Restore extended-remote support & map <GDB PID>-><1 + 3DS PID> (breaking change)

Once more, the "official" gdb client is the one than is the least compliant to its very own stub specs (compared to, say, IDA)

sysmodules/rosalina/include/gdb.h

@@ -124,6 +124,7 @@ typedef struct GDBContext
     Handle processAttachedEvent, continuedEvent;
     Handle eventToWaitFor;
 
+    bool multiprocessExtEnabled;
     bool catchThreadEvents;
     bool processEnded, processExited;
 

sysmodules/rosalina/include/gdb/debug.h

@@ -14,6 +14,7 @@ GDB_DECLARE_HANDLER(Restart);
 GDB_DECLARE_VERBOSE_HANDLER(Attach);
 GDB_DECLARE_HANDLER(Detach);
 GDB_DECLARE_HANDLER(Kill);
+GDB_DECLARE_VERBOSE_HANDLER(Kill);
 GDB_DECLARE_HANDLER(Break);
 GDB_DECLARE_HANDLER(Continue);
 GDB_DECLARE_VERBOSE_HANDLER(Continue);

sysmodules/rosalina/include/gdb/thread.h

@@ -9,6 +9,20 @@
 
 #include "gdb.h"
 
+static inline u32 GDB_ConvertFromRealPid(u32 pid)
+{
+    return pid + 1;
+}
+
+static inline u32 GDB_ConvertToRealPid(u32 pid)
+{
+    return pid - 1;
+}
+
+const char *GDB_ParseThreadId(GDBContext *ctx, u32 *outPid, u32 *outTid, const char *str, char lastSep);
+u32 GDB_ParseDecodeSingleThreadId(GDBContext *ctx, const char *str, char lastSep);
+int GDB_EncodeThreadId(GDBContext *ctx, char *outbuf, u32 tid);
+
 u32 GDB_GetCurrentThreadFromList(GDBContext *ctx, u32 *threadIds, u32 nbThreads);
 u32 GDB_GetCurrentThread(GDBContext *ctx);
 

sysmodules/rosalina/source/gdb/debug.c

@@ -138,7 +138,7 @@ GDB_DECLARE_VERBOSE_HANDLER(Attach)
         return GDB_ReplyErrno(ctx, EILSEQ);
 
     RecursiveLock_Lock(&ctx->lock);
-    ctx->pid = pid;
+    ctx->pid = GDB_ConvertToRealPid(pid);
     Result r = GDB_AttachToProcess(ctx);
     if(R_FAILED(r))
         GDB_DetachImmediatelyExtended(ctx);
@@ -154,6 +154,16 @@ GDB_DECLARE_VERBOSE_HANDLER(Attach)
 
 GDB_DECLARE_HANDLER(Detach)
 {
+    if (ctx->multiprocessExtEnabled)
+    {
+        //;pid
+        u32 pid;
+        if(ctx->commandData[0] != ';' || GDB_ParseHexIntegerList(&pid, ctx->commandData + 1, 1, 0) == NULL)
+            return GDB_ReplyErrno(ctx, EILSEQ);
+        pid = GDB_ConvertToRealPid(pid);
+        if (pid != ctx->pid)
+            return GDB_ReplyErrno(ctx, EPERM);
+    }
     ctx->state = GDB_STATE_DETACHING;
     if (ctx->flags & GDB_FLAG_EXTENDED_REMOTE)
         GDB_DetachImmediatelyExtended(ctx);
@@ -170,6 +180,29 @@ GDB_DECLARE_HANDLER(Kill)
     return 0;
 }
 
