__MAP_NOFAULT doesn't make sense with anon mappings, so return EINVAL if

that is attempted.
Minor cleanups:
 - Eliminate some always false and always true tests against MAP_ANON
 - We treat anon mappings with neither MAP_{SHARED,PRIVATE} as MAP_PRIVATE
   so explicitly indicate that

ok kettenis@ beck@

diff --git a/sys/uvm/uvm_map.c b/sys/uvm/uvm_map.c
index ddab1cb..1fb3f00 100644 (file)
--- a/sys/uvm/uvm_map.c
+++ b/sys/uvm/uvm_map.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: uvm_map.c,v 1.232 2017/08/12 16:30:10 guenther Exp $  */
+/*     $OpenBSD: uvm_map.c,v 1.233 2017/11/30 00:36:10 guenther Exp $  */
 /*     $NetBSD: uvm_map.c,v 1.86 2000/11/27 08:40:03 chs Exp $ */
 
 /*
@@ -1064,8 +1064,6 @@ uvm_mapanon(struct vm_map *map, vaddr_t *addr, vsize_t sz,
        entry->inheritance = inherit;
        entry->wired_count = 0;
        entry->advice = advice;
-       if (flags & UVM_FLAG_NOFAULT)
-               entry->etype |= UVM_ET_NOFAULT;
        if (flags & UVM_FLAG_COPYONW) {
                entry->etype |= UVM_ET_COPYONWRITE;
                if ((flags & UVM_FLAG_OVERLAY) == 0)

diff --git a/sys/uvm/uvm_mmap.c b/sys/uvm/uvm_mmap.c
index 16c98a8..fce6632 100644 (file)
--- a/sys/uvm/uvm_mmap.c
+++ b/sys/uvm/uvm_mmap.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: uvm_mmap.c,v 1.142 2017/01/21 05:42:03 guenther Exp $ */
+/*     $OpenBSD: uvm_mmap.c,v 1.143 2017/11/30 00:36:10 guenther Exp $ */
 /*     $NetBSD: uvm_mmap.c,v 1.49 2001/02/18 21:19:08 chs Exp $        */
 
 /*
@@ -459,8 +459,6 @@ sys_mmap(struct proc *p, void *v, register_t *retval)
                /*
                 * Old programs may not select a specific sharing type, so
                 * default to an appropriate one.
-                *
-                * XXX: how does MAP_ANON fit in the picture?
                 */
                if ((flags & (MAP_SHARED|MAP_PRIVATE)) == 0) {
 #if defined(DEBUG)
@@ -521,7 +519,7 @@ sys_mmap(struct proc *p, void *v, register_t *retval)
                        /* MAP_PRIVATE mappings can always write to */
                        maxprot |= PROT_WRITE;
                }
-               if ((flags & MAP_ANON) != 0 || (flags & __MAP_NOFAULT) != 0 ||
+               if ((flags & __MAP_NOFAULT) != 0 ||
                    ((flags & MAP_PRIVATE) != 0 && (prot & PROT_WRITE) != 0)) {
                        if (p->p_rlimit[RLIMIT_DATA].rlim_cur < size ||
                            p->p_rlimit[RLIMIT_DATA].rlim_cur - size <
@@ -533,25 +531,31 @@ sys_mmap(struct proc *p, void *v, register_t *retval)
                error = uvm_mmapfile(&p->p_vmspace->vm_map, &addr, size, prot, maxprot,
                    flags, vp, pos, p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur, p);
        } else {                /* MAP_ANON case */
-               /*
-                * XXX What do we do about (MAP_SHARED|MAP_PRIVATE) == 0?
-                */
                if (fd != -1)
                        return EINVAL;
 
 is_anon:       /* label for SunOS style /dev/zero */
 
-               if ((flags & MAP_ANON) != 0 || (flags & __MAP_NOFAULT) != 0 ||
-                   ((flags & MAP_PRIVATE) != 0 && (prot & PROT_WRITE) != 0)) {
-                       if (p->p_rlimit[RLIMIT_DATA].rlim_cur < size ||
-                           p->p_rlimit[RLIMIT_DATA].rlim_cur - size <
-                           ptoa(p->p_vmspace->vm_dused)) {
-                               return ENOMEM;
-                       }
+               /* __MAP_NOFAULT only makes sense with a backing object */
+               if ((flags & __MAP_NOFAULT) != 0)
+                       return EINVAL;
+
+               if (p->p_rlimit[RLIMIT_DATA].rlim_cur < size ||
+                   p->p_rlimit[RLIMIT_DATA].rlim_cur - size <
+                   ptoa(p->p_vmspace->vm_dused)) {
+                       return ENOMEM;
                }
+
+               /*
+                * We've been treating (MAP_SHARED|MAP_PRIVATE) == 0 as
+                * MAP_PRIVATE, so make that clear.
+                */
+               if ((flags & MAP_SHARED) == 0)
+                       flags |= MAP_PRIVATE;
+
                maxprot = PROT_MASK;
-               error = uvm_mmapanon(&p->p_vmspace->vm_map, &addr, size, prot, maxprot,
-                   flags, p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur, p);
+               error = uvm_mmapanon(&p->p_vmspace->vm_map, &addr, size, prot,
+                   maxprot, flags, p->p_rlimit[RLIMIT_MEMLOCK].rlim_cur, p);
        }
 
        if (error == 0)