From: Ard Biesheuvel <ardb@kernel.org>
To: Florian Fainelli <f.fainelli@gmail.com>,
Linus Walleij <linus.walleij@linaro.org>
Cc: Alexander A Sverdlin <alexander.sverdlin@nokia.com>,
Steven Rostedt <rostedt@goodmis.org>,
Ingo Molnar <mingo@redhat.com>,
Russell King <linux@armlinux.org.uk>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v7 0/2] ARM: Implement MODULE_PLT support in FTRACE
Date: Mon, 15 Feb 2021 19:31:49 +0100 [thread overview]
Message-ID: <CAMj1kXGEP3BNW6aLDaHFq2FCer-e8VXPU3c8xiojNXSqgzdw_g@mail.gmail.com> (raw)
In-Reply-To: <a5c1e655-cdbc-18d5-55fd-c1690c31acbe@gmail.com>
(+ Linus)
On Wed, 3 Feb 2021 at 19:24, Florian Fainelli <f.fainelli@gmail.com> wrote:
>
> On 1/27/21 3:09 AM, Alexander A Sverdlin wrote:
> > From: Alexander Sverdlin <alexander.sverdlin@nokia.com>
> >
> > FTRACE's function tracer currently doesn't always work on ARM with
> > MODULE_PLT option enabled. If the module is loaded too far, FTRACE's
> > code modifier cannot cope with introduced veneers and turns the
> > function tracer off globally.
> >
> > ARM64 already has a solution for the problem, refer to the following
> > patches:
> >
> > arm64: ftrace: emit ftrace-mod.o contents through code
> > arm64: module-plts: factor out PLT generation code for ftrace
> > arm64: ftrace: fix !CONFIG_ARM64_MODULE_PLTS kernels
> > arm64: ftrace: fix building without CONFIG_MODULES
> > arm64: ftrace: add support for far branches to dynamic ftrace
> > arm64: ftrace: don't validate branch via PLT in ftrace_make_nop()
> >
> > But the presented ARM variant has just a half of the footprint in terms of
> > the changed LoCs. It also retains the code validation-before-modification
> > instead of switching it off.
>
> Ard, Russell should this be sent to the patch tracker?
Apologies for the delay. Unfortunately, I don't have time to review this.
Linus?
WARNING: multiple messages have this Message-ID (diff)
From: Ard Biesheuvel <ardb@kernel.org>
To: Florian Fainelli <f.fainelli@gmail.com>,
Linus Walleij <linus.walleij@linaro.org>
Cc: Russell King <linux@armlinux.org.uk>,
Steven Rostedt <rostedt@goodmis.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Ingo Molnar <mingo@redhat.com>,
Alexander A Sverdlin <alexander.sverdlin@nokia.com>,
Linux ARM <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v7 0/2] ARM: Implement MODULE_PLT support in FTRACE
Date: Mon, 15 Feb 2021 19:31:49 +0100 [thread overview]
Message-ID: <CAMj1kXGEP3BNW6aLDaHFq2FCer-e8VXPU3c8xiojNXSqgzdw_g@mail.gmail.com> (raw)
In-Reply-To: <a5c1e655-cdbc-18d5-55fd-c1690c31acbe@gmail.com>
(+ Linus)
On Wed, 3 Feb 2021 at 19:24, Florian Fainelli <f.fainelli@gmail.com> wrote:
>
> On 1/27/21 3:09 AM, Alexander A Sverdlin wrote:
> > From: Alexander Sverdlin <alexander.sverdlin@nokia.com>
> >
> > FTRACE's function tracer currently doesn't always work on ARM with
> > MODULE_PLT option enabled. If the module is loaded too far, FTRACE's
> > code modifier cannot cope with introduced veneers and turns the
> > function tracer off globally.
> >
> > ARM64 already has a solution for the problem, refer to the following
> > patches:
> >
> > arm64: ftrace: emit ftrace-mod.o contents through code
> > arm64: module-plts: factor out PLT generation code for ftrace
> > arm64: ftrace: fix !CONFIG_ARM64_MODULE_PLTS kernels
> > arm64: ftrace: fix building without CONFIG_MODULES
> > arm64: ftrace: add support for far branches to dynamic ftrace
> > arm64: ftrace: don't validate branch via PLT in ftrace_make_nop()
> >
> > But the presented ARM variant has just a half of the footprint in terms of
> > the changed LoCs. It also retains the code validation-before-modification
> > instead of switching it off.
