pk: avoid out-of-memory errors

Estimate available memory and return -1 from mmap if not enough
is available, rather than assert-failing.

1 files changed, 1 insertions, 0 deletions

diff --git a/pk/boot.h b/pk/boot.h
index f8bc51c..3ba5a45 100644
--- a/pk/boot.h
+++ b/pk/boot.h
@@ -20,6 +20,7 @@ typedef struct {
   size_t brk_max;
   size_t mmap_max;
   size_t stack_top;
+  size_t vm_alloc_guess;
   uint64_t time0;
   uint64_t cycle0;
   uint64_t instret0;