On Wed, Apr 10, 2019 at 4:43 AM Ingo Molnar <[email protected]> wrote:
>
>
> * Elena Reshetova <[email protected]> wrote:
>
> > 2) Andy's tests, misc-tests: ./timing_test_64 10M sys_enosys
> > base: 10000000 loops in 1.62224s
> > = 162.22 nsec / loop
> > random_offset (prandom_u32() every syscall): 10000000 loops in 1.64660s
> > = 166.26 nsec / loop
>
> Stupid question, how did you manage to buil timing_test_64? Here it fails
> with a bog standard gcc 7.3.0 x86-64 distro toolchain:
>
> dagon:~/luto-misc-tests.git> make timing_test_64
> g++ -m64 -o timing_test_64 -O2 -g -std=gnu++11 -pthread -Wall
> timing_test.cc -lrt -ldl
> /usr/bin/ld: /tmp/cc8VRkuV.o: relocation R_X86_64_32S against
> `.text.startup' can not be used when making a PIE object; recompile with -fPIC
> /usr/bin/ld: final link failed: Nonrepresentable section on outputcollect2:
> error: ld returned 1 exit status
> Makefile:39: recipe for target 'timing_test_64' failed
>
I think your toolchain is screwy. If I create this file as ingo.c:
#include <stdio.h>
int main(int argc, char **argv)
{
printf("Hello world!");
return 0;
}
And build it like this, it fails:
$ gcc -o ingo -g ingo.c -pie
/usr/bin/ld: /tmp/ccofYU9N.o: relocation R_X86_64_32 against `.rodata'
can not be used when making a PIE object; recompile with -fPIC
/usr/bin/ld: final link failed: nonrepresentable section on output
collect2: error: ld returned 1 exit status
Which I assume means that -pie requires -fPIC, and your toolchain is
screwed up and is defaulting to useless options. I'm guessing you
should file a bug against your distro gcc package. For me, it works
if I remove -pie.
