nvservices debug unlock + license change

Source/Atmosphere/stratosphere/loader/source/oc/nvsrv/nvsrv.cpp

@@ -0,0 +1,102 @@
+/*
+ * Copyright (c) Souldbminer, Lightos and Horizon OC Contributors
+ *
+ * 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 "nvsrv.hpp"
+
+namespace ams::ldr::hoc::nvsrv {
+
+    namespace {
+
+        /* NvServices device names */
+        constexpr char DbgGpuPath[]  = "/dev/nvhost-dbg-gpu";
+        constexpr char ProfGpuPath[] = "/dev/nvhost-prof-gpu";
+        
+        /* Permission offset to patch */
+        constexpr size_t DevTablePermOffset = 0x68;
+
+        uintptr_t FindBytes(uintptr_t start, uintptr_t end, const void *needle, size_t len) {
+            const u8 *pat = reinterpret_cast<const u8 *>(needle);
+            for (uintptr_t addr = start; addr + len <= end; ++addr) {
+                if (std::memcmp(reinterpret_cast<const void *>(addr), pat, len) == 0) {
+                    return addr;
+                }
+            }
+            return 0;
+        }
+
+        /* Unlock the devices */
+        Result UnlockDevicePermission(uintptr_t mapped_nso, size_t nso_size, uintptr_t nso_address, const char *path, const char *description) {
+            const size_t path_len = std::strlen(path) + 1;
+
+            const uintptr_t str_addr = FindBytes(mapped_nso, mapped_nso + nso_size, path, path_len);
+            if (str_addr == 0) {
+                LOGGING("nvsrv: %s path string not found (nso_size=%lx)", description, static_cast<unsigned long>(nso_size));
+                R_THROW(ldr::ResultInvalidNvsrvDevTable());
+            }
+
+            const uintptr_t str_offset  = str_addr - mapped_nso;
+            const uintptr_t candidates[] = { str_offset, nso_address + str_offset };
+
+            uintptr_t entry_addr = 0;
+            for (uintptr_t ptr = mapped_nso; entry_addr == 0 && ptr + sizeof(uintptr_t) <= mapped_nso + nso_size; ptr += sizeof(uintptr_t)) {
+                const uintptr_t val = *reinterpret_cast<const uintptr_t *>(ptr);
+                for (uintptr_t cand : candidates) {
+                    if (val == cand) {
+                        entry_addr = ptr;
+                        break;
+                    }
+                }
+            }
+            if (entry_addr == 0) {
+                LOGGING("nvsrv: %s str@+%lx has no referencing table entry", description,
+                        static_cast<unsigned long>(str_offset), static_cast<unsigned long>(candidates[0]), static_cast<unsigned long>(candidates[1]));
+                R_THROW(ldr::ResultInvalidNvsrvDevTable());
+            }
+
+            const uintptr_t perm_addr = entry_addr + DevTablePermOffset;
+            if (perm_addr + sizeof(uintptr_t) > mapped_nso + nso_size) {
+                LOGGING("nvsrv: %s entry@+%lx perm field out of bounds", description, static_cast<unsigned long>(entry_addr - mapped_nso));
+                R_THROW(ldr::ResultInvalidNvsrvDevTable());
+            }
+
+            uintptr_t *perm = reinterpret_cast<uintptr_t *>(perm_addr);
+            LOGGING("nvsrv: %s entry@+%lx perm@+%lx was %lx", description,
+                    static_cast<unsigned long>(entry_addr - mapped_nso),
+                    static_cast<unsigned long>(perm_addr - mapped_nso),
+                    static_cast<unsigned long>(*perm));
+
+            PATCH_OFFSET(perm, static_cast<uintptr_t>(0));
+            R_SUCCEED();
+        }
+
+    }
+
+    void Patch(uintptr_t mapped_nso, size_t nso_size, uintptr_t nso_address) {
+        struct {
+            const char *path;
+            const char *description;
+        } targets[] = {
+            { DbgGpuPath,  "dbg-gpu"  },
+            { ProfGpuPath, "prof-gpu" },
+        };
+
+        for (auto &t : targets) {
+            const Result res = UnlockDevicePermission(mapped_nso, nso_size, nso_address, t.path, t.description);
+            LOGGING("nvsrv: %s unlock%s", t.description, R_SUCCEEDED(res) ? "ed" : " skipped");
+        }
+    }
+
+}