Re: [PATCH] s390: fix build error for sys_call_table_emu

Will Deacon
2020-06-18T11:52:12Z

On Thu, Jun 18, 2020 at 01:27:02PM +0200, Heiko Carstens wrote:
> On Thu, Jun 18, 2020 at 07:03:20PM +0800, Xiaoming Ni wrote:
> > Build error on s390:
> > arch/s390/kernel/entry.o: in function `sys_call_table_emu':
> > >> (.rodata+0x1288): undefined reference to `__s390_'
> >
> > In commit ("All arch: remove system call sys_sysctl")
> > 148 common fdatasync sys_fdatasync sys_fdatasync
> > -149 common _sysctl sys_sysctl compat_sys_sysctl
> > +149 common _sysctl sys_ni_syscall
> > 150 common mlock sys_mlock sys_mlock
> >
> > After the patch is integrated, there is a format error in the generated
> > arch/s390/include/generated/asm/syscall_table.h:
> > SYSCALL(sys_fdatasync, sys_fdatasync)
> > SYSCALL(sys_ni_syscall,) /* cause build error */
> > SYSCALL(sys_mlock,sys_mlock)
> >
> > There are holes in the system call number in
> > arch/s390/kernel/syscalls/syscall.tbl. When generating syscall_table.h,
> > these hole numbers will be automatically filled with "NI_SYSCALL".
> > Therefore, delete the number 149 to fix the current compilation failure.
> > Similarly, modify tools/perf/arch/s390/entry/syscalls/syscall.tbl.
> >
> > Fixes: ("All arch: remove system call sys_sysctl")
> > Fixes: https://lore.kernel.org/linuxppc-dev/20200616030734.87257-1-nixiaoming@huawei.com/
> > Reported-by: kernel test robot <lkp@intel.com>
> > Signed-off-by: Xiaoming Ni <nixiaoming@huawei.com>
> > ---
> > arch/s390/kernel/syscalls/syscall.tbl | 1 -
> > tools/perf/arch/s390/entry/syscalls/syscall.tbl | 1 -
> > 2 files changed, 2 deletions(-)
> >
> > diff --git a/arch/s390/kernel/syscalls/syscall.tbl b/arch/s390/kernel/syscalls/syscall.tbl
> > index f17aaf6fe5de..bcaf93994e3c 100644
> > --- a/arch/s390/kernel/syscalls/syscall.tbl
> > +++ b/arch/s390/kernel/syscalls/syscall.tbl
> > @@ -138,7 +138,6 @@
> > 146 common writev sys_writev compat_sys_writev
> > 147 common getsid sys_getsid sys_getsid
> > 148 common fdatasync sys_fdatasync sys_fdatasync
> > -149 common _sysctl sys_ni_syscall
>
> This is not correct. It should be changed to:
>
> 149 common _sysctl - -
>
> Otherwise the generated __NR__sysctl define will be lost from
> unistd.h, which should not happen. Looking at the link above it
> _looks_ like a similar mistake was done for arm64.

I think we're ok on arm64, since it's only the compat syscall table that
is being updated and we don't export compat uapi headers (rather, they
come from arch/arm/).

Will