Somewhat modernize the SysV shm code:
- Use real locking, replace Giant with global sx protecting the subsystem. Since the subsystem' lock is no longer dropped during the sleepsk, remove not needed SHMSEG_WANTED segment flag, and revert r278963. - To do proper code simplification possible after the change of the lock, restructure several functions into _locked body and originally-named wrapper which calls into _locked variant. This allows to eliminate the 'goto done2' spread over the code. - Merge shm_find_segment_by_shmid() and shm_find_segment_by_shmidx(). - Consistently change all function prototypes to ANSI C. Reviewed by: mjg (who has earlier version of the similar patch to introduce real locking) Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 2 weeks
This commit is contained in:
Konstantin Belousov
parent
85bad58226
commit
0555fb3523
Notes:
svn2git
2020-12-20 02:59:44 +00:00
svn path=/head/; revision=280323
@ -109,7 +109,6 @@ static int shmget_existing(struct thread *td, struct shmget_args *uap,
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#define SHMSEG_FREE 0x0200
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#define SHMSEG_REMOVED 0x0400
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#define SHMSEG_ALLOCATED 0x0800
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#define SHMSEG_WANTED 0x1000
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static int shm_last_free, shm_nused, shmalloced;
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vm_size_t shm_committed;
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@ -122,8 +121,7 @@ struct shmmap_state {
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static void shm_deallocate_segment(struct shmid_kernel *);
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static int shm_find_segment_by_key(key_t);
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static struct shmid_kernel *shm_find_segment_by_shmid(int);
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static struct shmid_kernel *shm_find_segment_by_shmidx(int);
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static struct shmid_kernel *shm_find_segment(int, bool);
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static int shm_delete_mapping(struct vmspace *vm, struct shmmap_state *);
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static void shmrealloc(void);
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static int shminit(void);
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@ -181,13 +179,17 @@ SYSCTL_INT(_kern_ipc, OID_AUTO, shm_use_phys, CTLFLAG_RWTUN,
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SYSCTL_INT(_kern_ipc, OID_AUTO, shm_allow_removed, CTLFLAG_RWTUN,
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&shm_allow_removed, 0,
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"Enable/Disable attachment to attached segments marked for removal");
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SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLTYPE_OPAQUE | CTLFLAG_RD,
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NULL, 0, sysctl_shmsegs, "",
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SYSCTL_PROC(_kern_ipc, OID_AUTO, shmsegs, CTLTYPE_OPAQUE | CTLFLAG_RD |
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CTLFLAG_MPSAFE, NULL, 0, sysctl_shmsegs, "",
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"Current number of shared memory segments allocated");
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static struct sx sysvshmsx;
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#define SYSVSHM_LOCK() sx_xlock(&sysvshmsx)
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#define SYSVSHM_UNLOCK() sx_xunlock(&sysvshmsx)
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#define SYSVSHM_ASSERT_LOCKED() sx_assert(&sysvshmsx, SA_XLOCKED)
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static int
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shm_find_segment_by_key(key)
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key_t key;
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shm_find_segment_by_key(key_t key)
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{
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int i;
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@ -198,46 +200,34 @@ shm_find_segment_by_key(key)
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return (-1);
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}
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/*
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* Finds segment either by shmid if is_shmid is true, or by segnum if
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* is_shmid is false.
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*/
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static struct shmid_kernel *
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shm_find_segment_by_shmid(int shmid)
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shm_find_segment(int arg, bool is_shmid)
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{
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int segnum;
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struct shmid_kernel *shmseg;
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int segnum;
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segnum = IPCID_TO_IX(shmid);
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segnum = is_shmid ? IPCID_TO_IX(arg) : arg;
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if (segnum < 0 || segnum >= shmalloced)
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return (NULL);
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shmseg = &shmsegs[segnum];
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if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
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(!shm_allow_removed &&
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(shmseg->u.shm_perm.mode & SHMSEG_REMOVED) != 0) ||
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shmseg->u.shm_perm.seq != IPCID_TO_SEQ(shmid))
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return (NULL);
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return (shmseg);
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}
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static struct shmid_kernel *
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shm_find_segment_by_shmidx(int segnum)
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{
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struct shmid_kernel *shmseg;
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if (segnum < 0 || segnum >= shmalloced)
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return (NULL);
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shmseg = &shmsegs[segnum];
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if ((shmseg->u.shm_perm.mode & SHMSEG_ALLOCATED) == 0 ||
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(!shm_allow_removed &&
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(shmseg->u.shm_perm.mode & SHMSEG_REMOVED) != 0))
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(is_shmid && shmseg->u.shm_perm.seq != IPCID_TO_SEQ(arg)))
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return (NULL);
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return (shmseg);
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}
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static void
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shm_deallocate_segment(shmseg)
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struct shmid_kernel *shmseg;
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shm_deallocate_segment(struct shmid_kernel *shmseg)
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{
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vm_size_t size;
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GIANT_REQUIRED;
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SYSVSHM_ASSERT_LOCKED();
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vm_object_deallocate(shmseg->object);
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shmseg->object = NULL;
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@ -261,9 +251,11 @@ shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s)
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int segnum, result;
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vm_size_t size;
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GIANT_REQUIRED;
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SYSVSHM_ASSERT_LOCKED();
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segnum = IPCID_TO_IX(shmmap_s->shmid);
