parallel compile, SMP, swapgs, cleanup, remove useless Reserved fields

code/kernel/ke_debug.c

@@ -3,18 +3,48 @@
 #include <stdint.h>
 #include <string.h>
 #include <ntlite/ddi/hal_api.h>
+#include <kernel/hal/hal_apic.h>
+#include <intrin.h>
 #include <kernel/ke_debug.h>
+#include <kernel/ke_cpu.h>
 #include <kernel/ke_spinlock.h>
 #include <kernel/ke_process.h>
 #include <kernel/ke_thread.h>
 #include <kernel/ke_sched.h>
 #include <kernel/mm_virt.h>
 #include <common/printf.h>
-int _fltused; // fuckass
+int _fltused; // MSVC floating-point helper anchor
 
 int gDebugEnabled = 0;
 void (*PrintChar)(char, uint32_t, uint32_t);
 
+static volatile long gPanicInProgress = 0;
+static volatile long gPanicStoppedCpuCount = 0;
+
+static _Noreturn void KiPanicSecondaryHalt(void) {
+    _disable();
+    _InterlockedIncrement(&gPanicStoppedCpuCount);
+    for (;;) __halt();
+}
+
+static int KiPanicIsActive(void) {
+    return _InterlockedCompareExchange((volatile long*)&gPanicInProgress, 0, 0) != 0;
+}
+
+// Returning NMI handler used for SMP control IPIs.  Panic NMIs stop the
+// target CPU permanently; TLB shootdown NMIs flush and return.  A genuinely
+// unexpected NMI is not handled here and will fall through to the normal fault
+// path in the assembly stub.
+__declspec(dllexport) int KeHandleNmiIpi(void) {
+    if (KiPanicIsActive())
+        KiPanicSecondaryHalt();
+
+    if (MmHandleTlbShootdownNmi())
+        return 1;
+
+    return 0;
+}
+
 void KiKernelPutChar(char c) {
     PrintChar(c, 0x00FF00, 0x000000);
 }
@@ -39,26 +69,48 @@ __declspec(dllexport) void DbgPrint(const char* fmt, ...) {
 
 // KePanic
 __declspec(dllexport) _Noreturn void KePanic(int code, const char* fmt, ...) {
-    // Silence! Stop the world!
+    // Silence this CPU first.
     _disable();
 
-    // Print a bright-red banner so the framebuffer is unmistakable.
-    // We call PrintChar directly so we can set a red foreground.
-    // (DbgPrint uses green; we want this visually distinct.)
-    static const char banner[] = "\n*** KERNEL PANIC ***\n";
-    for (const char* p = banner; *p; p++)
-        PrintChar(*p, 0xFF2222, 0x000000);
+    // Only one CPU owns the visible panic report.  CPUs that fault while the
+    // system is already panicking immediately join the stopped set.
+    if (_InterlockedCompareExchange((volatile long*)&gPanicInProgress, 1, 0) != 0) {
+        KiPanicSecondaryHalt();
+    }
 
-    // Print the panic code first, then the caller's message through the normal vprintf path.
-    printf("Panic code: %d\n", code);
+    // Stop every other CPU as early as possible.  This uses an NMI IPI so it
+    // still reaches CPUs with IF cleared inside spinlock/high-IRQL regions.
+    HalApicSendPanicIpi();
 
-    va_list va;
-    va_start(va, fmt);
-    vprintf(fmt, va);
-    va_end(va);
+    if (PrintChar) {
+        // Print a bright-red banner so the framebuffer is unmistakable.
+        static const char banner[] = "\n*** KERNEL PANIC ***\n";
+        const char* p;
+        KCPU* cpu = KeGetCurrentCpu();
+        THREAD* thread = KeGetCurrentThread();
 
-    // Die!
-    while (true) __halt();
+        for (p = banner; *p; p++)
+            PrintChar(*p, 0xFF2222, 0x000000);
+
+        printf("Panic code: %d\n", code);
+        if (cpu) {
+            printf("Panic CPU: %u LAPIC=%u",
+                   (unsigned)cpu->CpuIndex,
+                   (unsigned)cpu->LapicId);
+            if (thread)
+                printf(" thread=%p tid=%llu",
+                       thread,
+                       (unsigned long long)thread->ThreadId);
+            printf("\n");
+        }
+
+        va_list va;
+        va_start(va, fmt);
+        vprintf(fmt, va);
+        va_end(va);
+    }
+
+    for (;;) __halt();
 }
 
 // KePrintConsole - write user-visible console text in white-on-black.
@@ -434,6 +486,11 @@ _Noreturn void KeBugCheckProcess(int vector, uintptr_t rip, uintptr_t errCode, u
 }
 
 __declspec(dllexport) _Noreturn void KeFaultDispatchFrame(const KFAULT_FRAME* frame) {
+    // Panic NMIs are broadcast to stop all other CPUs.  Do not try to decode
+    // the interrupted context on a secondary CPU once another CPU owns panic.
+    if (KiPanicIsActive())
+        KiPanicSecondaryHalt();
+
     THREAD*  thread = KeGetCurrentThread();
     PROCESS* proc   = thread ? thread->Owner : (PROCESS*)0;
 
@@ -453,14 +510,26 @@ __declspec(dllexport) _Noreturn void KeFaultDispatchFrame(const KFAULT_FRAME* fr
                     (unsigned long long)frame->ErrorCode,
                     (unsigned long long)frame->Cr2);
         } else if (KiFaultHasErrorCode(vector)) {
-            KePanic(KE_PANIC_CODE_FAULT, "PANIC: %s | RIP: %016llx | Code: %04llx\n",
+            const uint8_t* ip = (const uint8_t*)(uintptr_t)frame->Rip;
+            KePanic(KE_PANIC_CODE_FAULT,
+                    "PANIC: %s | RIP: %016llx | Code: %04llx | CS=%04llx RFLAGS=%016llx RSP=%016llx | bytes=%02x %02x %02x %02x %02x %02x %02x %02x\n",
                     name,
                     (unsigned long long)frame->Rip,
-                    (unsigned long long)frame->ErrorCode);
+                    (unsigned long long)frame->ErrorCode,
+                    (unsigned long long)frame->Cs,
+                    (unsigned long long)frame->Rflags,
+                    (unsigned long long)frame->Rsp,
+                    ip[0], ip[1], ip[2], ip[3], ip[4], ip[5], ip[6], ip[7]);
         } else {
-            KePanic(KE_PANIC_CODE_FAULT, "PANIC: %s | RIP: %016llx\n",
+            const uint8_t* ip = (const uint8_t*)(uintptr_t)frame->Rip;
+            KePanic(KE_PANIC_CODE_FAULT,
+                    "PANIC: %s | RIP: %016llx | CS=%04llx RFLAGS=%016llx RSP=%016llx | bytes=%02x %02x %02x %02x %02x %02x %02x %02x\n",
                     name,
-                    (unsigned long long)frame->Rip);
+                    (unsigned long long)frame->Rip,
+                    (unsigned long long)frame->Cs,
+                    (unsigned long long)frame->Rflags,
+                    (unsigned long long)frame->Rsp,
+                    ip[0], ip[1], ip[2], ip[3], ip[4], ip[5], ip[6], ip[7]);
         }
     }