - mode_t mask; - register gid_t *gp; - int i, error; + int mode_req = ((mode & FREAD) ? S_IRUSR : 0) | + ((mode & FWRITE) ? S_IWUSR : 0); /* Otherwise, user id 0 always gets access. */ - if (cred->cr_uid == 0) + if (!suser(cred, NULL)) return (0); - mask = 0; - - /* Otherwise, check the owner. */ - if (cred->cr_uid == pinfo->psem_uid) { - if (mode & FREAD) - mask |= S_IRUSR; - if (mode & FWRITE) - mask |= S_IWUSR; - return ((pinfo->psem_mode & mask) == mask ? 0 : EACCES); - } - - /* Otherwise, check the groups. */ - for (i = 0, gp = cred->cr_groups; i < cred->cr_ngroups; i++, gp++) - if (pinfo->psem_gid == *gp) { - if (mode & FREAD) - mask |= S_IRGRP; - if (mode & FWRITE) - mask |= S_IWGRP; - return ((pinfo->psem_mode & mask) == mask ? 0 : EACCES); - } + return(posix_cred_access(cred, pinfo->psem_uid, pinfo->psem_gid, pinfo->psem_mode, mode_req)); +} + +static int +psem_unlink_internal(struct pseminfo *pinfo, struct psemcache *pcache) +{ + PSEM_SUBSYS_ASSERT_HELD(); + + if (!pinfo || !pcache) + return EINVAL; + + if ((pinfo->psem_flags & (PSEM_DEFINED | PSEM_ALLOCATED)) == 0) + return EINVAL; + + if (pinfo->psem_flags & PSEM_INDELETE) + return 0; + + AUDIT_ARG(posix_ipc_perm, pinfo->psem_uid, pinfo->psem_gid, + pinfo->psem_mode); - /* Otherwise, check everyone else. */ - if (mode & FREAD) - mask |= S_IROTH; - if (mode & FWRITE) - mask |= S_IWOTH; - return ((pinfo->psem_mode & mask) == mask ? 0 : EACCES); + pinfo->psem_flags |= PSEM_INDELETE; + pinfo->psem_usecount--; + + if (!pinfo->psem_usecount) { + psem_delete(pinfo); + FREE(pinfo,M_SHM); + } else { + pinfo->psem_flags |= PSEM_REMOVED; + } + + psem_cache_delete(pcache); + FREE(pcache, M_SHM); + return 0; } -struct sem_unlink_args { - const char *name; -}; int -sem_unlink(p, uap, retval) - struct proc *p; - register struct sem_unlink_args *uap; - register_t *retval; +sem_unlink(__unused proc_t p, struct sem_unlink_args *uap, __unused int32_t *retval) { - register struct filedesc *fdp = p->p_fd; - register struct file *fp; - int flags, i; + size_t i; int error=0; struct psemname nd; struct pseminfo *pinfo; - extern struct fileops psemops; - char * pnbuf; char * nameptr; char * cp; - size_t pathlen, plen; - int fmode, cmode ; - int incache = 0; - struct psemnode * pnode = PSEMNODE_NULL; + char * pnbuf; + size_t pathlen; struct psemcache *pcache = PSEMCACHE_NULL; - kern_return_t kret; pinfo = PSEMINFO_NULL; - MALLOC_ZONE(pnbuf, caddr_t, - MAXPATHLEN, M_NAMEI, M_WAITOK); + MALLOC_ZONE(pnbuf, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK); + if (pnbuf == NULL) { + return(ENOSPC); /* XXX non-standard */ + } pathlen = MAXPATHLEN; - error = copyinstr(uap->name, pnbuf, - MAXPATHLEN, &pathlen); + error = copyinstr(uap->name, pnbuf, MAXPATHLEN, &pathlen); if (error) { goto bad; } + AUDIT_ARG(text, pnbuf); if (pathlen > PSEMNAMLEN) { error = ENAMETOOLONG; goto bad; } + nameptr = pnbuf; #ifdef PSXSEM_NAME_RESTRICT - nameptr = pnbuf; if (*nameptr == '/') { while (*(nameptr++) == '/') { - plen--; + pathlen--; error = EINVAL; goto bad; } @@ -578,160 +766,173 @@ sem_unlink(p, uap, retval) } #endif /* PSXSEM_NAME_RESTRICT */ - plen = pathlen; - nameptr = pnbuf; nd.psem_nameptr = nameptr; - nd.psem_namelen = plen; + nd.psem_namelen = pathlen; nd. psem_hash =0; - for (cp = nameptr, i=1; *cp != 0 && i <= plen; i++, cp++) { + for (cp = nameptr, i=1; *cp != 0 && i <= pathlen; i++, cp++) { nd.psem_hash += (unsigned char)*cp * i; } + PSEM_SUBSYS_LOCK(); error = psem_cache_search(&pinfo, &nd, &pcache); - if (error == ENOENT) { + if (error != PSEMCACHE_FOUND) { + PSEM_SUBSYS_UNLOCK(); error = EINVAL; goto bad; } - if (!error) { - error = EINVAL; - goto bad; - } else - incache = 1; - if (error = psem_access(pinfo, pinfo->psem_mode, p->p_ucred, p)) - goto bad; - if ((pinfo->psem_flags & (PSEM_DEFINED | PSEM_ALLOCATED))==0) { - return (EINVAL); +#if CONFIG_MACF + error = mac_posixsem_check_unlink(kauth_cred_get(), pinfo, nameptr); + if (error) { + PSEM_SUBSYS_UNLOCK(); + goto bad; } - - if (pinfo->psem_flags & PSEM_INDELETE) { - error = 0; +#endif + if ( (error = psem_access(pinfo, pinfo->psem_mode, kauth_cred_get())) ) { + PSEM_SUBSYS_UNLOCK(); goto bad; } - pinfo->psem_flags |= PSEM_INDELETE; - pinfo->psem_usecount--; - if (!pinfo->psem_usecount) { - psem_delete(pinfo); - _FREE(pinfo,M_SHM); - } else - pinfo->psem_flags |= PSEM_REMOVED; + error = psem_unlink_internal(pinfo, pcache); + PSEM_SUBSYS_UNLOCK(); - psem_cache_delete(pcache); - _FREE(pcache, M_SHM); - error = 0; bad: - _FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI); - return (error); + FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI); + return error; } -struct sem_close_args { - sem_t *sem; -}; - int -sem_close(p, uap, retval) - struct proc *p; - struct sem_close_args *uap; - register_t *retval; +sem_close(proc_t p, struct sem_close_args *uap, __unused int32_t *retval) { - int fd = (int)uap->sem; - register struct filedesc *fdp = p->p_fd; - register struct file *fp; + int fd = CAST_DOWN_EXPLICIT(int,uap->sem); + struct fileproc *fp; int error = 0; + AUDIT_ARG(fd, fd); /* XXX This seems wrong; uap->sem is a pointer */ - if ((u_int)fd >= fdp->fd_nfiles || - (fp = fdp->fd_ofiles[fd]) == NULL || - (fdp->fd_ofileflags[fd] & UF_RESERVED)) - return (EBADF); - fdrelse(p, fd); - if( error = closef(fp, p)) + proc_fdlock(p); + error = fp_lookup(p,fd, &fp, 1); + if (error) { + proc_fdunlock(p); return(error); - return(0); + } + procfdtbl_markclosefd(p, fd); + fileproc_drain(p, fp); + fdrelse(p, fd); + error = closef_locked(fp, fp->f_fglob, p); + fileproc_free(fp); + proc_fdunlock(p); + return(error); } -struct sem_wait_args { - sem_t *sem; -}; +int +sem_wait(proc_t p, struct sem_wait_args *uap, int32_t *retval) +{ + __pthread_testcancel(1); + return(sem_wait_nocancel(p, (struct sem_wait_nocancel_args *)uap, retval)); +} int -sem_wait(p, uap, retval) - struct proc *p; - struct sem_wait_args *uap; - register_t *retval; +sem_wait_nocancel(proc_t p, struct sem_wait_nocancel_args *uap, __unused int32_t *retval) { - int fd = (int)uap->sem; - register struct filedesc *fdp = p->p_fd; - struct file *fp; + int fd = CAST_DOWN_EXPLICIT(int,uap->sem); + struct fileproc *fp; struct pseminfo * pinfo; struct psemnode * pnode ; kern_return_t kret; int error; - if (error = fdgetf(p, (int)uap->sem, &fp)) + error = fp_getfpsem(p, fd, &fp, &pnode); + if (error) return (error); - if (fp->f_type != DTYPE_PSXSEM) - return(EBADF); - if (((pnode = (struct psemnode *)fp->f_data)) == PSEMNODE_NULL ) - return(EINVAL); - if ((pinfo = pnode->pinfo) == PSEMINFO_NULL) - return(EINVAL); + if (((pnode = (struct psemnode *)fp->f_data)) == PSEMNODE_NULL ) { + error = EINVAL; + goto out; + } + PSEM_SUBSYS_LOCK(); + if ((pinfo = pnode->pinfo) == PSEMINFO_NULL) { + PSEM_SUBSYS_UNLOCK(); + error = EINVAL; + goto out; + } if ((pinfo->psem_flags & (PSEM_DEFINED | PSEM_ALLOCATED)) != PSEM_ALLOCATED) { - return(EINVAL); + PSEM_SUBSYS_UNLOCK(); + error = EINVAL; + goto out; } - +#if CONFIG_MACF + error = mac_posixsem_check_wait(kauth_cred_get(), pinfo); + if (error) { + PSEM_SUBSYS_UNLOCK(); + goto out; + } +#endif + PSEM_SUBSYS_UNLOCK(); kret = semaphore_wait(pinfo->psem_semobject); switch (kret) { case KERN_INVALID_ADDRESS: case KERN_PROTECTION_FAILURE: - return (EACCES); + error = EACCES; + break; case KERN_ABORTED: case KERN_OPERATION_TIMED_OUT: - return (EINTR); + error = EINTR; + break; case KERN_SUCCESS: - return(0); + error = 0; + break; default: - return (EINVAL); + error = EINVAL; + break; } -} +out: + fp_drop(p, fd, fp, 0); + return(error); -struct sem_trywait_args { - sem_t *sem; -}; +} int -sem_trywait(p, uap, retval) - struct proc *p; - struct sem_trywait_args *uap; - register_t *retval; +sem_trywait(proc_t p, struct sem_trywait_args *uap, __unused int32_t *retval) { - int fd = (int)uap->sem; - register struct filedesc *fdp = p->p_fd; - struct file *fp; + int fd = CAST_DOWN_EXPLICIT(int,uap->sem); + struct fileproc *fp; struct pseminfo * pinfo; struct psemnode * pnode ; kern_return_t kret; mach_timespec_t wait_time; int error; - if (error = fdgetf(p, (int)uap->sem, &fp)) + error = fp_getfpsem(p, fd, &fp, &pnode); + if (error) return (error); - if (fp->f_type != DTYPE_PSXSEM) - return(EBADF); - if (((pnode = (struct psemnode *)fp->f_data)) == PSEMNODE_NULL ) - return(EINVAL); - if ((pinfo = pnode->pinfo) == PSEMINFO_NULL) - return(EINVAL); + if (((pnode = (struct psemnode *)fp->f_data)) == PSEMNODE_NULL ) { + error = EINVAL; + goto out; + } + PSEM_SUBSYS_LOCK(); + if ((pinfo = pnode->pinfo) == PSEMINFO_NULL) { + PSEM_SUBSYS_UNLOCK(); + error = EINVAL; + goto out; + } if ((pinfo->psem_flags & (PSEM_DEFINED | PSEM_ALLOCATED)) != PSEM_ALLOCATED) { - return(EINVAL); + PSEM_SUBSYS_UNLOCK(); + error = EINVAL; + goto out; } - +#if CONFIG_MACF + error = mac_posixsem_check_wait(kauth_cred_get(), pinfo); + if (error) { + PSEM_SUBSYS_UNLOCK(); + goto out; + } +#endif + PSEM_SUBSYS_UNLOCK(); wait_time.tv_sec = 0; wait_time.tv_nsec = 0; @@ -739,121 +940,99 @@ sem_trywait(p, uap, retval) switch (kret) { case KERN_INVALID_ADDRESS: case KERN_PROTECTION_FAILURE: - return (EINVAL); + error = EINVAL; + break; case KERN_ABORTED: - return (EINTR); + error = EINTR; + break; case KERN_OPERATION_TIMED_OUT: - return (EAGAIN); + error = EAGAIN; + break; case KERN_SUCCESS: - return(0); + error = 0; + break; default: - return (EINVAL); + error = EINVAL; + break; } +out: + fp_drop(p, fd, fp, 0); + return(error); } -struct sem_post_args { - sem_t *sem; -}; - int -sem_post(p, uap, retval) - struct proc *p; - struct sem_post_args *uap; - register_t *retval; +sem_post(proc_t