Merge pull request #5272 from milescoviello/carry/siglongjmp-stack-windows-5270

fix(libkernel): switch the host stack bounds in siglongjmp on Windows

core/libs/prx/libkernel/System/src/SignalSets.cpp

@@ -109,6 +109,16 @@ asm(".text\n"
     "    popq %rsi\n"
     "    popq %rdi\n"
     "2:\n"
+#ifdef _WIN32
+    "    pushq %rdi\n"
+    "    pushq %rsi\n"
+    "    movq 16(%rdi), %rdi\n"
+    "    subq $8, %rsp\n"
+    "    call GuestStackSwitch_nid_no_patch\n"
+    "    addq $8, %rsp\n"
+    "    popq %rsi\n"
+    "    popq %rdi\n"
+#endif
     "    movq %rdi, %rdx\n"
     "    movl %esi, %eax\n"
     "    movq 0(%rdx), %rcx\n"

core/libs/tests/GuestUserContext.cpp

@@ -21,6 +21,8 @@ int APS5_VABI setcontext_nid_postfix(const UserUcontext* context);
 void APS5_VABI makecontext_nid_postfix(UserUcontext* context, ContextEntry entry, int count, ...);
 [[gnu::returns_twice]] int APS5_VABI setjmp_nid_postfix(std::uint64_t* buffer);
 [[noreturn]] void APS5_VABI longjmp_nid_postfix(std::uint64_t* buffer, int value);
+[[gnu::returns_twice]] int APS5_VABI sigsetjmp_nid_postfix(std::uint64_t* buffer, int saveMask);
+[[noreturn]] void APS5_VABI siglongjmp_nid_postfix(std::uint64_t* buffer, int value);
 int APS5_VABI sigprocmask_nid_postfix(int how, const void* set, void* previousSet);
 int* APS5_VABI __error_nid_postfix();
 
@@ -150,6 +152,7 @@ int g_entries = 0;
 Fibre g_dispatcher = {};
 Fibre g_job = {};
 int g_jobRuns = 0;
+bool g_signalJumps = false;
 
 void Require(bool value, const char* what) {
     if (!value) {
@@ -348,6 +351,14 @@ namespace {
 
 [[gnu::noinline]] void Switch(Fibre* from, Fibre* to) {
     from->started = 1;
+    if (g_signalJumps) {
+        if (sigsetjmp_nid_postfix(from->jump, 1) == 0) {
+            if (to->started) siglongjmp_nid_postfix(to->jump, 1);
+            setcontext_nid_postfix(&to->context);
+            Require(false, "setcontext into the job returned");
+        }
+        return;
+    }
     if (setjmp_nid_postfix(from->jump) == 0) {
         if (to->started) longjmp_nid_postfix(to->jump, 1);
         setcontext_nid_postfix(&to->context);
@@ -360,7 +371,7 @@ namespace {
 extern "C" void APS5_VABI JobEntry() {
     for (;;) {
         ++g_jobRuns;
-        CheckStackBounds(&g_jobStack, "the stack bounds follow longjmp onto the job stack");
+        CheckStackBounds(&g_jobStack, g_signalJumps ? "the stack bounds follow siglongjmp onto the job stack" : "the stack bounds follow longjmp onto the job stack");
         ThrowAndCatch();
         Switch(&g_job, &g_dispatcher);
     }
@@ -402,7 +413,11 @@ void CheckMakecontext() {
 #endif
 }
 
-void CheckJumpBuffers() {
+void CheckJumpBuffers(bool signalJumps) {
+    g_signalJumps = signalJumps;
+    g_jobRuns = 0;
+    g_dispatcher = {};
+    g_job = {};
 #ifdef _WIN32
     ULONG_PTR threadLow = 0;
     ULONG_PTR threadHigh = 0;
@@ -420,7 +435,7 @@ void CheckJumpBuffers() {
         ULONG_PTR low = 0;
         ULONG_PTR high = 0;
         GetCurrentThreadStackLimits(&low, &high);
-        Require(low == threadLow && high == threadHigh, "the stack bounds follow longjmp back to the thread stack");
+        Require(low == threadLow && high == threadHigh, signalJumps ? "the stack bounds follow siglongjmp back to the thread stack" : "the stack bounds follow longjmp back to the thread stack");
 #endif
     }
 }
@@ -466,7 +481,8 @@ int main(int argc, char** argv) {
     CheckSignalMask();
     std::thread([] {
         CheckMakecontext();
-        CheckJumpBuffers();
+        CheckJumpBuffers(false);
+        CheckJumpBuffers(true);
         GrowStack(32);
     }).join();
     return 0;