Hi Tglx, Andy, Sorry for old-posting,
2017-09-15 8:09 GMT+01:00 Thomas Gleixner <[email protected]>: > On Thu, 14 Sep 2017, Andy Lutomirski wrote: >> On Thu, Sep 14, 2017 at 9:00 AM, Thomas Gleixner <[email protected]> wrote: >> > On Thu, 14 Sep 2017, Andy Lutomirski wrote: >> >> On Thu, Sep 14, 2017 at 12:38 AM, Thomas Gleixner <[email protected]> >> >> wrote: >> >> > Hi! >> >> > >> >> > I've seen the following crash sporadically with commit 46c1e79fee: >> >> > >> >> > Have not seen that with 3882a734c19b, though I saw the PCID warnings on >> >> > that machine. >> >> > >> >> > I have no idea how to reproduce so bisecting is pretty much pointless. >> >> > Any >> >> > idea what to do? >> >> >> >> Does tools/testing/selftests/x86/sigreturn_64 reproduce it? >> > >> > Will try tomorrow once I figured out how to compile that stuff. Invoking a >> > simple make in that directory fails. >> >> What's the error? It works for me. > > gcc -m64 -o > /home/tglx/work/kernel/linus/linux/tools/testing/selftests/x86/sysret_ss_attrs_64 > -O2 -g -std=gnu99 -pthread -Wall sysret_ss_attrs.c thunks.S -lrt -ldl > /usr/bin/ld: /tmp/cco4vSkU.o: relocation R_X86_64_32S against `.text' can not > be used when making a shared object; recompile with -fPIC > /usr/bin/ld: final link failed: Nonrepresentable section on output > collect2: error: ld returned 1 exit status Had the same issue in copied thunks.S helper to CRIU. As I wanted to compile CRIU as pie also (which is the default now in some distributions), I fixed it up by using %rip-relative addressing and pushing segment descriptor to stack before long-jumping. Not sure if that's the issue for the selftest as it can be just always compiled as pic. Anyway, here is the commit if you want to look: https://github.com/0x7f454c46/criu/commit/cf36ea5d8408bf1e42c3bd21b9594369ea7123fb -- Dmitry
