From: Ard Biesheuvel <ard.biesheuvel@linaro.org>
To: Torsten Duwe <duwe@lst.de>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>,
Will Deacon <will.deacon@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Julien Thierry <julien.thierry@arm.com>,
Steven Rostedt <rostedt@goodmis.org>,
Josh Poimboeuf <jpoimboe@redhat.com>,
Ingo Molnar <mingo@redhat.com>, Arnd Bergmann <arnd@arndb.de>,
AKASHI Takahiro <takahiro.akashi@linaro.org>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
live-patching@vger.kernel.org
Subject: Re: [PATCH v3 1/4] DYNAMIC_FTRACE configurable with and without REGS
Date: Mon, 1 Oct 2018 16:52:27 +0200 [thread overview]
Message-ID: <CAKv+Gu-ZtJ-BpfPWU=soDCb2+dAd81p8OtaarWhmTe+Fk6A8ig@mail.gmail.com> (raw)
In-Reply-To: <20181001141643.331EE68BC7@newverein.lst.de>
Hi Torsten,
On 1 October 2018 at 16:16, Torsten Duwe <duwe@lst.de> wrote:
> In commit 06aeaaeabf69da4, many ftrace-related config options are
> consolidated. By accident, I guess, the choice about DYNAMIC_FTRACE
> and DYNAMIC_FTRACE_WITH_REGS is no longer available explicitly but
> determined by the sole availability on the architecture.
>
> This makes it hard to introduce DYNAMIC_FTRACE_WITH_REGS if it depends
> on new compiler features or other new properties of the toolchain
> without breaking existing configurations.
>
> This patch turns the def_bool into an actual choice. Should the toolchain
> not meet the requirements for _WITH_REGS it can be turned off.
>
I guess we now have Kbuild/Kconfig support for this, no? I mean, we
can now show/hide options depending on the capabilities of the
toolchain.
I am not saying it would be a better approach, though - I'd rather
have a warning than have things silently disabled, but other people
may think differently.
> Signed-off-by: Torsten Duwe <duwe@suse.de>
>
>
> --- a/kernel/trace/Kconfig
> +++ b/kernel/trace/Kconfig
> @@ -508,9 +508,15 @@ config DYNAMIC_FTRACE
> otherwise has native performance as long as no tracing is active.
>
> config DYNAMIC_FTRACE_WITH_REGS
> - def_bool y
> + bool "Include register content tracking in dynamic ftrace facility"
> + default y
> depends on DYNAMIC_FTRACE
> depends on HAVE_DYNAMIC_FTRACE_WITH_REGS
> + help
> + This architecture supports the inspection of register contents,
> + as passed between functions, at the dynamic ftrace points.
> + This is also a prerequisite for Kernel Live Patching (KLP).
> + When in doubt, say Y.
>
> config FUNCTION_PROFILER
> bool "Kernel function profiler"
next prev parent reply other threads:[~2018-10-01 14:52 UTC|newest]
Thread overview: 48+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-10-01 14:09 [PATCH v3 0/4] arm64 live patching Torsten Duwe
2018-10-01 14:16 ` [PATCH v3 1/4] DYNAMIC_FTRACE configurable with and without REGS Torsten Duwe
2018-10-01 14:52 ` Ard Biesheuvel [this message]
2018-10-01 15:03 ` Torsten Duwe
2018-10-01 15:06 ` Ard Biesheuvel
2018-10-01 15:10 ` Torsten Duwe
2018-10-01 15:14 ` Steven Rostedt
2018-10-01 14:16 ` [PATCH v3 2/4] arm64: implement ftrace with regs Torsten Duwe
2018-10-01 15:57 ` Ard Biesheuvel
2018-10-02 10:02 ` Torsten Duwe
2018-10-02 10:39 ` Ard Biesheuvel
2018-10-02 11:27 ` Mark Rutland
2018-10-02 12:18 ` Torsten Duwe
2018-10-02 12:57 ` Mark Rutland
2018-10-01 14:16 ` [PATCH v3 3/4] arm64: implement live patching Torsten Duwe
2018-10-17 13:39 ` Miroslav Benes
2018-10-18 12:58 ` Jessica Yu
2018-10-19 11:59 ` Miroslav Benes
2018-10-19 12:18 ` Jessica Yu
2018-10-19 15:14 ` Miroslav Benes
2018-10-19 13:46 ` Torsten Duwe
2018-10-19 13:52 ` Ard Biesheuvel
2018-10-19 15:21 ` Miroslav Benes
2018-10-20 14:10 ` Ard Biesheuvel
2018-10-22 12:53 ` Miroslav Benes
2018-10-22 14:54 ` Torsten Duwe
2018-10-23 17:55 ` [PATCH] arm64/module: use mod->klp_info section header information Jessica Yu
2018-10-23 19:32 ` kbuild test robot
2018-10-24 11:57 ` Miroslav Benes
2018-10-25 8:08 ` Petr Mladek
2018-10-25 9:00 ` Miroslav Benes
2018-10-25 11:42 ` Jessica Yu
2018-10-26 17:25 ` [PATCH v2] arm64/module: use mod->klp_info section header information for livepatch modules Jessica Yu
2018-10-29 13:24 ` Miroslav Benes
2018-10-29 13:32 ` Jessica Yu
2018-10-29 15:28 ` Will Deacon
2018-10-30 13:19 ` Jessica Yu
2018-11-01 15:18 ` Miroslav Benes
2018-11-01 16:07 ` Will Deacon
2018-11-05 12:30 ` Ard Biesheuvel
2018-11-05 17:57 ` [PATCH] arm64/module: use plt section indices for relocations Jessica Yu
2018-11-05 18:04 ` Ard Biesheuvel
2018-11-05 18:53 ` [PATCH v2] " Jessica Yu
2018-11-05 18:56 ` Ard Biesheuvel
2018-11-05 19:26 ` Will Deacon
2018-11-05 19:49 ` Jessica Yu
2018-11-06 9:44 ` Miroslav Benes
2018-10-01 14:16 ` [PATCH v3 4/4] arm64: reliable stacktraces Torsten Duwe
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