[compiler-rt] [scudo] limit VMA size for riscv64 for DefaultConfig (PR #76013)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

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

Author: Icenowy Zheng (Icenowy)

<details>
<summary>Changes</summary>

The VMA size for RISC-V 64-bit Sv39 virtual address map is currently only defined in FuchsiaConfig, which leads to scudo failure on RISC-V Linux Sv39 systems, and most current available RISC-V Linux systems support only Sv39 in hardware.

Copy the reduced VMA size definition to DefaultConfig.

---
Full diff: https://github.com/llvm/llvm-project/pull/76013.diff


1 Files Affected:

- (modified) compiler-rt/lib/scudo/standalone/allocator_config.h (+6) 


``````````diff
diff --git a/compiler-rt/lib/scudo/standalone/allocator_config.h b/compiler-rt/lib/scudo/standalone/allocator_config.h
index 3c6aa3acb0e45b..3b2ac5f86b6f8c 100644
--- a/compiler-rt/lib/scudo/standalone/allocator_config.h
+++ b/compiler-rt/lib/scudo/standalone/allocator_config.h
@@ -124,8 +124,14 @@ struct DefaultConfig {
   struct Primary {
     using SizeClassMap = DefaultSizeClassMap;
 #if SCUDO_CAN_USE_PRIMARY64
+#if SCUDO_RISCV64
+    // Support 39-bit VMA for riscv-64
+    static const uptr RegionSizeLog = 30U;
+    static const uptr GroupSizeLog = 19U;
+#else
     static const uptr RegionSizeLog = 32U;
     static const uptr GroupSizeLog = 21U;
+#endif
     typedef uptr CompactPtrT;
     static const uptr CompactPtrScale = 0;
     static const bool EnableRandomOffset = true;

``````````

</details>


https://github.com/llvm/llvm-project/pull/76013