On Fri, Jan 11, 2013 at 04:18:10PM +0900, Keun-O Park wrote: > From: sahara <keun-o.p...@windriver.com> > > This makes return_address return correct value for ftrace feature. > unwind_frame does not update frame->lr but frame->pc for backtrace. > And, the initialization for data.addr was missing so that wrong value > returned when unwind_frame failed. > > Signed-off-by: sahara <keun-o.p...@windriver.com>
Reviewed-by: Dave Martin <dave.mar...@linaro.org> This is the same as a patch I previously posted: http://lists.infradead.org/pipermail/linux-arm-kernel/2012-November/129381.html ...except for the initialisation of data.addr to NULL, which is needed in order to prevent a garbage pointer being returned in the case where the unwinder fails to unwind a frame before the required level is reached. Cheers ---Dave > --- > arch/arm/kernel/return_address.c | 5 +++-- > 1 files changed, 3 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/kernel/return_address.c > b/arch/arm/kernel/return_address.c > index 8085417..fafedd8 100644 > --- a/arch/arm/kernel/return_address.c > +++ b/arch/arm/kernel/return_address.c > @@ -26,7 +26,7 @@ static int save_return_addr(struct stackframe *frame, void > *d) > struct return_address_data *data = d; > > if (!data->level) { > - data->addr = (void *)frame->lr; > + data->addr = (void *)frame->pc; > > return 1; > } else { > @@ -41,7 +41,8 @@ void *return_address(unsigned int level) > struct stackframe frame; > register unsigned long current_sp asm ("sp"); > > - data.level = level + 1; > + data.level = level + 2; > + data.addr = NULL; > > frame.fp = (unsigned long)__builtin_frame_address(0); > frame.sp = current_sp; > -- > 1.7.1 > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-ker...@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
