};
#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 */
static int psem_access(struct pseminfo *pinfo, int mode, kauth_cred_t cred);
static int psem_cache_search(struct pseminfo **,
- struct psemname *, struct psemcache **);
+ 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);
+ int flags, vfs_context_t ctx);
static int psem_write (struct fileproc *fp, struct uio *uio,
- int flags, vfs_context_t ctx);
+ int flags, vfs_context_t ctx);
static int psem_ioctl (struct fileproc *fp, u_long com,
- caddr_t data, vfs_context_t ctx);
+ 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, vfs_context_t ctx);
+static int psem_kqfilter (struct fileproc *fp, struct knote *kn,
+ struct kevent_internal_s *kev, vfs_context_t ctx);
static const struct fileops psemops = {
- DTYPE_PSXSEM,
- psem_read,
- psem_write,
- psem_ioctl,
- psem_select,
- psem_closefile,
- psem_kqfilter,
- NULL
+ .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;
#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 )
if (pnp->psem_namelen > PSEMNAMLEN) {
psemstats.longnames++;
- return (0);
+ return PSEMCACHE_NOTFOUND;
}
pcpp = PSEMHASH(pnp);
if (pcp == 0) {
psemstats.miss++;
- return (0);
+ return PSEMCACHE_NOTFOUND;
}
/* We found a "positive" match, return the vnode */
/* TOUCH(ncp); */
*psemp = pcp->pseminfo;
*pcache = pcp;
- return (-1);
+ return PSEMCACHE_FOUND;
}
/*
* The nc_vpid field records whether this is a whiteout.
*/
psemstats.neghits++;
- return (ENOENT);
+ return PSEMCACHE_NEGATIVE;
}
/*
/* if the entry has already been added by some one else return */
- if (psem_cache_search(&dpinfo, pnp, &dpcp) == -1) {
- return(EEXIST);
+ if (psem_cache_search(&dpinfo, pnp, &dpcp) == PSEMCACHE_FOUND) {
+ return EEXIST;
}
if (psemnument >= posix_sem_max)
- return(ENOSPC);
+ return ENOSPC;
psemnument++;
/*
* Fill in cache info, if vp is NULL this is a "negative" cache entry.
}
#endif
LIST_INSERT_HEAD(pcpp, pcp, psem_hash);
- return(0);
+ return 0;
}
/*
psemnument--;
}
-#if NOT_USED
/*
- * 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.
*/
-static 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);
+
+out:
+ PSEM_SUBSYS_UNLOCK();
+
+ if (error)
+ printf("%s: Error %d removing all semaphores: %ld remain!\n",
+ __func__, error, psemnument);
+ return error;
}
-#endif /* NOT_USED */
int
sem_open(proc_t p, struct sem_open_args *uap, user_addr_t *retval)
* 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);
+ MALLOC_ZONE(pnbuf, caddr_t, MAXPATHLEN, M_NAMEI, M_WAITOK | M_ZERO);
if (pnbuf == NULL) {
error = ENOSPC;
goto bad;
PSEM_SUBSYS_LOCK();
error = psem_cache_search(&pinfo, &nd, &pcache);
- if (error == ENOENT) {
+ if (error == PSEMCACHE_NEGATIVE) {
error = EINVAL;
goto bad_locked;
-
}
- if (!error) {
- incache = 0;
- } else
+
+ if (error == PSEMCACHE_FOUND)
incache = 1;
+ else
+ incache = 0;
cmode &= ALLPERMS;
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);
+
+ 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;
+}
+
+
int
sem_unlink(__unused proc_t p, struct sem_unlink_args *uap, __unused int32_t *retval)
{
int error=0;
struct psemname nd;
struct pseminfo *pinfo;
- char * pnbuf;
char * nameptr;
char * cp;
- size_t pathlen, plen;
- int incache = 0;
+ char * pnbuf;
+ size_t pathlen;
struct psemcache *pcache = PSEMCACHE_NULL;
pinfo = PSEMINFO_NULL;
goto bad;
}
+ nameptr = pnbuf;
#ifdef PSXSEM_NAME_RESTRICT
- nameptr = pnbuf;
if (*nameptr == '/') {
while (*(nameptr++) == '/') {
- plen--;
+ pathlen--;
error = EINVAL;
goto bad;
}
}
#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) {
- PSEM_SUBSYS_UNLOCK();
- error = EINVAL;
- goto bad;
- } else
- incache = 1;
+
#if CONFIG_MACF
error = mac_posixsem_check_unlink(kauth_cred_get(), pinfo, nameptr);
if (error) {
goto bad;
}
- if ((pinfo->psem_flags & (PSEM_DEFINED | PSEM_ALLOCATED))==0) {
- PSEM_SUBSYS_UNLOCK();
- error = EINVAL;
- goto bad;
- }
-
- if ( (pinfo->psem_flags & PSEM_INDELETE) ) {
- PSEM_SUBSYS_UNLOCK();
- error = 0;
- goto bad;
- }
-
- AUDIT_ARG(posix_ipc_perm, pinfo->psem_uid, pinfo->psem_gid,
- pinfo->psem_mode);
-
- 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);
+ error = psem_unlink_internal(pinfo, pcache);
PSEM_SUBSYS_UNLOCK();
- FREE(pcache, M_SHM);
- error = 0;
+
bad:
FREE_ZONE(pnbuf, MAXPATHLEN, M_NAMEI);
- return (error);
+ return error;
}
int
}
static int
-psem_read(__unused struct fileproc *fp, __unused struct uio *uio,
- __unused int flags, __unused vfs_context_t ctx)
+psem_read(__unused struct fileproc *fp, __unused struct uio *uio,
+ __unused int flags, __unused vfs_context_t ctx)
{
return(ENOTSUP);
}
static int
-psem_write(__unused struct fileproc *fp, __unused struct uio *uio,
- __unused int flags, __unused vfs_context_t ctx)
+psem_write(__unused struct fileproc *fp, __unused struct uio *uio,
+ __unused int flags, __unused vfs_context_t ctx)
{
return(ENOTSUP);
}
static int
-psem_ioctl(__unused struct fileproc *fp, __unused u_long com,
- __unused caddr_t data, __unused vfs_context_t ctx)
+psem_ioctl(__unused struct fileproc *fp, __unused u_long com,
+ __unused caddr_t data, __unused vfs_context_t ctx)
{
return(ENOTSUP);
}
static int
-psem_select(__unused struct fileproc *fp, __unused int which,
- __unused void *wql, __unused vfs_context_t ctx)
+psem_select(__unused struct fileproc *fp, __unused int which,
+ __unused void *wql, __unused vfs_context_t ctx)
{
return(ENOTSUP);
}
static int
-psem_kqfilter(__unused struct fileproc *fp, __unused struct knote *kn,
- __unused vfs_context_t ctx)
+psem_kqfilter(__unused struct fileproc *fp, struct knote *kn,
+ __unused struct kevent_internal_s *kev, __unused vfs_context_t ctx)
{
- return (ENOTSUP);
+ kn->kn_flags = EV_ERROR;
+ kn->kn_data = ENOTSUP;
+ return 0;
}
int
projects / apple / xnu.git / blobdiff