[hle, service] fix errors related to race conditions triggering under SMG1 and SMG2 (#3927)

- service manager may add a service while someone else is finding it, so properly lock
- nvhost doesn't properly account for the fact that iterators GET FUCKING INVALIDATED
- use proper exit routine for mapping locked that failed (try/catch hell)

the last two were introduced by #3858, but the first one has been present since ???

either way, remember that ankerl map has invalidated iterators upon erase/insert, so i accounted for that and SMG1 (and probably smg2) boot fine now

Signed-off-by: lizzie <lizzie@eden-emu.dev>
Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/3927
Reviewed-by: crueter <crueter@eden-emu.dev>
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>

src/core/hle/service/nvdrv/devices/nvhost_as_gpu.cpp

@@ -199,25 +199,28 @@ NvResult nvhost_as_gpu::AllocateSpace(IoctlAllocSpace& params) {
     return NvResult::Success;
 }
 
-void nvhost_as_gpu::FreeMappingLocked(u64 offset) {
-    auto const it = mapping_map.find(offset);
-    auto const mapping = it->second;
-    if (!mapping.fixed) {
-        auto& allocator{mapping.big_page ? *vm.big_page_allocator : *vm.small_page_allocator};
-        u32 page_size_bits{mapping.big_page ? vm.big_page_size_bits : VM::PAGE_SIZE_BITS};
-        u32 page_size{mapping.big_page ? vm.big_page_size : VM::YUZU_PAGESIZE};
-        u64 aligned_size{Common::AlignUp(mapping.size, page_size)};
-        allocator.Free(u32(mapping.offset >> page_size_bits), u32(aligned_size >> page_size_bits));
+bool nvhost_as_gpu::FreeMappingLocked(u64 offset) noexcept {
+    if (auto const it = mapping_map.find(offset); it != mapping_map.end()) {
+        auto const mapping = it->second;
+        if (!mapping.fixed) {
+            auto& allocator{mapping.big_page ? *vm.big_page_allocator : *vm.small_page_allocator};
+            u32 page_size_bits{mapping.big_page ? vm.big_page_size_bits : VM::PAGE_SIZE_BITS};
+            u32 page_size{mapping.big_page ? vm.big_page_size : VM::YUZU_PAGESIZE};
+            u64 aligned_size{Common::AlignUp(mapping.size, page_size)};
+            allocator.Free(u32(mapping.offset >> page_size_bits), u32(aligned_size >> page_size_bits));
+        }
+        nvmap.UnpinHandle(mapping.handle);
+        // Sparse mappings shouldn't be fully unmapped, just returned to their sparse state
+        // Only FreeSpace can unmap them fully
+        if (mapping.sparse_alloc) {
+            gmmu->MapSparse(offset, mapping.size, mapping.big_page);
+        } else {
+            gmmu->Unmap(offset, mapping.size);
+        }
+        mapping_map.erase(offset);
+        return true;
     }
-    nvmap.UnpinHandle(mapping.handle);
-    // Sparse mappings shouldn't be fully unmapped, just returned to their sparse state
-    // Only FreeSpace can unmap them fully
-    if (mapping.sparse_alloc) {
-        gmmu->MapSparse(offset, mapping.size, mapping.big_page);
-    } else {
-        gmmu->Unmap(offset, mapping.size);
-    }
-    mapping_map.erase(it);
+    return false;
 }
 
 NvResult nvhost_as_gpu::FreeSpace(IoctlFreeSpace& params) {
@@ -232,7 +235,8 @@ NvResult nvhost_as_gpu::FreeSpace(IoctlFreeSpace& params) {
             return NvResult::BadValue;
 
         for (const auto mapping_offset : allocation.mappings)
-            FreeMappingLocked(mapping_offset);
+            if (!FreeMappingLocked(mapping_offset))
+                return NvResult::BadValue;
 
         // Unset sparse flag if required
         if (allocation.sparse)
@@ -402,8 +406,8 @@ NvResult nvhost_as_gpu::UnmapBuffer(IoctlUnmapBuffer& params) {
         }
 
         nvmap.UnpinHandle(mapping.handle);
-        mapping_map.erase(it);
-        map_buffer_offsets.erase(offset_it);
+        mapping_map.erase(params.offset);
+        map_buffer_offsets.erase(params.offset);
     }
     return NvResult::Success;
 }

src/core/hle/service/nvdrv/devices/nvhost_as_gpu.h

@@ -157,7 +157,7 @@ private:
     NvResult GetVARegions1(IoctlGetVaRegions& params);
     NvResult GetVARegions3(IoctlGetVaRegions& params, std::span<VaRegion> regions);
 
-    void FreeMappingLocked(u64 offset);
+    [[nodiscard]] bool FreeMappingLocked(u64 offset) noexcept;
 
     Module& module;
 

src/core/hle/service/sm/sm.h

@@ -67,22 +67,24 @@ public:
     Result GetServicePort(Kernel::KClientPort** out_client_port, const std::string& name);
 
     template <std::derived_from<SessionRequestHandler> T>
-    std::shared_ptr<T> GetService(const std::string& service_name, bool block = false) const {
-        auto service = registered_services.find(service_name);
-        if (service == registered_services.end() && !block) {
-            LOG_DEBUG(Service, "Can't find service: {}", service_name);
+    std::shared_ptr<T> GetService(const std::string& name, bool block = false) const {
+        std::unique_lock l{lock};
+        auto it = registered_services.find(name);
+        if (it == registered_services.end() && !block) {
+            LOG_DEBUG(Service, "Can't find service: {}", name);
             return nullptr;
         } else if (block) {
             using namespace std::literals::chrono_literals;
-            while (service == registered_services.end()) {
+            while (it == registered_services.end()) {
+                l.unlock();
                 Kernel::Svc::SleepThread(
                     kernel.System(),
                     std::chrono::duration_cast<std::chrono::nanoseconds>(100ms).count());
-                service = registered_services.find(service_name);
+                l.lock();
+                it = registered_services.find(name);
             }
         }
-
-        return std::static_pointer_cast<T>(service->second());
+        return std::static_pointer_cast<T>(it->second());
     }
 
     void InvokeControlRequest(HLERequestContext& context);
@@ -96,7 +98,7 @@ private:
     std::unique_ptr<Controller> controller_interface;
 
     /// Map of registered services, retrieved using GetServicePort.
-    std::mutex lock;
+    mutable std::mutex lock;
     ankerl::unordered_dense::map<std::string, SessionRequestHandlerFactory> registered_services;
     ankerl::unordered_dense::map<std::string, Kernel::KClientPort*> service_ports;