From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:43429) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QuriD-0006QC-3n for qemu-devel@nongnu.org; Sat, 20 Aug 2011 16:00:10 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1QuriB-0008NX-U9 for qemu-devel@nongnu.org; Sat, 20 Aug 2011 16:00:09 -0400 Received: from v220110690675601.yourvserver.net ([78.47.199.172]:59072) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1QuriB-0008Ms-IU for qemu-devel@nongnu.org; Sat, 20 Aug 2011 16:00:07 -0400 Message-ID: <4E501243.2090806@mail.berlios.de> Date: Sat, 20 Aug 2011 22:00:03 +0200 From: Stefan Weil MIME-Version: 1.0 References: <4E48BF2F.7080901@web.de> In-Reply-To: <4E48BF2F.7080901@web.de> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PULL] slirp: Fix issues with -mms-bitfields List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Jan Kiszka Cc: Blue Swirl , Anthony Liguori , qemu-devel Am 15.08.2011 08:39, schrieb Jan Kiszka: > The following changes since commit > 3b6ffe50300f13240e1b46420ad05da1116df410: > > hw/scsi-bus.c: Fix use of uninitialised variable (2011-08-14 19:34:25 > +0000) > > are available in the git repository at: > git://git.kiszka.org/qemu.git queues/slirp > > Jan Kiszka (1): > slirp: Fix bit field types in IP header structs > > slirp/ip.h | 8 ++++---- > slirp/tcp.h | 4 ++-- > 2 files changed, 6 insertions(+), 6 deletions(-) > > --- > > slirp: Fix bit field types in IP header structs > > -mms-bitfields prevents that the bitfields in current IP header structs > are packed into a single byte as it is required. Fix this by using > uint8_t as backing type. > > Signed-off-by: Jan Kiszka > --- > slirp/ip.h | 8 ++++---- > slirp/tcp.h | 4 ++-- > 2 files changed, 6 insertions(+), 6 deletions(-) > > diff --git a/slirp/ip.h b/slirp/ip.h > index 48ea38e..72dbe9a 100644 > --- a/slirp/ip.h > +++ b/slirp/ip.h > @@ -74,10 +74,10 @@ typedef uint32_t n_long; /* long as received from > the net */ > */ > struct ip { > #ifdef HOST_WORDS_BIGENDIAN > - u_int ip_v:4, /* version */ > + uint8_t ip_v:4, /* version */ > ip_hl:4; /* header length */ > #else > - u_int ip_hl:4, /* header length */ > + uint8_t ip_hl:4, /* header length */ > ip_v:4; /* version */ > #endif > uint8_t ip_tos; /* type of service */ > @@ -140,10 +140,10 @@ struct ip_timestamp { > uint8_t ipt_len; /* size of structure (variable) */ > uint8_t ipt_ptr; /* index of current entry */ > #ifdef HOST_WORDS_BIGENDIAN > - u_int ipt_oflw:4, /* overflow counter */ > + uint8_t ipt_oflw:4, /* overflow counter */ > ipt_flg:4; /* flags, see below */ > #else > - u_int ipt_flg:4, /* flags, see below */ > + uint8_t ipt_flg:4, /* flags, see below */ > ipt_oflw:4; /* overflow counter */ > #endif > union ipt_timestamp { > diff --git a/slirp/tcp.h b/slirp/tcp.h > index 9d06836..b3817cb 100644 > --- a/slirp/tcp.h > +++ b/slirp/tcp.h > @@ -51,10 +51,10 @@ struct tcphdr { > tcp_seq th_seq; /* sequence number */ > tcp_seq th_ack; /* acknowledgement number */ > #ifdef HOST_WORDS_BIGENDIAN > - u_int th_off:4, /* data offset */ > + uint8_t th_off:4, /* data offset */ > th_x2:4; /* (unused) */ > #else > - u_int th_x2:4, /* (unused) */ > + uint8_t th_x2:4, /* (unused) */ > th_off:4; /* data offset */ > #endif > uint8_t th_flags; Tested-by: Stefan Weil There remain some issues with other packed structs which are obviously no longer packed with -mms-bitfields, for example those from bt.h, but slirp looks good with this patch. I used pahole (thanks Blue Swirl for this hint) and codiff to investigate and compare the structs with and without -mms-bitfields: * create qemu.exe (or any binary which you want) * convert it to elf format using objcopy -Oelf32-i386 (or the cross variant) * apply pahole -a to the resulting elf file (without -a some structs are missing) Cheers, Stefan W.