kern: generate fatal error on panic

fusee/fusee-primary/src/panic.c

@@ -42,6 +42,8 @@ static const char *get_error_desc_str(uint32_t error_desc) {
             return "SError";
         case 0x301:
             return "Bad SVC";
+        case 0xF00:
+	        return "Kernel Panic";
         case 0xFFD:
 	        return "Stack overflow";
         case 0xFFE:

libraries/libmesosphere/include/mesosphere/board/nintendo/nx/kern_k_system_control.hpp

@@ -63,7 +63,7 @@ namespace ams::kern::board::nintendo::nx {
 
             /* Power management. */
             static void SleepSystem();
-            static NORETURN void StopSystem();
+            static NORETURN void StopSystem(void *arg = nullptr);
 
             /* User access. */
             static void CallSecureMonitorFromUser(ams::svc::lp64::SecureMonitorArguments *args);

libraries/libmesosphere/include/mesosphere/kern_build_config.hpp

@@ -28,4 +28,5 @@
 #define MESOSPHERE_ENABLE_DEBUG_PRINT
 #endif
 
-#define MESOSPHERE_BUILD_FOR_TRACING
+//#define MESOSPHERE_BUILD_FOR_TRACING
+#define MESOSPHERE_ENABLE_PANIC_REGISTER_DUMP

libraries/libmesosphere/source/arch/arm64/kern_panic_asm.s

@@ -0,0 +1,88 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * 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 <mesosphere/kern_build_config.hpp>
+
+#if defined(MESOSPHERE_ENABLE_PANIC_REGISTER_DUMP)
+
+#define MESOSPHERE_GENERATE_PANIC_EXCEPTION_CONTEXT        \
+    /* Save x0/x1 to stack. */                             \
+    stp     x0, x1, [sp, #-16]!;                           \
+                                                           \
+    /* Get the exception context for the core. */          \
+    adr     x0, _ZN3ams4kern26g_panic_exception_contextsE; \
+    mrs     x1, mpidr_el1;                                 \
+    and     x1, x1, #0xFF;                                 \
+    lsl     x1, x1, #0x8;                                  \
+    add     x0, x0, x1;                                    \
+    lsr     x1, x1, #0x3;                                  \
+    add     x0, x0, x1;                                    \
+                                                           \
+    /* Save x0/x1/sp to the context. */                    \
+    ldr     x1, [sp, #(8 *  0)];                           \
+    str     x1, [x0, #(8 *  0)];                           \
+    ldr     x1, [sp, #(8 *  1)];                           \
+    str     x1, [x0, #(8 *  1)];                           \
+                                                           \
+    /* Save all other registers to the context. */         \
+    stp     x2, x3,   [x0, #(8 *  2)];                     \
+    stp     x4, x5,   [x0, #(8 *  4)];                     \
+    stp     x6, x7,   [x0, #(8 *  6)];                     \
+    stp     x8, x9,   [x0, #(8 *  8)];                     \
+    stp     x10, x11, [x0, #(8 * 10)];                     \
+    stp     x12, x13, [x0, #(8 * 12)];                     \
+    stp     x14, x15, [x0, #(8 * 14)];                     \
+    stp     x16, x17, [x0, #(8 * 16)];                     \
+    stp     x18, x19, [x0, #(8 * 18)];                     \
+    stp     x20, x21, [x0, #(8 * 20)];                     \
+    stp     x22, x23, [x0, #(8 * 22)];                     \
+    stp     x24, x25, [x0, #(8 * 24)];                     \
+    stp     x26, x27, [x0, #(8 * 26)];                     \
+    stp     x28, x29, [x0, #(8 * 28)];                     \
+                                                           \
+    add     x1, sp, #16;                                   \
+    stp     x30, x1,  [x0, #(8 * 30)];                     \
+                                                           \
+    /* Restore x0/x1. */                                   \
+    ldp     x0, x1, [sp], #16;
+
+#else
+
+#define MESOSPHERE_GENERATE_PANIC_EXCEPTION_CONTEXT
+
+#endif
+
+/* ams::kern::Panic(const char *file, int line, const char *format, ...) */
+.section    .text._ZN3ams4kern5PanicEPKciS2_z, "ax", %progbits
+.global     _ZN3ams4kern5PanicEPKciS2_z
+.type       _ZN3ams4kern5PanicEPKciS2_z, %function
+_ZN3ams4kern5PanicEPKciS2_z:
+    /* Generate the exception context. */
+    MESOSPHERE_GENERATE_PANIC_EXCEPTION_CONTEXT
+
+    /* Jump to the architecturally-common implementation function. */
+    b _ZN3ams4kern9PanicImplEPKciS2_z
+
+
+/* ams::kern::Panic() */
+.section    .text._ZN3ams4kern5PanicEv, "ax", %progbits
+.global     _ZN3ams4kern5PanicEv
+.type       _ZN3ams4kern5PanicEv, %function
+_ZN3ams4kern5PanicEv:
+    /* Generate the exception context. */
+    MESOSPHERE_GENERATE_PANIC_EXCEPTION_CONTEXT
+
+    /* Jump to the architecturally-common implementation function. */
+    b _ZN3ams4kern9PanicImplEv

