fix(libSceVdecSavc): ignore unwritable version pointers in sceSdecGetVersionSw

core/libs/prx/libSceVdecSavc/Export.cpp

@@ -3,6 +3,7 @@
 #include <cstddef>
 #include "SceTypes.hpp"
 #include "prx/libc/include/General.hpp"
+#include <cerrno>
 
 extern "C" {
 
@@ -17,7 +18,11 @@ int APS5_VABI sceSdecDestroySw() {
 }
 
 void APS5_VABI sceSdecGetVersionSw(std::uint32_t* version) {
-    if (version != nullptr) *version = 0u;
+    if (version == nullptr) return;
+    const std::uint32_t value = 0u;
+    const auto preserved = errno;
+    GuestCopyOut_nid_no_patch(version, &value, sizeof(value));
+    errno = preserved;
 }
 
 int APS5_VABI sceSdecQueryMemorySw() {

core/libs/tests/GuestSdecVersion.cpp

@@ -38,6 +38,7 @@ void CheckVersion(GetVersion getVersion, std::uint32_t expected, const char* nam
 
 int main() {
     CheckVersion(sceSdecGetVersionSw, 0u, "sceSdecGetVersionSw");
+    sceSdecGetVersionSw(reinterpret_cast<std::uint32_t*>(0x10));
     CheckVersion(sceSdecGetVersionSw2, 0x13590001u, "sceSdecGetVersionSw2");
     CheckVersion(sceSdecGetVersionSwHevc, 0x13590001u, "sceSdecGetVersionSwHevc");
     std::puts("sdec version tests passed");

docs/dev/debt/libSceVdecSavc.md

@@ -3,4 +3,4 @@
 ### Unknown function info
 
 - [sceSdecCreateSw, sceSdecDestroySw and sceSdecQueryMemorySw](../../../core/libs/prx/libSceVdecSavc/Export.cpp) (libSceVdecSavc) - names and NIDs are present in the [PS5 3.20 export inventory](https://github.com/DNNDHH/PS5-3.20_Libs/blob/b2a77c09cd71c01f34c790cfbe98c751a13262ad/libSceVdecSavc.c), but no credible prototypes were found. The declarations have no parameters solely to resolve known imports; this is not an ABI claim and callers must not call them until signatures are verified
-- [sceSdecGetVersionSw](../../../core/libs/prx/libSceVdecSavc/Export.cpp) (libSceVdecSavc) - the prototype and behaviour follow firmware 13.42's libSceVdecSavc.sprx, read from disassembly and run under an emulator, not measured on a console: it takes a `uint32_t*`, writes 0 there unless the pointer is null, and returns nothing
+- [sceSdecGetVersionSw](../../../core/libs/prx/libSceVdecSavc/Export.cpp) (libSceVdecSavc) - the prototype and behaviour follow firmware 13.42's libSceVdecSavc.sprx, read from disassembly and run under an emulator, not measured on a console: it takes a `uint32_t*`, writes 0 there unless the pointer is null, and returns nothing; an unwritable version pointer is ignored defensively, as console behavior on unmapped or read-only memory is not measured