[U-Boot] [PATCH 1/1] net: remove superfluous __packed attribute

[Tom Rini]

On Thu, Oct 03, 2019 at 07:01:22PM +0200, Heinrich Schuchardt wrote:

> struct ip_udp_hdr is naturally packed. There is no point in adding a
> __packed attribute. With the attribute the network stack does not compile
> using GCC 9.2.1:
> 
> net/net.c: In function ‘net_process_received_packet’:
> net/net.c:1288:23: error: taking address of packed member of ‘struct
> ip_udp_hdr’ may result in an unaligned pointer value
> [-Werror=address-of-packed-member]
>  1288 |    sumptr = (ushort *)&(ip->udp_src);
>       |                       ^~~~~~~~~~~~~~
> 
> So let's remove the attribute.
> 
> Signed-off-by: Heinrich Schuchardt <xypron.glpk at gmx.de>
> ---
>  include/net.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/net.h b/include/net.h
> index 75a16e4c8f..bd875b56f5 100644
> --- a/include/net.h
> +++ b/include/net.h
> @@ -390,7 +390,7 @@ struct ip_udp_hdr {
>  	u16		udp_dst;	/* UDP destination port		*/
>  	u16		udp_len;	/* Length of UDP packet		*/
>  	u16		udp_xsum;	/* Checksum			*/
> -} __attribute__((packed));
> +};
> 
>  #define IP_UDP_HDR_SIZE		(sizeof(struct ip_udp_hdr))
>  #define UDP_HDR_SIZE		(IP_UDP_HDR_SIZE - IP_HDR_SIZE)

This came from:
commit 704f3acfcf55343043bbed01c5fb0a0094a68e8a
Author: Denis Pynkin <denis.pynkin at collabora.com>
Date:   Fri Jul 21 19:28:42 2017 +0300

    net: Use packed structures for networking
    
    PXE boot is broken with GCC 7.1 due option '-fstore-merging' enabled
    by default for '-O2':
    
    BOOTP broadcast 1
    data abort
    pc : [<8ff8bb30>]          lr : [<00004f1f>]
    reloc pc : [<17832b30>]    lr : [<878abf1f>]
    sp : 8f558bc0  ip : 00000000     fp : 8ffef5a4
    r10: 8ffed248  r9 : 8f558ee0     r8 : 8ffef594
    r7 : 0000000e  r6 : 8ffed700     r5 : 00000000  r4 : 8ffed74e
    r3 : 00060101  r2 : 8ffed230     r1 : 8ffed706  r0 : 00000ddd
    Flags: nzcv  IRQs off  FIQs off  Mode SVC_32
    Resetting CPU ...
    
    Core reason is usage of structures for network headers without packed
    attribute.
    
    Reviewed-by: Yauheni Kaliuta <yauheni.kaliuta at redhat.com>
    Signed-off-by: Denis Pynkin <denis.pynkin at collabora.com>
    Acked-by: Joe Hershberger <joe.hershberger at ni.com>

... so adding a few folks to the list and lets see if patchwork picks up
this tag:
Fixes: 704f3acfcf55 ("net: Use packed structures for networking")

-- 
Tom
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 833 bytes
Desc: not available
URL: <http://lists.denx.de/pipermail/u-boot/attachments/20191003/221b11fc/attachment.sig>