libraries/libmesosphere/source/board/nintendo/nx/kern_k_system_control.cpp

@@ -532,13 +532,63 @@ namespace ams::kern::board::nintendo::nx {
         KSleepManager::SleepSystem();
     }
 
-    void KSystemControl::StopSystem() {
+    void KSystemControl::StopSystem(void *arg) {
+        if (arg != nullptr) {
+            /* NOTE: Atmosphere extension; if we received an exception context from Panic(), */
+            /*       generate a fatal error report using it. */
+            const KExceptionContext *e_ctx = static_cast<const KExceptionContext *>(arg);
+            auto *f_ctx = GetPointer<::ams::impl::FatalErrorContext>(KMemoryLayout::GetDeviceVirtualAddress(KMemoryRegionType_LegacyLpsIram) + 0x3E000);
+
+            /* Clear the fatal context. */
+            std::memset(f_ctx, 0xCC, sizeof(*f_ctx));
+
+            /* Set metadata. */
+            f_ctx->magic      = ::ams::impl::FatalErrorContext::Magic;
+            f_ctx->error_desc = ::ams::impl::FatalErrorContext::KernelPanicDesc;
+            f_ctx->program_id = (static_cast<u64>(util::FourCC<'M', 'E', 'S', 'O'>::Code) << 0) | (static_cast<u64>(util::FourCC<'S', 'P', 'H', 'R'>::Code) << 32);
+
+            /* Set identifier. */
+            f_ctx->report_identifier = KHardwareTimer::GetTick();
+
+            /* Set module base. */
+            f_ctx->module_base = KMemoryLayout::GetKernelCodeRegionExtents().GetAddress();
+
+            /* Copy registers. */
+            for (size_t i = 0; i < util::size(e_ctx->x); ++i) {
+                f_ctx->gprs[i] = e_ctx->x[i];
+            }
+            f_ctx->sp = e_ctx->sp;
+
+            /* Dump stack trace. */
+            {
+                uintptr_t fp = e_ctx->x[29];
+                for (f_ctx->stack_trace_size = 0; f_ctx->stack_trace_size < ::ams::impl::FatalErrorContext::MaxStackTrace && fp != 0 && util::IsAligned(fp, 0x10) && cpu::GetPhysicalAddressWritable(nullptr, fp, true); ++(f_ctx->stack_trace_size)) {
+                    struct {
+                        uintptr_t fp;
+                        uintptr_t lr;
+                    } *stack_frame = reinterpret_cast<decltype(stack_frame)>(fp);
+
+                    f_ctx->stack_trace[f_ctx->stack_trace_size] = stack_frame->lr;
+                    fp = stack_frame->fp;
+                }
+            }
+
+            /* Dump stack. */
+            {
+                uintptr_t sp = e_ctx->sp;
+                for (f_ctx->stack_dump_size = 0; f_ctx->stack_dump_size < ::ams::impl::FatalErrorContext::MaxStackDumpSize && cpu::GetPhysicalAddressWritable(nullptr, sp + f_ctx->stack_dump_size, true); f_ctx->stack_dump_size += sizeof(u64)) {
+                    *reinterpret_cast<u64 *>(f_ctx->stack_dump + f_ctx->stack_dump_size) = *reinterpret_cast<u64 *>(sp + f_ctx->stack_dump_size);
+                }
+            }
+
+            /* Trigger a reboot to rcm. */
+            smc::init::SetConfig(smc::ConfigItem::ExosphereNeedsReboot, smc::UserRebootType_ToRcm);
+        }
+
         if (g_call_smc_on_panic) {
-            /* Display a panic screen via secure monitor. */
+            /* If we should, instruct the secure monitor to display a panic screen. */
             smc::Panic(0xF00);
         }
-        u32 dummy;
-        smc::init::ReadWriteRegister(std::addressof(dummy), 0x7000E400, 0x10, 0x10);
         AMS_INFINITE_LOOP();
     }
 

