[Qemu-devel] [PATCH] mttcg: Set jmp_env to handle exit from tb_gen_code

[Pranith Kumar <bobby.prani@gmail.com>]

tb_gen_code() can exit execution using cpu_exit_loop() when it cannot
allocate new tb's. To handle this, we need to properly set the jmp_env
pointer ahead of calling tb_gen_code().

CC:Alex Bennée <alex.bennee@linaro.org> 
CC: Richard Henderson <rth@twiddle.net>
Signed-off-by: Pranith Kumar <bobby.prani@gmail.com>
---
 cpu-exec.c | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/cpu-exec.c b/cpu-exec.c
index 97d79612d9..4b70988b24 100644
--- a/cpu-exec.c
+++ b/cpu-exec.c
@@ -236,23 +236,22 @@ static void cpu_exec_step(CPUState *cpu)
 
     cpu_get_tb_cpu_state(env, &pc, &cs_base, &flags);
     tb_lock();
-    tb = tb_gen_code(cpu, pc, cs_base, flags,
-                     1 | CF_NOCACHE | CF_IGNORE_ICOUNT);
-    tb->orig_tb = NULL;
-    tb_unlock();
-
-    cc->cpu_exec_enter(cpu);
-
     if (sigsetjmp(cpu->jmp_env, 0) == 0) {
+        tb = tb_gen_code(cpu, pc, cs_base, flags,
+                         1 | CF_NOCACHE | CF_IGNORE_ICOUNT);
+        tb->orig_tb = NULL;
+        tb_unlock();
+
+        cc->cpu_exec_enter(cpu);
         /* execute the generated code */
         trace_exec_tb_nocache(tb, pc);
         cpu_tb_exec(cpu, tb);
-    }
+        cc->cpu_exec_exit(cpu);
 
-    cc->cpu_exec_exit(cpu);
-    tb_lock();
-    tb_phys_invalidate(tb, -1);
-    tb_free(tb);
+        tb_lock();
+        tb_phys_invalidate(tb, -1);
+        tb_free(tb);
+    }
     tb_unlock();
 }
 
-- 
2.11.0