p, struct sem_post_args *uap, __unused int32_t *retval) { - int fd = (int)uap->sem; - register struct filedesc *fdp = p->p_fd; - struct file *fp; + int fd = CAST_DOWN_EXPLICIT(int,uap->sem); + struct fileproc *fp; struct pseminfo * pinfo; struct psemnode * pnode ; kern_return_t kret; int error; - if (error = fdgetf(p, (int)uap->sem, &fp)) + error = fp_getfpsem(p, fd, &fp, &pnode); + if (error) return (error); - if (fp->f_type != DTYPE_PSXSEM) - return(EBADF); - if (((pnode = (struct psemnode *)fp->f_data)) == PSEMNODE_NULL ) - return(EINVAL); - if ((pinfo = pnode->pinfo) == PSEMINFO_NULL) - return(EINVAL); + if (((pnode = (struct psemnode *)fp->f_data)) == PSEMNODE_NULL ) { + error = EINVAL; + goto out; + } + PSEM_SUBSYS_LOCK(); + if ((pinfo = pnode->pinfo) == PSEMINFO_NULL) { + PSEM_SUBSYS_UNLOCK(); + error = EINVAL; + goto out; + } if ((pinfo->psem_flags & (PSEM_DEFINED | PSEM_ALLOCATED)) != PSEM_ALLOCATED) { - return(EINVAL); + PSEM_SUBSYS_UNLOCK(); + error = EINVAL; + goto out; } - +#if CONFIG_MACF + error = mac_posixsem_check_post(kauth_cred_get(), pinfo); + if (error) { + PSEM_SUBSYS_UNLOCK(); + goto out; + } +#endif + PSEM_SUBSYS_UNLOCK(); kret = semaphore_signal(pinfo->psem_semobject); switch (kret) { case KERN_INVALID_ADDRESS: case KERN_PROTECTION_FAILURE: - return (EINVAL); + error = EINVAL; + break; case KERN_ABORTED: case KERN_OPERATION_TIMED_OUT: - return (EINTR); + error = EINTR; + break; case KERN_SUCCESS: - return(0); + error = 0; + break; default: - return (EINVAL); + error = EINVAL; + break; } -} - -struct sem_init_args { - sem_t *sem; - int phsared; - unsigned int value; -}; - -int -sem_init(p, uap, retval) - struct proc *p; - struct sem_init_args *uap; - register_t *retval; -{ - return(ENOSYS); -} - -struct sem_destroy_args { - sem_t *sem; -}; - -int -sem_destroy(p, uap, retval) - struct proc *p; - struct sem_destroy_args *uap; - register_t *retval; -{ - return(ENOSYS); -} - -struct sem_getvalue_args { - sem_t *sem; - int * sval; -}; - -int -sem_getvalue(p, uap, retval) - struct proc *p; - struct sem_getvalue_args *uap; - register_t *retval; -{ - return(ENOSYS); +out: + fp_drop(p, fd, fp, 0); + return(error); } static int -psem_close(pnode, flags, cred, p) - register struct psemnode *pnode; - int flags; - struct ucred *cred; - struct proc *p; +psem_close(struct psemnode *pnode, __unused int flags) { int error=0; - kern_return_t kret; - register struct pseminfo *pinfo; + struct pseminfo *pinfo; - if ((pinfo = pnode->pinfo) == PSEMINFO_NULL) + PSEM_SUBSYS_LOCK(); + if ((pinfo = pnode->pinfo) == PSEMINFO_NULL){ + PSEM_SUBSYS_UNLOCK(); return(EINVAL); + } if ((pinfo->psem_flags & PSEM_ALLOCATED) != PSEM_ALLOCATED) { + PSEM_SUBSYS_UNLOCK(); return(EINVAL); } #if DIAGNOSTIC @@ -864,29 +1043,41 @@ psem_close(pnode, flags, cred, p) pinfo->psem_usecount--; if ((pinfo->psem_flags & PSEM_REMOVED) && !pinfo->psem_usecount) { + PSEM_SUBSYS_UNLOCK(); + /* lock dropped as only semaphore is destroyed here */ error = psem_delete(pinfo); - _FREE(pinfo,M_SHM); + FREE(pinfo,M_SHM); + } else { + PSEM_SUBSYS_UNLOCK(); } - _FREE(pnode, M_SHM); + /* subsystem lock is dropped when we get here */ + FREE(pnode, M_SHM); return (error); } static int -psem_closefile(fp, p) - struct file *fp; - struct proc *p; +psem_closefile(struct fileglob *fg, __unused vfs_context_t ctx) { + int error; - return (psem_close(((struct psemnode *)fp->f_data), fp->f_flag, - fp->f_cred, p)); + /* + * Not locked as psem_close is called only from here and is locked + * properly + */ + error = psem_close(((struct psemnode *)fg->fg_data), fg->fg_flag); + + return(error); } -int +static int psem_delete(struct pseminfo * pinfo) { kern_return_t kret; kret = semaphore_destroy(kernel_task, pinfo->psem_semobject); +#if CONFIG_MACF + mac_posixsem_label_destroy(pinfo); +#endif switch (kret) { case KERN_INVALID_ADDRESS: @@ -903,43 +1094,91 @@ psem_delete(struct pseminfo * pinfo) } static int -psem_read(fp, uio, cred, flags, p) - struct file *fp; - struct uio *uio; - struct ucred *cred; - int flags; - struct proc *p; +psem_read(__unused struct fileproc *fp, __unused struct uio *uio, + __unused int flags, __unused vfs_context_t ctx) { - return(EOPNOTSUPP); + return(ENOTSUP); } static int -psem_write(fp, uio, cred, flags, p) - struct file *fp; - struct uio *uio; - struct ucred *cred; - int flags; - struct proc *p; +psem_write(__unused struct fileproc *fp, __unused struct uio *uio, + __unused int flags, __unused vfs_context_t ctx) { - return(EOPNOTSUPP); + return(ENOTSUP); } static int -psem_ioctl(fp, com, data, p) - struct file *fp; - u_long com; - caddr_t data; - struct proc *p; +psem_ioctl(__unused struct fileproc *fp, __unused u_long com, + __unused caddr_t data, __unused vfs_context_t ctx) { - return(EOPNOTSUPP); + return(ENOTSUP); } static int -psem_select(fp, which, wql, p) - struct file *fp; - int which; - void *wql; - struct proc *p; +psem_select(__unused struct fileproc *fp, __unused int which, + __unused void *wql, __unused vfs_context_t ctx) { - return(EOPNOTSUPP); + return(ENOTSUP); } + +static int +psem_kqfilter(__unused struct fileproc *fp, struct knote *kn, + __unused struct kevent_internal_s *kev, __unused vfs_context_t ctx) +{ + kn->kn_flags = EV_ERROR; + kn->kn_data = ENOTSUP; + return 0; +} + +int +fill_pseminfo(struct psemnode *pnode, struct psem_info * info) +{ + struct pseminfo *pinfo; + struct vinfo_stat *sb; + + PSEM_SUBSYS_LOCK(); + if ((pinfo = pnode->pinfo) == PSEMINFO_NULL){ + PSEM_SUBSYS_UNLOCK(); + return(EINVAL); + } + +#if 0 + if ((pinfo->psem_flags & PSEM_ALLOCATED) != PSEM_ALLOCATED) { + PSEM_SUBSYS_UNLOCK(); + return(EINVAL); + } +#endif + + sb = &info->psem_stat; + bzero(sb, sizeof(struct vinfo_stat)); + + sb->vst_mode = pinfo->psem_mode; + sb->vst_uid = pinfo->psem_uid; + sb->vst_gid = pinfo->psem_gid; + sb->vst_size = pinfo->psem_usecount; + bcopy(&pinfo->psem_name[0], &info->psem_name[0], PSEMNAMLEN+1); + + PSEM_SUBSYS_UNLOCK(); + return(0); +} + +#if CONFIG_MACF +void +psem_label_associate(struct fileproc *fp, struct vnode *vp, vfs_context_t ctx) +{ + struct psemnode *pnode; + struct pseminfo *psem; + + PSEM_SUBSYS_LOCK(); + pnode = (struct psemnode *)fp->f_fglob->fg_data; + if (pnode != NULL) { + psem = pnode->pinfo; + if (psem != NULL) + mac_posixsem_vnode_label_associate( + vfs_context_ucred(ctx), psem, psem->psem_label, + vp, vp->v_label); + } + PSEM_SUBSYS_UNLOCK(); +} +#endif +