diff mbox series

[2/4] translator: always pair plugin_gen_insn_{start, end} calls

Message ID 20230108164731.61469-3-cota@braap.org (mailing list archive)
State New, archived
Headers show
Series plugin patches to fix #1381 | expand

Commit Message

Emilio Cota Jan. 8, 2023, 4:47 p.m. UTC 
Related: #1381

Signed-off-by: Emilio Cota <cota@braap.org>
---
 accel/tcg/translator.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

Comments

Philippe Mathieu-Daudé Jan. 8, 2023, 7:56 p.m. UTC | #1 
On 8/1/23 17:47, Emilio Cota wrote:
> Related: #1381
> 
> Signed-off-by: Emilio Cota <cota@braap.org>
> ---
>   accel/tcg/translator.c | 15 ++++++++++-----
>   1 file changed, 10 insertions(+), 5 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Aaron Lindsay Jan. 10, 2023, 3:26 p.m. UTC | #2 
On Jan 08 11:47, Emilio Cota wrote:
> Related: #1381
> 
> Signed-off-by: Emilio Cota <cota@braap.org>
> ---
>  accel/tcg/translator.c | 15 ++++++++++-----
>  1 file changed, 10 insertions(+), 5 deletions(-)

Tested-by: Aaron Lindsay <aaron@os.amperecomputing.com>
diff mbox series

Patch

diff --git a/accel/tcg/translator.c b/accel/tcg/translator.c
index 061519691f..ef5193c67e 100644
--- a/accel/tcg/translator.c
+++ b/accel/tcg/translator.c
@@ -100,19 +100,24 @@  void translator_loop(CPUState *cpu, TranslationBlock *tb, int max_insns,
             ops->translate_insn(db, cpu);
         }
 
-        /* Stop translation if translate_insn so indicated.  */
-        if (db->is_jmp != DISAS_NEXT) {
-            break;
-        }
-
         /*
          * We can't instrument after instructions that change control
          * flow although this only really affects post-load operations.
+         *
+         * Calling plugin_gen_insn_end() before we possibly stop translation
+         * is important. Even if this ends up as dead code, plugin generation
+         * needs to see a matching plugin_gen_insn_{start,end}() pair in order
+         * to accurately track instrumented helpers that might access memory.
          */
         if (plugin_enabled) {
             plugin_gen_insn_end();
         }
 
+        /* Stop translation if translate_insn so indicated.  */
+        if (db->is_jmp != DISAS_NEXT) {
+            break;
+        }
+
         /* Stop translation if the output buffer is full,
            or we have executed all of the allowed instructions.  */
         if (tcg_op_buf_full() || db->num_insns >= db->max_insns) {