Fix annoying page zero bug

85f4c385 · Silas Boyd-Wickizer · a8028fca · 85f4c385
--- a/kernel/vm.cc
+++ b/kernel/vm.cc
@@ -608,9 +608,10 @@ vmap::pagefault(uptr va, u32 err)
            err, va, m->va_type, m->n->ref(), myproc()->pid);
  if (m->n && !m->n->page[npg])
-    // m->n->ip != nullptr implies we'll copy over the page
+    // XXX(sbw) you might think we don't need to zero if ONDEMAND;
-    // with loadpg before returning
+    // however, our vmnode might include not backed by a file
-    if (m->n->allocpg(npg, m->n->ip == nullptr) < 0) {
+    // (e.g. the bss section of an ELF segment)
+    if (m->n->allocpg(npg, true) < 0) {
      cprintf("pagefault: couldn't allocate pages\n");
      return -1;
    }