diff options
Diffstat (limited to 'sys/vm/vm_mmap.c')
| -rw-r--r-- | sys/vm/vm_mmap.c | 52 |
1 files changed, 37 insertions, 15 deletions
diff --git a/sys/vm/vm_mmap.c b/sys/vm/vm_mmap.c index 43d75a562922..6328ff74a018 100644 --- a/sys/vm/vm_mmap.c +++ b/sys/vm/vm_mmap.c @@ -188,7 +188,7 @@ mmap(p, uap) register struct mmap_args *uap; { register struct filedesc *fdp = p->p_fd; - register struct file *fp; + register struct file *fp = NULL; struct vnode *vp; vm_offset_t addr; vm_size_t size, pageoff; @@ -283,6 +283,12 @@ mmap(p, uap) return (EBADF); if (fp->f_type != DTYPE_VNODE) return (EINVAL); + + /* + * don't let the descriptor disappear on us if we block + */ + fhold(fp); + /* * POSIX shared-memory objects are defined to have * kernel persistence, and are not defined to support @@ -332,8 +338,10 @@ mmap(p, uap) else disablexworkaround = suser(p); if (vp->v_type == VCHR && disablexworkaround && - (flags & (MAP_PRIVATE|MAP_COPY))) - return (EINVAL); + (flags & (MAP_PRIVATE|MAP_COPY))) { + error = EINVAL; + goto done; + } /* * Ensure that file and memory protections are * compatible. Note that we only worry about @@ -344,10 +352,12 @@ mmap(p, uap) * proc does a setuid? */ maxprot = VM_PROT_EXECUTE; /* ??? */ - if (fp->f_flag & FREAD) + if (fp->f_flag & FREAD) { maxprot |= VM_PROT_READ; - else if (prot & PROT_READ) - return (EACCES); + } else if (prot & PROT_READ) { + error = EACCES; + goto done; + } /* * If we are sharing potential changes (either via * MAP_SHARED or via the implicit sharing of character @@ -364,17 +374,23 @@ mmap(p, uap) struct vattr va; if ((error = VOP_GETATTR(vp, &va, - p->p_ucred, p))) - return (error); + p->p_ucred, p))) { + goto done; + } if ((va.va_flags & - (SF_SNAPSHOT|IMMUTABLE|APPEND)) == 0) + (SF_SNAPSHOT|IMMUTABLE|APPEND)) == 0) { maxprot |= VM_PROT_WRITE; - else if (prot & PROT_WRITE) - return (EPERM); - } else if ((prot & PROT_WRITE) != 0) - return (EACCES); - } else + } else if (prot & PROT_WRITE) { + error = EPERM; + goto done; + } + } else if ((prot & PROT_WRITE) != 0) { + error = EACCES; + goto done; + } + } else { maxprot |= VM_PROT_WRITE; + } handle = (void *)vp; } @@ -387,13 +403,17 @@ mmap(p, uap) */ if (max_proc_mmap && vms->vm_map.nentries >= max_proc_mmap * vms->vm_refcnt) { - return (ENOMEM); + error = ENOMEM; + goto done; } error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot, flags, handle, pos); if (error == 0) p->p_retval[0] = (register_t) (addr + pageoff); +done: + if (fp) + fdrop(fp, p); return (error); } @@ -576,6 +596,7 @@ munmap(p, uap) return (0); } +#if 0 void munmapfd(p, fd) struct proc *p; @@ -586,6 +607,7 @@ munmapfd(p, fd) */ p->p_fd->fd_ofileflags[fd] &= ~UF_MAPPED; } +#endif #ifndef _SYS_SYSPROTO_H_ struct mprotect_args { |