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-rw-r--r--src/support/allocators/secure.h8
-rw-r--r--src/support/cleanse.cpp38
-rw-r--r--src/support/cleanse.h5
-rw-r--r--src/support/lockedpool.cpp21
-rw-r--r--src/support/lockedpool.h4
5 files changed, 38 insertions, 38 deletions
diff --git a/src/support/allocators/secure.h b/src/support/allocators/secure.h
index 7cd0df135d..0e31ad3ce3 100644
--- a/src/support/allocators/secure.h
+++ b/src/support/allocators/secure.h
@@ -1,5 +1,5 @@
// Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Copyright (c) 2009-2019 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
@@ -40,7 +40,11 @@ struct secure_allocator : public std::allocator<T> {
T* allocate(std::size_t n, const void* hint = 0)
{
- return static_cast<T*>(LockedPoolManager::Instance().alloc(sizeof(T) * n));
+ T* allocation = static_cast<T*>(LockedPoolManager::Instance().alloc(sizeof(T) * n));
+ if (!allocation) {
+ throw std::bad_alloc();
+ }
+ return allocation;
}
void deallocate(T* p, std::size_t n)
diff --git a/src/support/cleanse.cpp b/src/support/cleanse.cpp
index 17a4a4c2b2..a8ddcd793f 100644
--- a/src/support/cleanse.cpp
+++ b/src/support/cleanse.cpp
@@ -1,5 +1,5 @@
// Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Copyright (c) 2009-2019 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
@@ -11,33 +11,25 @@
#include <Windows.h> // For SecureZeroMemory.
#endif
-/* Compilers have a bad habit of removing "superfluous" memset calls that
- * are trying to zero memory. For example, when memset()ing a buffer and
- * then free()ing it, the compiler might decide that the memset is
- * unobservable and thus can be removed.
- *
- * Previously we used OpenSSL which tried to stop this by a) implementing
- * memset in assembly on x86 and b) putting the function in its own file
- * for other platforms.
- *
- * This change removes those tricks in favour of using asm directives to
- * scare the compiler away. As best as our compiler folks can tell, this is
- * sufficient and will continue to be so.
- *
- * Adam Langley <agl@google.com>
- * Commit: ad1907fe73334d6c696c8539646c21b11178f20f
- * BoringSSL (LICENSE: ISC)
- */
void memory_cleanse(void *ptr, size_t len)
{
- std::memset(ptr, 0, len);
-
- /* As best as we can tell, this is sufficient to break any optimisations that
- might try to eliminate "superfluous" memsets. If there's an easy way to
- detect memset_s, it would be better to use that. */
#if defined(_MSC_VER)
+ /* SecureZeroMemory is guaranteed not to be optimized out by MSVC. */
SecureZeroMemory(ptr, len);
#else
+ std::memset(ptr, 0, len);
+
+ /* Memory barrier that scares the compiler away from optimizing out the memset.
+ *
+ * Quoting Adam Langley <agl@google.com> in commit ad1907fe73334d6c696c8539646c21b11178f20f
+ * in BoringSSL (ISC License):
+ * As best as we can tell, this is sufficient to break any optimisations that
+ * might try to eliminate "superfluous" memsets.
+ * This method is used in memzero_explicit() the Linux kernel, too. Its advantage is that it
+ * is pretty efficient because the compiler can still implement the memset() efficiently,
+ * just not remove it entirely. See "Dead Store Elimination (Still) Considered Harmful" by
+ * Yang et al. (USENIX Security 2017) for more background.
+ */
__asm__ __volatile__("" : : "r"(ptr) : "memory");
#endif
}
diff --git a/src/support/cleanse.h b/src/support/cleanse.h
index 5298214e44..8c1210a114 100644
--- a/src/support/cleanse.h
+++ b/src/support/cleanse.h
@@ -1,5 +1,5 @@
// Copyright (c) 2009-2010 Satoshi Nakamoto
-// Copyright (c) 2009-2018 The Bitcoin Core developers
+// Copyright (c) 2009-2019 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
@@ -8,7 +8,8 @@
#include <stdlib.h>
-// Attempt to overwrite data in the specified memory span.
