From f08b32761ead91f77c11b351003e719193f6ecca Mon Sep 17 00:00:00 2001
From: Szymon Morek <szymon.morek@intel.com>
Date: Thu, 6 Mar 2025 17:04:43 +0000
Subject: [PATCH] fix: avoid race when evicting resources

Related-To: NEO-13843

DrmMemoryOperationsHandler::mutex is used for residency
handling.
However, this mutex is not being locked during eviction when vm bind
failed.
This is causing races for example when ULLS controller wants to make
resources resident, and user thread wants to evict
them.
Fix is to explicitly obtain lock in problematic path.

Signed-off-by: Szymon Morek <szymon.morek@intel.com>
---
 shared/source/os_interface/linux/drm_buffer_object.cpp          | 2 ++
 .../os_interface/linux/drm_memory_operations_handler_bind.cpp   | 2 +-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/shared/source/os_interface/linux/drm_buffer_object.cpp b/shared/source/os_interface/linux/drm_buffer_object.cpp
index 91886f94cc..707feb1000 100644
--- a/shared/source/os_interface/linux/drm_buffer_object.cpp
+++ b/shared/source/os_interface/linux/drm_buffer_object.cpp
@@ -326,6 +326,7 @@ int BufferObject::pin(BufferObject *const boToPin[], size_t numberOfBos, OsConte
     auto retVal = 0;
 
     if (this->drm->isVmBindAvailable()) {
+        auto lock = static_cast<DrmMemoryOperationsHandler *>(this->drm->getRootDeviceEnvironment().memoryOperationsInterface.get())->lockHandlerIfUsed();
         retVal = bindBOsWithinContext(boToPin, numberOfBos, osContext, vmHandleId, false);
     } else {
         StackVec<ExecObject, maxFragmentsCount + 1> execObject(numberOfBos + 1);
@@ -339,6 +340,7 @@ int BufferObject::validateHostPtr(BufferObject *const boToPin[], size_t numberOf
     auto retVal = 0;
 
     if (this->drm->isVmBindAvailable()) {
+        auto lock = static_cast<DrmMemoryOperationsHandler *>(this->drm->getRootDeviceEnvironment().memoryOperationsInterface.get())->lockHandlerIfUsed();
         for (size_t i = 0; i < numberOfBos; i++) {
             retVal = boToPin[i]->bind(osContext, vmHandleId, false);
             if (retVal) {
diff --git a/shared/source/os_interface/linux/drm_memory_operations_handler_bind.cpp b/shared/source/os_interface/linux/drm_memory_operations_handler_bind.cpp
index 74cbe41709..5174cd0595 100644
--- a/shared/source/os_interface/linux/drm_memory_operations_handler_bind.cpp
+++ b/shared/source/os_interface/linux/drm_memory_operations_handler_bind.cpp
@@ -157,7 +157,7 @@ MemoryOperationsStatus DrmMemoryOperationsHandlerBind::mergeWithResidencyContain
 }
 
 std::unique_lock<std::mutex> DrmMemoryOperationsHandlerBind::lockHandlerIfUsed() {
-    return std::unique_lock<std::mutex>();
+    return std::unique_lock<std::mutex>(mutex);
 }
 
 MemoryOperationsStatus DrmMemoryOperationsHandlerBind::evictUnusedAllocations(bool waitForCompletion, bool isLockNeeded) {