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KASSERT(segnum >= 0 && segnum < shmalloced,
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("segnum %d shmalloced %d", segnum, shmalloced));
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shmseg = &shmsegs[segnum];
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size = round_page(shmseg->u.shm_segsz);
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result = vm_map_remove(&vm->vm_map, shmmap_s->va, shmmap_s->va + size);
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@ -279,138 +271,110 @@ shm_delete_mapping(struct vmspace *vm, struct shmmap_state *shmmap_s)
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return (0);
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}
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#ifndef _SYS_SYSPROTO_H_
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struct shmdt_args {
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const void *shmaddr;
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};
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#endif
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int
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sys_shmdt(td, uap)
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struct thread *td;
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struct shmdt_args *uap;
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static int
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kern_shmdt_locked(struct thread *td, const void *shmaddr)
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{
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struct proc *p = td->td_proc;
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struct shmmap_state *shmmap_s;
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#ifdef MAC
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struct shmid_kernel *shmsegptr;
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#endif
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int i;
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int error = 0;
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int error, i;
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SYSVSHM_ASSERT_LOCKED();
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if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
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return (ENOSYS);
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mtx_lock(&Giant);
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shmmap_s = p->p_vmspace->vm_shm;
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if (shmmap_s == NULL) {
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error = EINVAL;
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goto done2;
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}
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if (shmmap_s == NULL)
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return (EINVAL);
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for (i = 0; i < shminfo.shmseg; i++, shmmap_s++) {
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if (shmmap_s->shmid != -1 &&
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shmmap_s->va == (vm_offset_t)uap->shmaddr) {
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shmmap_s->va == (vm_offset_t)shmaddr) {
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break;
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}
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}
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if (i == shminfo.shmseg) {
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error = EINVAL;
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goto done2;
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}
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if (i == shminfo.shmseg)
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return (EINVAL);
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#ifdef MAC
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shmsegptr = &shmsegs[IPCID_TO_IX(shmmap_s->shmid)];
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error = mac_sysvshm_check_shmdt(td->td_ucred, shmsegptr);
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if (error != 0)
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goto done2;
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return (error);
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#endif
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error = shm_delete_mapping(p->p_vmspace, shmmap_s);
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done2:
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mtx_unlock(&Giant);
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return (error);
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}
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#ifndef _SYS_SYSPROTO_H_
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struct shmat_args {
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int shmid;
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struct shmdt_args {
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const void *shmaddr;
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int shmflg;
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};
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#endif
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int
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kern_shmat(td, shmid, shmaddr, shmflg)
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struct thread *td;
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int shmid;
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const void *shmaddr;
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int shmflg;
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sys_shmdt(struct thread *td, struct shmdt_args *uap)
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{
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int error;
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SYSVSHM_LOCK();
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error = kern_shmdt_locked(td, uap->shmaddr);
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SYSVSHM_UNLOCK();
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return (error);
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}
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static int
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kern_shmat_locked(struct thread *td, int shmid, const void *shmaddr,
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int shmflg)
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{
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struct proc *p = td->td_proc;
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int i;
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struct shmid_kernel *shmseg;
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struct shmmap_state *shmmap_s = NULL;
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vm_offset_t attach_va;
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vm_prot_t prot;
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vm_size_t size;
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int rv;
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int error = 0;
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int error, i, rv;
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SYSVSHM_ASSERT_LOCKED();
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if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
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return (ENOSYS);
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mtx_lock(&Giant);
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shmmap_s = p->p_vmspace->vm_shm;
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if (shmmap_s == NULL) {
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shmmap_s = malloc(shminfo.shmseg * sizeof(struct shmmap_state),
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M_SHM, M_WAITOK);
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/*
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* If malloc() above sleeps, the Giant lock is
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* temporarily dropped, which allows another thread to
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* allocate shmmap_state and set vm_shm. Recheck
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* vm_shm and free the new shmmap_state if another one
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* is already allocated.
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*/
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if (p->p_vmspace->vm_shm != NULL) {
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free(shmmap_s, M_SHM);
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shmmap_s = p->p_vmspace->vm_shm;
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} else {
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for (i = 0; i < shminfo.shmseg; i++)
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shmmap_s[i].shmid = -1;
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p->p_vmspace->vm_shm = shmmap_s;
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}
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}
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shmseg = shm_find_segment_by_shmid(shmid);
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if (shmseg == NULL) {
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error = EINVAL;
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goto done2;
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for (i = 0; i < shminfo.shmseg; i++)
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shmmap_s[i].shmid = -1;
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KASSERT(p->p_vmspace->vm_shm == NULL, ("raced"));
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p->p_vmspace->vm_shm = shmmap_s;
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}
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shmseg = shm_find_segment(shmid, true);
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if (shmseg == NULL)
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return (EINVAL);
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error = ipcperm(td, &shmseg->u.shm_perm,
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(shmflg & SHM_RDONLY) ? IPC_R : IPC_R|IPC_W);
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if (error)
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goto done2;
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if (error != 0)
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return (error);
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#ifdef MAC
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error = mac_sysvshm_check_shmat(td->td_ucred, shmseg, shmflg);
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if (error != 0)
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goto done2;
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return (error);
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#endif
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for (i = 0; i < shminfo.shmseg; i++) {
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if (shmmap_s->shmid == -1)
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break;
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shmmap_s++;
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}
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if (i >= shminfo.shmseg) {
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error = EMFILE;
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goto done2;
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}
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if (i >= shminfo.shmseg)
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return (EMFILE);
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size = round_page(shmseg->u.shm_segsz);
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prot = VM_PROT_READ;
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if ((shmflg & SHM_RDONLY) == 0)
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prot |= VM_PROT_WRITE;
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if (shmaddr) {
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if (shmflg & SHM_RND) {
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if (shmaddr != NULL) {
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if ((shmflg & SHM_RND) != 0)
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attach_va = (vm_offset_t)shmaddr & ~(SHMLBA-1);
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} else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0) {
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else if (((vm_offset_t)shmaddr & (SHMLBA-1)) == 0)
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attach_va = (vm_offset_t)shmaddr;
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} else {
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error = EINVAL;
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goto done2;
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}
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else
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return (EINVAL);
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} else {
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/*
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* This is just a hint to vm_map_find() about where to
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@ -428,8 +392,7 @@ kern_shmat(td, shmid, shmaddr, shmflg)
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prot, prot, MAP_INHERIT_SHARE | MAP_PREFAULT_PARTIAL);
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if (rv != KERN_SUCCESS) {
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vm_object_deallocate(shmseg->object);
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error = ENOMEM;
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goto done2;
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return (ENOMEM);
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}
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shmmap_s->va = attach_va;
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@ -438,34 +401,49 @@ kern_shmat(td, shmid, shmaddr, shmflg)
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shmseg->u.shm_atime = time_second;
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shmseg->u.shm_nattch++;
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td->td_retval[0] = attach_va;
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done2:
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mtx_unlock(&Giant);
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return (error);
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}
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int
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sys_shmat(td, uap)
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struct thread *td;
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struct shmat_args *uap;
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kern_shmat(struct thread *td, int shmid, const void *shmaddr, int shmflg)
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{
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return kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg);
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int error;
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SYSVSHM_LOCK();
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error = kern_shmat_locked(td, shmid, shmaddr, shmflg);
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SYSVSHM_UNLOCK();
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return (error);
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}
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int
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kern_shmctl(td, shmid, cmd, buf, bufsz)
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struct thread *td;
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#ifndef _SYS_SYSPROTO_H_
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struct shmat_args {
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int shmid;
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int cmd;
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void *buf;
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size_t *bufsz;
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const void *shmaddr;
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int shmflg;
