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106f7fc8 · Nickolai Zeldovich · 6ef0e613 · 106f7fc8 · 106f7fc8
--- a/include/vm.hh
+++ b/include/vm.hh
@@ -32,7 +32,7 @@ struct vmnode {
  void decref();
  void incref();
  u64 ref();
-  int allocall(bool zero = true);
+  void allocall(bool zero = true);
  int allocpg(int idx, bool zero = true);
  int loadall();
  int loadpg(off_t off);

--- a/kernel/vm.cc
+++ b/kernel/vm.cc
@@ -33,7 +33,7 @@ vmnode::vmnode(u64 npg, vmntype ntype, inode *i, u64 off, u64 s)
    panic("vmnode too big\n");
  memset(page, 0, npg * sizeof(page[0]));
  if (type == EAGER && ip) {
-    assert(allocall(false) == 0);
+    allocall(false);
    assert(loadall() == 0);
  }
 }
@@ -94,16 +94,12 @@ vmnode::allocpg(int idx, bool zero)
  return 0;
 }

-int
+void
 vmnode::allocall(bool zero)
 {
-  for(u64 i = 0; i < npages; i++) {
-    if (allocpg(i, zero) < 0) {
-      cprintf("allocall: OOM -- leaving half-filled vmnode\n");
-      return -1;
-    }
-  }
-  return 0;
+  for(u64 i = 0; i < npages; i++)
+    if (allocpg(i, zero) < 0)
+      throw std::bad_alloc();
 }

 vmnode *
@@ -115,15 +111,14 @@ vmnode::copy()
  if (empty)
    return c;

-  if (c->allocall(false) < 0) {
-    cprintf("vmn_copy: out of memory\n");
-    delete c;
-    throw std::bad_alloc();
-  }
+  auto cleanup = scoped_cleanup([&c]() { delete c; });
+  c->allocall(false);
+
  for(u64 i = 0; i < npages; i++)
    if (page[i])
      memmove(c->page[i], page[i], PGSIZE);

+  cleanup.dismiss();
  return c;
 }

@@ -602,10 +597,8 @@ vmap::pagefault(uptr va, u32 err)
    // XXX(sbw) you might think we don't need to zero if ONDEMAND;
    // however, our vmnode might include not backed by a file
    // (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;
-    }
+    if (m->n->allocpg(npg, true) < 0)
+      throw std::bad_alloc();

  // XXX(sbw) If m->n->page[npg] has contents (e.g. was loaded in
  // a parent before fork) we shouldn't call loadpg