+GDB_DECLARE_VERBOSE_HANDLER(Kill)
+{
+    if (ctx->multiprocessExtEnabled)
+    {
+        //;pid . ';' is already consumed by our caller
+        u32 pid;
+        if(GDB_ParseHexIntegerList(&pid, ctx->commandData, 1, 0) == NULL)
+            return GDB_ReplyErrno(ctx, EILSEQ);
+        pid = GDB_ConvertToRealPid(pid);
+        if (pid != ctx->pid)
+            return GDB_ReplyErrno(ctx, EPERM);
+    }
+
+    int ret = GDB_ReplyOk(ctx);
+
+    ctx->state = GDB_STATE_DETACHING;
+    ctx->flags |= GDB_FLAG_TERMINATE_PROCESS;
+    if (ctx->flags & GDB_FLAG_EXTENDED_REMOTE)
+        GDB_DetachImmediatelyExtended(ctx);
+
+    return ret;
+}
+
 GDB_DECLARE_HANDLER(Break)
 {
     if(!(ctx->flags & GDB_FLAG_PROCESS_CONTINUING))
@@ -232,7 +265,7 @@ GDB_DECLARE_HANDLER(Continue)
 
 GDB_DECLARE_VERBOSE_HANDLER(Continue)
 {
-    char *pos = ctx->commandData;
+    const char *pos = ctx->commandData;
     bool currentThreadFound = false;
     while(pos != NULL && *pos != 0 && !currentThreadFound)
     {
@@ -247,18 +280,21 @@ GDB_DECLARE_VERBOSE_HANDLER(Continue)
             break;
         }
 
-        char *nextpos = (char *)strchr(pos, ';');
+        u32 pid, tid;
-        if(strncmp(pos, "-1", 2) == 0)
-            currentThreadFound = true;
-        else
-        {
-            u32 threadId;
-            if(GDB_ParseHexIntegerList(&threadId, pos, 1, ';') == NULL)
-                return GDB_ReplyErrno(ctx, EILSEQ);
-            currentThreadFound = currentThreadFound || threadId == ctx->currentThreadId;
-        }
 
-        pos = nextpos;
+        const char *nextpos = GDB_ParseThreadId(ctx, &pid, &tid, pos, ';');
+        if (nextpos == NULL)
+            return GDB_ReplyErrno(ctx, EILSEQ);
+
+        if (tid == 0)
+            currentThreadFound = true;
+        if (pid != (u32)-1 && pid != ctx->pid)
+            return GDB_ReplyErrno(ctx, EPERM);
+        else
+            currentThreadFound = currentThreadFound || tid == ctx->currentThreadId;
+
+        if (nextpos != NULL && *nextpos != '\0')
+            pos = nextpos + 1;
     }
 
     if(ctx->currentThreadId == 0 || currentThreadFound)
@@ -269,12 +305,18 @@ GDB_DECLARE_VERBOSE_HANDLER(Continue)
 
 GDB_DECLARE_HANDLER(GetStopReason)
 {
+    char pidbuf[32];
+    if (ctx->multiprocessExtEnabled && ctx->state == GDB_STATE_ATTACHED)
+        sprintf(pidbuf, ";process:%lx", GDB_ConvertFromRealPid(ctx->pid));
+    else
+        pidbuf[0] = '\0';
+
     if (ctx->processEnded && ctx->processExited) {
-        return GDB_SendPacket(ctx, "W00", 3);
+        return GDB_SendFormattedPacket(ctx, "W00%s", pidbuf);
     } else if (ctx->processEnded && !ctx->processExited) {
-        return GDB_SendPacket(ctx, "X0f", 3);
+        return GDB_SendFormattedPacket(ctx, "X0f%s", pidbuf);
     } else if (ctx->debug == 0) {
-        return GDB_SendPacket(ctx, "W00", 3);
+        return GDB_SendFormattedPacket(ctx, "W00%s", pidbuf);
     } else {
         return GDB_SendStopReply(ctx, &ctx->latestDebugEvent);
     }
@@ -287,7 +329,10 @@ static int GDB_ParseCommonThreadInfo(char *out, GDBContext *ctx, int sig)
     s64 dummy;
     u32 core;
     Result r = svcGetDebugThreadContext(&regs, ctx->debug, threadId, THREADCONTEXT_CONTROL_ALL);
-    int n = sprintf(out, "T%02xthread:%lx;", sig, threadId);
+
+    char tidbuf[32];
+    GDB_EncodeThreadId(ctx, tidbuf, ctx->currentThreadId);
+    int n = sprintf(out, "T%02xthread:%s;", sig, tidbuf);
 