>
> Ard, Russell should this be sent to the patch tracker?
Apologies for the delay. Unfortunately, I don't have time to review this.
Linus?
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next prev parent reply other threads:[~2021-02-15 18:32 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-27 11:09 [PATCH v7 0/2] ARM: Implement MODULE_PLT support in FTRACE Alexander A Sverdlin
2021-01-27 11:09 ` Alexander A Sverdlin
2021-01-27 11:09 ` [PATCH v7 1/2] ARM: PLT: Move struct plt_entries definition to header Alexander A Sverdlin
2021-01-27 11:09 ` Alexander A Sverdlin
2021-01-27 20:25 ` Florian Fainelli
2021-01-27 20:25 ` Florian Fainelli
2021-01-27 11:09 ` [PATCH v7 2/2] ARM: ftrace: Add MODULE_PLTS support Alexander A Sverdlin
2021-01-27 11:09 ` Alexander A Sverdlin
2021-01-27 19:36 ` Florian Fainelli
2021-01-27 19:36 ` Florian Fainelli
2021-03-07 17:26 ` Qais Yousef
2021-03-07 17:26 ` Qais Yousef
2021-03-08 7:58 ` Alexander Sverdlin
2021-03-08 7:58 ` Alexander Sverdlin
2021-03-09 17:42 ` Qais Yousef
2021-03-09 17:42 ` Qais Yousef
2021-03-10 7:23 ` Alexander Sverdlin
2021-03-10 7:23 ` Alexander Sverdlin
2021-03-10 16:14 ` Florian Fainelli
2021-03-10 16:14 ` Florian Fainelli
2021-03-10 17:17 ` Alexander Sverdlin
2021-03-10 17:17 ` Alexander Sverdlin
2021-03-12 17:24 ` Qais Yousef
2021-03-12 17:24 ` Qais Yousef
2021-03-12 18:35 ` Florian Fainelli
2021-03-12 18:35 ` Florian Fainelli
2021-03-14 22:02 ` Qais Yousef
2021-03-14 22:02 ` Qais Yousef
2021-03-21 19:06 ` Qais Yousef
2021-03-21 19:06 ` Qais Yousef
2021-03-22 15:01 ` Steven Rostedt
2021-03-22 15:01 ` Steven Rostedt
2021-03-22 16:32 ` Qais Yousef
2021-03-22 16:32 ` Qais Yousef
2021-03-22 17:02 ` Alexander Sverdlin
2021-03-22 17:02 ` Alexander Sverdlin
2021-03-23 22:22 ` Qais Yousef
2021-03-23 22:22 ` Qais Yousef
2021-03-24 3:37 ` Florian Fainelli
2021-03-24 3:37 ` Florian Fainelli
2021-03-24 16:10 ` Qais Yousef
2021-03-24 16:10 ` Qais Yousef
2021-03-24 9:04 ` Alexander Sverdlin
2021-03-24 9:04 ` Alexander Sverdlin
2021-03-24 15:57 ` Qais Yousef
2021-03-24 15:57 ` Qais Yousef
2021-03-24 16:33 ` Alexander Sverdlin
2021-03-24 16:33 ` Alexander Sverdlin
2021-03-24 16:46 ` Qais Yousef
2021-03-24 16:46 ` Qais Yousef
2021-03-15 9:19 ` Alexander Sverdlin
2021-03-15 9:19 ` Alexander Sverdlin
2021-02-03 18:23 ` [PATCH v7 0/2] ARM: Implement MODULE_PLT support in FTRACE Florian Fainelli
2021-02-03 18:23 ` Florian Fainelli
2021-02-15 18:31 ` Ard Biesheuvel [this message]
2021-02-15 18:31 ` Ard Biesheuvel
2021-03-02 8:29 ` Linus Walleij
2021-03-02 8:29 ` Linus Walleij
2021-03-02 10:00 ` Alexander Sverdlin
2021-03-02 10:00 ` Alexander Sverdlin
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