3 files changed, 22 insertions, 1 deletions
diff --git a/lib/Support/Unix/Host.inc b/lib/Support/Unix/Host.inc
index 457217125a222..0ba6a25aa198d 100644
--- a/lib/Support/Unix/Host.inc
+++ b/lib/Support/Unix/Host.inc
@@ -45,5 +45,11 @@ std::string sys::getDefaultTargetTriple() {
     TargetTripleString += getOSVersion();
   }
 
+  // Override the default target with an environment variable named by LLVM_TARGET_TRIPLE_ENV.
+#if defined(LLVM_TARGET_TRIPLE_ENV)
+  if (const char *EnvTriple = std::getenv(LLVM_TARGET_TRIPLE_ENV))
+    TargetTripleString = EnvTriple;
+#endif
+
   return Triple::normalize(TargetTripleString);
 }
diff --git a/lib/Support/Unix/Memory.inc b/lib/Support/Unix/Memory.inc
index edbc7938f0cbf..dd39ef935bf92 100644
--- a/lib/Support/Unix/Memory.inc
+++ b/lib/Support/Unix/Memory.inc
@@ -195,6 +195,10 @@ Memory::AllocateRWX(size_t NumBytes, const MemoryBlock* NearBlock,
 #if defined(__APPLE__) && (defined(__arm__) || defined(__arm64__))
   void *pa = ::mmap(start, PageSize*NumPages, PROT_READ|PROT_EXEC,
                     flags, fd, 0);
+#elif defined(__NetBSD__) && defined(PROT_MPROTECT)
+  void *pa =
+      ::mmap(start, PageSize * NumPages,
+             PROT_READ | PROT_WRITE | PROT_MPROTECT(PROT_EXEC), flags, fd, 0);
 #else
   void *pa = ::mmap(start, PageSize*NumPages, PROT_READ|PROT_WRITE|PROT_EXEC,
                     flags, fd, 0);
diff --git a/lib/Support/Unix/Program.inc b/lib/Support/Unix/Program.inc
index 2df0eaff47e52..1704fa4799428 100644
--- a/lib/Support/Unix/Program.inc
+++ b/lib/Support/Unix/Program.inc
@@ -449,11 +449,22 @@ bool llvm::sys::commandLineFitsWithinSystemLimits(StringRef Program, ArrayRef<co
   size_t ArgLength = Program.size() + 1;
   for (ArrayRef<const char*>::iterator I = Args.begin(), E = Args.end();
        I != E; ++I) {
-    ArgLength += strlen(*I) + 1;
+    size_t length = strlen(*I);
+
+    // Ensure that we do not exceed the MAX_ARG_STRLEN constant on Linux, which
+    // does not have a constant unlike what the man pages would have you
+    // believe. Since this limit is pretty high, perform the check
+    // unconditionally rather than trying to be aggressive and limiting it to
+    // Linux only.
+    if (length >= (32 * 4096))
+      return false;
+
+    ArgLength += length + 1;
     if (ArgLength > size_t(HalfArgMax)) {
       return false;
     }
   }
+
   return true;
 }
 }