Re: [PATCH v2] um: Avoid longjmp/setjmp symbol clashes with libpthread.a

[Richard Weinberger]

Florian,

Am 24.05.2017 um 02:32 schrieb Florian Fainelli:
> Building a statically linked UML kernel on a Centos 6.9 host resulted in
> the following linking failure (GCC 4.4, glibc-2.12):
> 
> /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/libpthread.a(libpthread.o):
> In function `siglongjmp':
> (.text+0x8490): multiple definition of `longjmp'
> arch/x86/um/built-in.o:/local/users/fainelli/openwrt/trunk/build_dir/target-x86_64_musl/linux-uml/linux-4.4.69/arch/x86/um/setjmp_64.S:44:
> first defined here
> /usr/lib/gcc/x86_64-redhat-linux/4.4.7/../../../../lib64/libpthread.a(libpthread.o):
> In function `sem_open':
> (.text+0x77cd): warning: the use of `mktemp' is dangerous, better use
> `mkstemp'
> collect2: ld returned 1 exit status
> make[4]: *** [vmlinux] Error 1
> 
> Adopt a solution similar to the one done for vmap where we define
> longjmp/setjmp to be kernel_longjmp/setjmp. In the process, make sure we
> do rename the functions in arch/x86/um/setjmp_*.S accordingly.

What is not so clear to me, why are you facing this build issue and other users, including me,
not?

Thanks,
//richard