[sanitizer] Implement a __asan_default_options() equivalent for Scudo
Summary:
Currently, the Scudo Hardened Allocator only gets its flags via the SCUDO_OPTIONS environment variable.
With this patch, we offer the opportunity for programs to define their own options via __scudo_default_options() which behaves like __asan_default_options() (weak symbol).
A relevant test has been added as well, and the documentation updated accordingly.
I also used this patch as an opportunity to rename a few variables to comply with the LLVM naming scheme, and replaced a use of Report with dieWithMessage for consistency (and to avoid a callback).
Reviewers: llvm-commits, kcc
Differential Revision: https://reviews.llvm.org/D23018
llvm-svn: 277536
diff --git a/compiler-rt/lib/scudo/scudo_flags.cpp b/compiler-rt/lib/scudo/scudo_flags.cpp
index 430dcd2..f0d2088 100644
--- a/compiler-rt/lib/scudo/scudo_flags.cpp
+++ b/compiler-rt/lib/scudo/scudo_flags.cpp
@@ -17,9 +17,12 @@
#include "sanitizer_common/sanitizer_flags.h"
#include "sanitizer_common/sanitizer_flag_parser.h"
+extern "C" SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+const char* __scudo_default_options();
+
namespace __scudo {
-Flags scudo_flags_dont_use_directly; // use via flags().
+Flags ScudoFlags; // Use via getFlags().
void Flags::setDefaults() {
#define SCUDO_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
@@ -34,6 +37,10 @@
#undef SCUDO_FLAG
}
+static const char *callGetScudoDefaultOptions() {
+ return (&__scudo_default_options) ? __scudo_default_options() : "";
+}
+
void initFlags() {
SetCommonFlagsDefaults();
{
@@ -45,11 +52,16 @@
Flags *f = getFlags();
f->setDefaults();
- FlagParser scudo_parser;
- RegisterScudoFlags(&scudo_parser, f);
- RegisterCommonFlags(&scudo_parser);
+ FlagParser ScudoParser;
+ RegisterScudoFlags(&ScudoParser, f);
+ RegisterCommonFlags(&ScudoParser);
- scudo_parser.ParseString(GetEnv("SCUDO_OPTIONS"));
+ // Override from user-specified string.
+ const char *ScudoDefaultOptions = callGetScudoDefaultOptions();
+ ScudoParser.ParseString(ScudoDefaultOptions);
+
+ // Override from environment.
+ ScudoParser.ParseString(GetEnv("SCUDO_OPTIONS"));
InitializeCommonFlags();
@@ -75,7 +87,7 @@
}
Flags *getFlags() {
- return &scudo_flags_dont_use_directly;
+ return &ScudoFlags;
}
}