Merge pull request #9083 from liamwhite/take-a-chance-on-me

kernel: fix slab heap ABA
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liamwhite 2022-10-19 16:27:59 -04:00 committed by GitHub
commit 925fb63478
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@ -8,6 +8,7 @@
#include "common/assert.h" #include "common/assert.h"
#include "common/common_funcs.h" #include "common/common_funcs.h"
#include "common/common_types.h" #include "common/common_types.h"
#include "common/spin_lock.h"
namespace Kernel { namespace Kernel {
@ -36,28 +37,34 @@ public:
} }
void* Allocate() { void* Allocate() {
Node* ret = m_head.load(); // KScopedInterruptDisable di;
do { m_lock.lock();
if (ret == nullptr) {
break;
}
} while (!m_head.compare_exchange_weak(ret, ret->next));
Node* ret = m_head;
if (ret != nullptr) [[likely]] {
m_head = ret->next;
}
m_lock.unlock();
return ret; return ret;
} }
void Free(void* obj) { void Free(void* obj) {
Node* node = static_cast<Node*>(obj); // KScopedInterruptDisable di;
Node* cur_head = m_head.load(); m_lock.lock();
do {
node->next = cur_head; Node* node = static_cast<Node*>(obj);
} while (!m_head.compare_exchange_weak(cur_head, node)); node->next = m_head;
m_head = node;
m_lock.unlock();
} }
private: private:
std::atomic<Node*> m_head{}; std::atomic<Node*> m_head{};
Common::SpinLock m_lock;
}; };
} // namespace impl } // namespace impl