libraries/libmesosphere/source/board/nintendo/nx/kern_secure_monitor.cpp

@@ -24,6 +24,10 @@ namespace ams::kern::board::nintendo::nx::smc {
             u64 x[8];
         };
 
+        enum UserFunctionId : u32 {
+            UserFunctionId_SetConfig = 0xC3000401,
+        };
+
         enum FunctionId : u32 {
             FunctionId_CpuSuspend          = 0xC4000001,
             FunctionId_CpuOff              = 0x84000002,
@@ -136,6 +140,35 @@ namespace ams::kern::board::nintendo::nx::smc {
             args.x[7] = x7;
         }
 
+        void CallUserSecureMonitorFunctionForInit(SecureMonitorArguments &args) {
+            /* Load arguments into registers. */
+            register u64 x0 asm("x0") = args.x[0];
+            register u64 x1 asm("x1") = args.x[1];
+            register u64 x2 asm("x2") = args.x[2];
+            register u64 x3 asm("x3") = args.x[3];
+            register u64 x4 asm("x4") = args.x[4];
+            register u64 x5 asm("x5") = args.x[5];
+            register u64 x6 asm("x6") = args.x[6];
+            register u64 x7 asm("x7") = args.x[7];
+
+            /* Actually make the call. */
+            __asm__ __volatile__("smc #0"
+                                : "+r"(x0), "+r"(x1), "+r"(x2), "+r"(x3), "+r"(x4), "+r"(x5), "+r"(x6), "+r"(x7)
+                                :
+                                : "x8", "x9", "x10", "x11", "x12", "x13", "x14", "x15", "x16", "x17", "x18", "cc", "memory"
+                                );
+
+            /* Store arguments to output. */
+            args.x[0] = x0;
+            args.x[1] = x1;
+            args.x[2] = x2;
+            args.x[3] = x3;
+            args.x[4] = x4;
+            args.x[5] = x5;
+            args.x[6] = x6;
+            args.x[7] = x7;
+        }
+
         /* Global lock for generate random bytes. */
         KSpinLock g_generate_random_lock;
 
@@ -177,6 +210,12 @@ namespace ams::kern::board::nintendo::nx::smc {
             return static_cast<SmcResult>(args.x[0]) == SmcResult::Success;
         }
 
+        bool SetConfig(ConfigItem config_item, u64 value) {
+            SecureMonitorArguments args = { UserFunctionId_SetConfig, static_cast<u32>(config_item), 0, value };
+            CallUserSecureMonitorFunctionForInit(args);
+            return static_cast<SmcResult>(args.x[0]) == SmcResult::Success;
+        }
+
     }
 
     void GetConfig(u64 *out, size_t num_qwords, ConfigItem config_item) {

libraries/libmesosphere/source/board/nintendo/nx/kern_secure_monitor.hpp

@@ -83,6 +83,12 @@ namespace ams::kern::board::nintendo::nx::smc {
         using MemorySize                  = util::BitPack32::Field<Reserved9::Next,                   2, smc::MemorySize>;
     };
 
+    enum UserRebootType {
+        UserRebootType_None      = 0,
+        UserRebootType_ToRcm     = 1,
+        UserRebootType_ToPayload = 2,
+    };
+
     /* TODO: Rest of Secure Monitor API. */
     void GenerateRandomBytes(void *dst, size_t size);
     void GetConfig(u64 *out, size_t num_qwords, ConfigItem config_item);
@@ -102,6 +108,8 @@ namespace ams::kern::board::nintendo::nx::smc {
         void GenerateRandomBytes(void *dst, size_t size);
         bool ReadWriteRegister(u32 *out, u64 address, u32 mask, u32 value);
 
