[Qemu-trivial] [PATCH v2 4/5] linux-user/uname: Fix GCC 9 build warnings

[Alistair Francis]

Fix this warning when building with GCC9 on Fedora 30:
In function ‘strncpy’,
    inlined from ‘sys_uname’ at /home/alistair/qemu/linux-user/uname.c:94:3:
/usr/include/bits/string_fortified.h:106:10: error: ‘__builtin_strncpy’ output 
may be truncated copying 64 bytes from a string of length 64 
[-Werror=stringop-truncation]
  106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Alistair Francis <address@hidden>
---
 linux-user/uname.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/linux-user/uname.c b/linux-user/uname.c
index 313b79dbad..2fc6096a5b 100644
--- a/linux-user/uname.c
+++ b/linux-user/uname.c
@@ -73,7 +73,7 @@ const char *cpu_to_uname_machine(void *cpu_env)
 #define COPY_UTSNAME_FIELD(dest, src) \
   do { \
       /* __NEW_UTS_LEN doesn't include terminating null */ \
-      (void) strncpy((dest), (src), __NEW_UTS_LEN); \
+      (void) memcpy((dest), (src), MIN(strlen(src), __NEW_UTS_LEN)); \
       (dest)[__NEW_UTS_LEN] = '\0'; \
   } while (0)
 
-- 
2.21.0