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};
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#endif
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int
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sys_shmat(struct thread *td, struct shmat_args *uap)
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{
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return (kern_shmat(td, uap->shmid, uap->shmaddr, uap->shmflg));
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}
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static int
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kern_shmctl_locked(struct thread *td, int shmid, int cmd, void *buf,
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size_t *bufsz)
|
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{
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int error = 0;
|
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struct shmid_kernel *shmseg;
|
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struct shmid_ds *shmidp;
|
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struct shm_info shm_info;
|
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int error;
|
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|
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SYSVSHM_ASSERT_LOCKED();
|
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|
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if (!prison_allow(td->td_ucred, PR_ALLOW_SYSVIPC))
|
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return (ENOSYS);
|
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|
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mtx_lock(&Giant);
|
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error = 0;
|
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switch (cmd) {
|
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/*
|
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* It is possible that kern_shmctl is being called from the Linux ABI
|
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@ -481,9 +459,8 @@ kern_shmctl(td, shmid, cmd, buf, bufsz)
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if (bufsz)
|
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*bufsz = sizeof(shminfo);
|
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td->td_retval[0] = shmalloced;
|
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goto done2;
|
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return (0);
|
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case SHM_INFO: {
|
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struct shm_info shm_info;
|
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shm_info.used_ids = shm_nused;
|
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shm_info.shm_rss = 0; /*XXX where to get from ? */
|
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shm_info.shm_tot = 0; /*XXX where to get from ? */
|
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@ -491,56 +468,50 @@ kern_shmctl(td, shmid, cmd, buf, bufsz)
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shm_info.swap_attempts = 0; /*XXX where to get from ? */
|
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shm_info.swap_successes = 0; /*XXX where to get from ? */
|
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memcpy(buf, &shm_info, sizeof(shm_info));
|
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if (bufsz)
|
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if (bufsz != NULL)
|
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*bufsz = sizeof(shm_info);
|
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td->td_retval[0] = shmalloced;
|
||||
goto done2;
|
||||
return (0);
|
||||
}
|
||||
}
|
||||
if (cmd == SHM_STAT)
|
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shmseg = shm_find_segment_by_shmidx(shmid);
|
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else
|
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shmseg = shm_find_segment_by_shmid(shmid);
|
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if (shmseg == NULL) {
|
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error = EINVAL;
|
||||
goto done2;
|
||||
}
|
||||
shmseg = shm_find_segment(shmid, cmd != SHM_STAT);
|
||||
if (shmseg == NULL)
|
||||
return (EINVAL);
|
||||
#ifdef MAC
|
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error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, cmd);
|
||||
if (error != 0)
|
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goto done2;
|
||||
return (error);
|
||||
#endif
|
||||
switch (cmd) {
|
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case SHM_STAT:
|
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case IPC_STAT:
|
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error = ipcperm(td, &shmseg->u.shm_perm, IPC_R);
|
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if (error)
|
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goto done2;
|
||||
if (error != 0)
|
||||
return (error);
|
||||
memcpy(buf, &shmseg->u, sizeof(struct shmid_ds));
|
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if (bufsz)
|
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if (bufsz != NULL)
|
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*bufsz = sizeof(struct shmid_ds);
|
||||
if (cmd == SHM_STAT)
|
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td->td_retval[0] = IXSEQ_TO_IPCID(shmid, shmseg->u.shm_perm);
|
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if (cmd == SHM_STAT) {
|
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td->td_retval[0] = IXSEQ_TO_IPCID(shmid,
|
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shmseg->u.shm_perm);
|
||||
}
|
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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 +592,16 @@ sys_shmctl(td, uap)
|
||||
|
||||
|
||||
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;
|
||||
int error;
|
||||
|
||||
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 +616,15 @@ 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 +645,8 @@ 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 +661,7 @@ 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 +686,9 @@ 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 +700,8 @@ 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 +713,52 @@ 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 +767,15 @@ 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 +783,10 @@ 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 +844,7 @@ static struct syscall_helper_data shm32_syscalls[] = {
|
||||
#endif
|
||||
|
||||
static int
|
||||
shminit()
|
||||
shminit(void)
|
||||
{
|
||||
int i, error;
|
||||
|
||||
@ -919,6 +872,7 @@ shminit()
|
||||
shm_last_free = 0;
|
||||
shm_nused = 0;
|
||||
shm_committed = 0;
|
||||
sx_init(&sysvshmsx, "sysvshmsx");
|
||||
shmexit_hook = &shmexit_myhook;
|
||||
shmfork_hook = &shmfork_myhook;
|
||||
|
||||
@ -934,7 +888,7 @@ shminit()
|
||||
}
|
||||
|
||||
static int
|
||||
shmunload()
|
||||
shmunload(void)
|
||||
{
|
||||
int i;
|
||||
|
||||
@ -961,14 +915,19 @@ 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))
|
||||
@ -1000,21 +959,22 @@ oshmctl(struct thread *td, struct oshmctl_args *uap)
|
||||
|
||||
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;
|
||||
#ifdef MAC
|
||||
error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg, uap->cmd);
|
||||
if (error != 0)
|
||||
goto done2;
|
||||
break;
|
||||
#ifdef MAC
|
||||
error = mac_sysvshm_check_shmctl(td->td_ucred, shmseg,
|
||||
uap->cmd);
|
||||
if (error != 0)
|
||||
break;
|
||||
#endif
|
||||
ipcperm_new2old(&shmseg->u.shm_perm, &outbuf.shm_perm);
|
||||
outbuf.shm_segsz = shmseg->u.shm_segsz;
|
||||
@ -1026,15 +986,12 @@ oshmctl(struct thread *td, struct oshmctl_args *uap)
|
||||
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);
|
||||
@ -1048,27 +1005,27 @@ 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);
|
||||
}
|
||||
|
||||
@ -1309,9 +1266,7 @@ 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;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user