+        bool SetConfig(ConfigItem config_item, u64 value);
+
     }
 
 }

libraries/libmesosphere/source/kern_panic.cpp

@@ -27,6 +27,11 @@ namespace ams::result::impl {
 
 namespace ams::kern {
 
+    /* NOTE: This is not exposed via a header, but is referenced via assembly. */
+    /* NOTE: Nintendo does not save register contents on panic; we use this */
+    /*       to generate an atmosphere fatal report on panic. */
+    constinit KExceptionContext g_panic_exception_contexts[cpu::NumCores];
+
     namespace {
 
         constexpr std::array<s32, cpu::NumCores> NegativeArray = [] {
@@ -73,18 +78,38 @@ namespace ams::kern {
             } while (!g_current_ticket.compare_exchange_weak(compare, desired));
         }
 
+        ALWAYS_INLINE KExceptionContext *GetPanicExceptionContext(int core_id) {
+            #if defined(MESOSPHERE_ENABLE_PANIC_REGISTER_DUMP)
+                return std::addressof(g_panic_exception_contexts[core_id]);
+            #else
+                return nullptr;
+            #endif
+        }
+
         [[gnu::unused]] void PrintCurrentState() {
             /* Wait for it to be our turn to print. */
             WaitCoreTicket();
 
+            /* Get the current exception context. */
             const s32 core_id    = GetCurrentCoreId();
+            const auto *core_ctx = GetPanicExceptionContext(core_id);
+
+            /* Print the state. */
             MESOSPHERE_RELEASE_LOG("Core[%d] Current State:\n", core_id);
 
-            /* TODO: Dump register state. */
-
             #ifdef ATMOSPHERE_ARCH_ARM64
+                /* Print registers. */
+                if (core_ctx != nullptr) {
+                    MESOSPHERE_RELEASE_LOG("    Registers:\n");
+                    for (size_t i = 0; i < util::size(core_ctx->x); ++i) {
+                        MESOSPHERE_RELEASE_LOG("        X[%02zx]: %p\n", i, reinterpret_cast<void *>(core_ctx->x[i]));
+                    }
+                    MESOSPHERE_RELEASE_LOG("        SP:   %p\n", reinterpret_cast<void *>(core_ctx->x[30]));
+                }
+
+                /* Print backtrace. */
                 MESOSPHERE_RELEASE_LOG("    Backtrace:\n");
-                uintptr_t fp = reinterpret_cast<uintptr_t>(__builtin_frame_address(0));
+                uintptr_t fp = core_ctx != nullptr ? core_ctx->x[29] : reinterpret_cast<uintptr_t>(__builtin_frame_address(0));
                 for (size_t i = 0; i < 32 && fp && util::IsAligned(fp, 0x10) && cpu::GetPhysicalAddressWritable(nullptr, fp, true); i++) {
                     struct {
                         uintptr_t fp;
@@ -107,12 +132,12 @@ namespace ams::kern {
                 PrintCurrentState();
             #endif
 
-            KSystemControl::StopSystem();
+            KSystemControl::StopSystem(GetPanicExceptionContext(GetCurrentCoreId()));
         }
 
     }
 
-    NORETURN WEAK_SYMBOL void Panic(const char *file, int line, const char *format, ...) {
+    NORETURN void PanicImpl(const char *file, int line, const char *format, ...) {
         #ifdef MESOSPHERE_BUILD_FOR_DEBUGGING
             /* Wait for it to be our turn to print. */
             WaitCoreTicket();
@@ -133,7 +158,7 @@ namespace ams::kern {
         StopSystem();
     }
 
-    NORETURN WEAK_SYMBOL void Panic() {
+    NORETURN void PanicImpl() {
         StopSystem();
     }
 

