Hi, i am sure but it works for me.

actually, it little strange, because,
after modification, first time, it getting segfaults,
later, it works fine.

flags in util-linux-2.23 was created automatically.

musl linux system could be set by this method:
https://github.com/pikhq/bootstrap-linux/issues/8
https://github.com/pikhq/bootstrap-linux/issues/9
http://plan9assembler.wordpress.com/2013/04/26/bootstrap-linux-musl-cross/

gcc-4.8
CC = gcc -std=gnu99
CCDEPMODE = depmode=gcc3
CFLAGS = -g -O2
CPP = gcc -E

TIA




On Mon, May 27, 2013 at 11:29 PM, Szabolcs Nagy <nsz@port70.net> wrote:

> * plan9assembler <plan9assembler@gmail.com> [2013-05-27 23:05:37 +0900]:
> > util-linux-2.23 mount segfault error seems to be solved.
> > no more segfault error, when i test mount binary.
> >
> > i modified follow macros in musl /include/bits/ioctl.h and musl libc
> > reinstalled.
> >
> > - #define _IOR(a,b,c) _IOC(2,(a),(b),sizeof(c))
> > - #define _IOWR(a,b,c) _IOC(3,(a),(b),sizeof(c))
> >
> > + #define _IOR(a,b,c) _IOC(2U,(a),(b),sizeof(c))
> > + #define _IOWR(a,b,c) _IOC(3U,(a),(b),sizeof(c))
> >
>
> hm are you sure this was the change that solved the segfault?
>
> that would be scary since the linux headers have signed
> int left shift overflows in many places
> (and as far as i know users of those headers dont use
> special compilation flags to make signed overflow
> well-defined like gcc -fwrapv)
>
> which compiler did you use and with what flags?
> (this could break a lot of legacy code)
>