From: linux@armlinux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH 1/2] arm64: Fix static use of function graph
Date: Thu, 2 Nov 2017 10:18:31 +0000 [thread overview]
Message-ID: <20171102101831.GU9463@n2100.armlinux.org.uk> (raw)
In-Reply-To: <20171102044306.GL10563@linaro.org>
On Thu, Nov 02, 2017 at 01:43:07PM +0900, AKASHI Takahiro wrote:
> On Wed, Nov 01, 2017 at 02:33:43PM +0000, Julien Thierry wrote:
> > Function graph does not work currently when CONFIG_DYNAMIC_TRACE is not
> > set. This is because ftrace_function_trace is not always set to ftrace_stub
> > when function_graph is in use.
> >
> > Do not skip checking of graph tracer functions when ftrace_function_trace
> > is set.
> >
> > Signed-off-by: Julien Thierry <julien.thierry@arm.com>
> > Cc: Catalin Marinas <catalin.marinas@arm.com>
> > Cc: Will Deacon <will.deacon@arm.com>
> > Cc: Mark Rutland <mark.rutland@arm.com>
> > Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
>
> Reviewed-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
>
> I think that arm has the same issue, hoping the following patch
> will fix it:
> ===
> >From e25bcf50d1acde698285a0c64f72d97f8b17e3fb Mon Sep 17 00:00:00 2001
> From: AKASHI Takahiro <takahiro.akashi@linaro.org>
> Date: Thu, 2 Nov 2017 11:35:04 +0900
> Subject: [PATCH] arm: ftrace: function_graph with DYNAMIC_FTRACE
>
> ---
> arch/arm/kernel/entry-ftrace.S | 12 +++++-------
> 1 file changed, 5 insertions(+), 7 deletions(-)
>
> diff --git a/arch/arm/kernel/entry-ftrace.S b/arch/arm/kernel/entry-ftrace.S
> index efcd9f25a14b..ef94c73ad996 100644
> --- a/arch/arm/kernel/entry-ftrace.S
> +++ b/arch/arm/kernel/entry-ftrace.S
> @@ -68,8 +68,12 @@
> ldr r2, [r0]
> adr r0, .Lftrace_stub
> cmp r0, r2
> - bne 1f
> + beq 1f
>
> + mcount_get_lr r1 @ lr of instrumented func
> + mcount_adjust_addr r0, lr @ instrumented function
> + blx r2
NAK. Not all CPUs support "blx". I don't see why you'd make this
gratuitous change when just moving code around. Please separate
your changes in future.
--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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next prev parent reply other threads:[~2017-11-02 10:18 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-01 14:33 [PATCH 0/2] Ftrace fixes Julien Thierry
2017-11-01 14:33 ` [PATCH 1/2] arm64: Fix static use of function graph Julien Thierry
2017-11-01 16:43 ` Steven Rostedt
2017-11-02 4:43 ` AKASHI Takahiro
2017-11-02 10:18 ` Russell King - ARM Linux [this message]
2017-11-03 9:25 ` Julien Thierry
2017-11-06 1:36 ` AKASHI Takahiro
2017-11-01 14:33 ` [PATCH 2/2] perf: Fix ftrace builtin when kernel doesn't have function_graph Julien Thierry
2017-11-01 16:44 ` Steven Rostedt
2017-11-01 16:58 ` Julien Thierry
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