[scudo] Adding a public Scudo interface

Summary:
The first and only function to start with allows to set the soft or hard RSS
limit at runtime. Add associated tests.

Reviewers: alekseyshl

Reviewed By: alekseyshl

Subscribers: mgorny, #sanitizers, llvm-commits

Differential Revision: https://reviews.llvm.org/D41128

llvm-svn: 320611

3 files changed, 46 insertions, 0 deletions

diff --git a/compiler-rt/lib/scudo/scudo_allocator.cpp b/compiler-rt/lib/scudo/scudo_allocator.cpp
index 47804c44c4f..19c89810a3e 100644
--- a/compiler-rt/lib/scudo/scudo_allocator.cpp
+++ b/compiler-rt/lib/scudo/scudo_allocator.cpp
@@ -597,6 +597,14 @@ struct ScudoAllocator {
     initThreadMaybe();
     return FailureHandler::OnBadRequest();
   }
+
+  void setRssLimit(uptr LimitMb, bool HardLimit) {
+    if (HardLimit)
+      HardRssLimitMb = LimitMb;
+    else
+      SoftRssLimitMb = LimitMb;
+    CheckRssLimit = HardRssLimitMb || SoftRssLimitMb;
+  }
 };
 
 static ScudoAllocator Instance(LINKER_INITIALIZED);
@@ -726,3 +734,13 @@ int __sanitizer_get_ownership(const void *Ptr) {
 uptr __sanitizer_get_allocated_size(const void *Ptr) {
   return Instance.getUsableSize(Ptr);
 }
+
+// Interface functions
+
+extern "C" {
+void __scudo_set_rss_limit(unsigned long LimitMb, int HardLimit) {  // NOLINT
+  if (!SCUDO_CAN_USE_PUBLIC_INTERFACE)
+    return;
+  Instance.setRssLimit(LimitMb, !!HardLimit);
+}
+}  // extern "C"
diff --git a/compiler-rt/lib/scudo/scudo_interface_internal.h b/compiler-rt/lib/scudo/scudo_interface_internal.h
new file mode 100644
index 00000000000..3f39e0c4ee0
--- /dev/null
+++ b/compiler-rt/lib/scudo/scudo_interface_internal.h
@@ -0,0 +1,22 @@
+//===-- scudo_interface_internal.h ------------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+///
+/// Private Scudo interface header.
+///
+//===----------------------------------------------------------------------===//
+
+#ifndef SCUDO_INTERFACE_INTERNAL_H_
+#define SCUDO_INTERFACE_INTERNAL_H_
+
+extern "C" {
+SANITIZER_INTERFACE_ATTRIBUTE
+void __scudo_set_rss_limit(unsigned long LimitMb, int HardLimit);  // NOLINT
+}  // extern "C"
+
+#endif  // SCUDO_INTERFACE_INTERNAL_H_
diff --git a/compiler-rt/lib/scudo/scudo_platform.h b/compiler-rt/lib/scudo/scudo_platform.h
index a915c9843a5..e1c9c32e9a6 100644
--- a/compiler-rt/lib/scudo/scudo_platform.h
+++ b/compiler-rt/lib/scudo/scudo_platform.h
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 ///
 /// Scudo platform specific definitions.
+/// TODO(kostyak): add tests for the compile time defines.
 ///
 //===----------------------------------------------------------------------===//
 
@@ -45,6 +46,11 @@
 # define SCUDO_SHARED_TSD_POOL_SIZE 32U
 #endif  // SCUDO_SHARED_TSD_POOL_SIZE
 
+// The following allows the public interface functions to be disabled.
+#ifndef SCUDO_CAN_USE_PUBLIC_INTERFACE
+# define SCUDO_CAN_USE_PUBLIC_INTERFACE 1
+#endif
+
 namespace __scudo {
 
 #if SANITIZER_CAN_USE_ALLOCATOR64