     if(R_FAILED(r))
         return n;
@@ -450,7 +495,12 @@ int GDB_SendStopReply(GDBContext *ctx, const DebugEventInfo *info)
         {
             // exited (no error / unhandled exception), SIGTERM (process terminated) * 2
             static const char *processExitReplies[] = { "W00", "X0f", "X0f" };
-            return GDB_SendPacket(ctx, processExitReplies[(u32)info->exit_process.reason], 3);
+            char pidbuf[32];
+            if (ctx->multiprocessExtEnabled && ctx->state == GDB_STATE_ATTACHED)
+                sprintf(pidbuf, ";process:%lx", GDB_ConvertFromRealPid(ctx->pid));
+            else
+                pidbuf[0] = '\0';
+            return GDB_SendFormattedPacket(ctx, "%s%s", processExitReplies[(u32)info->exit_process.reason], pidbuf);
         }
 
         case DBGEVENT_EXCEPTION:

sysmodules/rosalina/source/gdb/query.c

@@ -5,6 +5,7 @@
 *   SPDX-License-Identifier: (MIT OR GPL-2.0-or-later)
 */
 
+#define _GNU_SOURCE
 #include "gdb/query.h"
 #include "gdb/xfer.h"
 #include "gdb/thread.h"
@@ -89,11 +90,23 @@ int GDB_HandleWriteQuery(GDBContext *ctx)
 
 GDB_DECLARE_QUERY_HANDLER(Supported)
 {
+    const char *pos = ctx->commandData, *nextpos = pos;
+    do
+    {
+        pos = nextpos;
+        nextpos = strchrnul(pos, ';');
+        if (*nextpos != ';' && *nextpos != '\0')
+            return GDB_ReplyErrno(ctx, EILSEQ);
+
+        if (strncmp(pos, "multiprocess+", nextpos - pos) == 0)
+            ctx->multiprocessExtEnabled = true;
+    } while (*nextpos++ != '\0');
+
     return GDB_SendFormattedPacket(ctx,
         "PacketSize=%x;"
         "qXfer:features:read+;qXfer:osdata:read+;"
         "QStartNoAckMode+;QThreadEvents+;QCatchSyscalls+;"
-        "vContSupported+;swbreak+",
+        "vContSupported+;swbreak+;multiprocess+",
 
         GDB_BUF_LEN // should have been sizeof(ctx->buffer) but GDB memory functions are bugged
     );

sysmodules/rosalina/source/gdb/server.c

@@ -199,6 +199,7 @@ int GDB_CloseClient(GDBContext *ctx)
     ctx->state = GDB_STATE_DISCONNECTED;
 
     ctx->catchThreadEvents = false;
+    ctx->multiprocessExtEnabled = false;
 
     memset(&ctx->latestDebugEvent, 0, sizeof(DebugEventInfo));
     memset(ctx->memoryOsInfoXmlData, 0, sizeof(ctx->memoryOsInfoXmlData));

