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- Hold a lock on the vnode acquired from the file table across the call to

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vm_mmap() as well as the GETATTR etc.
 - If the handle is a vnode in vm_mmap() assert that it is locked.
 - Wiggle Giant around a little to account for the extra vnode operation.
This commit is contained in:
Jeff Roberson 2002-07-06 22:14:38 +00:00
parent c031d11bb4
commit f6b5b182e8
1 changed files with 14 additions and 3 deletions
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17
sys/vm/vm_mmap.c
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@ -217,6 +217,7 @@ mmap(td, uap)
flags = uap->flags;
pos = uap->pos;
vp = NULL;
fp = NULL;
/* make sure mapping fits into numeric range etc */
if ((ssize_t) uap->len < 0 ||
@ -310,6 +311,9 @@ mmap(td, uap)
if (fp->f_flag & FPOSIXSHM)
flags |= MAP_NOSYNC;
vp = (struct vnode *) fp->f_data;
error = vget(vp, LK_EXCLUSIVE, td);
if (error)
goto done;
if (vp->v_type != VREG && vp->v_type != VCHR) {
error = EINVAL;
goto done;
@ -322,7 +326,11 @@ mmap(td, uap)
error = EINVAL;
goto done;
}
vp = (struct vnode*)obj->handle;
if (obj->handle != vp) {
vput(vp);
vp = (struct vnode*)obj->handle;
vget(vp, LK_EXCLUSIVE, td);
}
}
/*
* XXX hack to handle use of /dev/zero to map anon memory (ala
@ -423,14 +431,16 @@ mmap(td, uap)
mtx_unlock(&Giant);
error = vm_mmap(&vms->vm_map, &addr, size, prot, maxprot,
flags, handle, pos);
mtx_lock(&Giant);
if (error == 0)
td->td_retval[0] = (register_t) (addr + pageoff);
goto done2;
done:
if (vp)
vput(vp);
mtx_unlock(&Giant);
done2:
if (fp)
fdrop(fp, td);
return (error);
}
@ -1165,6 +1175,7 @@ vm_mmap(vm_map_t map, vm_offset_t *addr, vm_size_t size, vm_prot_t prot,
} else {
vp = (struct vnode *) handle;
mtx_lock(&Giant);
ASSERT_VOP_LOCKED(vp, "vm_mmap");
if (vp->v_type == VCHR) {
type = OBJT_DEVICE;
handle = (void *)(intptr_t)vp->v_rdev;