+/** Secure overwrite a buffer (possibly containing secret data) with zero-bytes. The write
+ * operation will not be optimized out by the compiler. */
void memory_cleanse(void *ptr, size_t len);
#endif // BITCOIN_SUPPORT_CLEANSE_H
diff --git a/src/support/lockedpool.cpp b/src/support/lockedpool.cpp
index fc1f660aec..f3cc12201c 100644
--- a/src/support/lockedpool.cpp
+++ b/src/support/lockedpool.cpp
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2018 The Bitcoin Core developers
+// Copyright (c) 2016-2019 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
@@ -10,10 +10,6 @@
#endif
#ifdef WIN32
-#ifdef _WIN32_WINNT
-#undef _WIN32_WINNT
-#endif
-#define _WIN32_WINNT 0x0501
#define WIN32_LEAN_AND_MEAN 1
#ifndef NOMINMAX
#define NOMINMAX
@@ -27,6 +23,10 @@
#endif
#include <algorithm>
+#ifdef ARENA_DEBUG
+#include <iomanip>
+#include <iostream>
+#endif
LockedPoolManager* LockedPoolManager::_instance = nullptr;
std::once_flag LockedPoolManager::init_flag;
@@ -75,7 +75,7 @@ void* Arena::alloc(size_t size)
// Create the used-chunk, taking its space from the end of the free-chunk
const size_t size_remaining = size_ptr_it->first - size;
- auto alloced = chunks_used.emplace(size_ptr_it->second + size_remaining, size).first;
+ auto allocated = chunks_used.emplace(size_ptr_it->second + size_remaining, size).first;
chunks_free_end.erase(size_ptr_it->second + size_ptr_it->first);
if (size_ptr_it->first == size) {
// whole chunk is used up
@@ -88,7 +88,7 @@ void* Arena::alloc(size_t size)
}
size_to_free_chunk.erase(size_ptr_it);
- return reinterpret_cast<void*>(alloced->first);
+ return reinterpret_cast<void*>(allocated->first);
}
void Arena::free(void *ptr)
@@ -141,7 +141,7 @@ Arena::Stats Arena::stats() const
}
#ifdef ARENA_DEBUG
-static void printchunk(char* base, size_t sz, bool used) {
+static void printchunk(void* base, size_t sz, bool used) {
std::cout <<
"0x" << std::hex << std::setw(16) << std::setfill('0') << base <<
" 0x" << std::hex << std::setw(16) << std::setfill('0') << sz <<
@@ -153,7 +153,7 @@ void Arena::walk() const
printchunk(chunk.first, chunk.second, true);
std::cout << std::endl;
for (const auto& chunk: chunks_free)
- printchunk(chunk.first, chunk.second, false);
+ printchunk(chunk.first, chunk.second->first, false);
std::cout << std::endl;
}
#endif
@@ -248,6 +248,9 @@ void *PosixLockedPageAllocator::AllocateLocked(size_t len, bool *lockingSuccess)
void *addr;
len = align_up(len, page_size);
addr = mmap(nullptr, len, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
+ if (addr == MAP_FAILED) {
+ return nullptr;
+ }
if (addr) {
*lockingSuccess = mlock(addr, len) == 0;
#ifdef MADV_DONTDUMP
diff --git a/src/support/lockedpool.h b/src/support/lockedpool.h
index 48ffd7b307..de668f0773 100644
--- a/src/support/lockedpool.h
+++ b/src/support/lockedpool.h
@@ -1,4 +1,4 @@
-// Copyright (c) 2016-2018 The Bitcoin Core developers
+// Copyright (c) 2016-2019 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
@@ -22,7 +22,7 @@ public:
virtual ~LockedPageAllocator() {}
/** Allocate and lock memory pages.
* If len is not a multiple of the system page size, it is rounded up.
- * Returns 0 in case of allocation failure.
+ * Returns nullptr in case of allocation failure.
*
* If locking the memory pages could not be accomplished it will still
* return the memory, however the lockingSuccess flag will be false.
generated by cgit v1.2.3 (git 2.26.2) at 2024-08-19 14:53:57 +0000