Re: linux-next: build failure after merge of the mm tree

[Uros Bizjak]

On Thu, Aug 15, 2024 at 9:42 AM Uros Bizjak <ubizjak@xxxxxxxxx> wrote:
>
> On Thu, Aug 15, 2024 at 1:38 AM Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> >
> > Hi all,
> >
> > After merging the mm tree, today's linux-next build (powerpc
> > ppc64_defconfig) failed like this:
> >
> > In file included from include/linux/kcsan-checks.h:13,
> >                  from include/linux/instrumented.h:12,
> >                  from include/asm-generic/bitops/instrumented-atomic.h:14,
> >                  from arch/powerpc/include/asm/bitops.h:321,
> >                  from include/linux/bitops.h:68,
> >                  from arch/powerpc/include/asm/mce.h:12,
> >                  from arch/powerpc/include/asm/paca.h:32,
> >                  from arch/powerpc/include/asm/percpu.h:30,
> >                  from include/linux/err.h:9,
> >                  from arch/powerpc/include/asm/ptrace.h:22,
> >                  from arch/powerpc/kernel/vdso/sigtramp64.S:14:
> > include/linux/compiler_attributes.h:55: warning: "__always_inline" redefined
> >    55 | #define __always_inline                 inline __attribute__((__always_inline__))
> >       |
> > In file included from include/linux/stddef.h:5,
> >                  from include/linux/string.h:9,
> >                  from arch/powerpc/include/asm/paca.h:16:
> > include/uapi/linux/stddef.h:8: note: this is the location of the previous definition
> >     8 | #define __always_inline inline
> >       |
> > include/linux/compiler_attributes.h:91:20: error: missing binary operator before token "("
> >    91 | #if __has_attribute(__copy__)
> >       |                    ^
> > include/linux/compiler_attributes.h:104:20: error: missing binary operator before token "("
> >   104 | #if __has_attribute(__counted_by__)
> >       |                    ^
> > include/linux/compiler_attributes.h:107: warning: "__counted_by" redefined
> >   107 | # define __counted_by(member)
> >       |
> > include/uapi/linux/stddef.h:55: note: this is the location of the previous definition
> >    55 | #define __counted_by(m)
> >       |
> > include/linux/compiler_attributes.h:116:20: error: missing binary operator before token "("
> >   116 | #if __has_attribute(__diagnose_as_builtin__)
> >       |                    ^
> > include/linux/compiler_attributes.h:139:20: error: missing binary operator before token "("
> >   139 | #if __has_attribute(__designated_init__)
> >       |                    ^
> > include/linux/compiler_attributes.h:150:20: error: missing binary operator before token "("
> >   150 | #if __has_attribute(__error__)
> >       |                    ^
> > include/linux/compiler_attributes.h:161:20: error: missing binary operator before token "("
> >   161 | #if __has_attribute(__externally_visible__)
> >       |                    ^
> > include/linux/compiler_attributes.h:198:20: error: missing binary operator before token "("
> >   198 | #if __has_attribute(__no_caller_saved_registers__)
> >       |                    ^
> > include/linux/compiler_attributes.h:209:20: error: missing binary operator before token "("
> >   209 | #if __has_attribute(__noclone__)
> >       |                    ^
> > include/linux/compiler_attributes.h:226:20: error: missing binary operator before token "("
> >   226 | #if __has_attribute(__fallthrough__)
> >       |                    ^
> > include/linux/compiler_attributes.h:252:20: error: missing binary operator before token "("
> >   252 | #if __has_attribute(__nonstring__)
> >       |                    ^
> > include/linux/compiler_attributes.h:264:20: error: missing binary operator before token "("
> >   264 | #if __has_attribute(__no_profile_instrument_function__)
> >       |                    ^
> > include/linux/compiler_attributes.h:283:20: error: missing binary operator before token "("
> >   283 | #if __has_attribute(__no_stack_protector__)
> >       |                    ^
> > include/linux/compiler_attributes.h:294:20: error: missing binary operator before token "("
> >   294 | #if __has_attribute(__overloadable__)
> >       |                    ^
> > include/linux/compiler_attributes.h:313:20: error: missing binary operator before token "("
> >   313 | #if __has_attribute(__pass_dynamic_object_size__)
> >       |                    ^
> > include/linux/compiler_attributes.h:318:20: error: missing binary operator before token "("
> >   318 | #if __has_attribute(__pass_object_size__)
> >       |                    ^
> > include/linux/compiler_attributes.h:342:20: error: missing binary operator before token "("
> >   342 | #if __has_attribute(__uninitialized__)
> >       |                    ^
> > include/linux/compiler_attributes.h:388:20: error: missing binary operator before token "("
> >   388 | #if __has_attribute(__warning__)
> >       |                    ^
> > include/linux/compiler_attributes.h:405:20: error: missing binary operator before token "("
> >   405 | #if __has_attribute(disable_sanitizer_instrumentation)
> >       |                    ^
> >
> > Caused by commit
> >
> >   8e53757638ec ("err.h: add ERR_PTR_PCPU(), PTR_ERR_PCPU() and IS_ERR_PCPU() functions")
> >
> > Does include/linux/err.h really need to include asm/percpu.h?  __percpu is
> > defined in compiler_types.h which is included in every c code compile.
>
> Currently it is not needed, but with the proposed patch [1]
>
> [1] https://lore.kernel.org/lkml/20240812115945.484051-4-ubizjak@xxxxxxxxx/
>
> that repurposes __percpu to also include percpu named address
> qualifier, it will be needed, because per_cpu_qual will be defined in
> include/asm-generic/percpu.h.
>
> I looked a bit at the error and noticed that the error happens when
> building VDSO sigtramp64.S that includes:
>
> #include <asm/ptrace.h> /* XXX for __SIGNAL_FRAMESIZE */
>
> The crash happens through this include, so perhaps XXX above marks
> some expected problem with the include that my change was unlucky
> enough to trigger?

OTOH, powerpc percpu.h includes paca.h that further includes
linux/string.h. AFAICS, nothing in paca.h requires linux/string.h
(which includes many other headers), so perhaps removing "#include
linux/string.h" from paca.h makes the header "light enough" to be
included in err.h.through percpu.h.

Uros.