From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57516) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1frkJI-0002LH-2f for qemu-devel@nongnu.org; Mon, 20 Aug 2018 09:33:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1frkEX-0007v3-Bb for qemu-devel@nongnu.org; Mon, 20 Aug 2018 09:28:41 -0400 References: <20180818025653.21192-1-f4bug@amsat.org> <66dfe354-9c2c-8642-a905-03155555fe99@redhat.com> From: David Hildenbrand Message-ID: Date: Mon, 20 Aug 2018 15:28:34 +0200 MIME-Version: 1.0 In-Reply-To: <66dfe354-9c2c-8642-a905-03155555fe99@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable Subject: Re: [Qemu-devel] [PATCH] migration: Replace strncpy() by g_strlcpy() List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Paolo Bonzini , =?UTF-8?Q?Philippe_Mathieu-Daud=c3=a9?= , Juan Quintela , "Dr. David Alan Gilbert" , Howard Spoelstra Cc: qemu-trivial@nongnu.org, qemu-devel@nongnu.org On 20.08.2018 15:23, Paolo Bonzini wrote: > On 18/08/2018 04:56, Philippe Mathieu-Daud=C3=A9 wrote: >> Fedora 29 comes with GCC 8.1 which added the 'stringop-truncation' che= cks. >> >> Replace the strncpy() calls by g_strlcpy() to avoid the following warn= ing: >> >> migration/global_state.c: In function 'global_state_store_running': >> migration/global_state.c:45:5: error: 'strncpy' specified bound 100 = equals destination size [-Werror=3Dstringop-truncation] >> strncpy((char *)global_state.runstate, >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> state, sizeof(global_state.runstate)); >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> >> Reported-by: Howard Spoelstra >> Signed-off-by: Philippe Mathieu-Daud=C3=A9 >> --- >> See http://lists.nongnu.org/archive/html/qemu-devel/2018-07/msg03723.h= tml >> >> migration/global_state.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/migration/global_state.c b/migration/global_state.c >> index 8e8ab5c51e..d5df502cd5 100644 >> --- a/migration/global_state.c >> +++ b/migration/global_state.c >> @@ -42,7 +42,7 @@ int global_state_store(void) >> void global_state_store_running(void) >> { >> const char *state =3D RunState_str(RUN_STATE_RUNNING); >> - strncpy((char *)global_state.runstate, >> + g_strlcpy((char *)global_state.runstate, >> state, sizeof(global_state.runstate)); >> } >> =20 >> >=20 > This is wrong because strlcpy doesn't zero the rest of Two RB-s and it is still wrong implies that string operations are still the root of all evil. :) > global_state.runstate, so you could end up with something like > "running\0ate\0\0..." in global_state.runstate However, the same mistak= e > is already present in vl.c's runstate_store. >=20 > Juan, David, what to do? strncpy is easy to misuse, but we do have > cases where it's correct and it should tingle the reviewers' spidey > senses... I wouldn't mind disabling the warning, and using strncpy in > runstate_store, because in practice it's already reported by Coverity > and it can be shut up there. Maybe really set it to zero (memset) before using the g_strlcpy? I am not a fan of disabling warnings, but if you think this is easier/cleaner, let's go for that. >=20 > Thanks, >=20 > Paolo >=20 --=20 Thanks, David / dhildenb