From 8b56098d64754a7452f6defb437fbd978e3950d2 Mon Sep 17 00:00:00 2001
From: TuxSH <tuxsh@sfr.fr>
Date: Sun, 28 Apr 2019 15:04:42 +0200
Subject: [PATCH] Fix TIO encoding bug

---
 sysmodules/rosalina/include/gdb/net.h |  2 +-
 sysmodules/rosalina/source/gdb/net.c  | 13 +++++++++----
 sysmodules/rosalina/source/gdb/tio.c  | 15 ++++++++++-----
 3 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/sysmodules/rosalina/include/gdb/net.h b/sysmodules/rosalina/include/gdb/net.h
index 10a950b..199bf65 100644
--- a/sysmodules/rosalina/include/gdb/net.h
+++ b/sysmodules/rosalina/include/gdb/net.h
@@ -33,7 +33,7 @@
 u8 GDB_ComputeChecksum(const char *packetData, u32 len);
 void GDB_EncodeHex(char *dst, const void *src, u32 len);
 u32 GDB_DecodeHex(void *dst, const char *src, u32 len);
-u32 GDB_EscapeBinaryData(void *dst, const void *src, u32 len, u32 maxLen);
+u32 GDB_EscapeBinaryData(u32 *encodedCount, void *dst, const void *src, u32 len, u32 maxLen);
 u32 GDB_UnescapeBinaryData(void *dst, const void *src, u32 len);
 const char *GDB_ParseIntegerList(u32 *dst, const char *src, u32 nb, char sep, char lastSep, u32 base, bool allowPrefix);
 const char *GDB_ParseHexIntegerList(u32 *dst, const char *src, u32 nb, char lastSep);
diff --git a/sysmodules/rosalina/source/gdb/net.c b/sysmodules/rosalina/source/gdb/net.c
index 0fe93c7..9602c2b 100644
--- a/sysmodules/rosalina/source/gdb/net.c
+++ b/sysmodules/rosalina/source/gdb/net.c
@@ -75,15 +75,19 @@ u32 GDB_DecodeHex(void *dst, const char *src, u32 len)
     return (!ok) ? i - 1 : i;
 }
 
-u32 GDB_EscapeBinaryData(void *dst, const void *src, u32 len, u32 maxLen)
+u32 GDB_EscapeBinaryData(u32 *encodedCount, void *dst, const void *src, u32 len, u32 maxLen)
 {
     u8 *dst8 = (u8 *)dst;
     const u8 *src8 = (const u8 *)src;
 
-    for(u32 i = 0; i < len && (u32)dst8 - (u32)dst < maxLen; i++)
+    maxLen = maxLen >= len ? len : maxLen;
+
+    while((uintptr_t)dst8 < (uintptr_t)dst + maxLen)
     {
         if(*src8 == '$' || *src8 == '#' || *src8 == '}' || *src8 == '*')
         {
+            if ((uintptr_t)dst8 + 1 >= (uintptr_t)dst + maxLen)
+                break;
             *dst8++ = '}';
             *dst8++ = *src8++ ^ 0x20;
         }
@@ -91,7 +95,8 @@ u32 GDB_EscapeBinaryData(void *dst, const void *src, u32 len, u32 maxLen)
             *dst8++ = *src8++;
     }
 
-    return dst8 - (u8 *)dst;
+    *encodedCount = dst8 - (u8 *)dst;
+    return src8 - (u8 *)src;
 }
 
 u32 GDB_UnescapeBinaryData(void *dst, const void *src, u32 len)
@@ -99,7 +104,7 @@ u32 GDB_UnescapeBinaryData(void *dst, const void *src, u32 len)
     u8 *dst8 = (u8 *)dst;
     const u8 *src8 = (const u8 *)src;
 
-    for(u32 i = 0; i < len; i++)
+    while((uintptr_t)src8 < (uintptr_t)src + len)
     {
         if(*src8 == '}')
         {
diff --git a/sysmodules/rosalina/source/gdb/tio.c b/sysmodules/rosalina/source/gdb/tio.c
index 09a22e1..9da3428 100644
--- a/sysmodules/rosalina/source/gdb/tio.c
+++ b/sysmodules/rosalina/source/gdb/tio.c
@@ -332,6 +332,7 @@ GDB_DECLARE_TIO_HANDLER(Close)
 
 GDB_DECLARE_TIO_HANDLER(Read)
 {
+    // GDB, with it code quality we're all aware of, always ask to read GDB_BUF_LEN, even if the packet can't fit...
     // "$F<num>;<data>#XX"
     char buf2[GDB_BUF_LEN - 4];
     u8 buf[sizeof(buf2) - 2 - 8];
@@ -355,10 +356,13 @@ GDB_DECLARE_TIO_HANDLER(Read)
     if (err != 0)
         return GDB_TioReplyErrno(ctx, err);
 
-    int pos = sprintf(buf2, "F%lx;", (u32)numRead);
-    u32 actualCount = GDB_EscapeBinaryData(buf2 + pos, buf, (u32)numRead, sizeof(buf));
+    char hdr[16];
+    u32 encodedCount;
+    u32 actualCount = GDB_EscapeBinaryData(&encodedCount, buf2 + 10, buf, (u32)numRead, sizeof(buf));
+    sprintf(hdr, "F%08lx;", (u32)actualCount); // buffer might not fit the entire read data
+    memcpy(buf2, hdr, 10);
 
-    return GDB_SendPacket(ctx, buf2, pos + actualCount);
+    return GDB_SendPacket(ctx, buf2, 10 + encodedCount);
 }
 
 GDB_DECLARE_TIO_HANDLER(Write)
@@ -448,9 +452,10 @@ GDB_DECLARE_TIO_HANDLER(Stat)
     GDB_TioMakeStructStat(&gdbStFinal, &gdbSt);
 
     char buf[3 + 2 * sizeof(struct gdbhio_stat)] = "F0;";
-    u32 actualCount = GDB_EscapeBinaryData(buf + 3, buf, sizeof(struct gdbhio_stat), 2 * sizeof(struct gdbhio_stat));
+    u32 encodedCount;
+    GDB_EscapeBinaryData(&encodedCount, buf + 3, buf, sizeof(struct gdbhio_stat), 2 * sizeof(struct gdbhio_stat));
 
-    return GDB_SendPacket(ctx, buf, 3 + actualCount);
+    return GDB_SendPacket(ctx, buf, 3 + encodedCount);
 }
 
 GDB_DECLARE_TIO_HANDLER(Unlink)