tools/syz-trace2syz/proggen: fix vma allocation

There are 2 bugs:
1. We always allocate 1 page, even if use more.
2. VMA addresses are not aligned, so most mmap-like functions fail with EINVAL.
The added test currently panics with "unaligned vma address".

1 files changed, 6 insertions, 0 deletions

diff --git a/prog/target.go b/prog/target.go
index f99c45c5b..56fbb860d 100644
--- a/prog/target.go
+++ b/prog/target.go
@@ -264,6 +264,12 @@ func (pg *ProgGen) Allocate(size uint64) uint64 {
 	return pg.ma.alloc(nil, size)
 }
 
+func (pg *ProgGen) AllocateVMA(npages uint64) uint64 {
+	psize := pg.target.PageSize
+	addr := pg.ma.alloc(nil, (npages+1)*psize)
+	return (addr + psize - 1) & ^(psize - 1)
+}
+
 func (pg *ProgGen) Finalize() (*Prog, error) {
 	if err := pg.p.validate(); err != nil {
 		return nil, err