remote-packet-patch.diff

From 404d815ed23fe1a627eff04975bec27b3fc8bd35 Mon Sep 17 00:00:00 2001
From: 8dcc <8dcc.git@gmail.com>
Date: Fri, 6 Jan 2023 15:50:27 +0100
Subject: [PATCH] Patch g remote packet error

---
 gdb/remote.c | 29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/gdb/remote.c b/gdb/remote.c
index 1a34812..aaec4dd 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -8463,11 +8463,30 @@ remote_target::process_g_packet (struct regcache *regcache)
   buf_len = strlen (rs->buf.data ());
 
   /* Further sanity checks, with knowledge of the architecture.  */
-  if (buf_len > 2 * rsa->sizeof_g_packet)
-    error (_("Remote 'g' packet reply is too long (expected %ld bytes, got %d "
-	     "bytes): %s"),
-	   rsa->sizeof_g_packet, buf_len / 2,
-	   rs->buf.data ());
+  /* HACKFIX for changing architectures for qemu. It's ugly. Don't use, unless
+     you have to. Just a tiny modification of the patch of Matias Vara
+     (http://forum.osdev.org/viewtopic.php?f=13&p=177644) */
+  if (buf_len > 2 * rsa->sizeof_g_packet) {
+    warning(_("Assuming long-mode change. [Remote 'g' packet reply is too long "
+            "(expected %ld bytes, got %d bytes): %s"),
+            rsa->sizeof_g_packet, buf_len / 2, rs->buf.data());
+
+    rsa->sizeof_g_packet = buf_len;
+
+    for (i = 0; i < gdbarch_num_regs(gdbarch); i++) {
+        if (rsa->regs[i].pnum == -1)
+            continue;
+
+        if (rsa->regs[i].offset >= rsa->sizeof_g_packet)
+            rsa->regs[i].in_g_packet = 0;
+        else
+            rsa->regs[i].in_g_packet = 1;
+    }
+
+    /* HACKFIX: Make sure at least the lower half of EIP is set correctly, so
+       the proper breakpoint is recognized (and triggered). */
+    rsa->regs[8].offset = 16 * 8;
+  }
 
   /* Save the size of the packet sent to us by the target.  It is used
      as a heuristic when determining the max size of packets that the
-- 
2.38.2