[compiler-rt] [LoongArch][sanitizer] Fix SC_ADDRERR_{RD,WR} missing in the musl environment (PR #108557)

[via llvm-commits]

https://github.com/heiher created https://github.com/llvm/llvm-project/pull/108557

Fixes #108550

>From 8f9d73bb173d382fc0fbcf36b5275acf3e396797 Mon Sep 17 00:00:00 2001
From: WANG Rui <wangrui at loongson.cn>
Date: Fri, 13 Sep 2024 20:34:57 +0800
Subject: [PATCH] [LoongArch][sanitizer] Fix SC_ADDRERR_{RD,WR} missing in the
 musl environment

Fixes #108550
---
 compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp
index 16d06c69a38f32..f4a2f46c6ea022 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp
@@ -2018,6 +2018,18 @@ SignalContext::WriteFlag SignalContext::GetWriteFlag() const {
     return Unknown;
   return esr & ESR_ELx_WNR ? Write : Read;
 #  elif defined(__loongarch__)
+     // In the musl environment, the Linux kernel uapi sigcontext.h is not
+     // included in signal.h. To avoid missing the SC_ADDRERR_{RD,WR} macros,
+     // copy them here. The LoongArch Linux kernel uapi is already stable,
+     // so there's no need to worry about the value changing.
+#    ifndef SC_ADDRERR_RD
+       // Address error was due to memory load
+#      define SC_ADDRERR_RD		(1 << 30)
+#    endif
+#    ifndef SC_ADDRERR_WR
+       // Address error was due to memory store
+#      define SC_ADDRERR_WR		(1 << 31)
+#    endif
   u32 flags = ucontext->uc_mcontext.__flags;
   if (flags & SC_ADDRERR_RD)
     return SignalContext::Read;