sysmodules/rosalina/source/gdb/thread.c

@@ -10,6 +10,103 @@
 #include "fmt.h"
 #include <stdlib.h>
 
+const char *GDB_ParseThreadId(GDBContext *ctx, u32 *outPid, u32 *outTid, const char *str, char lastSep)
+{
+    const char *pos = str;
+    u32 pid = ctx->pid;
+    u32 tid = 0;
+
+    // pPID.TID | PID
+    if (ctx->multiprocessExtEnabled)
+    {
+        // Check for 'p'
+        if (*pos != 'p')
+        {
+            // Test -1 first.
+            // Note: this means we parse -1, p-1.0, p0.0 the same which is a bug
+            if (strcmp(pos, "-1") == 0)
+            {
+                pid = (u32)-1;
+                tid = 0;
+                pos += 2;
+            }
+            else
+            {
+                pos = GDB_ParseHexIntegerList(&pid, pos, 1, 0);
+                if (pos == NULL)
+                    return NULL;
+                pid = GDB_ConvertToRealPid(pid);
+                tid = 0;
+            }
+            *outPid = pid;
+            *outTid = 0;
+            return pos;
+        }
+        else
+            ++pos;
+
+        // -1 pid?
+        if (strncmp(pos, "-1.", 3) == 0)
+        {
+            pid = (u32)-1; // Should encode as 0 but oh well
+            pos += 3;
+        }
+        else
+        {
+            pos = GDB_ParseHexIntegerList(&pid, pos, 1, '.');
+            if (pos == NULL)
+                return NULL;
+            pid = GDB_ConvertToRealPid(pid);
+            ++pos;
+        }
+    }
+
+    // Fallthrough
+    // TID
+    if (strncmp(pos, "-1", 2) == 0)
+    {
+        tid = 0; // TID 0 is always invalid
+        pos += 2;
+    }
+    else
+    {
+        pos = GDB_ParseHexIntegerList(&tid, pos, 1, lastSep);
+        if (pos == NULL)
+            return NULL;
+    }
+
+    if (pid == (u32)-1 && tid != 0)
+        return NULL; // this is never allowed
+
+    if (pos != NULL)
+    {
+        *outPid = pid;
+        *outTid = tid;
+    }
+    return pos;
+}
+
+
+u32 GDB_ParseDecodeSingleThreadId(GDBContext *ctx, const char *str, char lastSep)
+{
+    u32 pid, tid;
+    if (GDB_ParseThreadId(ctx, &pid, &tid, str, lastSep) == NULL)
+        return 0;
+
+    if (pid != ctx->pid)
+        return 0;
+
+    return tid;
+}
+
+int GDB_EncodeThreadId(GDBContext *ctx, char *outbuf, u32 tid)
+{
+    if (ctx->multiprocessExtEnabled)
+        return sprintf(outbuf, "p%lx.%lx", GDB_ConvertFromRealPid(ctx->pid), tid);
+    else
+        return sprintf(outbuf, "%lx", tid);
+}
+
 static s32 GDB_GetDynamicThreadPriority(GDBContext *ctx, u32 threadId)
 {
     Handle process, thread;
@@ -95,27 +192,30 @@ GDB_DECLARE_HANDLER(SetThreadId)
 {
     if(ctx->commandData[0] == 'g')
     {
-        if(strncmp(ctx->commandData + 1, "-1", 2) == 0)
+        u32 pid = 0, tid = 0;
-            return GDB_ReplyErrno(ctx, EILSEQ); // a thread must be specified
+        if (GDB_ParseThreadId(ctx, &pid, &tid, ctx->commandData + 1, 0) == NULL)
-
-        u32 id;
-        if(GDB_ParseHexIntegerList(&id, ctx->commandData + 1, 1, 0) == NULL)
             return GDB_ReplyErrno(ctx, EILSEQ);
-        ctx->selectedThreadId = id;
+
+        // Allow ptid = p0.0; note that this catches some -1 forms, which is a bug
+        if (pid != (u32)-1 && pid != ctx->pid)
+            return GDB_ReplyErrno(ctx, EILSEQ);
+
+        ctx->selectedThreadId = tid;
         return GDB_ReplyOk(ctx);
     }
     else if(ctx->commandData[0] == 'c')
     {
         // We can't stop/continue particular threads (uncompliant behavior)
-        if(strncmp(ctx->commandData + 1, "-1", 2) == 0)
+
-            ctx->selectedThreadIdForContinuing = 0;
+        u32 pid, tid;
-        else
+        if (GDB_ParseThreadId(ctx, &pid, &tid, ctx->commandData + 1, 0) == NULL)
-        {
-            u32 id;
-            if(GDB_ParseHexIntegerList(&id, ctx->commandData + 1, 1, 0) == NULL)
             return GDB_ReplyErrno(ctx, EILSEQ);
-            ctx->selectedThreadIdForContinuing = id;
+
-        }
+        // Allow gdb pid.tid = -1.-1, (we're also accepting pid = 0 but that's a bug)
+        if (pid != (u32)-1 && pid != ctx->pid)
+            return GDB_ReplyErrno(ctx, EPERM);
+
+        ctx->selectedThreadIdForContinuing = tid;
 
         return GDB_ReplyOk(ctx);
     }
@@ -125,14 +225,14 @@ GDB_DECLARE_HANDLER(SetThreadId)
 
