From ddca9c0cba8e3c858b7998c67ae2739f58b5b681 Mon Sep 17 00:00:00 2001
From: tangbinzy <tangbin_yewu@cmss.chinamobile.com>
Date: Fri, 21 Jul 2023 06:41:38 +0000
Subject: [PATCH] accel/tcg/cpu-exec: Fix precise single-stepping  after
 interrupt mainline inclusion commit 5b7b197c87cefbd24bd1936614fd4e00ccc279ab
 category: bugfix

---------------------------------------------------------------

In some cases, cpu->exit_request can be false after handling the
interrupt, leading to another TB being executed instead of returning
to the main loop.

Fix this by returning true unconditionally when in single-step mode.

Fixes: ba3c35d9c402 ("tcg/cpu-exec: precise single-stepping after an interrupt")
Signed-off-by: Luc Michel <lmichel@kalray.eu>
Message-Id: <20220214132656.11397-1-lmichel@kalray.eu>
[rth: Unlock iothread mutex; simplify indentation]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

Signed-off-by: tangbinzy <tangbin_yewu@cmss.chinamobile.com>
---
 accel/tcg/cpu-exec.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c
index 409ec8c38c..7fb87afedc 100644
--- a/accel/tcg/cpu-exec.c
+++ b/accel/tcg/cpu-exec.c
@@ -798,8 +798,12 @@ static inline bool cpu_handle_interrupt(CPUState *cpu,
                  * raised when single-stepping so that GDB doesn't miss the
                  * next instruction.
                  */
-                cpu->exception_index =
-                    (cpu->singlestep_enabled ? EXCP_DEBUG : -1);
+                if (unlikely(cpu->singlestep_enabled)) {
+                    cpu->exception_index = EXCP_DEBUG;
+                    qemu_mutex_unlock_iothread();
+                    return true;
+                }
+                cpu->exception_index = -1;   
                 *last_tb = NULL;
             }
             /* The target hook may have updated the 'cpu->interrupt_request';
-- 
2.41.0.windows.1