[compiler-rt] [sanitizer] Warn if allocator size exceeds max user virtual address (PR #152428)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Thurston Dang (thurstond)

<details>
<summary>Changes</summary>

This warns the user of incompatible configurations, such as 39-bit and 42-bit VMAs for AArch64 non-Android Linux ASan (https://github.com/llvm/llvm-project/issues/145259).

---
Full diff: https://github.com/llvm/llvm-project/pull/152428.diff


1 Files Affected:

- (modified) compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h (+12) 


``````````diff
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h b/compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h
index 51ac1b6ae4975..56d40c19b0f0c 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_allocator_primary64.h
@@ -113,6 +113,18 @@ class SizeClassAllocator64 {
   // ~(uptr)0.
   void Init(s32 release_to_os_interval_ms, uptr heap_start = 0) {
     uptr TotalSpaceSize = kSpaceSize + AdditionalSize();
+
+    uptr MaxAddr = GetMaxUserVirtualAddress();
+    // VReport does not call the sanitizer allocator.
+    VReport(3, "Max user virtual address: 0x%zx\n", MaxAddr);
+    VReport(3, "Total space size for primary allocator: 0x%zx\n",
+            TotalSpaceSize);
+    if (TotalSpaceSize >= MaxAddr)
+      VReport(0, "Error: heap size %zx exceeds max user virtual address %zx\n",
+              TotalSpaceSize, MaxAddr);
+    // We can't easily adjust the requested heap size, because kSpaceSize is
+    // const (for optimization) and used throughout the code.
+
     PremappedHeap = heap_start != 0;
     if (PremappedHeap) {
       CHECK(!kUsingConstantSpaceBeg);

``````````

</details>


https://github.com/llvm/llvm-project/pull/152428