On Thu, 12 Sep 2019 20:02:16 +0200
Christophe Leroy <christophe.leroy@xxxxxx> wrote:
> Le 12/09/2019 à 19:26, Michal Suchanek a écrit :
> > There are numerous references to 32bit functions in generic and 64bit
> > code so ifdef them out.
> >
> > Signed-off-by: Michal Suchanek <msuchanek@xxxxxxx>
> > ---
> > v2:
> > - fix 32bit ifdef condition in signal.c
> > - simplify the compat ifdef condition in vdso.c - 64bit is redundant
> > - simplify the compat ifdef condition in callchain.c - 64bit is redundant
> > v3:
> > - use IS_ENABLED and maybe_unused where possible
> > - do not ifdef declarations
> > - clean up Makefile
> > v4:
> > - further makefile cleanup
> > - simplify is_32bit_task conditions
> > - avoid ifdef in condition by using return
> > v5:
> > - avoid unreachable code on 32bit
> > - make is_current_64bit constant on !COMPAT
> > - add stub perf_callchain_user_32 to avoid some ifdefs
> > v6:
> > - consolidate current_is_64bit
> > v7:
> > - remove leftover perf_callchain_user_32 stub from previous series version
> > v8:
> > - fix build again - too trigger-happy with stub removal
> > - remove a vdso.c hunk that causes warning according to kbuild test robot
> > ---
> > arch/powerpc/include/asm/thread_info.h | 4 +--
> > arch/powerpc/kernel/Makefile | 7 ++---
> > arch/powerpc/kernel/entry_64.S | 2 ++
> > arch/powerpc/kernel/signal.c | 3 +-
> > arch/powerpc/kernel/syscall_64.c | 6 ++--
> > arch/powerpc/kernel/vdso.c | 3 +-
> > arch/powerpc/perf/callchain.c | 39 ++++++++++++++------------
> > 7 files changed, 33 insertions(+), 31 deletions(-)
> >
> > diff --git a/arch/powerpc/include/asm/thread_info.h b/arch/powerpc/include/asm/thread_info.h
> > index 8e1d0195ac36..c128d8a48ea3 100644
> > --- a/arch/powerpc/include/asm/thread_info.h
> > +++ b/arch/powerpc/include/asm/thread_info.h
> > @@ -144,10 +144,10 @@ static inline bool test_thread_local_flags(unsigned int flags)
> > return (ti->local_flags & flags) != 0;
> > }
> >
> > -#ifdef CONFIG_PPC64
> > +#ifdef CONFIG_COMPAT
> > #define is_32bit_task() (test_thread_flag(TIF_32BIT))
> > #else
> > -#define is_32bit_task() (1)
> > +#define is_32bit_task() (IS_ENABLED(CONFIG_PPC32))
> > #endif
> >
> > #if defined(CONFIG_PPC64)
>
> [...]
>
> > +static inline int current_is_64bit(void)
> > +{
> > + if (!IS_ENABLED(CONFIG_COMPAT))
> > + return IS_ENABLED(CONFIG_PPC64);
> > + /*
> > + * We can't use test_thread_flag() here because we may be on an
> > + * interrupt stack, and the thread flags don't get copied over
> > + * from the thread_info on the main stack to the interrupt stack.
> > + */
> > + return !test_ti_thread_flag(task_thread_info(current), TIF_32BIT);
> > +}
>
>
> Since at least commit ed1cd6deb013 ("powerpc: Activate
> CONFIG_THREAD_INFO_IN_TASK")
> [https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ed1cd6d]
> the above comment is wrong and current_is_64bit() is equivalent to
> !is_32bit_task()
>
> See https://github.com/linuxppc/issues/issues/275
>
> Christophe
I aim at changing the code as little as possible here. A separate patch
on top removing this function would be ok?
Thanks
Michal
