* 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)