kern: implement transfer memory (and SVCs)

2025-05-16 08:04:23 -04:00 · 2020-07-23 00:44:33 -07:00 · 2020-07-23 00:44:33 -07:00 · d87a9f011c
commit d87a9f011c
parent 28aab09b5d
8 changed files with 312 additions and 19 deletions
--- a/libraries/libmesosphere/source/kern_k_transfer_memory.cpp
+++ b/libraries/libmesosphere/source/kern_k_transfer_memory.cpp
@ -0,0 +1,116 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+#include <mesosphere.hpp>
+
+namespace ams::kern {
+
+    Result KTransferMemory::Initialize(KProcessAddress addr, size_t size, ams::svc::MemoryPermission own_perm) {
+        MESOSPHERE_ASSERT_THIS();
+
+        /* Set members. */
+        this->owner = GetCurrentProcessPointer();
+
+        /* Initialize the page group. */
+        auto &page_table = this->owner->GetPageTable();
+        new (GetPointer(this->page_group)) KPageGroup(page_table.GetBlockInfoManager());
+
+        /* Ensure that our page group's state is valid on exit. */
+        auto pg_guard = SCOPE_GUARD { GetReference(this->page_group).~KPageGroup(); };
+
+        /* Lock the memory. */
+        R_TRY(page_table.LockForTransferMemory(GetPointer(this->page_group), addr, size, ConvertToKMemoryPermission(own_perm)));
+
+        /* Set remaining tracking members. */
+        this->owner->Open();
+        this->owner_perm     = own_perm;
+        this->address        = addr;
+        this->is_initialized = true;
+        this->is_mapped      = false;
+
+        /* We succeeded. */
+        pg_guard.Cancel();
+        return ResultSuccess();
+    }
+
+    void KTransferMemory::Finalize() {
+        MESOSPHERE_ASSERT_THIS();
+
+        /* Unmap. */
+        if (!this->is_mapped) {
+            const size_t size = GetReference(this->page_group).GetNumPages() * PageSize;
+            MESOSPHERE_R_ABORT_UNLESS(this->owner->GetPageTable().UnlockForTransferMemory(this->address, size, GetReference(this->page_group)));
+        }
+
+        /* Close the page group. */
+        GetReference(this->page_group).Close();
+        GetReference(this->page_group).Finalize();
+
+        /* Perform inherited finalization. */
+        KAutoObjectWithSlabHeapAndContainer<KTransferMemory, KAutoObjectWithList>::Finalize();
+    }
+
+    void KTransferMemory::PostDestroy(uintptr_t arg) {
+        KProcess *owner = reinterpret_cast<KProcess *>(arg);
+        owner->ReleaseResource(ams::svc::LimitableResource_TransferMemoryCountMax, 1);
+        owner->Close();
+    }
+
+    Result KTransferMemory::Map(KProcessAddress address, size_t size, ams::svc::MemoryPermission map_perm) {
+        MESOSPHERE_ASSERT_THIS();
+
+        /* Validate the size. */
+        R_UNLESS(GetReference(this->page_group).GetNumPages() == util::DivideUp(size, PageSize), svc::ResultInvalidSize());
+
+        /* Validate the permission. */
+        R_UNLESS(this->owner_perm == map_perm, svc::ResultInvalidState());
+
+        /* Lock ourselves. */
+        KScopedLightLock lk(this->lock);
+
+        /* Ensure we're not already mapped. */
+        R_UNLESS(!this->is_mapped, svc::ResultInvalidState());
+
+        /* Map the memory. */
+        const KMemoryState state = (this->owner_perm == ams::svc::MemoryPermission_None) ? KMemoryState_Transfered : KMemoryState_SharedTransfered;
+        R_TRY(GetCurrentProcess().GetPageTable().MapPageGroup(address, GetReference(this->page_group), state, KMemoryPermission_UserReadWrite));
+
+        /* Mark ourselves as mapped. */
+        this->is_mapped = true;
+
+        return ResultSuccess();
+    }
+
+    Result KTransferMemory::Unmap(KProcessAddress address, size_t size) {
+        MESOSPHERE_ASSERT_THIS();
+
+        /* Validate the size. */
+        R_UNLESS(GetReference(this->page_group).GetNumPages() == util::DivideUp(size, PageSize), svc::ResultInvalidSize());
+
+        /* Lock ourselves. */
+        KScopedLightLock lk(this->lock);
+
+        /* Unmap the memory. */
+        const KMemoryState state = (this->owner_perm == ams::svc::MemoryPermission_None) ? KMemoryState_Transfered : KMemoryState_SharedTransfered;
+        R_TRY(GetCurrentProcess().GetPageTable().UnmapPageGroup(address, GetReference(this->page_group), state));
+
+        /* Mark ourselves as unmapped. */
+        MESOSPHERE_ASSERT(this->is_mapped);
+        this->is_mapped = false;
+
+        return ResultSuccess();
+    }
+
+}