Re: [Bugme-new] [Bug 18942] New: change to include/linux/netdevice.h prevents compilation for ARM architecture with AEABI enabled

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On Wed, 22 Sep 2010 08:39:05 GMT bugzilla-daemon@bugzilla.kernel.org wrote:

https://bugzilla.kernel.org/show_bug.cgi?id=18942

           Summary: change to include/linux/netdevice.h prevents
                    compilation for ARM architecture with AEABI enabled
           Product: Platform Specific/Hardware
           Version: 2.5
    Kernel Version: 2.6.35.4
          Platform: All
        OS/Version: Linux
              Tree: Mainline
            Status: NEW
          Severity: blocking
          Priority: P1
         Component: ARM
        AssignedTo: linux-arm-kernel@lists.arm.linux.org.uk
        ReportedBy: ilya@total-knowledge.com
        Regression: No


I am trying to compile the latest kernel, and am running into the following
error:
In file included from include/linux/icmpv6.h:173,
                 from include/linux/ipv6.h:220,
                 from include/net/ipv6.h:16,
                 from include/linux/sunrpc/clnt.h:25,
                 from include/linux/nfs_fs.h:48,
                 from init/do_mounts.c:20:
include/linux/netdevice.h:1005: error: width of 'reg_state' exceeds its type
include/linux/netdevice.h:1010: error: width of 'rtnl_link_state' exceeds its
type


There was a change not too long ago, which converted reg_state to a bitfield,
which apparently doesn't work when -mabi=aapcs.
I tested it with a gcc versions 4.2.0, 4.4.2, and 4.4.4 and it holds true for
all of them.

Here is simple test case:
struct test {
        enum { NETREG_UNINITIALIZED=0,
        } reg_state:16;
};

int main(int argc, char** argv)
{
        struct test tt;
        tt.reg_state=NETREG_UNINITIALIZED;
        return 0;
}

Compiles without -mabi=aapcs option, fails with.

Bummer.  I guess that this abi requires that enums have `int' width for
some reason?

Does -mabi=aapcs actually get used, officially?  All I can see in
Linus's tree is

z:/usr/src/linux-2.6.36-rc5> grep -r aapcs .
./arch/arm/Makefile:CFLAGS_ABI  :=-mabi=aapcs-linux -mno-thumb-interwork