libstrat: Custom exception handlers/std::abort

include/stratosphere.hpp

@@ -37,4 +37,6 @@
 
 #include "stratosphere/results.hpp"
 
-#include "stratosphere/title_ids.hpp"
+#include "stratosphere/title_ids.hpp"
+
+#include "stratosphere/on_crash.hpp"

include/stratosphere/on_crash.hpp

@@ -0,0 +1,27 @@
+/*
+ * Copyright (c) 2018-2019 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 <switch.h>
+#include <cstdlib>
+#include "services/bpc_ams.h"
+
+static constexpr size_t AtmosphereFatalErrorNumGprs = 29;
+
+static constexpr u32 AtmosphereFatalErrorMagic = 0x30454641; /* "AFE0" */
+
+/* Will be called by libstratosphere on crash. */
+void StratosphereCrashHandler(ThreadExceptionDump *ctx);

include/stratosphere/services/bpc_ams.h

@@ -0,0 +1,54 @@
+/*
+ * Copyright (c) 2018-2019 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 <switch.h>
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+    u32 magic;
+    u32 error_desc;
+    u64 title_id;
+    union {
+        u64 gprs[32];
+        struct {
+            u64 _gprs[29];
+            u64 fp;
+            u64 lr;
+            u64 sp;
+        };
+    };
+    u64 pc;
+    u64 padding;
+    u32 pstate;
+    u32 afsr0;
+    u32 afsr1;
+    u32 esr;
+    u64 far;
+    u64 report_identifier; /* Normally just system tick. */
+} AtmosphereFatalErrorContext;
+
+Result bpcAmsInitialize(void);
+void bpcAmsExit(void);
+
+Result bpcAmsRebootToFatalError(AtmosphereFatalErrorContext *ctx);
+
+#ifdef __cplusplus
+}
+#endif

source/bpc_ams.c

@@ -0,0 +1,76 @@
+/*
+ * Copyright (c) 2018-2019 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 <switch.h>
+#include <switch/arm/atomics.h>
+#include <stratosphere/services/bpc_ams.h>
+
+static Service g_bpcAmsSrv;
+static u64 g_bpcAmsAmsRefcnt;
+
+Result bpcAmsInitialize(void) {
+    atomicIncrement64(&g_bpcAmsAmsRefcnt);
+
+    if (serviceIsActive(&g_bpcAmsSrv)) {
+        return 0;
+    }
+
+    Handle h;
+    Result rc = svcConnectToNamedPort(&h, "bpc:ams");
+    if (R_SUCCEEDED(rc)) {
+        serviceCreate(&g_bpcAmsSrv, h);
+    }
+
+    return rc;
+}
+
+void bpcAmsExit(void) {
+    if (atomicDecrement64(&g_bpcAmsAmsRefcnt) == 0)
+        serviceClose(&g_bpcAmsSrv);    
+}
+
+Result bpcAmsRebootToFatalError(AtmosphereFatalErrorContext *ctx) {
+    IpcCommand c;
+    ipcInitialize(&c);
+    ipcAddSendBuffer(&c, ctx, sizeof(*ctx), BufferType_Normal);
+    
+    struct {
+        u64 magic;
+        u64 cmd_id;
+    } *raw;
+    
+    raw = serviceIpcPrepareHeader(&g_bpcAmsSrv, &c, sizeof(*raw));
+
+    raw->magic = SFCI_MAGIC;
+    raw->cmd_id = 65000;
+
+    Result rc = serviceIpcDispatch(&g_bpcAmsSrv);
+
+    if (R_SUCCEEDED(rc)) {
+        IpcParsedCommand r;
+        struct {
+            u64 magic;
+            u64 result;
+        } *resp;
+
+        serviceIpcParse(&g_bpcAmsSrv, &r, sizeof(*resp));
+        resp = r.Raw;
+
+        rc = resp->result;
+    }
+
+    return rc;
+}

source/on_crash.cpp

@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2018-2019 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 <mutex>
+#include <switch.h>
+#include <stratosphere.hpp>
+
+extern "C" {
+    __attribute__((weak)) u64 __stratosphere_title_id = 0;
+    void __attribute__((weak)) __libstratosphere_exception_handler(AtmosphereFatalErrorContext *ctx);
+    
+    /* Redefine abort, so that it triggers these handlers. */
+    void abort();
+};
+
+void StratosphereCrashHandler(ThreadExceptionDump *ctx) {
+    AtmosphereFatalErrorContext ams_ctx;
+    /* Convert thread dump to atmosphere dump. */
+    {
+        ams_ctx.magic = AtmosphereFatalErrorMagic;
+        ams_ctx.error_desc = ctx->error_desc;
+        ams_ctx.title_id = __stratosphere_title_id;
+        for (size_t i = 0; i < AtmosphereFatalErrorNumGprs; i++) {
+            ams_ctx.gprs[i] = ctx->cpu_gprs[i].x;
+        }
+        ams_ctx.fp = ctx->fp.x;
+        ams_ctx.lr = ctx->lr.x;
+        ams_ctx.sp = ctx->sp.x;
+        ams_ctx.pc = ctx->pc.x;
+        ams_ctx.pstate = ctx->pstate;
+        ams_ctx.afsr0 = ctx->afsr0;
+        ams_ctx.afsr1 = ctx->afsr1;
+        ams_ctx.far = ctx->far.x;
+        ams_ctx.report_identifier = armGetSystemTick();
+    }
+    
+    /* Just call the user exception handler. */
+    __libstratosphere_exception_handler(&ams_ctx);
+}
+
+/* Default exception handler behavior. */    
+void __attribute__((weak)) __libstratosphere_exception_handler(AtmosphereFatalErrorContext *ctx) {
+    Result rc = bpcAmsInitialize();
+    if (R_SUCCEEDED(rc)) {
+        rc = bpcAmsRebootToFatalError(ctx);
+        bpcAmsExit();
+    }
+    if (R_FAILED(rc)) {
+        std::abort();
+    }
+    while (1) { }
+}
+
+/* Custom abort handler, so that std::abort will trigger these. */
+void abort() {
+    /* Just perform a data abort. */
+    while (true) {
+        *((volatile u64 *)0x8) = 0xCAFEBABE;
+    }
+}