target/ppc: fix compile error in kvmppc_define_rtas_kernel_token()

gcc9 reports :

In file included from /usr/include/string.h:494,
                 from ./include/qemu/osdep.h:101,
                 from ./target/ppc/kvm.c:17:
In function ‘strncpy’,
    inlined from ‘kvmppc_define_rtas_kernel_token’ at ./target/ppc/kvm.c:2648:5:
/usr/include/bits/string_fortified.h:106:10: error: ‘__builtin_strncpy’ specified bound 120 equals destination size [-Werror=stringop-truncation]
  106 |   return __builtin___strncpy_chk (__dest, __src, __len, __bos (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20190615081252.28602-1-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>

diff --git a/target/ppc/kvm.c b/target/ppc/kvm.c
index 4b4989c0af50d031dc9ee8064ff7b8a97c81fbd1..9014ed029fa81786b2803d280abe3215405b4be5 100644 (file)
--- a/target/ppc/kvm.c
+++ b/target/ppc/kvm.c
@@ -2650,7 +2650,7 @@ int kvmppc_define_rtas_kernel_token(uint32_t token, const char *function)
         return -ENOENT;
     }
 
-    strncpy(args.name, function, sizeof(args.name));
+    strncpy(args.name, function, sizeof(args.name) - 1);
 
     return kvm_vm_ioctl(kvm_state, KVM_PPC_RTAS_DEFINE_TOKEN, &args);
 }