sys: allow to specify number of pages for vma type

Allows to write vma[4] or vma[5-10] to specify desired number of pages.

2 files changed, 40 insertions, 0 deletions

diff --git a/prog/prog_test.go b/prog/prog_test.go
index 72e8868e7..218a76821 100644
--- a/prog/prog_test.go
+++ b/prog/prog_test.go
@@ -8,9 +8,12 @@ import (
 	"math/rand"
 	"testing"
 	"time"
+
+	"github.com/google/syzkaller/sys"
 )
 
 func initTest(t *testing.T) (rand.Source, int) {
+	t.Parallel()
 	iters := 10000
 	if testing.Short() {
 		iters = 100
@@ -49,3 +52,37 @@ func TestSerialize(t *testing.T) {
 		}
 	}
 }
+
+func TestVmaType(t *testing.T) {
+	rs, iters := initTest(t)
+	meta := sys.CallMap["syz_test$vma0"]
+	r := newRand(rs)
+	for i := 0; i < iters; i++ {
+		s := newState(nil)
+		calls := r.generateParticularCall(s, meta)
+		c := calls[len(calls)-1]
+		if c.Meta.Name != "syz_test$vma0" {
+			t.Fatalf("generated wrong call %v", c.Meta.Name)
+		}
+		if len(c.Args) != 6 {
+			t.Fatalf("generated wrong number of args %v", len(c.Args))
+		}
+		check := func(v, l *Arg, min, max uintptr) {
+			if v.Kind != ArgPointer {
+				t.Fatalf("vma has bad type: %v, want %v", v.Kind, ArgPointer)
+			}
+			if l.Kind != ArgPageSize {
+				t.Fatalf("len has bad type: %v, want %v", l.Kind, ArgPageSize)
+			}
+			if v.AddrPagesNum < min || v.AddrPagesNum > max {
+				t.Fatalf("vma has bad number of pages: %v, want [%v-%v]", v.AddrPagesNum, min, max)
+			}
+			if l.AddrPage < min || l.AddrPage > max {
+				t.Fatalf("len has bad number of pages: %v, want [%v-%v]", l.AddrPage, min, max)
+			}
+		}
+		check(c.Args[0], c.Args[1], 1, 1e5)
+		check(c.Args[2], c.Args[3], 5, 5)
+		check(c.Args[4], c.Args[5], 7, 9)
+	}
+}
diff --git a/prog/rand.go b/prog/rand.go
index e56893b66..a8b33ea08 100644
--- a/prog/rand.go
+++ b/prog/rand.go
@@ -596,6 +596,9 @@ func (r *randGen) generateArg(s *state, typ sys.Type) (arg *Arg, calls []*Call)
 		}
 	case *sys.VmaType:
 		npages := r.randPageCount()
+		if a.RangeBegin != 0 || a.RangeEnd != 0 {
+			npages = uintptr(int(a.RangeBegin) + r.Intn(int(a.RangeEnd-a.RangeBegin+1)))
+		}
 		arg := r.randPageAddr(s, a, npages, nil, true)
 		return arg, nil
 	case *sys.FlagsType: