diff mbox series

[v5,4/5] migration: Fix stringop-truncation warning

Message ID 20190103085638.17600-5-philmd@redhat.com
State New
Headers show
Series Fix strncpy() warnings for GCC8 new -Wstringop-truncation | expand

Commit Message

Philippe Mathieu-Daudé Jan. 3, 2019, 8:56 a.m. UTC 
From: Marc-André Lureau <marcandre.lureau@redhat.com>

GCC 8 added a -Wstringop-truncation warning:

  The -Wstringop-truncation warning added in GCC 8.0 via r254630 for
  bug 81117 is specifically intended to highlight likely unintended
  uses of the strncpy function that truncate the terminating NUL
  character from the source string.

This new warning leads to compilation failures:

    CC      migration/global_state.o
  qemu/migration/global_state.c: In function 'global_state_store_running':
  qemu/migration/global_state.c:45:5: error: 'strncpy' specified bound 100 equals destination size [-Werror=stringop-truncation]
       strncpy((char *)global_state.runstate, state, sizeof(global_state.runstate));
       ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  make: *** [qemu/rules.mak:69: migration/global_state.o] Error 1

Adding an assert is enough to silence GCC.

(alternatively, we could hard-code "running")

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
[PMD: More verbose commit message]
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 migration/global_state.c | 1 +
 1 file changed, 1 insertion(+)
diff mbox series

Patch

diff --git a/migration/global_state.c b/migration/global_state.c
index 8e8ab5c51e..01805c567a 100644
--- a/migration/global_state.c
+++ b/migration/global_state.c
@@ -42,6 +42,7 @@  int global_state_store(void)
 void global_state_store_running(void)
 {
     const char *state = RunState_str(RUN_STATE_RUNNING);
+    assert(strlen(state) < sizeof(global_state.runstate));
     strncpy((char *)global_state.runstate,
            state, sizeof(global_state.runstate));
 }