Re: [PATCH v5 2/2] extable: verify address is read-only

From: Eddie Kovsky
Date: Fri Apr 07 2017 - 15:29:54 EST


On 04/07/17, kbuild test robot wrote:
> Hi Eddie,
>
> [auto build test ERROR on next-20170330]
> [cannot apply to linus/master linux/master jeyu/modules-next v4.9-rc8 v4.9-rc7 v4.9-rc6 v4.11-rc5]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
>
> url: https://github.com/0day-ci/linux/commits/Eddie-Kovsky/module-verify-address-is-read-only/20170407-004322
> config: i386-randconfig-x010-201714 (attached as .config)
> compiler: gcc-6 (Debian 6.2.0-3) 6.2.0 20160901
> reproduce:
> # save the attached .config to linux build tree
> make ARCH=i386
>
> All errors (new ones prefixed by >>):
>
> kernel/extable.c: In function 'core_kernel_rodata':
> >> kernel/extable.c:169:29: error: '__start_ro_after_init' undeclared (first use in this function)
> if (addr >= (unsigned long)__start_ro_after_init &&
> ^~~~~~~~~~~~~~~~~~~~~
> kernel/extable.c:169:29: note: each undeclared identifier is reported only once for each function it appears in
> >> kernel/extable.c:170:28: error: '__end_ro_after_init' undeclared (first use in this function)
> addr < (unsigned long)__end_ro_after_init)
> ^~~~~~~~~~~~~~~~~~~
>
> vim +/__start_ro_after_init +169 kernel/extable.c
>
> 163 int core_kernel_rodata(unsigned long addr)
> 164 {
> 165 if (addr >= (unsigned long)__start_rodata &&
> 166 addr < (unsigned long)__end_rodata)
> 167 return 1;
> 168
> > 169 if (addr >= (unsigned long)__start_ro_after_init &&
> > 170 addr < (unsigned long)__end_ro_after_init)
> 171 return 1;
> 172
> 173 return 0;
>
> ---
> 0-DAY kernel test infrastructure Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all Intel Corporation


This looks like a false alarm.

The test build is based on next-20170330. Kees' patch for the section
names [start|end]_ro_after_init didn't appear in next until 20170403.

I cannot reproduce the build error using this config on recent versions
of next. Am I missing something here?

Eddie