[PATCH 1a/4] accel/tcg: Fix tb_invalidate_phys_page_unwind

[Philippe Mathieu-Daudé]

When called from syscall(), we are not within a TB and pc == 0.
We can skip the check for invalidating the current TB.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
[PMD: Split patch in 2]
Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
---
 accel/tcg/tb-maint.c | 17 ++++++++++++-----
 1 file changed, 12 insertions(+), 5 deletions(-)

diff --git a/accel/tcg/tb-maint.c b/accel/tcg/tb-maint.c
index 1b8e860647..c9b8d3c6c3 100644
--- a/accel/tcg/tb-maint.c
+++ b/accel/tcg/tb-maint.c
@@ -1024,8 +1024,18 @@ void tb_invalidate_phys_page(tb_page_addr_t addr)
  */
 bool tb_invalidate_phys_page_unwind(tb_page_addr_t addr, uintptr_t pc)
 {
-    assert(pc != 0);
-#ifdef TARGET_HAS_PRECISE_SMC
+    /*
+     * Without precise smc semantics, or when outside of a TB,
+     * we can skip to invalidate.
+     */
+#ifndef TARGET_HAS_PRECISE_SMC
+    pc = 0;
+#endif
+    if (!pc) {
+        tb_invalidate_phys_page(addr);
+        return false;
+    }
+
     assert_memory_lock();
     {
         TranslationBlock *current_tb = tcg_tb_lookup(pc);
@@ -1058,9 +1068,6 @@ bool tb_invalidate_phys_page_unwind(tb_page_addr_t addr, 
uintptr_t pc)
             return true;
         }
     }
-#else
-    tb_invalidate_phys_page(addr);
-#endif /* TARGET_HAS_PRECISE_SMC */
     return false;
 }
 #else
-- 
2.38.1