diff options
Diffstat (limited to 'usr/src/uts/common/os/shm.c')
| -rw-r--r-- | usr/src/uts/common/os/shm.c | 41 |
1 files changed, 39 insertions, 2 deletions
diff --git a/usr/src/uts/common/os/shm.c b/usr/src/uts/common/os/shm.c index bacc595f78..5deae96d73 100644 --- a/usr/src/uts/common/os/shm.c +++ b/usr/src/uts/common/os/shm.c @@ -21,6 +21,7 @@ /* * Copyright (c) 1986, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright 2016 Joyent, Inc. */ /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ @@ -319,6 +320,7 @@ shmat(int shmid, caddr_t uaddr, int uflags, uintptr_t *rvp) size_t share_size; struct shm_data ssd; uintptr_t align_hint; + long curprot; /* * Pick a share pagesize to use, if (!isspt(sp)). @@ -453,6 +455,7 @@ shmat(int shmid, caddr_t uaddr, int uflags, uintptr_t *rvp) } } + curprot = sp->shm_opts & SHM_PROT_MASK; if (!isspt(sp)) { error = sptcreate(size, &segspt, sp->shm_amp, prot, flags, share_szc); @@ -462,8 +465,8 @@ shmat(int shmid, caddr_t uaddr, int uflags, uintptr_t *rvp) } sp->shm_sptinfo->sptas = segspt->s_as; sp->shm_sptseg = segspt; - sp->shm_sptprot = prot; - } else if ((prot & sp->shm_sptprot) != sp->shm_sptprot) { + sp->shm_opts = (sp->shm_opts & ~SHM_PROT_MASK) | prot; + } else if ((prot & curprot) != curprot) { /* * Ensure we're attaching to an ISM segment with * fewer or equal permissions than what we're @@ -748,6 +751,23 @@ shmctl(int shmid, int cmd, void *arg) } break; + /* Stage segment for removal, but don't remove until last detach */ + case SHM_RMID: + if ((error = secpolicy_ipc_owner(cr, (kipc_perm_t *)sp)) != 0) + break; + + /* + * If attached, just mark it as a pending remove, otherwise + * we must perform the normal ipc_rmid now. + */ + if ((sp->shm_perm.ipc_ref - 1) > 0) { + sp->shm_opts |= SHM_RM_PENDING; + } else { + mutex_exit(lock); + return (ipc_rmid(shm_svc, shmid, cr)); + } + break; + default: error = EINVAL; break; @@ -778,6 +798,23 @@ shm_detach(proc_t *pp, segacct_t *sap) sp->shm_ismattch--; sp->shm_dtime = gethrestime_sec(); sp->shm_lpid = pp->p_pid; + if ((sp->shm_opts & SHM_RM_PENDING) != 0 && + sp->shm_perm.ipc_ref == 2) { + /* + * If this is the last detach of the segment across the whole + * system then now we can perform the delayed IPC_RMID. + * The ipc_ref count has 1 for the original 'get' and one for + * each 'attach' (see 'stat' handling in shmctl). + */ + sp->shm_opts &= ~SHM_RM_PENDING; + mutex_enter(&shm_svc->ipcs_lock); + ipc_rmsvc(shm_svc, (kipc_perm_t *)sp); /* Drops lock */ + ASSERT(!MUTEX_HELD(&shm_svc->ipcs_lock)); + ASSERT(((kipc_perm_t *)sp)->ipc_ref > 0); + + /* Lock was dropped, need to retake it for following rele. */ + (void) ipc_lock(shm_svc, sp->shm_perm.ipc_id); + } ipc_rele(shm_svc, (kipc_perm_t *)sp); /* Drops lock */ kmem_free(sap, sizeof (segacct_t)); |