Re: [PATCH v7 6/7] arm64: ftrace: Add CALLER_ADDRx macros

[AKASHI Takahiro]

Hi Will,

On 04/16/2014 10:52 PM, Will Deacon wrote:
> On Sat, Mar 15, 2014 at 05:45:52AM +0000, AKASHI Takahiro wrote:
> > CALLER_ADDRx returns caller's address at specified level in call stacks.
> > They are used for several tracers like irqsoff and preemptoff.
> > Strange to say, however, they are refered even without FTRACE.
> >
> > Signed-off-by: AKASHI Takahiro <takahiro.akashi@xxxxxxxxxx>
> > ---
> >   arch/arm64/include/asm/ftrace.h    | 13 ++++++++-
> >   arch/arm64/kernel/Makefile         |  3 ++-
> >   arch/arm64/kernel/return_address.c | 55 ++++++++++++++++++++++++++++++++++++++
> >   3 files changed, 69 insertions(+), 2 deletions(-)
> >   create mode 100644 arch/arm64/kernel/return_address.c
> >
> > diff --git a/arch/arm64/include/asm/ftrace.h b/arch/arm64/include/asm/ftrace.h
> > index ed5c448..c44c4b1 100644
> > --- a/arch/arm64/include/asm/ftrace.h
> > +++ b/arch/arm64/include/asm/ftrace.h
> > @@ -18,6 +18,7 @@
> >
> >   #ifndef __ASSEMBLY__
> >   extern void _mcount(unsigned long);
> > +extern void *return_address(unsigned int);
> >
> >   struct dyn_arch_ftrace {
> >   	/* No extra data needed for arm64 */
> > @@ -33,6 +34,16 @@ static inline unsigned long ftrace_call_adjust(unsigned long addr)
> >   	 */
> >   	return addr;
> >   }
> > -#endif /* __ASSEMBLY__ */
> > +
> > +#define HAVE_ARCH_CALLER_ADDR
> > +
> > +#define CALLER_ADDR0 ((unsigned long)__builtin_return_address(0))
> > +#define CALLER_ADDR1 ((unsigned long)return_address(1))
> > +#define CALLER_ADDR2 ((unsigned long)return_address(2))
> > +#define CALLER_ADDR3 ((unsigned long)return_address(3))
> > +#define CALLER_ADDR4 ((unsigned long)return_address(4))
> > +#define CALLER_ADDR5 ((unsigned long)return_address(5))
> > +#define CALLER_ADDR6 ((unsigned long)return_address(6))
> > +#endif /* ifndef __ASSEMBLY__ */
>
> Hmm, I thought you were going to take a look at reworking the core code for
> this, as Steve and I suggested?
>
>    http://lists.infradead.org/pipermail/linux-arm-kernel/2014-March/240239.html

Sorry that I've forgot to submit a new revision with this change.
I will post it soon.

Thanks,
-Takahiro AKASHI

> Will
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