libraries/libstratosphere/include/stratosphere/ams/ams_types.hpp

@@ -65,47 +65,9 @@ namespace ams::exosphere {
 
 namespace ams {
 
-    struct FatalErrorContext : sf::LargeData, sf::PrefersMapAliasTransferMode {
+    struct FatalErrorContext : ::ams::impl::FatalErrorContext, sf::LargeData, sf::PrefersMapAliasTransferMode {};
-        static constexpr size_t MaxStackTrace = 0x20;
-        static constexpr size_t MaxStackDumpSize = 0x100;
-        static constexpr size_t ThreadLocalSize = 0x100;
-        static constexpr size_t NumGprs = 29;
-        static constexpr uintptr_t StdAbortMagicAddress = 0x8;
-        static constexpr u64       StdAbortMagicValue = 0xA55AF00DDEADCAFEul;
-        static constexpr u32       StdAbortErrorDesc = 0xFFE;
-        static constexpr u32       StackOverflowErrorDesc = 0xFFD;
-        static constexpr u32       DataAbortErrorDesc = 0x101;
-        static constexpr u32       Magic = util::FourCC<'A', 'F', 'E', '2'>::Code;
 
-        u32 magic;
+    static_assert(sizeof(FatalErrorContext) == sizeof(::ams::impl::FatalErrorContext));
-        u32 error_desc;
-        u64 program_id;
-        union {
-            u64 gprs[32];
-            struct {
-                u64 _gprs[29];
-                u64 fp;
-                u64 lr;
-                u64 sp;
-            };
-        };
-        u64 pc;
-        u64 module_base;
-        u32 pstate;
-        u32 afsr0;
-        u32 afsr1;
-        u32 esr;
-        u64 far;
-        u64 report_identifier; /* Normally just system tick. */
-        u64 stack_trace_size;
-        u64 stack_dump_size;
-        u64 stack_trace[MaxStackTrace];
-        u8  stack_dump[MaxStackDumpSize];
-        u8  tls[ThreadLocalSize];
-    };
-
-    static_assert(sizeof(FatalErrorContext) == 0x450, "sizeof(FatalErrorContext)");
-    static_assert(util::is_pod<FatalErrorContext>::value, "FatalErrorContext");
 
 #ifdef ATMOSPHERE_GIT_BRANCH
     NX_CONSTEXPR const char *GetGitBranch() {

libraries/libvapours/include/vapours.hpp

@@ -27,3 +27,5 @@
 #include <vapours/results.hpp>
 #include <vapours/crypto.hpp>
 #include <vapours/svc.hpp>
+
+#include <vapours/ams/ams_fatal_error_context.hpp>

libraries/libvapours/include/vapours/ams/ams_fatal_error_context.hpp

@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2018-2020 Atmosphère-NX
+ *
+ * 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/>.
+ */
+#pragma once
+#include <vapours/includes.hpp>
+#include <vapours/defines.hpp>
+
+namespace ams::impl {
+
+    struct FatalErrorContext {
+        static constexpr size_t MaxStackTrace = 0x20;
+        static constexpr size_t MaxStackDumpSize = 0x100;
+        static constexpr size_t ThreadLocalSize = 0x100;
+        static constexpr size_t NumGprs = 29;
+        static constexpr uintptr_t StdAbortMagicAddress = 0x8;
+        static constexpr u64       StdAbortMagicValue = 0xA55AF00DDEADCAFEul;
+        static constexpr u32       StdAbortErrorDesc = 0xFFE;
+        static constexpr u32       StackOverflowErrorDesc = 0xFFD;
+        static constexpr u32       KernelPanicDesc = 0xF00;
+        static constexpr u32       DataAbortErrorDesc = 0x101;
+        static constexpr u32       Magic = util::FourCC<'A', 'F', 'E', '2'>::Code;
+
+        u32 magic;
+        u32 error_desc;
+        u64 program_id;
+        union {
+            u64 gprs[32];
+            struct {
+                u64 _gprs[29];
+                u64 fp;
+                u64 lr;
+                u64 sp;
+            };
+        };
+        u64 pc;
+        u64 module_base;
+        u32 pstate;
+        u32 afsr0;
+        u32 afsr1;
+        u32 esr;
+        u64 far;
+        u64 report_identifier; /* Normally just system tick. */
+        u64 stack_trace_size;
+        u64 stack_dump_size;
+        u64 stack_trace[MaxStackTrace];
+        u8  stack_dump[MaxStackDumpSize];
+        u8  tls[ThreadLocalSize];
+    };
+
+    static_assert(sizeof(FatalErrorContext) == 0x450);
+    static_assert(std::is_standard_layout<FatalErrorContext>::value);
+    static_assert(std::is_trivial<FatalErrorContext>::value);
+
+}