From 1832ec2ac2f9fe1a507a34fb2734cd6b6f3490a9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marcin=20Miko=C5=82ajczyk?= <marcinmikolajcz@gmail.com>
Date: Tue, 13 May 2025 22:54:22 +0200
Subject: [PATCH] Implement sceKernelIsStack (#2917)

---
 src/core/libraries/kernel/memory.cpp |  8 ++++++++
 src/core/libraries/kernel/memory.h   |  1 +
 src/core/memory.cpp                  | 29 ++++++++++++++++++++++++++++
 src/core/memory.h                    |  2 ++
 4 files changed, 40 insertions(+)

diff --git a/src/core/libraries/kernel/memory.cpp b/src/core/libraries/kernel/memory.cpp
index dd0e07302..7af67d6d3 100644
--- a/src/core/libraries/kernel/memory.cpp
+++ b/src/core/libraries/kernel/memory.cpp
@@ -290,6 +290,13 @@ int PS4_SYSV_ABI sceKernelGetDirectMemoryType(u64 addr, int* directMemoryTypeOut
                                        directMemoryEndOut);
 }
 
+int PS4_SYSV_ABI sceKernelIsStack(void* addr, void** start, void** end) {
+    LOG_DEBUG(Kernel_Vmm, "called, addr = {:#x}, start = {:#x}, end = {:#x}", fmt::ptr(addr),
+              fmt::ptr(start), fmt::ptr(end));
+    auto* memory = Core::Memory::Instance();
+    return memory->IsStack(std::bit_cast<VAddr>(addr), start, end);
+}
+
 s32 PS4_SYSV_ABI sceKernelBatchMap(OrbisKernelBatchMapEntry* entries, int numEntries,
                                    int* numEntriesOut) {
     return sceKernelBatchMap2(entries, numEntries, numEntriesOut,
@@ -636,6 +643,7 @@ void RegisterMemory(Core::Loader::SymbolsResolver* sym) {
     LIB_FUNCTION("7oxv3PPCumo", "libkernel", 1, "libkernel", 1, 1, sceKernelReserveVirtualRange);
     LIB_FUNCTION("BC+OG5m9+bw", "libkernel", 1, "libkernel", 1, 1, sceKernelGetDirectMemoryType);
     LIB_FUNCTION("pO96TwzOm5E", "libkernel", 1, "libkernel", 1, 1, sceKernelGetDirectMemorySize);
+    LIB_FUNCTION("yDBwVAolDgg", "libkernel", 1, "libkernel", 1, 1, sceKernelIsStack);
     LIB_FUNCTION("NcaWUxfMNIQ", "libkernel", 1, "libkernel", 1, 1, sceKernelMapNamedDirectMemory);
     LIB_FUNCTION("L-Q3LEjIbgA", "libkernel", 1, "libkernel", 1, 1, sceKernelMapDirectMemory);
     LIB_FUNCTION("WFcfL2lzido", "libkernel", 1, "libkernel", 1, 1, sceKernelQueryMemoryProtection);
diff --git a/src/core/libraries/kernel/memory.h b/src/core/libraries/kernel/memory.h
index 3e2bf8de5..92e158a00 100644
--- a/src/core/libraries/kernel/memory.h
+++ b/src/core/libraries/kernel/memory.h
@@ -158,6 +158,7 @@ void PS4_SYSV_ABI _sceKernelRtldSetApplicationHeapAPI(void* func[]);
 int PS4_SYSV_ABI sceKernelGetDirectMemoryType(u64 addr, int* directMemoryTypeOut,
                                               void** directMemoryStartOut,
                                               void** directMemoryEndOut);
+int PS4_SYSV_ABI sceKernelIsStack(void* addr, void** start, void** end);
 
 s32 PS4_SYSV_ABI sceKernelBatchMap(OrbisKernelBatchMapEntry* entries, int numEntries,
                                    int* numEntriesOut);
diff --git a/src/core/memory.cpp b/src/core/memory.cpp
index 6438670d3..ec03d6c5e 100644
--- a/src/core/memory.cpp
+++ b/src/core/memory.cpp
@@ -949,4 +949,33 @@ int MemoryManager::GetDirectMemoryType(PAddr addr, int* directMemoryTypeOut,
     return ORBIS_OK;
 }
 
+int MemoryManager::IsStack(VAddr addr, void** start, void** end) {
+    auto vma_handle = FindVMA(addr);
+    if (vma_handle == vma_map.end()) {
+        return ORBIS_KERNEL_ERROR_EINVAL;
+    }
+
+    const VirtualMemoryArea& vma = vma_handle->second;
+    if (!vma.Contains(addr, 0) || vma.IsFree()) {
+        return ORBIS_KERNEL_ERROR_EACCES;
+    }
+
+    auto stack_start = 0ul;
+    auto stack_end = 0ul;
+    if (vma.type == VMAType::Stack) {
+        stack_start = vma.base;
+        stack_end = vma.base + vma.size;
+    }
+
+    if (start != nullptr) {
+        *start = reinterpret_cast<void*>(stack_start);
+    }
+
+    if (end != nullptr) {
+        *end = reinterpret_cast<void*>(stack_end);
+    }
+
+    return ORBIS_OK;
+}
+
 } // namespace Core
diff --git a/src/core/memory.h b/src/core/memory.h
index 4920aa397..4c143ff6f 100644
--- a/src/core/memory.h
+++ b/src/core/memory.h
@@ -223,6 +223,8 @@ public:
 
     void InvalidateMemory(VAddr addr, u64 size) const;
 
+    int IsStack(VAddr addr, void** start, void** end);
+
 private:
     VMAHandle FindVMA(VAddr target) {
         return std::prev(vma_map.upper_bound(target));