 GDB_DECLARE_HANDLER(IsThreadAlive)
 {
-    u32 threadId;
     s64 dummy;
     u32 mask;
 
-    if(GDB_ParseHexIntegerList(&threadId, ctx->commandData, 1, 0) == NULL)
+    u32 tid = GDB_ParseDecodeSingleThreadId(ctx, ctx->commandData, 0);
+    if (tid == 0)
         return GDB_ReplyErrno(ctx, EILSEQ);
 
-    Result r = svcGetDebugThreadParam(&dummy, &mask, ctx->debug, threadId, DBGTHREAD_PARAMETER_SCHEDULING_MASK_LOW);
+    Result r = svcGetDebugThreadParam(&dummy, &mask, ctx->debug, tid, DBGTHREAD_PARAMETER_SCHEDULING_MASK_LOW);
     if(R_SUCCEEDED(r) && mask != 2)
         return GDB_ReplyOk(ctx);
     else
@@ -144,7 +244,9 @@ GDB_DECLARE_QUERY_HANDLER(CurrentThreadId)
     if(ctx->currentThreadId == 0)
         ctx->currentThreadId = GDB_GetCurrentThread(ctx);
 
-    return ctx->currentThreadId != 0 ? GDB_SendFormattedPacket(ctx, "QC%lx", ctx->currentThreadId) : GDB_ReplyErrno(ctx, EPERM);
+    char buf[32];
+    GDB_EncodeThreadId(ctx, buf, ctx->currentThreadId);
+    return ctx->currentThreadId != 0 ? GDB_SendFormattedPacket(ctx, "QC%s", buf) : GDB_ReplyErrno(ctx, EPERM);
 }
 
 static void GDB_GenerateThreadListData(GDBContext *ctx)
@@ -168,7 +270,11 @@ static void GDB_GenerateThreadListData(GDBContext *ctx)
     char *bufptr = ctx->threadListData;
 
     for(u32 i = 0; i < nbAliveThreads; i++)
-        bufptr += sprintf(bufptr, i == (nbAliveThreads - 1) ? "%lx" : "%lx,", aliveThreadIds[i]);
+    {
+        bufptr += GDB_EncodeThreadId(ctx, bufptr, aliveThreadIds[i]);
+        if (i < nbAliveThreads - 1)
+            *bufptr++ = ',';
+    }
 }
 
 static int GDB_SendThreadData(GDBContext *ctx)
@@ -242,7 +348,8 @@ GDB_DECLARE_QUERY_HANDLER(ThreadExtraInfo)
 
     u32 tls = 0;
 
-    if(GDB_ParseHexIntegerList(&id, ctx->commandData, 1, 0) == NULL)
+    id = GDB_ParseDecodeSingleThreadId(ctx, ctx->commandData, 0);
+    if (id == 0)
         return GDB_ReplyErrno(ctx, EILSEQ);
 
     for(u32 i = 0; i < MAX_DEBUG_THREAD; i++)

sysmodules/rosalina/source/gdb/verbose.c

@@ -22,6 +22,7 @@ static const struct
     { "File", GDB_VERBOSE_HANDLER(File) },
     { "MustReplyEmpty", GDB_HANDLER(Unsupported) },
     { "Run", GDB_VERBOSE_HANDLER(Run) },
+    { "Kill", GDB_VERBOSE_HANDLER(Kill) },
 };
 
 GDB_DECLARE_HANDLER(VerboseCommand)

sysmodules/rosalina/source/gdb/xfer.c

@@ -9,6 +9,7 @@
 
 #include "gdb/xfer.h"
 #include "gdb/net.h"
+#include "gdb/thread.h"
 #include "fmt.h"
 
 #include "osdata_cfw_version_template_xml.h"
@@ -161,7 +162,7 @@ GDB_DECLARE_XFER_OSDATA_HANDLER(Processes)
                 memcpy(name, &out, 8);
                 svcCloseHandle(processHandle);
 
-                n = sprintf(ctx->processesOsInfoXmlData + pos, item, pid, name);
+                n = sprintf(ctx->processesOsInfoXmlData + pos, item, GDB_ConvertFromRealPid(pid), name);
                 pos += (u32)n;
             }