From: Kirill A. S. <ki...@sh...> - 2011-04-22 00:28:23
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On Sat, Apr 16, 2011 at 01:03:13AM +0200, Richard Weinberger wrote: > In some cases gcc-4.6 will optimize away current_thread_info(). > To prevent gcc from doing so the stack address has to be obtained > via inline asm. > > LKML-Reference: http://marc.info/?i=201...@no... > > Signed-off-by: Richard Weinberger <ri...@no...> Acked-by: Kirill A. Shutemov <ki...@sh...> Also reproducible with gcc version 4.5.2 (Ubuntu/Linaro 4.5.2-8ubuntu4). > --- > arch/um/include/asm/thread_info.h | 5 ++++- > 1 files changed, 4 insertions(+), 1 deletions(-) > > diff --git a/arch/um/include/asm/thread_info.h b/arch/um/include/asm/thread_info.h > index e2cf786..5bd1bad 100644 > --- a/arch/um/include/asm/thread_info.h > +++ b/arch/um/include/asm/thread_info.h > @@ -49,7 +49,10 @@ static inline struct thread_info *current_thread_info(void) > { > struct thread_info *ti; > unsigned long mask = THREAD_SIZE - 1; > - ti = (struct thread_info *) (((unsigned long) &ti) & ~mask); > + void *p; > + > + asm volatile ("" : "=r" (p) : "0" (&ti)); > + ti = (struct thread_info *) (((unsigned long)p) & ~mask); > return ti; > } > > -- > 1.6.6.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to maj...@vg... > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- Kirill A. Shutemov |