[GWP-ASan] Add thread ID to PRNG seed.
Summary:
Adds thread ID to PRNG seed for increased entropy. In particular, this allows
multiple runs in quick succession that will have different PRNG seeds, allowing
for better demos/testing.
Reviewers: kcc
Reviewed By: kcc
Subscribers: kubamracek, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D64453
llvm-svn: 366253
GitOrigin-RevId: b157dcacb5b96fd64900906911832a8ac3bb189e
diff --git a/guarded_pool_allocator.h b/guarded_pool_allocator.h
index 400d50c..28a4111 100644
--- a/guarded_pool_allocator.h
+++ b/guarded_pool_allocator.h
@@ -132,6 +132,10 @@
// occur.
static void reportError(uintptr_t AccessPtr, Error E = Error::UNKNOWN);
+ // Get the current thread ID, or kInvalidThreadID if failure. Note: This
+ // implementation is platform-specific.
+ static uint64_t getThreadID();
+
private:
static constexpr size_t kInvalidSlotID = SIZE_MAX;
@@ -146,10 +150,6 @@
void markReadWrite(void *Ptr, size_t Size) const;
void markInaccessible(void *Ptr, size_t Size) const;
- // Get the current thread ID, or kInvalidThreadID if failure. Note: This
- // implementation is platform-specific.
- static uint64_t getThreadID();
-
// Get the page size from the platform-specific implementation. Only needs to
// be called once, and the result should be cached in PageSize in this class.
static size_t getPlatformPageSize();
diff --git a/random.cpp b/random.cpp
index 67f4a22..90493da 100644
--- a/random.cpp
+++ b/random.cpp
@@ -7,12 +7,14 @@
//===----------------------------------------------------------------------===//
#include "gwp_asan/random.h"
+#include "gwp_asan/guarded_pool_allocator.h"
#include <time.h>
namespace gwp_asan {
uint32_t getRandomUnsigned32() {
- thread_local uint32_t RandomState = static_cast<uint64_t>(time(nullptr));
+ thread_local uint32_t RandomState =
+ time(nullptr) + GuardedPoolAllocator::getThreadID();
RandomState ^= RandomState << 13;
RandomState ^= RandomState >> 17;
RandomState ^= RandomState << 5;